Manipulating Li2S2/Li2S mixed discharge products of all-solid-state lithium sulfur batteries for improved cycle life

Jung Tae Kim; Adwitiya Rao; Heng-Yong Nie; Yang Hu; Weihan Li; Feipeng Zhao; Sixu Deng; Xiaoge Hao; Jiamin Fu; Jing Luo; Hui Duan; Changhong Wang; Chandra Veer Singh; Xueliang Sun

doi:10.1038/s41467-023-42109-5

Manipulating Li₂S₂/Li₂S mixed discharge products of all-solid-state lithium sulfur batteries for improved cycle life

Nat Commun. 2023 Oct 12;14(1):6404. doi: 10.1038/s41467-023-42109-5.

Authors

Jung Tae Kim¹, Adwitiya Rao², Heng-Yong Nie^{3

4}, Yang Hu¹, Weihan Li¹, Feipeng Zhao¹, Sixu Deng¹, Xiaoge Hao¹, Jiamin Fu¹, Jing Luo¹, Hui Duan¹, Changhong Wang^{5

6}, Chandra Veer Singh⁷, Xueliang Sun^{8

9}

Affiliations

¹ Department of Mechanical and Materials Engineering, University of Western Ontario, 1151 Richmond St, London, Ontario, ON, N6A 3K7, Canada.
² Department of Materials Science and Engineering, University of Toronto, Ontario, ON, M5S 3E4, Canada.
³ Surface Science Western, University of Western Ontario, 999 Collip Circle, London, Ontario, ON, N6G 0J3, Canada.
⁴ Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond St, London, Ontario, ON, N6A 3K7, Canada.
⁵ Department of Mechanical and Materials Engineering, University of Western Ontario, 1151 Richmond St, London, Ontario, ON, N6A 3K7, Canada. changhongwang@eias.ac.cn.
⁶ Eastern Institute for Advanced Study, Eastern Institute of Technology, Ningbo, Zhejiang, 315200, P.R. China. changhongwang@eias.ac.cn.
⁷ Department of Materials Science and Engineering, University of Toronto, Ontario, ON, M5S 3E4, Canada. chandraveer.singh@utoronto.ca.
⁸ Department of Mechanical and Materials Engineering, University of Western Ontario, 1151 Richmond St, London, Ontario, ON, N6A 3K7, Canada. xsun9@uwo.ca.
⁹ Eastern Institute for Advanced Study, Eastern Institute of Technology, Ningbo, Zhejiang, 315200, P.R. China. xsun9@uwo.ca.

Abstract

All-solid-state lithium-sulfur batteries offer a compelling opportunity for next-generation energy storage, due to their high theoretical energy density, low cost, and improved safety. However, their widespread adoption is hindered by an inadequate understanding of their discharge products. Using X-ray absorption spectroscopy and time-of-flight secondary ion mass spectrometry, we reveal that the discharge product of all-solid-state lithium-sulfur batteries is not solely composed of Li₂S, but rather consists of a mixture of Li₂S and Li₂S₂. Employing this insight, we propose an integrated strategy that: (1) manipulates the lower cutoff potential to promote a Li₂S₂-dominant discharge product and (2) incorporates a trace amount of solid-state catalyst (LiI) into the S composite electrode. This approach leads to all-solid-state cells with a Li-In alloy negative electrode that deliver a reversible capacity of 979.6 mAh g^-1 for 1500 cycles at 2.0 A g^-1 at 25 °C. Our findings provide crucial insights into the discharge products of all-solid-state lithium-sulfur batteries and may offer a feasible approach to enhance their overall performance.