Creep Localization Empowering High-Capacity Alloy Anodes for Durable All-Solid-State Lithium Batteries.

Abstract

High-capacity alloy anodes (Si, Al, and Sn) promise critical materials for developing high-energy all-solid-state lithium batteries (ASSLBs). However, their implementation remains fundamentally constrained by severe interfacial stress, large volume changes, and high stack pressures. Here, a novel "creep localization" strategy is proposed to address these intrinsic limitations by coupling a creep-susceptible (InSn₄)_0.37·(InBi)_0.63 alloy anode with a titanium mesh possessing a high area moment of inertia. The investigations reveal a synergistic interface stabilization mechanism: InSnBi undergoes adaptive creep to maintain ionic-electronic interpenetrating networks, while the titanium framework, through its flexural rigidity, redistributes localized stress and prevents heterogeneous stress concentrations from driving InSnBi creep toward the cathode. This hierarchical stress management mechanism ensures stable cycling by accommodating substantial volume fluctuations, thereby enabling ASSLBs to realize stable cycling at high loading (23.05 mAh cm^-2) and low stack pressures (3 MPa), respectively. Remarkably, the as-assembled LiCoO₂||InSnBi full-cell with a capacity of 5.56 mAh cm^-2 maintains a retention of 81.6% over 3000 cycles at a 2C rate. This work presents a new paradigm for addressing the electro-chemo-mechanical coupling degradation of ASSLBs, representing a milestone advancement for developing high-energy ASSLBs.