Application of electrochemical impedance spectroscopy in bio-fuel cell characterization: A review

ww.sciencedirect.com

i n t e r n a t i o n a l j o u r n a l o f h yd r o g e n e n e r g y x x x ( 2 0 1 4 ) 1e1 2

Available online at w

ScienceDirect

journal homepage: www.elsevier .com/locate/he

Review

Application of electrochemical impedancespectroscopy in bio-fuel cell characterization: Areview

Diwakar Kashyap a, Prabhat K. Dwivedi b, Jitendra K. Pandey a,Young Ho Kim c, Gyu Man Kim d, Ashutosh Sharma b, Sanket Goel a,*

a University of Petroleum and Energy Studies (UPES), Dehradun 248007, Indiab Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016, Indiac Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, 88 Dongnae-ro, Dong-gu,

Daegu, Republic of Koread School of Mechanical Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea

a r t i c l e i n f o

Article history:

Received 12 June 2014

Received in revised form

20 September 2014

Accepted 1 October 2014

Available online xxx

Keywords:

Enzymatic bio fuel cell

Microbial fuel cell

Electrochemical impedance spec-

troscopy

Internal resistance

Biosensors

* Corresponding author.E-mail addresses: [email protected],

Please cite this article in press as: Kashycharacterization: A review, International

http://dx.doi.org/10.1016/j.ijhydene.2014.10.00360-3199/Copyright © 2014, Hydrogen Ener

a b s t r a c t

Fuel cell is an efficient energy conversion device converting chemical energy directly into

electrical energy. It is a fact that, to boost the fuel cell performance, resistance (charge

transfer resistance, mass transfer resistance and electrolyte resistance) should be

decreased. For this, many techniques have been used for cell testing such as: cyclic vol-

tammetry, current interruption measurement, chronoamperometry, chro-

nopotentiometry, polarization curve and electrochemical impedance spectroscopy (EIS).

Among these techniques, EIS is a well-established, non-intrusive, non-destructive, semi-

quantitative, and an efficient technique for identification of each circuit element. In this

review article, application of electrochemical impedance spectroscopy in identification of

individual components of total resistance and their dependence on different factors in

biofuel cell along with some recent advancement in this technique have been discussed.

Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights

reserved.

Introduction

Fuel cell is an efficient energy conversion device that converts

chemical energy directly into electrical energy. The power

output of a fuel cell depends onmany factors, such as kinetics

of reaction, fuel flow rate, operating temperature, internal

[email protected] (S

ap D, et al., ApplicationJournal of Hydrogen En

03gy Publications, LLC. Publ

resistance, and electrical load. While high conversion effi-

ciency (>80%) is themain advantage of fuel cell, slow kinetics,

high internal resistance and fuel crossover are few downsides

that limit power output from these devices [1,2]. Many tech-

niques such as: Cyclic Voltammetry, Polarization Curve,

Chronopotentiometry, Chronoamperometry, Current Inter-

ruption, and Electrochemical Impedance Spectroscopy (EIS),

. Goel).

of electrochemical impedance spectroscopy in bio-fuel cellergy (2014), http://dx.doi.org/10.1016/j.ijhydene.2014.10.003

ished by Elsevier Ltd. All rights reserved.

mailto:[email protected]

mailto:[email protected]

www.sciencedirect.com/science/journal/03603199

www.elsevier.com/locate/he

http://dx.doi.org/10.1016/j.ijhydene.2014.10.003



i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n en e r g y x x x ( 2 0 1 4 ) 1e1 22

have been used for testing and diagnose of fuel cells with each

techniquehaving its ownadvantages anddisadvantages [3e8].

The overall internal resistance of a fuel cell has many con-

tributors such as electrode resistance, electrolyte resistance,

charge transfer resistance, double layer capacitance, mass

transfer resistanceandother ohmic losses. In order to enhance

the performance of fuel cell and draw optimum power, iden-

tification of different components of total internal resistance

and its mitigation is necessary. These contributors of total in-

ternal resistance can't be reduced using a single strategy.

Separation of the individual contributors helps to optimization

fuel cell performance by assisting to optimize cell fabrication

methods, catalyst loading, and membrane thickness [9e11].

The cyclic voltammetry is most commonly used technique

to study redox reaction. In this technique the direction of

potential is swiped between two fixed points and the resulting

current is recorded. The capacitive current affects the sensi-

tivity of cyclic voltammetry measurements, so normal and

differential pulse voltammetry have been developed to reduce

the effects of capacitive currents during measurement [4,12].

In current interruption technique ohmic load is immediately

released and the resulting decrease in potential with time is

recorded. This technique is used to measure the total internal

resistance of cell, but it is not able to differentiate between the

ohmic resistance,mass transfer resistance and kinetic effects,

and only suitable for systems in which ohmic resistance is

dominant [13]. In polarization measurement, cell potential is

plotted against current under load. The internal resistance of

a fuel cell is inversely proportional to the power density and

can be calculated from the slope of polarization curves [14]. All

of the abovementioned techniques are not able to identify the

individual components of total internal resistance and mea-

surement is also affected by non-faradaic component (double-

layer charging of electrode/electrolyte interface) to different

extent. EIS is a non-destructive and powerful technique

capable of providing information about all resistive, capaci-

tive, and inductive contributors in short period of time using

appropriate equivalent circuit model. In addition to its po-

tential application in analysis of electrochemical systems

such as: fuel cell, batteries, corrosion, and sensors, recently

this technique has also been used in a variety of applications,

such as to study sol gel synthesis, reverse osmosis, catalysis

Table 1 e Comparison of different techniques used for fuel cel

Techniques Advantages

Cyclic voltammetry (a) Most extensively used technique to study redo

reaction.

Current interruption (a) Used to determine internal resistance of electr

chemical system

(b) Easy to recognize measurement errors associa

with magnetic and galvanic coupling.

Polarization curve (a) Provides information on the performance loss

the individual cell or stack under operating condi

(Fuel flow rate, humidity, temperature, load)

EIS (a) Able to separate different contributors of total

internal resistance (Charge transfer, mass transp

electrolyte resistance)

Please cite this article in press as: Kashyap D, et al., Applicationcharacterization: A review, International Journal of Hydrogen En

and determination of critical micelle concentration [15e17].

Different techniques used for fuel cell testing has been

compared in Table 1.

Fundamental of EIS

Resistance is the ability of circuit element to hinder the flow of

electrons. Ohm's law, used to calculate the resistance, is only

applicable to an ideal circuit; that shows linearity and inde-

pendent of frequency. Unlike resistance, impedance depends

on frequency. In order to measure impedance of a circuit

element a small alternating current (AC) is applied and cor-

responding potential is measured as a function of frequency.

The initial impedance measurement was performed to

determine the capacitance of ideally polarizable electrodes

and alternating current polarography [18,19]. A small AC

current and corresponding potential is represented by

following equations:

Et ¼ Eo sinðutÞ (1)

It ¼ Io sinðutþ fÞ (2)

Impedance ðZÞ ¼ Et

It¼ Eo sinðutÞ

Io sinðutþ fÞ (3)

EIS can be performed in two or three electrodes system,

whereby the three electrode system used to analyse electro-

chemical reaction at one electrode, in which one electrode

(anode/cathode) acts as working electrode and other electrode

works as counter electrode, andmeasurement is done against

the reference electrode. Two electrodes system is used for

performance analysis of a complete cell, in which one elec-

trode acts as working electrode and other counter electrode.

The current flowing at an electrified interface, in an electro-

chemical reaction, contains both faradic as well as non-

faradaic components. The faradic component arises from

the electron transfer reaction and non-faradaic current results

from double layer capacitance. Solution resistance, charge

transfer resistance, mass transfer resistance and polarization

resistance are the main Faradaic components. Impedance of

common circuit element is shown in Table 2.

l testing.

