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 a high ionic conductivity sulfide-based solid electrolytes, enhancing the performance of ASSBs. The study was 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.