[Supplementary Information]

All-solid-state lithium-ion batteries with TiS2 nanosheets and sulphide solid electrolytes

Dae Yang Oh,a Young Eun Choi,a Dong Hyeon Kim,a Young-Gi Lee,b Byeong-Su Kim,c Jongnam Park,a Hiesang Sohn,d Yoon Seok Jung*,a

a School of Energy and Chemical Engineering, Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea

b Power Control Device Research Team, Electronics and Telecommunications Research

Institute (ETRI), 218, Gajeongno, Yuseong-gu, Daejeon, 305-700, South Korea

c Department of Chemistry, Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea

d The Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park, PA, 16802, USA

*Correspondence - ysjung@unist.ac.kr

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Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2016

Supplementary Experimental

The BM-TiS2 powders were obtained by milling 250 mg of TiS2 powders at 500 rpm for 2 h

under Ar in a steel vial (80 ml) with 5 ZrO2 balls (5 mm in diameter). For the AFM

measurement, a specially treated Si wafer was used. The Si wafer was soaked into RCA solution

(H2O : H2O2 : ammonia = 5 : 1 : 1 vol%) at 60 oC to make a hydrophillic surface. The pretreated

Si wafer was then put into a 10 mM polyethyleneimine (PEI) aqueous solution for 3 h to deposit

PEI on surface, which was followed by washing with deionized water several times. The PEI-

coated Si wafer was soaked into the TiS2-NS dispersion for 1 h and washed with deionized water.

The AFM image was obtained using DI-3100 (Veeco). Amorphous TiO2 powders were prepared

by sol-gel method.S1 After tetrabutyl orthotitanate (TBOT) was dissolved in ethanol, the as-

prepared TBOT solution was dropped into an aqueous solution containing benzyl alcohol at 0 oC

with stirring until molar ratio of TBOT : benzyl alcohol : ethanol : water is 1 : 3 : 30 : 5. The

white precipitates gathered by filtration and washing were subjected to vacuum-drying at 100 oC

for 12 h. The Ti K-edge XANES and EXAFS data were obtained on the BL8C beamline (wide-

energy XAFS) at the Pohang Light Sources (PLS) under a ring current of 400 mA at 2.5 GeV.

[S1] D. Eder, A. H. Windle, J. Mater. Chem. 2008, 18, 2036-2043.

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Fig. S1 First- and second-cycle charge-discharge voltage profiles of TiS2-NS/Li liquid-

electrolyte cells cycled between 1.5-3.0 V at 50 mA g-1. The cells were a) discharged first or b)

charged first. In the discharge-first voltage profiles (a), discharge capacity at second cycle is

higher than that at first cycle by 26 mA h g-1, which is considered to originate from the remained

Li in TiS2-NS. Consistently, in the charge-first voltage profile (b), charge capacity at first cycle

appears to be not zero, but 29 mA h g-1, indicating that the actual composition of TiS2-NS is

Li0.1TiS2.

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~11 layers

X X

Distance (nm)0 100 200 300 400 500 600

Hei

ght (

nm)

0

1

2

3

4

5

6

7

Fig. S2 AFM image of TiS2-NS.

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Fig. S3 Ti K-edge a) XANES and b) EXAFS spectra for b-TiS2, amorphous TiO2, and TiS2-NS.

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250 nm

a)

b)

Ti

S O

Fig. S4 a) Scanning TEM image and its corresponding EDXS elemental maps for TiS2-NS. b)

EDXS signals for TiS2-NS.

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Fig. S5 The differential voltage profiles in the second cycle for TiS2/Li-In all-solid-state cells

with a) b-TiS2 and b) TiS2-NS, and c) for TiS2-NS/Li liquid-electrolyte cell.

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Fig. S6 Second-cycle discharge-charge voltage profiles for b-TiS2 and TiS2-NS in all-solid-state

cell with high wt fraction of SE (64.5 wt%) in the composite electrode layers (The weight ratio

of TiS2:SE:super P was 10:20:1.).

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Fig. S7 Second-cycle discharge-charge voltage profiles and their corresponding differential

voltage profiles for ball-milled TiS2 (BM-TiS2) in all-solid-state cell.

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Fig. S8 Rate performance of ball-milled TiS2 (BM-TiS2)/Li-In all-solid-state cell. a) Discharge

capacity varied by C-rates as a function of cycle number. b) Discharge-charge voltage profiles at

different C-rates. The data for b-TiS2 and TiS2-NS are also shown for comparison.

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