Disadvantages

x (a) Capacitance current and back ground charging current

are the main problems in normal cyclic voltammetry.

(b) The ratio of the peak faradaic current to the charging

current decreases with increasing voltage

o-

ted

(a) Only show total ohmic drop across the electrode and only

suitable for system in which ohmic resistance is dominant

(b) Not able to differentiate charge transfer, mass transport

and other ohmic losses

es in

tions

(a) Underlying mechanism is difficult to analyse, because

different contributors of potential drop overlap.

ort,

(a) Only applicable to steady state or quasi steady state

systems

(b) Data analysis is difficult using basic fitting models.




Table 2 e Impedance of common circuit elements.

Components Impedance

Resistor Z ¼ R

Inductor Z ¼ iuL

Capacitor Z ¼ 1/iuL

Warburg constant Z ¼ R=ffiffiffiffiffiju

pConstant phase element Z ¼ 1=QðujÞa

Fig. 2 e Representation of impedance spectra.

i n t e r n a t i o n a l j o u r n a l o f h yd r o g e n e n e r g y x x x ( 2 0 1 4 ) 1e1 2 3

The Randles equivalent circuit model of an electrode

electrolyte interface in fuel cell is shown in Fig. 1.

The resistance of Randles circuit is mathematically repre-

sented by Equation (4), and it is graphically shown in Fig. 2.

ZðuÞ ¼ Rp þ su�1=2

s1=2ðCd þ 1Þ2 þ u2C2d

�Rp þ s�1=2

�2þ j

hCd

�Rp þ su�1=2

�2 þ su�1=2�Cdsu

1=2 þ 1�2i

ðCdsu1=2 þ 1Þ2 þ u2C2d

�Rp þ su�1=2

�2 (4)

Here u ¼ 2pf, f is frequency, and j is √�1

where

s ¼ RT

F2ffiffiffiffiffin2

pA

1

D1=2o Coðx; tÞ

þ 1

D1=2R CRðx; tÞ

!(5)

The equation describes a semicircle with a radius of Rp/2,

with a high frequency intercept of Rs and a low frequency

intercept of (Rsþ Rp) on the Z0 (u) axis, is obtainedwheneZ00 (u)

is plotted against Z0 (u). TheWarburg impedance is related to s

by the equation.

Zw ¼�2u

�1=2

s (6)

Different techniques such as AC Bridges, Lissajous Curves,

Phase Sensitive Detection, Frequency Response Analyser

(FRA) and Fast Fourier Transform (FFT) have been used to

represent impedance spectra [20e26]. The FRA is most

commonly used technique to measure impedance of a system

in which a small sine wave (5e15 mV) of a particular fre-

quency is overlaid on a desired direct current to the working

electrode and resulting current is measured as a function of

frequency. But, this technique is only applicable to linear and

stable system, and takes long time to scan the full spectrum.

In order to reduce the measurement time, a new technique

was developed that is called First Generation Fourier Trans-

form EIS. In this technique AC signal of various frequencies

was mixed and impedance was measured by applying Fourier

Transform to the output signal. This technique was further

Fig. 1 e An idealized Randles circuit.


developed to study the various electrochemical phenomena,

such as corrosion of metals, which was further modified by

Chang et al., and called Second Generation Fourier Transform

EIS [27e32]. In this technique a small step signal, integral form

of Dirac delta function, obtained by adding ac voltage of

different frequencies applied at a given dc voltage and the

resulting chronoamperometry current is recorded. The ob-

tained output voltage and current signal is deconvulated into

frequency domain and impedance was obtained by dividing

voltage with current at all frequencies. The Dynamic EIS was

developed by combining first generation FTEIS (seven fre-

quencies ranging from 60 to 997 Hz) and CV [25,33,34]. This

techniquewas further developed to study the quasi-reversible

redox system and capacitances calculation of TiO2 films that

is called Potentio-dynamic EIS (PDEIS) [35,36].

Application of EIS in biofuel cell (BFC)

BFC is a bio-electrochemical energy conversion device. It is

divided into two sub-categories: Microbial Biofuel Cell (MFC)

and Enzymatic Biofuel Cell (EBFC). The former uses microor-

ganisms, whereas the latter uses purified enzymes to catalyse

redox reaction. In BFC, fuel is oxidized at the anode, oxidant is

reduced at the cathode and electrons are forced to move

through the external circuit. The electrons generated in redox

reaction are collected either by Direct Electron Transfer (DET)

or Mediated Electron Transfer (MET) [37,38]. MFC is further

sub-divided into liquid phase and solid phase, depending on

the type of fuel used [39]. Solid phase MFC uses rice hull, bean

residue, ground coffee waste as a substrate, whereas liquid

phase MFCs generate power from domestic and food pro-

cessing industries’ waste, and water treatment plant [40e42].

Solid phase MFC has high internal resistance because of dif-

ficulty in electron transfer in solid phase substrates. The EBFC

uses glucose, ethanol, methanol, and glycerol as fuel and has

been envisioned as power feeding source for small portable

electronic devices and sensors because of high conversion

efficiency, operation under normal temperature and ability to

produce power without noble metal catalysts. But many





bottlenecks, such as charge transfer resistance, activation

over-potential, concentration polarization and other ohmic

losses limit its performance. In order to be alleviate these

bottlenecks and enhance performance, individual compo-

nents of total resistance should be identified andminimised to

get optimum power [43].

Effect of electrode material

The electrode is said to be polarized, when potential applied to

the electrode is different from equilibrium potential, and

magnitude of this value is called over potential. The complex

electrochemical reaction in BFC is affected by interaction of

catalyst with electrodes,mediators and effect of substrate and

product diffusion. The electrodematerial and its interaction of

microbial biofilm play an important role in overall perfor-

mance of MFC [44]. Electrode polarization resistance depends

on material and it could be reduced by using electrode having

high electrical conductivity, coating on electrode, adding

catalyst and using thin electrolyte [45]. Traditional carbon

based electrodes such as: graphite felts, graphite rod and

carbon cloth has been extensively studied because of large

surface area, low cost, high thermal and chemical stability

[46e48]. But these electrodes are bulky and difficult to employ

in microfluidic channel; therefore gold is commonly used as

electrode material in microfluidic BFC. It has been observed

that the carbon cloth electrode exhibit better performance as

compared to the metal electrode, which could be further

enhanced by electrode coating. Carbon cloth electrode has

also been incorporated as electrode material in microfluidic

BFC. In order to increase the conductivity of electrode man-

ganese, iron, quinines, and neutral red has been added to

carbon based materials [49].

Activation polarization is the condition in which the rate of

reaction is controlled by slowest step in a series of reaction.

Oxygen is the preferred oxidant because of limitless avail-

ability, high redox potential, and nontoxic waste product, but

show kinetics is the rate limiting step in all types of fuel cell.

The commonly used strategies to reduce the activation over-

potential are: increasing the operation temperature, using

catalyst, increasing electrode roughness, and increasing

Fig. 3 e EIS spectra of cathodes inserted in MFCs. Reproduced


reactant concentration [50]. Martin et al. examined the effect

of different material (Platinum, Mn2O3, Fe2O3, and Carbon

black) on oxygen reduction reaction and cathode polarization

resistance using EIS. In this experiment, carbon supported

cathode was formed by adding Platinum, Mn2O3, and Fe2O3 to

the carbon powder. It was observed that the Mn2O3 provide

highest oxygen reduction reaction potential and platinum

exhibit the best volumetric power density. The carbon cath-

ode showed highest charge transfer as well as total resistance

and except carbon cathode, performance of all electrodes

decline with time. The flattened semicircle in EIS spectrum

(Fig. 3) of platinum electrode revealed that the rate of oxygen

reduction was limited by mass transport resistance and the

electrolyte resistance is the supreme components in all

cathodes. The resistance calculated for platinum, Mn2O3,

Fe2O3 and carbon black from EIS was 9.6 U, 7.8 U, 7.6 U, and

21.6 U respectively and corresponding volumetric power

density was 90 Wm�3, 32 Wm�3, 15 Wm�3, and 8 Wm�3

respectively [51].

