Advantages of High-Entropy Alloy Anodes over Conventional Anodes for Enhanced Interfacial Stability and Electrochemical Performance in Solid-State Batteries

One of the core challenges in developing next-generation solid-state batteries (SSBs) with high safety and energy density lies in the interfacial instability between conventional anodes and solid-state electrolytes (SSEs). This instability leads to high impedance, severe side reactions, and dendrite growth that can short-circuit cells. High-entropy alloys (HEAs), as emerging multi-principal-element anode materials, leverage configurational entropy and lattice-distortion effects to address these interfacial issues. This review synthesizes recent experimental and computational advances, evaluating the advantages of HEA anodes over conventional anodes in terms of interfacial stability and electrochemical performance. HEA anodes exhibit notable improvements, including approximately 2.4 higher capacity than graphite, capacity retention above 90% after 100 cycles, significantly reduced interfacial impedance, and stable operation across wide temperature ranges. These gains arise from HEA-specific mechanisms: multi-element cooperation enabled by the entropy effect, lattice distortion that buffers mechanical stress, and interfacial stabilization that suppresses impedance growth. Overall, HEA anodes demonstrate substantial promise for advancing SSB technology and provide guidance for the rational design of next-generation high-performance anodes.