Net-like Al–Si Anode Integrating Structural Anchoring with Built-In 3D Ion Channels for High-Power-Density All-Solid-State Lithium Batteries

Abstract

Aluminum (Al) holds great promise as an anode material for all-solid-state lithium batteries (ASSLBs), owing to its high theoretical specific capacity and intrinsically low cost. Nevertheless, its practical implementation is critically constrained by dramatic volume expansion and uneven lithiation, along with the subsequent interfacial chemo-electrochemical degradation. Here, we synthesized a net-like "expansion anchor" structure in an Al88Si12-10%Li anode via eutectic composition engineering and a targeted pre-lithiation strategy. This architecture exploits the inherent thermodynamic and kinetic disparities between Al and Si to guide the formation of a nanoscale lithium–silicon expanded network. The pre-formed network not only imposes controllable compressive pre-stress on the Al particles to accommodate the volume expansion but also constructs continuous 3D lithium-ion transport pathways to deepen the reversible (de)lithiation depth. Dual functions reduce the electrode expansion from 45.5 to 14.7% without particle pulverization. The resultant full cells deliver exceptional rate capability up to 10C and maintain stable cycling at 6C for 500 cycles with 75.6% capacity retention. Furthermore, it exhibits robust performance under high areal loading (over 4 mA h·cm–2), delivering a competitive electrode-level power density of up to 1200 W·kg–1. This designed microstructural engineering establishes a scalable pathway for the development of high-performance alloy anodes in next-generation ASSLBs.