In another study, effect of commonly used cathode mate-

rials such as graphite felt (GF), carbon paper (CP) and stainless

steel mess (SSM) was comparatively studied by EIS. It was

observed that the order of charge transfer resistance of bio-

cathode follows the order GF > CP > SSM. GF has low charge

transfer resistance, but high diffusion resistance limits the

rate of reaction. In case of SSM electrode the rate of reaction

was limited by charge transfer resistance that is observed as a

small straight line in low frequency region (Fig. 4) of Nyquist

plot [52].

In fuel cell, themovement of charge from site of reaction to

the electrode and vice versa involves some resistance called

charge transfer resistance, which is inversely proportional to

the rate of reaction [53,54]. In microbial fuel cell, biofilm on

electrode provides large conductive surface that facilitate the

electron transfer and reduces the charge transfer resistance.

The effect of microbial film (Shewanella oneidensis MR-1) on

electrode surface on coating of bacterial layer on charge

transfer resistance has been examined. A layer of bacteria was

grown on anode and the difference in charge transfer resis-

tance of anode with and without bacterial filmwas examined.

It was observed that development of biofilm on electrode

with permission from Ref. [51] Copyright Elsevier (2011).




Fig. 4 e EIS (Nyquist plots) of the bio-cathode in MFC. The

inset shows the details at high frequency. Reproducedwith

permission from Ref. [52]. Copyright Elsevier (2012).


significantly reduced the polarization resistance of anode

from 7.79 MU to 10.2 kU. In a similar study, a layer of bacte-

rium, Geobacter sulfurreducens, was grown on anode and sig-

nificant decrease in polarization resistance and increase in

capacitance was observed [55,56]. The resistance of biofuel

cell calculated by EIS is compared in Table 3.

Table 3 e Resistance of BFC calculated by EIS.

Type of cell Electrode

Dual chamber (a)Graphite felt (a)11

(b)Stainless steel mess (b)23

(c)Carbon paper (c)82

Single chamber (a)Carbon (a)18

(b)Fe2O3 (b)4.1

(c)Mn2O3 (c)3.6

(d)Platinum (d)4.4

Single chamber Platinum coated on carbon cloth 17e7

Dual chamber Electroplated platinum

on bare graphite electrode

Cath

Anode: bare graphite electrode Anod

Submersible Anode: carbon paper Ohm

Cathode: carbon paper Char

Single chamber

sediment MFC

Anode: carbon cloth Cath

resis

Rota

Cathode: platinum coated cathode Tota

Rota

Non

Microfluidic MFC Graphite electrode Inter

Floating MFC Anode: granular graphite Anod

Cathode: platinum wire

Single chamber MFC Graphite felt anode Tota

Carbon cloth cathode

Single chamber MFC Reticulated vitreous

carbon electrode

Tota

Implantable biofuel cell Anode: Au/Au NPs/enzyme Tota

Cathode: Au/Au NPs/Bilirubin oxidase

Enzymatic biofuel cell Platinum cathode Char

873.1


In another study, effect of bacterial biofilm on the charge

transfer resistance of anode was examined. The charge

transfer resistance of Loofah sponge-derived carbon (LSC),

Nitrogen-enriched Carbon Nanoparticle decorated LSC anode

(NCP/LSC), Reticulated Vitreous Carbon (RVC), Graphite Plate,

Carbon Felt (CF), and Graphene-coated Sponge (GS) was ana-

lysed using EIS (Fig. 5).

It was observed that the charge transfer resistance

decreased in all electrodes with formation of biofilm on

anode. The NCP/LSC/biofilm anode had lowest charge

transfer resistance, whereas GS/biofilm anode had the high-

est. The highest charge transfer resistance was found in

the case of GS electrode because of low conductivity of

graphene. The trend of charge transfer resistance was NCP/

LSC > LSC > RVC >GS > CF > GP, that was consistencewith the

maximum power output [66].

Oxygen reduction is kinetically slow reaction and platinum

is most commonly used to catalyse reaction. Gas diffusion

cathodehasbeenmost extensively studied forMFC.Thecost of

cathode material, catalyst and carbon black are the main

components of overall investment. A cost effective gas diffu-

sion cathode was fabricated by growing Co3O4 on stainless

steel mesh by ammonia evaporation method. In this experi-

ment carbon cloth anode and gas diffusion electrode cathode

was examined. The charge transfer resistance of SSM/Co3O4

was smaller than the pure SSM and SSM-Nafion-Co3O4, which

showed that the smaller activation resistance of Co3O4. The

performance of the cathode was comparable to the Pt/C

Resistance Current Ref.

U (a)350 mA m�2 [52]

U (b)210 mA m�2

0 U (c)18 mA m�2

.1 ± 2.4 U (a)12.7 ± 0.9 Wm�3 [51]

± 0.4 U (b)24.9 ± 5.4 Wm�3

± 0.4 U (c)45.1 ± 3.3 Wm�3

± 0.5 U (d)83.2 ± 2.9 Wm�3

.2 kU (pH 7e10) 223.8 ± 8.1 mA m�2 (pH 8) [57]

231.3 ± 1.1 mA m�2 (pH 10)

ode-8.51*103 U 23 mW [58]

e- 1.02*104 U

ic resistance: 7 U 1772 mA m�2 [59]

ge transfer resistance: 2 U

ode charge transfer

tance: 65.1 U

ting: 28 U

49 mW m�2 [60]

l anode resistance:

ting: 105.5 U

rotating:78 U

nal resistance (EIS): 2.35 K U 618 mW m�2 [61]

e polarization resistance: 20 U 390 mW m�3 [62]

l resistance: 50 U 430 mW m�2 [63]

l resistance: 350 U 40 Wm�3 [42]

l resistance: 5.5 kU 2 mW cm�2 [64]

ge transfer resistance:

U

Laccase/Pt: 102 mW cm�2

PEDOT/Laccase/Pt-744.13 U

[65]





cathode with reduced cost [67]. The charge transfer resistance

of glassy carbon electrode modified with multi-walled carbon

nanotubes, platinumblack, poly pyrrole and enzymes (Laccase

andCatalase)hasbeen investigatedusingEIS. In thiswork, four

different electrodes: glassy carbon/poly pyrrole (GC/PPy),

glassy carbon/MWCNT/poly pyrrole (GC/MWCNTs/PPy), glassy

carbon/MWCNT/platinum black/poly payroll (GC/MWCNTs/

Ptb/PPy), glassy carbon/MWCNT/platinum black/Laccase-

catalase/poly pyrrole (GC/MWCNTs/Ptb/PPy/LAc-Cat/PPy)

were fabricated. The charge transfer resistance decreases in

the order of GC/PPy > GC/MWCNTs/PPy > GC/MWCNTs/Ptb/

PPy > GC/MWCNTs/Ptb/PPy/LAc-Cat/PPy. The charge transfer

resistancewas low in caseofMWCNTs/PPybecauseof increase

in the surface area of the electrode. The electro-deposition of

platinum black further increased the surface area and

decreased the charge transfer resistance. The addition of

enzyme to the electrode catalyses the oxygen reduction reac-

tion and decreased the charge transfer resistance [68].

