Achieving an Ultrastable Halide-Based All-Solid-State Lithium Battery via High-Valent Doping-Induced s-p-d Hybridization

Halide solid electrolytes (SEs) show great potential in all-solid-state batteries (ASSBs) because of their high ionic conductivity and high oxidative stability. But the long-term cycling stability remains a major concern due to the cathode/halide interface side reactions, especially under high current density. Herein, a s-p-d orbital hybridization strategy is proposed via introducing Zr 4+ and F − into Li 3 InCl 6 (LIC-ZrF 4 ) to regulate the electron localization structure around the central In 3+ . The electron transfer between the cation and Cl is alleviated by the enlarged bandgap (4.485–4.894 eV) with ZrF 4 introduction, and more electrons aggregate around In 3+ after s-p-d hybridization among Zr, In, and Cl. This effectively prevents LIC-ZrF 4 from being attacked by O atoms in LiNi 0 . 8 Co 0 . 1 Mn 0 . 1 (NCM811) and significantly suppresses the interface side reactions. The in situ formed LiF-containing layer further enhances the interface stability. The assembled ASSB (NCM811/LIC-ZrF 4 /LPSC/Li-In) exhibits a state-of-the-art capacity retention (96.7%@500cycles@1C; 80.7%@1600 cycles@2C). Furthermore, the ionic conductivity of LIC-ZrF 4 is also enhanced from 0.6 to 1.5 mS cm −1 while the electronic conductivity is decreased from 3.66 × 10 −8 to 8.39 × 10 −9 S cm −1 . This work highlights the crucial role of s-p-d hybridization on the electron localization regulation and the interface stability, and presents some distinct insights into developing high-performance halides-based ASSBs.