Mobile Energy Company.

Akio FurukawaManagerNi Battery System Section No.2Technical service departmentAlkaline Technology Business UnitMobile Energy CompanyComponents Business GroupSanyo Electric Co., Ltd.

Development of

Dry Cell Replaceable Ni-MH Batteries

Mobile Energy Company.

1300mAh

1450mAh

1600mAh

1700mAh

1850mAh

2100mAh

2300mAh

11% UP

10% UP

6% UP

9% UP

14% UP

10% UP

Sanyo Electric Co., Ltd.

The capacity of AA size Ni-MH batteries

has been increased remarkably.

Improvement of the active material is necessary

to increase the capacity furthermore.

Further increase of capacity requires

a breakthrough technology

History of AA size Dry Cell Replaceable

Ni-MH Batteries

Mobile Energy Company.

Development of a new alloy with higher capacity and better corrosion resistance than the current alloy (AB5type) as the key active material of the negative electrode.

Development of higher capacity Ni-MH battery with the new alloy.

Purpose

Method

Optimization of the composition of the new alloy (Super-

lattice alloy) to improve corrosion resistance.

Mobile Energy Company.

AB5 alloy (Mm-Ni-Co-Mn-Al)

0.70.32.8Co0.5

Cycle condition:1It=1000mACharge:1It , V(10mV)Discharge:1It , E.V=1.0VRoom temperature

0.70.33.3

Cap

acit

y (

% v

s. in

itia

l)

40

50

60

70

80

90

100

110

0 100 200 300 400 500 600

Cycle Number

The charge and discharge cycle characteristics

Mobile Energy Company.

Test conditionCharge:150mA/g x2hr50minDischarge:150mA/g, E.V.= 0.7V

-MH

ele

ctr

od

e p

ote

nti

al

(V v

s.

Hg

O/H

g)

0.830.173.10.2

AB5 alloy(Mm-Ni-Co-Mn-Al)

0.6

0.7

0.8

0.9

1.0

0 100 200 300 400

Discharge capacity(mAh/g)

40

50

60

70

80

90

100

110

0 200 400 600 800 1000

Cycle Number

Mm0.83Mg0.17Ni3.1Al0.2

Cap

acit

y (

% v

s. in

itia

l)

Cycle condition:1It=1700mACharge:1It , V(10mV)Discharge:1It , E.V.=1.0VRoom temperature

AB5 alloy(Mm-Ni-Co-Mn-Al)

+10%

+30%

Comparison between the current AB5 type alloy

and the super-lattice alloy

Mobile Energy Company.

Discharge capacity (mAh)

Ce

ll V

olt

ag

e(V

)

0.80.9

11.11.21.31.41.51.61.71.8

0 500 1000 1500 2000 2500

Test Condition:

Charge: 250mA x 16hr at=25Discharge: 500mA, E.V.=1.0V

Ni-MH 2300

using AB5 alloy

Ni-MH 2500

using superlattice alloy

The cell capacity increase by using super-lattice alloy

Mobile Energy Company.

Sanyo HR-3U

(Typ. 2500mAh)

Brand A : AA

(Printed 2400mAh)

The capacity of HR-3U is the highest !!

The cycle life of HR-3U(Typ.2500mAh)

is the longest in the class.

Brand B : AA

(Printed 2500mAh)

Brand C : AA

(Printed 2300mAh)

Accelerated cycle test

Mobile Energy Company.

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

0 10 20 30 40 50 60 70 80 90

Charge & Discharge Time (min)

Cell

Voltage (

V)

1Cycle

2Cycles

3Cycles

4Cycles

5Cycles

Before Test

Cycle Condition :

Charge : 2500mA (-V=10mV)

Rest : 1h

Discharge : 2500mA (E.V.=1.0V)

Rest : 1h

Ambient Temp. : 20C

n=2

Storage Condition :

Ambient Temp. : 40C

Storage Term : 1Month

Cell is connected with Resistor.

(2ohm)

HR-3U(Typ.2500mAh) showed the best

recovery against Over-discharge !

Capacity loss is very small

Mobile Energy Company.

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

0 10 20 30 40 50 60 70 80 90Charge & Discharge Time (min)

Cell

Voltage (

V)

1Cycle

2Cycles

3Cycles

4Cycles

5Cycles

Before Test

Storage Condition :

Ambient Temp. : 40C

Storage Term : 1Month

Cell is connected with Resistor.

(2ohm)

Cycle Condition :

Charge : 2300mA (-dV=10mV)

Rest : 1h

Discharge : 2300mA (E.V.=0.8V)

Rest : 1h

Ambient Temp. : 20C

n=2

An Example

Recovery from over-discharge of Others AA; Big capacity loss!

Very big capacity loss

Mobile Energy Company.

Sanyo HR-3U

(Typ. 2500mAh)

Brand A : AA

(Printed 2400mAh)

At 40 deg.C

Brand B : AA

(Printed 2300mAh)

HR-3U(Typ.2500mAh) has the best

charge-retention (The slowest Self-discharge)

Brand C : AA

(Printed 2300mAh)

Mobile Energy Company.

0306090

120150

The Super-lattice hydrogen absorbing alloy (a breakthrough technology

in Ni-MH battery history since 1990) contributed the highest capacity

and best performance in AA size Dry Cell Replaceable Ni-MH Batteries.

AA : Typ. 2500mAh, AAA : Typ. 900mAh

The highest capacity in the world

with balanced performance.

High temp. Charge(40)

Recovery fromOver-discharge(60,14days)

Cell capacity

Low temp. discharge (0)

Self-discharge(40,14days)

High-rate discharge(3It)

Ni-MH 2500(Superlattice alloy)

Ni-MH 2300(AB5 alloy)

AA size Dry Cell Replaceable Ni-MH Battery

with Super-lattice hydrogen absorbing alloy

Mobile Energy Company.

1300mAh

1450mAh

1600mAh

1700mAh

1850mAh

2100mAh

2300mAh

2500mAh

11% UP

10% UP

6% UP

9% UP

14% UP

10% UP

9% UP

Sanyo Electric Co., Ltd.

History of AA size Dry Cell Replaceable

Ni-MH Batteries

Mobile Energy Company.

A new Super-lattice hydrogen absorbing alloy with higher

capacity and better corrosion resistance than the current alloy (AB5type) as the key active material of negative electrode of Ni-MH

battery was successfully developed.

The high capacity (2500mAh*) of AA size Dry Cell Replaceable Ni-

MH Battery was developed with the Super-lattice hydrogen

absorbing alloy and has been shipped since July 2004.

2500mAh* is still the highest capacity (among mass-produced AA

size Ni-MH batteries ) in the world at this moment (Feb. 20, 2005).

(*:The capacity is defined by IEC 61951-2)

Conclusion