The EIS has been employed to study the effect of bacterial

biofilm on double layer capacitance at electrode/electrode

interface EIS [69,70]. It was observed that the double layer

capacitance became twice on addition of bacterial (Geobacter

sulfurreducens) biofilm as compared to electrode without the

bacteria. It was also observed that the electron conduction

was facilitated by the conductive pili of bacteria. The capaci-

tance of cathode was larger than anode, which might have

been because of higher surface area of the cathode. There was

no appreciable change in capacitances of anode and cathode

observed with change in pH. The addition of mediator also

increases the anode and cathode capacitance. It was observed

that the without mediator anode and cathode capacitance

was 1.2 mF and 2.4 mF respectively, but addition of methyl

orange increases the anode and cathode capacitance 7.9 mF

and 9.5 mF respectively and addition of methyl red increases

the anode and cathode capacitance 18 mF cm�2 and

11 mF cm�2 respectively [76].

Fig. 5 e Nyquist plots of the different anodes in the MFCs

after inoculation. The inset contains an enlarged view of

the NCP/LSC anode in the high-frequency range.

Reproduced with permission from Ref. [66]. Copyright ACS

(2013).


Hydrophilicity of electrode not only affects the attachment

of enzyme to the electrode, but also affects electrode polari-

zation. Hydrophilicity is a favourable condition for enzymes

immobilization on electrode and the reactant from solution

can easily access the active sites of the enzymes [72,73]. The

effect of hydrophilicity on enzyme loading to the electrode

and electrode polarization was studied using EIS. In this

experiment two electrodes were fabricated, OMC-1 and OMC-

2, by impregnation of carbon material and enzyme on silicon

template, and by impregnation of carbon material, enzyme

and PVA to the silicon template respectively.

PVA have many hydroxyl group that makes it highly sol-

uble in water. In spite of high surface area of OMC-1 electrode,

it has low enzyme loading because of low hydrophilicity,

whereas high hydrophilicity of OMC-2 results in high enzyme

loading and low electrode polarization, hence faster charge

transfer between electrode and reactant species. The charge

transfer resistance of OMC-1 and OMC-2 was 17.5 U cm2 and

5.2 U cm2 respectively [74]. The impedance spectra of these

two electrodes is shown in Fig. 6.

Effect of mediators on charge transfer resistance and poweroutput

Typically, a bacterium synthesizes an endogenous mediator

that facilitates electron transfer in intracellular environment. In

microbial fuel cell, microorganism adheres to the electrode

surfaceandfacilitateselectrontransfer,while theothers secrete

soluble mediators for electron transfer shuttles electron from

bacteria to electrode and vice versa. Even though the redox

mediator facilitates fast electron transfer, but because of its low

concentration inanolytecharge transfer resistance still remains

high. The addition of mediators to the electrolyte significantly

decreases the charge transfer resistance for the substrate

Fig. 6 e Electrochemical impedance spectroscopy (EIS) of

10 mM Fe(CN)63¡/4¡ in 1.0 M KCl using OMC-1 (black) and

OMC-2 (red). The inset is the randle equivalent circuit.

Reproduced with permission from Ref. [74]. Copyright

Elsevier (2010). (For interpretation of the references to

colour in this figure legend, the reader is referred to the

web version of this article.)





oxidation and enhances the kinetics of electron transfer from

thesubstrate to theanode.EIShasbeensuccessfullyexploitedto

analyse the response of such mediators on charge transfer

resistance. Bio-electrochemical reaction and charge transfer

reactionoffer high impedance andgenerally observed formmid

to high frequency region in Nyquist plot [75].

The difference in charge transfer resistance and power

output of a MFC, with and without mediator, was analysed

using EIS. The anode and cathode was made up of graphite

and platinum sheet respectively and two chambers were

separated by fermion membrane. It was observed that the

addition of mediator increases the open circuit potential and

current density of MFC bymore than 50%. The current density

with addition of mediator methyl orange and methyl red was

164 mW cm�2 and 207 mW cm�2 respectively, whereas

without mediator it was 106 mW cm�2. The open circuit

voltage of cell without mediator was 425 mV, but enhanced to

512 mV and 585 mV with addition of methyl orange and

methyl red respectively. The solution resistance of MFC was

410 U without mediator, whereas this value was reduced to

282 U and 153 U with addition of methyl orange and methyl

red respectively. In the similar way, anode polarization

resistance without mediator was 470.7 U, but reduced to 330 U

and 176 U for methyl orange and methyl red respectively [76].

The effect of riboflavin addition on performance of lactate-

fed air breathing MFC was studied using EIS. Riboflavin is a

redox mediator and its concentration in this experiment was

10e20 times higher than themediators secreted by bacteria. It

was revealed by EIS that Riboflavin addition decreased the

charge transfer resistance that was confirmed by reduction in

magnitude of low frequency arc in Nyquist plot. In another

study, effect of mediator (Riboflavin, Humic acid and

Anthraquinone-2, 6-disulphonic disodium salt) on simulta-

neous decolourization of dye and bioelectricity generation

Fig. 7 e Nyquist plots of the anode between frequencies 10 kHz a

to the anolyte. Inset graph show the expanded view of the box

Copyright Wiley 2009.


was analysed by EIS. In this case the anode and cathode was

made up of graphite felt and platinum coated carbon paper

respectively. Here, addition of mediator showed significant

increase in power output of MFC. The power density of MFC

withoutmediator was 53.1 mWm�2, whereas addition of 1 g/L

Humic acid, 0.005 mM AQDS and 0.005 mM riboflavin

increased power density to 61.1 mW m�2, 67 mW m�2 and

72.4 mW m�2 respectively. Increasing the concentration of

riboflavin to 0.05 mM further increased the power density to

100 mW m�2. In this present case also, EIS confirmed the

reduction of charge transfer resistance with addition of

mediator to the MFC [77,78].

The effect of redox mediator ferricyanide on charge

transfer resistance was studied in two chambers MFC. In this

experiment the anode and cathode was made of porous

graphite felt (surface area 20 cm2/g) and Graphite felt (surface

area 0.47m2/g) respectively. As the reduction of ferricyanide is

fast process, so charge transfer resistance is low and arc was

not extended into low frequency region of the Nyquist plot

(Fig. 7). When oxygen was used as the terminal electron

acceptor, the cathode plots shows second Nyquist arc at low

frequency, which might have arisen either from the slow ki-

netics of oxygen reduction reaction or from the charge

transfer and mass transfer resistance [77].

Influence of Electrolyte's pH

Bacterial micro floras in anode and cathode chamber need

different pH for optimum activity. In general, the neutrophilic

bacteria used for fuel oxidation at anode require a neutral

condition; while bacteria used for oxygen reduction in cath-

ode chamber require alkaline environment for optimal

growth. In two chamberedMFC, the pH of anodic and cathodic

compartments can be maintained separately to get optimum

nd 10 mHz before and after the addition of 5 mM riboflavin

ed region reproduced with permission from Ref. [77].





bacterial growth; hence maximum power output. The EIS has

been employed to examine the effect of pH on the perfor-

mance electrodes [54]. Zhen et al. employed EIS to investigate

the effect of electrolyte pH on the performance of air cathode

MFC. A single chambered cell was fabricated, in which anode

(graphite felt) and cathode (platinum coated carbon cloth) was

placed 2 cm apart, and connected to a 1000 U resistor. Anode

was capped with a plastic cover to prevent oxygen intrusion

and cathode was covered with 5% Nafion solution to make it

water-proof. It was observed that the maximum and mini-

mum current density obtained at pH 9 and pH 5 respectively.

The peak current density was relatively stable, varying be-

tween 223.8 ± 8.1mAm�2 and 231.3 ± 1.1mAm�2, in pH range

8e10 [57]. The anodic polarization resistance was found to be

the lowest at pH 7, while the cathodic polarization resistance

decreased with the increase in pH of electrolyte from 5 to 10.

The cathodic polarization resistance was higher than the

anodic polarization resistance and electrode polarization re-

sistances dominated over solution resistance.

