A Universal Design of Lithium Anode via Dynamic Stability Strategy for Practical All‐solid‐state Batteries

All‐solid‐state Li‐metal battery (ASSLB) chemistry with thin solid‐state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li‐metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra‐thin LMA (20 μm) is in‐situ constructed with uniform highly Li‐ion conductive solid‐electrolyte interphase and composite‐polymer interphase (CPI) via electroplating process. As a result, the passivation layer with poor Li‐ion conduction on Li anode can be dissolved and small surface resistance can be achieved due to the good compatibility of CPI to SSEs. The cycling of Li symmetric cell with Li6PS5Cl thin film electrolyte (< 100 μm) shows a high critical current density of > 2.0 mA cm‐2 with excellent cycling stability at 1.0 mA cm‐2. The ASSLBs paring with Ni‐rich LiNi0.6Mn0.2Co0.2O2 cathode demonstrated the feasibility of engineered LMA design by presenting good rate capability from 0.1C to 1.0 C at room temperature, as well as long‐term cycling stability (81% retention after 100 cycles). This work represents a general pathway to make thin dendrite‐free LMA available for high‐energy‐density ASSLBs.