Interface Modulation of Metal Sulfide Anodes for Long‐Cycle‐Life Sodium‐Ion Batteries

• DOI: 10.1002/adma.202208705
• Publication Date: 2023-01-20T11:04:51Z
• Authors: Mei Yang; Xiaoqing Chang; Liuqi Wang; Xingyu Wang; Mengyan Gu; Hao Huang; Lingyu Tang; Yiren Zhong; Hui Xia
• Keywords: Sodium nitrate

Although studies of transition metal sulfides (TMS) as anode materials for sodium-ion batteries are extensively reported, the short cycle life is still a thorny problem that impedes their practical application. In this work, new capacity fading mechanism TMS electrodes demonstrated; is, parasitic reaction between electrolyte anions (i.e., ClO4- ) and yields non-conductive unstable solid-electrolyte interphase (SEI) meanwhile, corrosively turns into less-active oxides. This knowledge guides development an electrochemical strategy to manipulate anion decomposition construct stable interface prevents extensive reactions. It shown introducing sodium nitrate radically changes Na+ solvation structure by populating ions in first sheath, generating conductive SEI layer containing both Na3 N NaF. The optimized enables iron sulfide stably over 2000 cycles with negligible loss, similar enhancement performance demonstrated on number other sulfides. work discloses sulfides' cycling failure from unique perspective highlights critical importance manipulating chemistry batteries.