It is well known fact that most bacteria show optimal ac-

tivity in neutral environment, and that was the reason behind

the high activity of anode at neutral pH. High acidity/basicity

has negative effect on bacterial metabolism; hence decreases

the fuel cell performance. But, the oxygen reduction reaction

is favourable at higher pH; hence decrease in cathode polari-

zation resistance was observed with increase in pH. The high

pH (8e10) inhibited the anodic bacterial activities to some

extent, but might be favourable to the cathodic reaction, thus

improving the overall performance. The anodic polarization

resistance first decreased from pH 5.0 to 7.0 then increased

from 7.0 to 10.0, while the cathodic polarization resistance

decreased with increase in pH from 5.0 to 10.0. The increase in

rate of cathodic reaction at high alkalinity was most likely

result of abiotic factor. The current density also rises with

increase in pH (7e10) as a result of decreased in cathode

polarization resistance. Although anode polarization resis-

tance increased (578e1855 U) in this pH range, but cathode

polarization resistance decreased (17e7.2 kU), that was the

rate limiting factor, hence overall current generation

enhanced [57].

Gil et al. examined a double chambered MFC and achieved

85% of the highest current at pH 5.0. In addition, the pH range

for optimum activity was found in pH range 7.0e8.0 [81]. In

above mentioned cases, it was observed that low pH (pH 5e6)

resulted in lower electricity generation. However, Zhen et al.

showed severe inhibition on electricity generation at pH 5 and

only 10% of the peak current was obtained [57]. Gil et al. per-

formed experiment in a two-chamber MFC and showed the

results of pH on anodic process only, whereas in case of Zhen

et al. one-chamber MFC was studied and the pH of the elec-

trolyte affects both anodic and cathodic reactions. The

cathodic reaction was the limiting factor and polarization

resistance was slightly higher than the anodic polarization

resistance possibly because of high ohmic resistance caused

by a water-proof layer [81].

Effect of experimental conditions

The performance of BFC also depends on the concentration of

ions in electrolyte, separation between electrodes, rotation of


electrode, magnetic field, surface area of proton exchange

membrane, mode of operation, and type of fuel [79,80,84]. The

EIS can be employed to study the effects of these factors on

power output of BFC. The solution resistance is an important

contributor of total resistance that determines the power

output of fuel cell. Increasing the number of ions in solution

decreases the electrolyte resistance [82,83]. Manohar et al.

reported that the solution and membrane resistance is the

dominant factor that constitutes the 95% of total internal

resistance [58]. In another study, He et al. reported that the

solution resistance constitute 50.3% of total resistance. The

power output of MFC is also a function of the surface area of

Proton Exchange Membrane (PEM); it increases with an

increment in surface area of PEM. Increase in power density

with increase in surface area of proton exchange membrane

was examined using EIS. If surface area of membrane is larger

than that of electrode, power output is limited by internal

resistance. It was observed that membrane having surface

area 3.5 cm2, 6.2 cm2 and 30.6 cm2 delivered power density

45mWm�2, 68mWm�2 and 190mWm�2 for respectively [85].

The power density of microbial fuel cell is inversely pro-

portion to the separation between electrodes; shorter distance

between electrodes provide smaller ion diffusion length and

low electrolyte resistance [87]. It was observed that the

decreasing the distance between electrodes from 383 mm to

160 mm in microfluidic MFC, power density increased from

0.023 to 4.012 mW m�2 [88]. In a submersible microbial fuel

cell, various impedance contributors (electrodes, electrolytes,

distance between electrode and membrane) was analysed

using EIS. In this experiment, two anodes (A1, A2) and two

cathodes (C1, C2) were fabricated and EIS measurement was

performed against different combination of anode and cath-

ode. It was observed that, increasing the distance between the

electrodes, the internal resistance increased from 7 U to 20 U,

but ohmic resistance remained constant. A serial resistance

shift of roughly at 6.9 U and an inductive behaviour at high

frequency (>90 kHz) was also observed for combination C2/A2

membrane electrode assembly. At intermediate frequency, a

semicircle of diameter 2 U was observed from 70 to 300 kHz

that corresponds to typical range for double layer capaci-

tances [59].

Concentration polarization develops if the rate of con-

sumption of substrate is higher than the rate of transport to

the site of reaction. It was observed that the optimum activity

of MFC was observed at carbonenitrogen ratio 31:1 and addi-

tion of degrading enzyme enhances the open circuit voltage

and current density [86]. The change in internal resistance and

ohmic losses of a two chambered microbial fuel cell using

different substrate (glucose, cheese whey) was examined by

EIS. In this experiment, individual components of total inter-

nal resistance for both substrateswere determined by EIS. The

polarization resistance of anode was higher than cathode, but

no significant change in anode polarization resistance was

observed for both substrates. When glucose was consumed

anode polarization resistance significantly increased, and low

frequency process in the bode plot shifted to higher frequency

and high frequency process disappeared that attributed to the

consumption of substrate [71].

The rotating electrode enhances the transport of ions and

concentration of dissolved oxygen resulting in low ohmic





resistance and increment in performance of cathode, but high

concentration of dissolved oxygen has negative effect on the

anodic bacterial metabolism [60,89]. Habouzit et al. observed

that increasing the air flow rate in cathodic chamber increases

the power output; whereas increasing the air flow rate in

anodic chamber decreases the power output. It has been

believed that at high flow rate oxygen permeate through the

proton exchange membrane and having negative effect on

performance of anode. The problem of oxygen permeation to

the anode could be solved by applying cathode coatings like

polytetrafluoroethylene [90,91]. He et al., studied river sedi-

ment MFC in which platinum coated cathode was kept above

the anode and a horizontal shaft rotates the cathode that is

half submerged in water. All measurements were performed

against Ag/AgCl reference electrode. The rotating cathode

enhances the oxygen availability to the cathode; hence

enhancing rate of reaction. The total anodic resistance was

105.5 U and 78.0 U for the rotating and nonrotating cathode

respectively, in which anodic charge transfer resistance

increased from 28 U to 65 U, but the ohmic resistance

decreased from 50 U to 40 U. Power density delivered by non-

rotating and rotating cathodewas 29mWm�2 and 49mWm�2

respectively [60].

Huang et al. examined a floating MFC, in which anode was

placed in marine or rover sediment and cathode in aerobic

water. The cell was fabricated in a tube made of cation ex-

change membrane. The tube was filled with granular

graphite that acts as anode in which three platinum wires

was inserted for current collection. The nickel coated carbon

fibre cathode containing two layers of catalyst. The first

catalyst layer, platinum/carbon fibre paste, was applied to

the outer surface of the tube, and the second catalyst layer

was mixed with a Nafion solution was applied on outer sur-

face of the carbon fibres. EIS analysis revealed that perfor-

mance of cell was limited by anode polarization resistance.

The capacitance of anode didn't change significantly, but

polarization resistance of first decreased with time then

started increasing. The internal resistance of anode was low

as compared to cathode and no significant change with time

was observed [62].

The perspective of microbial fuel cell, in batch mode waste

water treatment plant, using reticulated vitreous carbon

electrodes was examined to assess the suitability of material.

It was observed that the anodic and cathodic over potential

contribute 15% and 85% of total over potential respectively. In

addition, the material showed good stability and maximum

power delivered by cell was 40 Wm�3. EIS revealed that the

activation polarization and concentration polarization at

cathode was the main reason behind the poor performance of

cathode. Straight line at low frequency region of impedance

spectra resulted from limited diffusion of oxygen to the

cathode, called as Warburg impedance [42].

Many research groups have examined the impact of mag-

netic field on charge transfer resistance in MFC using EIS and

reported that magnetic field boost the microbial metabolic

activity; hence enhancement in the performance of fuel cell

by decreasing charge transfer resistance [92,93]. Yin et al.,

examined two chambered MFC, made up of carbon cloth

electrodes, to observe the change in charge transfer resistance

and mass transfer resistance on application of magnetic field.


