Manipulating Li<sub>2</sub>S<sub>2</sub>/Li<sub>2</sub>S mixed discharge products of all-solid-state lithium sulfur batteries for improved cycle life.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37828044.
- Also identified by DOI 10.1038/s41467-023-42109-5 and PMC identifier 10570351.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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 Li<sub>2</sub>S, but rather consists of a mixture of Li<sub>2</sub>S and Li<sub>2</sub>S<sub>2</sub>. Employing this insight, we propose an integrated strategy that: (1) manipulates the lower cutoff potential to promote a Li<sub>2</sub>S<sub>2</sub>-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<sup>-1</sup> for 1500 cycles at 2.0 A g<sup>-1</sup> 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.