Supplementary Figure 1. Thermogravimetric analysis of materials. (a) as prepared MnO2

nanosheets, (b) 75S/MnO2 prepared by melt diffusion at 155 oC. TGA studies were carried out at a

flow rate of 10 oC/min under air.

(b)

(a)

3% interlayer water

Supplementary Figure 2. SEM micrograph of the sulfur-MnO2 nanosheet mixture before melt

diffusion.

Supplementary Figure 3. EDS mapping of S, Mn, K and O in a representative S/MnO2 nanosheet

composite particle.

Supplementary Figure 4. Summary of polysulphide adsorptivity per 10 mg of active material as

determined by an electrochemical titration method.1

Supplementary Figure 5. S 2p spectrum of sodium thiosulphate and its mixture with Li2S4

(Na2S2O3-PS). To prepare the material, 80 mg anhydrous Na2S2O3 and 20 mg Li2S4 were stirred

for 2 hours in 10 ml of DME in the glovebox, and Na2S2O3-PS was collected by centrifugation. For

sodium thiosulphate alone (a), there are two sulphur environments: the S 2p3/2 peak at 167.5 eV (red)

is attributed to the central S=O while the S 2p3/2 peak at 161.5 eV (blue) is from the peripheral S in

the thiosulphate that bears the negative charge. For Na2S2O3-PS (b), we observe the S 2p3/2 signal of

the central S (red) and peripheral S for thiosulphate (blue) and the terminal S (blue, overlapped) and

bridging S (green) of the residual polysulphides. An additional peak at 168.8 eV (magenta) appears

for the Na2S2O3-PS sample, which is attributed to the reaction of thiosulphate and polysulphides to

form the polythionate complex (see text). This peak can be ascribed to the S=O in the polythionate,

whereas its bridging sulphur atoms are overlapped with those of the SB0 in S4

2-.

Binding Energy (eV)

a)

b)

Supplementary Figure 6. FTIR spectra of Li2S4; MnO2-Li2S4; -MnO2 and Na2S2O3; see legend.

The spectra were collected under N2.

Supplementary Figure 7. C 1s spectrum of graphene oxide (GO) and GO-Li2S4 (GO-LiPS).

The C 1s region of GO are assigned to 3 components: C-C at 285 eV (which dominates any traces of

adventitious carbon in the sample), C-O or C-OH at 287 eV, and C=O at 288.2 eV. The relative

intensity ratio of the C-C : C-O groups increases from 1.4: 1 for GO to 1.8: 1 for GO-Li2S4,

indicating that GO is slightly reduced by LiPS on the surface. In addition to the increased C-C

intensity, the C-O(H) peak is shifted by 0.7 eV to lower binding energy and the C=O peak is shifted

by 0.9 eV to higher binding energy. Exactly the same peak shift was reported in thermally reduced

GO by Zangmeister, C. D.2

C-C C-O(H)

C=O

Supplementary Figure 8. Comparison of the atomic concentration of each identified S 2p peak for

the electrodes discharged to specific states.

Polythionate

complex

Supplementary Figure 9. High resolution S 2p XPS analysis of (a) Na2S2 and (b) Li2S. The

spectra demonstrate that the S22-

groups in Na2S2 and the S2-

groups in Li2S exhibit S 2p3/2 binding

energies of 161.8 and 160.2 eV, respectively.

(b)

(a)

Supplementary Figure 10. Ex-situ XPS measurements of the 75S/MnO2 nanosheet electrodes on

partial charge.

Polythionate

complex

Thiosulfate

S8

SB0 ST

-1

Supplementary Figure 11. Rate capability of the 75S/MnO2 nanosheets at various current

densities. The cells were cycled in a 1.8- 3.0 V window at current densities corresponding to rates of

C/20, C/5, C/2 and 1C; a window between 1.7- 3.0 V was used for the 2C, 3C rates; and a window of

1.6- 3.0 V for 4C rates (1C = 1675 mA g-1

).

Supplementary Figure 12. SEM images showing the similarity in the morphology of a) the fresh

75S/MnO2 electrode, and b) after 1000 cycles.

Supplementary References:

1 Dominko, R.; Demir-Cakan, R.; Morcrette, M.; Tarascon, J.-M. Analytical detection of soluble

polysulphides in a modified Swagelok cell. Electrochem. Commun., 13, 117-120 (2013) 2 Zangmeister, C. D. Preparation and evaluation of graphite oxide reduced at 220⁰C. Chem. Mater. 22, 5625–

5629 (2010).