A static magnate was attached to the external walls of the

anode and magnetic field strength of 100 mT, 200 mT, 300 mT

was applied and impedancewasmeasured in frequency range

100 KHze1 MHz. In Nyquist plot of both electrodes, only one

semicircle was observed in high frequency range that corre-

sponds to transfer resistance. The charge transfer resistance

was minimum for magnetic field strength 200 mT and highest

for MFC without magnetic field. The dependency of charge

transfer resistance on magnetic field strength followed the

order 200 mT < 100 mT < 300 mT < no magnetic field. The

considerable increase in open circuit potential was also found

for 100 mT and 200 mT magnetic field [94].

Limitations of EIS

Although EIS has been successfully used to study electro-

chemical reaction in fuel cell, but this technique is only

applicable to linear or quasi linear system. The system should

be stable during impedance measurements in order to get

valid spectrum. The technical precision of the instrumenta-

tion, operating procedures and data analysis using basic

fitting model are the main limitations [95]. The amplitude of

perturbation signal should be small enough, so that system

approaches at least quasi-linear conditions, but should be

large enough to be recognized and not buried in noise.

Impedance at high frequency generally represents the ohmic

resistance, whereas resistive behaviour dominated in low

frequency range, but the frequency range in which measure-

ment performed is not well defined [83,96].

Conclusion

EIS is a non-destructive, convenient and powerful technique

for testing and diagnosis of biofuel cell. In this review

article, we have discussed how EIS has been harnessed to

get information about the electrode and electrolyte resis-

tance, charge transfer resistance, and capacitive current in

biofuel cell. In addition, effect of experimental conditions

affecting biofuel cell performance such as pH, mediator,

temperature, concentration of electrolyte and separation

between electrodes has also been discussed. The perfor-

mance of EIS is not limited by the non-Faradaic components

of electrified surface, but operating procedures and data

fitting using basic fitting models are challenges. In addition,

system should be stable during the measurement and

amplitude of perturbation signals should be small. Further it

is also shown that bio-electrochemical reaction taking place

is electrode electrolyte interface is very complex and cannot

be fully comprehend by using a single technique. Therefore

to address this issue, EIS is used along with other electro-

chemical techniques such as cyclic voltammetry and po-

larization measurement. While testing and diagnosis of fuel

cell and batteries are discussed in this review, there are

many new applications of EIS have been emerged such as

CMC determination, fouling identification in reverse

osmosis; nano-sensor and nano-channel characterization

has been immerged.





Acknowledgement

The authors from India thank the Department of Science and

Technology, Government of India for financial support under

Indo-Korea Project (INT/Korea/P-18/2013). The authors from

Korea thank Korean Government (KMEST) for financial sup-

port under National Research Foundation of Korea Grant

(NRF2012K1A3A1A19038448).

r e f e r e n c e s

[1] Carrette L, Friedrich KA, Stimming U. Fuel cells: principles,types, fuels, and applications. Chem Phys Chem2000;1(4):162e93.

[2] O'hayre RP, Cha SW, Colella WG, Prinz FB. Fuel cellfundamentals. John Wiley and Sons; 2008. ISBN: 978-0-470-25843-92006.

[3] He Z, Mansfeld F. Exploring the use of electrochemicalimpedance spectroscopy (EIS) in microbial fuel cell studies.Energy & Environ Sci 2009;2(2):215e9.

[4] Katz E, MacVittie K. Implanted biofuel cells operating in vivoe methods, applications and perspectives e feature article.Energy Environ Sci 2013;6:2791e803.

[5] Asghari S, Mokmeli A, Samavati M. Study of PEM fuel cellperformance by electrochemical impedance spectroscopy.Int J Hydrogen Energy 2010;35(17):9283e90.

[6] Homolka D, Hung LQ, Hofmanova A, Khalil MW, Koryta J,Marecek V, et al. Faradaic ion transfer across the interface oftwo immiscible electrolyte solutions: chronopotentiometryand cyclic voltammetry. Anal Chem 1980;52(11):1606e10.

[7] Denuault G, Mirkin MV, Bard AJ. Direct determination ofdiffusion coefficients by chronoamperometry at microdiskelectrodes. J Electroanal Chem Interfacial Electrochem1991;308(1):27e38.

[8] Aelterman P, Versichele M, Marzorati M, Boon N,Verstraete W. Loading rate and external resistance controlthe electricity generation of microbial fuel cells withdifferent three-dimensional anodes. Bioresour Technol2008;99(18):8895e902.

[9] Fan Y, Sharbrough E, Liu H. Quantification of the internalresistance distribution of microbial fuel cells. Environ SciTechnol 2008;42(21):8101e7.

[10] Liang P, Huang X, Fan MZ, Cao XX, Wang C. Compositionand distribution of internal resistance in three types ofmicrobial fuel cells. Appl Microbiol Biotechnol2007;77(3):551e8.

[11] Dob AM, Garron SA, Wurst JW. Apparatus for measuringinternal resistance of wet cell storage batteries having non-removable cell caps. 1991. Google Patents.

[12] Vielstich W. Cyclic voltammetry. In: Handbook of fuel cells.John Wiley & Sons, Ltd; 2010.

[13] Wruck WJ, Machado RM, Chapman TW. Currentinterruptiondinstrumentation and applications. JElectrochem Soc 1987;134(3):539e46.

[14] Logan BE, Hamelers B, Rozendal R, Schr€oder U, Keller J,Freguia S, et al. Microbial fuel cells: methodology andtechnology. Environ Sci Technol 2006;40(17):5181e92.

[15] Hu Z, Antony A, Leslie G, Le-Clech P. Real-timemonitoring of scale formation in reverse osmosis usingelectrical impedance spectroscopy. J Membr Sci2014;453(0):320e7.

[16] Nandigana VVR, Aluru NR. Characterization ofelectrochemical properties of a microenanochannel


integrated system using computational impedancespectroscopy (CIS). Electrochim Acta 2013;105(0):514e23.

[17] Ghasemi S, Darestani MT, Abdollahi Z, Hawkett BS,Gomes VG. Electrical impedance spectroscopy fordetermining critical micelle concentration of ionicemulsifiers. Colloids Surfaces A Physicochem Eng Aspects2014;441(0):195e203.

[18] Engblom SO, Wasberg M, Bobacka J, Ivaska A. Experiences ofan on-line fourier transform faradaic admittancemeasurement (FT-FAM) system based on digital signalprocessors. In: Ivaska A, Lewenstam A, Sara R, editors.Contemporary electroanalytical chemistry. US: Springer;1990. p. 21e9.

[19] O'Halloran RJ, Williams LFG, Lloyd CP. A microprocessorbased isopotential contouring system for monitoring surfacecorrosion. Corrosion 1984;40(7):344e9.

[20] Ramanauskas R, Quintana P, Maldonado L, Pom�es R, Pech-Canul MA. Corrosion resistance and microstructure ofelectrodeposited Zn and Zn alloy coatings. Surf CoatingsTechnol 1997;92(1e2):16e21.

[21] Lasia A. Electrochemical impedance spectroscopy and itsapplications. In: Conway BE, Bockris JOM, White R, editors.Modern aspects of electrochemistry. US: Springer; 2002.p. 143e248.

[22] De Levie R, Husovsky AA. Instrument for the automaticmeasurement of the electrode admittance. J ElectroanalChem Interfacial Electrochem 1969;20(2):181e93.

[23] Davis F, Higson SPJ. Biofuel cellsdrecent advances andapplications. Biosens Bioelectron 2007:1224e35.

[24] Diard JP, Le Gorrec B, Montella C. Theoretical formulation ofthe odd harmonic test criterion for EIS measurements. JElectroanal Chem 1994;377(1e2):61e73.

