Novel solid-state electrolyte developed to enhance performance of all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries (ASSBs) have garnered attention for their high energy density and superior safety. However, their commercialization remains challenging due to the lack of solid-state electrolytes (SSEs) with both high ionic conductivity and stable interfaces. To date, only a few SSEs have achieved ionic conductivities exceeding 10 mS/cm at room temperature.

Recently, a research team led by Prof. Wu Zhongshuai and Assoc. Prof. Shi Haodong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed high ionic conductivity sulfide-based solid electrolytes, enhancing the performance of ASSBs. The study is published in ACS Energy Letters.

Researchers developed the novel electrolyte, Li_20/3(GeSiSb)_1/3S₅I (LGSSSI), by employing a multi-cation (Ge, Si, Sb) doping and substitution strategy. The electrolyte exhibited exceptional ionic conductivity, attributed to its low lithium-ion migration activation energy (0.17 eV). After cold pressing, LGSSSI achieved an ionic conductivity of 12.7 mS/cm, which further increased to 32.2 mS/cm after hot pressing.

Integrated with LGSSSI, ASSBs achieved high cycling stability under ultra-high cathode mass loading (100 mg/cm²) and across a wide temperature range (-20°C to 60°C). In addition, LGSSSI demonstrated excellent interfacial compatibility with various cathode and anode materials, including LiNi_0.8Mn_0.1Co_0.1O₂, LiCoO₂ cathodes, lithium-indium alloy, and silicon-carbon composite anodes.

“Our study lays a foundation for achieving ASSBs with wide temperature adaptability, high cathode loading, and long cycle life,” said Prof. Wu.