Recent Paper: Deciphering the Role of Fluorination in Dual-Halogen Electrolytes for All-Solid-State Batteries: A Case Study of New Li2HfCl6−xFx Solid Electrolytes

We are happy to share our latest work published in Angewandte Chemie: "Deciphering the Role of Fluorination in Dual-Halogen Electrolytes for All-Solid-State Batteries: A Case Study of New Li₂HfCl_6−xF_x Solid Electrolytes." The paper was first authored by group member Lanting Qian.

We synthesized a series of dual-halogen solid electrolytes (SEs), based on a new Pnma phase of Li₂HfCl₆. By systematically fluorinating it to various degrees, Li₂HfCl_5.5F_0.5 was identified as the optimal formulation. ASSBs assembled using it as the catholyte exhibited greatly enhanced electrochemical stability compared to those employing Li₂HfCl₆. We explicitly demonstrate that this is due to the formation of an in-situ-generated, LiF-rich cathode-electrolyte interphase, not enhanced anodic stability of the catholyte.

DOI: 10.1002/anie.202509209