[25] Smith DE. The acquisition of electrochemical responsespectra by on-line fast fourier transform. Data processing inelectrochemistry. Anal Chem 1976;48(2):221Ae2240A.

[26] Creason SC, Hayes JW, Smith DE. Fourier transform faradaicadmittance measurements III. Comparison of measurementefficiency for various test signal waveforms. J ElectroanalChem Interfacial Electrochem 1973;47(1):9e46.

[27] Darowicki K, Orlikowski J, Lentka G. Instantaneousimpedance spectra of a non-stationary model electricalsystem. J Electroanal Chem 2000;486(2):106e10.

[28] Darowicki K, Andrearczyk K. Determination of occurrence ofanodic excursion peaks by dynamic electrochemicalimpedance spectroscopy, atomic force microscopy and cyclicvoltammetry. J Power Sources 2009;189(2):988e93.

[29] Arutunow A, Darowicki K. DEIS assessment of AISI 304stainless steel dissolution process in conditions ofintergranular corrosion. Electrochim Acta2008;53(13):4387e95.

[30] Yoo J-S, Park S-M. An electrochemical impedancemeasurement technique employing fourier transform. AnalChem 2000;72(9):2035e41.

[31] Yoo JS, Song I, Lee JH, Park SM. Real-time impedancemeasurements during electrochemical experiments andtheir application to aniline oxidation. Anal Chem2003;75(14):3294e300.

[32] Chang BY, Hong SY, Yoo JS, Park SM. Determination ofelectron transfer kinetic parameters by fourier transformelectrochemical impedance spectroscopic analysis. J PhysChem B 2006;110(39):19386e92.

[33] H�azı̀ J, Elton DM, Czerwinski WA, Schiewe J, Vicente-Beckett VA, Bond AM. Microcomputer-basedinstrumentation for multi-frequency fourier transformalternating current (admittance and impedance)voltammetry. J Electroanal Chem 1997;437(1e2):1e15.

[34] Chang B-Y, Park S-M. Electrochemical impedancespectroscopy. Annu Rev Anal Chem 2010;3(1):207e29.


http://refhub.elsevier.com/S0360-3199(14)02806-7/sref1







































































































































































[35] Ragoisha GA, Bondarenko AS. Potentiodynamicelectrochemical impedance spectroscopy. Electrochim Acta2005;50(7e8):1553e63.

[36] Bondarenko A, Ragoisha G. Variable MOTT-Schottky plotsacquisition by potentiodynamic electrochemical impedancespectroscopy. J Solid State Electrochem 2005;9(12):845e9.

[37] Chaudhuri SK, Lovley DR. Electricity generation by directoxidation of glucose in mediatorless microbial fuel cells. NatBiotechnol 2003;21(10):1229e32.

[38] Rabaey K, Lissens G, Siciliano SD, Verstraete W. A microbialfuel cell capable of converting glucose to electricity at highrate and efficiency. Biotechnol Lett 2003;25(18):1531e5.

[39] Reimers CE, Tender LM, Fertig S, Wang W. Harvesting energyfrom the marine sediment-water interface. Environ SciTechnol 2001;35(1):192e5.

[40] Lu N, Zhou SG, Zhuang L, Zhang JT, Ni JR. Electricitygeneration from starch processing wastewater usingmicrobial fuel cell technology. Biochem Eng J2009;43(3):246e51.

[41] Pant D, Van Bogaert G, Diels L, Vanbroekhoven K. A review ofthe substrates used in microbial fuel cells (MFCs) forsustainable energy production. Bioresour Technol2010;101(6):1533e43.

[42] Lepage G, Albernaz FO, Perrier G, Merlin G. Characterizationof a microbial fuel cell with reticulated carbon foamelectrodes. Bioresour Technol 2012;124(0):199e207.

[43] BardAJ, Faulkner LR. Electrochemicalmethods: fundamentalsand applications, vol. 2. New York: Wiley; 1980.

[44] Huang L, Regan JM, Quan X. Electron transfer mechanisms,new applications, and performance of biocathode microbialfuel cells. Bioresour Technol 2011;102(1):316e23.

[45] Ouitrakul S, Sriyudthsak M, Charojrochkul S, Kakizono T.Impedance analysis of bio-fuel cell electrodes. BiosensBioelectron 2007;23(5):721e7.

[46] K€otz R, Carlen M. Principles and applications ofelectrochemical capacitors. Electrochim Acta2000;45(15e16):2483e98.

[47] Frackowiak E, B�eguin F. Carbon materials for theelectrochemical storage of energy in capacitors. Carbon2001;39(6):937e50.

[48] Richter H, McCarthy K, Nevin KP, Johnson JP, Rotello VM,Lovley DR. Electricity generation by geobactersulfurreducens attached to gold electrodes. Langmuir2008;24(8):4376e9.

[49] Lowy DA, Tender LM. Harvesting energy from the marinesedimentewater interface: III. Kinetic activity of quinone-and antimony-based anode materials. J Power Sources2008;185(1):70e5.

[50] Schr€oder U, Nießen J, Scholz F. A generation of microbial fuelcells with current outputs boosted by more than one order ofmagnitude. Angew Chem Int Ed 2003;42(25):2880e3.

[51] Martin E, Tartakovsky B, Savadogo O. Cathode materialsevaluation in microbial fuel cells: a comparison of carbon,Mn2O3, Fe2O3 and platinum materials. Electrochim Acta2011;58(0):58e66.

[52] Zhang Y, Sun J, Hu Y, Li S, Xu Q. Bio-cathode materialsevaluation in microbial fuel cells: a comparison of graphitefelt, carbon paper and stainless steel mesh materials. Int JHydrogen Energy 2012;37(22):16935e42.

[53] Larminie J, Dicks A, McDonald MS. Fuel cell systemsexplained, vol. 2. Chichester: Wiley; 2003.

[54] Zhang Y, Sun J, Hou B, Hu Y. Performance improvement ofair-cathode single-chamber microbial fuel cell using amesoporous carbon modified anode. J Power Sources2011;196(18):7458e64.

[55] Manohar AK, Bretschger O, Nealson KH, Mansfeld F. Thepolarization behavior of the anode in a microbial fuel cell.Electrochim Acta 2008;53(9):3508e13.


[56] Srikanth S, Marsili E, Flickinger MC, Bond DR.Electrochemical characterization of geobactersulfurreducens cells immobilized on graphite paperelectrodes. Biotechnol Bioeng 2008;99(5):1065e73.

[57] He Z, Huang Y, Manohar AK, Mansfeld F. Effect of electrolytepH on the rate of the anodic and cathodic reactions in an air-cathode microbial fuel cell. Bioelectrochemistry2008;74(1):78e82.

[58] Manohar AK, Bretschger O, Nealson KH, Mansfeld F. The useof electrochemical impedance spectroscopy (EIS) in theevaluation of the electrochemical properties of a microbialfuel cell. Bioelectrochemistry 2008;72(2):149e54.

[59] Min B, Poulsen FW, Thygesen A, Angelidaki I. Electric powergeneration by a submersible microbial fuel cell equippedwith a membrane electrode assembly. Bioresour Technol2012;118(0):412e7.

[60] He Z, Shao H, Angenent LT. Increased power productionfrom a sediment microbial fuel cell with a rotating cathode.Biosens Bioelectron 2007;22(12):3252e5.

[61] Ye D, Yang Y, Li J, Zhu X, Liao Q, Deng B, et al. Performance ofa microfluidic microbial fuel cell based on graphiteelectrodes. Int J Hydrogen Energy 2013;38(35):15710e5.

[62] Huang Y, He Z, Kan J, Manohar AK, Nealson KH, Mansfeld F.Electricity generation from a floating microbial fuel cell.Bioresour Technol 2012;114(0):308e13.

