1

Supporting information for:

In-situ Reactive Assembly of Scalable Core-Shell Sulfur-MnO2

Composite Cathodes

Xiao Liang and Linda F. Nazar*

University of Waterloo, Department of Chemistry, Waterloo, Ontario, Canada N2L 3G1

* Address correspondence to lfnazar@uwaterloo.ca.

2

Figure S1. XPS study of the MnO2 shell material showing the majority component of Mn4+ on

the surface, with 5% of Mn3+. The spectrum of the shell from the micron-sized sulfur is shown for

clarity; the shell from the nano-sized sulfur particle showed the same spectrum.

Mn4+

642.5 eV

Mn3+

641.4 eV

Satellite

peaks

648 644 640 636

Inte

nsi

ty (

a.u

.)

Binding energy (eV)

3

Figure S2. Cycling performance of the MnO2 shell at C/2. The electrode was composed

of 80% MnO2 shell, 10% Super P and 10% PVDF by weight. The electrolyte used here is

the same as the Li-S cells (see text).

0 5 10 15 20 25 30 351.6

2.0

2.4

2.8

3.2V

olt

ag

e (

V v

s. L

i/Li

+)

Capacity (mAh/g- MnO2)

1st

2nd

3rd

10th

200th

0 200 400 600 800 10000

5

10

15

20

25

30

35

Ca

pa

city

(m

Ah

/g)

Cycle number

a

b

4

Figure S3. Robustness-test of rinsed NS-core/MnO2 demonstrating rate capability in a

range of current densities corresponding to C/5 - 8 C. The cell was examined in the

voltage window between 1.8- 3.0 V for C/20, C/5, C/2 and 1C rates; 1.7- 3.0 V for 2C,

and 3C rates, 1.6- 3.0 V for 4C rates and 1.5-3.0 V for 6C, 7C, and 8C rates (1C = 1675

mAh g-1).

0 20 40 60 80 100 120 140 1600

400

800

1200

1600

C/5

8C7C6C5C

C/5C/5

4C3C2C1CC/2

C/5

Charge

Dishcarge

Cycle number

Ca

pa

city

(m

Ah

g-1)

0 200 400 600 800 1000 1200 1400 1600

1.6

2.0

2.4

2.8

3.2

Capacity (mAh g-1)

Voltage (V vs. Li/Li+)

C/20

C/5

C/2

1C

2C

3C

4C

5C

6C

7C

8C

a

b

5

Figure S4. An SEM image of particles of SS-core/MnO2 and the corresponding EDX

elemental mapping of S (yellow), Mn (green), and O (blue).

S

Mn O

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Figure S5. XRD pattern of the SS-core/MnO2 composite, and that of the δ-MnO2

birnessite shell after the sulfur was removed.

10 20 30 40 50 60 70 80

JCPDS 80-1098 Birnessite

MnO2 shell

In

ten

sity

(a

. u

.)

2 theta degree

SS-core/MnO2

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Figure S6. Voltage profile of the rinsed SS-core/MnO2 electrode in Li-S cells at different

C rates.

0 200 400 600 800 1000 12001.6

2.0

2.4

2.8

0.5C

Vo

lta

ge

(V

vs.

Li/

Li+)

Capacity (mAh g-1)

2C

8

Figure S7. Electrodes after the 6th cycle at C/2 for the (a) pristine SS-core/MnO2

electrode and (b) rinsed SS-core/MnO2 electrode.

a

b