High-Rate Charging All-Solid-State Batteries Enabled by a Multiphase Electron-Ion Co-Conductive Alloy Anode

The practical implementation of high-rate charging all-solid-state batteries (ASSBs) is severely hindered by sluggish Li-ion transport and persistent solid–solid interface degradation. In this work, we design a lithiophilic quaternary Li-Al-Si-Zn (ASZ@Li) alloy anode with a multiphase electron–ion co-conductive network (EICN) to overcome these critical limitations. When assembled with a LiNi0.9Co0.05Mn0.05O2 (Ni90) cathode, the resultant full cell achieves ultra-rapid charge–discharge within 72 s at 50 C, yielding a specific capacity of 105.6 mAh g–1 (57.9% of its 1 C capacity). Notably, the cell delivers outstanding cycling durability: it retains 80% of its initial capacity after 2,050 cycles at 20 C and 80% of its initial capacity even after 1460 cycles at 50 C. Even under a high areal loading of 30 mg cm–2 (6.73 mAh cm–2), the cell maintains 86% of its initial capacity after 520 cycles at 2 C, a critical metric for practical high-energy-density battery systems. Systematic experiments combined with first-principles calculations reveal the distinct roles of each phase in the ASZ@Li anode. LiAl domains ensure robust electronic percolation, LiZn phases promote uniform Li deposition and fast Li-ion transport, and Si-rich regions alleviate mechanical strain during cycling. This multiphase synergistic effect efficiently reduces interfacial impedance, enhances Li-ion diffusion kinetics, and stabilizes the electrode/electrolyte interface, paving the way for a robust, scalable anode design paradigm for high-rate ASSBs.