[63] Chi M, He H, Wang H, Zhou M, Gu T. Graphite felt anodemodified by electropolymerization of nano-polypyrrole toimprove microbial fuel cell (MFC) production ofbioelectricity. J Microb Biochem Technol S 2013;12:2.

[64] Andoralov V, Falk M, Suyatin DB, Granmo M, Sotres J,Ludwig R, et al. Biofuel cell based on microscalenanostructured electrodes with inductive coupling to ratbrain neurons. Sci reports 2013;3.

[65] Li Y, Chen SM, Wu TY, Ku SH, Ali MA, AlHemaid FM.Immobilization of laccase into poly (3, 4-ethylenedioxythiophene) assisted biocathode for biofuel cellapplications. Int J Electrochem Sci 2012;7(11).

[66] Yuan Y, Zhou S, Liu Y, Tang J. Nanostructured macroporousbioanode based on polyaniline-modified natural loofahsponge for high-performance microbial fuel cells. Environ SciTechnol 2013;47(24):14525e32.

[67] Gong XB, You SJ, Wang XH, Zhang JN, Gan Y, Ren NQ. A novelstainless steel mesh/cobalt oxide hybrid electrode forefficient catalysis of oxygen reduction in a microbial fuel cell.Biosens Bioelectron 2014;55(0):237e41.

[68] Ammam M, Fransaer J. Combination of laccase and catalasein construction of H2O2eO2 based biocathode forapplications in glucose biofuel cells. Biosens Bioelectron2013;39(1):274e81.

[69] Kim T, Kang J, Lee JH, Yoon J. Influence of attached bacteriaand biofilm on double-layer capacitance during biofilmmonitoring by electrochemical impedance spectroscopy.Water Res 2011;45(15):4615e22.

[70] Malvankar NS, Mester T, Tuominen MT, Lovley DR.Supercapacitors based on c-type cytochromes usingconductive nanostructured networks of living bacteria.ChemPhysChem 2012;13(2):463e8.

[71] Tremouli A, Antonopoulou G, Bebelis S, Lyberatos G.Operation and characterization of a microbial fuel cell fedwith pretreated cheese whey at different organic loads.Bioresour Technol 2013;131(0):380e9.

[72] Habouzit F, G�evaudan G, Hamelin J, Steyer JP, Bernet N.Influence of support material properties on the potentialselectionof archaeaduring initial adhesionof amethanogenicconsortium. Bioresour Technol 2011;102(5):4054e60.

[73] Hadjiev D, Dimitrov D, Martinov M, Sire O. Enhancement ofthe biofilm formation on polymeric supports by surfaceconditioning. Enzyme Microb Technol 2007;40(4):840e8.





























































































































































































[74] Guo CX, Hu FP, Lou XW, Li CM. High-performance biofuel cellmade with hydrophilic ordered mesoporous carbon aselectrode material. J Power Sources 2010;195(13):4090e7.

[75] Dos Santos AB, Traverse J, Cervantes FJ, Van Lier JB.Enhancing the electron transfer capacity and subsequentcolor removal in bioreactors by applying thermophilicanaerobic treatment and redox mediators. Biotechnol Bioeng2005;89(1):42e52.

[76] Hosseini MG, Ahadzadeh I. Electrochemical impedance studyon methyl orange and methyl red as power enhancingelectron mediators in glucose fed microbial fuel cell. JTaiwan Inst Chem Eng 2013;44(4):617e21.

[77] Ramasamy RP, Gadhamshetty V, Nadeau LJ, Johnson GR.Impedance spectroscopy as a tool for non-intrusivedetection of extracellular mediators in microbial fuel cells.Biotechnol Bioeng 2009;104(5):882e91.

[78] Sun J, Li W, Li Y, Hu Y, Zhang Y. Redox mediator enhancedsimultaneous decolorization of azo dye and bioelectricitygeneration in air-cathode microbial fuel cell. BioresourTechnol 2013;142(0):407e14.

[79] Rozendal RA, Hamelers HV, Molenkamp RJ, Buisman CJ.Performance of single chamber biocatalyzed electrolysiswith different types of ion exchange membranes. Water Res2007;41(9):1984e94.

[80] Rozendal RA, Hamelers HVM, Buisman CJN. Effectsof membrane cation transport on pH and microbialfuel cell performance. Environ Sci Technol2006;40(17):5206e11.

[81] Gil GC, Chang IS, Kim BH, Kim M, Jang JK, Park HS, et al.Operational parameters affecting the performance of amediator-less microbial fuel cell. Biosens Bioelectron2003;18(4):327e34.

[82] Rousseau R, Dominguez-Benetton X, D�elia ML, Bergel A.Microbial bioanodes with high salinity tolerance formicrobial fuel cells and microbial electrolysis cells.Electrochem Commun 2013;33(0):1e4.

[83] Aaron D, Tsouris C, Hamilton CY, Borole AP. Assessment ofthe effects of flow rate and ionic strength on theperformance of an air-cathode microbial fuel cell usingelectrochemical impedance spectroscopy. Energies2010;3(4):592e606.

[84] Oh S-E, Logan B. Proton exchange membrane and electrodesurface areas as factors that affect power generation in


microbial fuel cells. Appl Microbiol Biotechnol2006;70(2):162e9.

[85] Choi S, Lee HS, Yang Y, Parameswaran P, Torres CI,Rittmann BE, et al. A mL-scale micromachined microbial fuelcell having high power density. Lab a Chip 2011;11(6):1110e7.

[86] Rabaey K, Verstraete W. Microbial fuel cells: novelbiotechnology for energy generation. Trends Biotechnol2005;23(6):291e8.

[87] Qian F, Baum M, Gu Q, Morse DE. A 1.5 [small micro]Lmicrobial fuel cell for on-chip bioelectricity generation. LabChip 2009;9(21):3076e81.

[88] Hou H, Li L, Cho Y, de Figueiredo P, Han A. Microfabricatedmicrobial fuel cell arrays reveal electrochemically activemicrobes. PLoS One 2009;4(8):e6570.

[89] Kim B, Chang I, Gadd G. Challenges in microbial fuel celldevelopment and operation. Appl Microbiol Biotechnol2007;76(3):485e94.

[90] Tugtas AE, Cavdar P, Calli B. Continuous flow membrane-less air cathode microbial fuel cell with spunbonded olefindiffusion layer. Bioresour Technol 2011;102(22):10425e30.

[91] Min B, Logan BE. Continuous electricity generation fromdomestic wastewater and organic substrates in a flat platemicrobial fuel cell. Environ Sci Technol2004;38(21):5809e14.

[92] Li WW, Sheng GP, Liu XW, Cai PJ, Sun M, Xiao X, et al. Impactof a static magnetic field on the electricity production ofshewanella-inoculated microbial fuel cells. BiosensBioelectron 2011;26(10):3987e92.

[93] Sahebjamei H, Abdolmaleki P, Ghanati F. Effects of magneticfield on the antioxidant enzyme activities of suspension-cultured tobacco cells. Bioelectromagnetics 2007;28(1):42e7.

[94] Yin Y, Huang G, Tong Y, Liu Y, Zhang L. Electricity productionand electrochemical impedance modeling of microbial fuelcells under static magnetic field. J Power Sources2013;237(0):58e63.

[95] He Z, Wagner N, Minteer SD, Angenent LT. An upflowmicrobial fuel cell with an interior cathode: assessment ofthe internal resistance by impedance spectroscopy. EnvironSci Technol 2006;40(17):5212e7.

[96] Jung S, Mench MM, Regan JM. Impedance characteristics andpolarization behavior of a microbial fuel cell in response toshort-term changes in medium pH. Environ Sci Technol2011;45(20):9069e74.


















































































































Documents

Application of electrochemical impedance spectroscopy in bio-fuel cell characterization: A review