• High-entropy materials (HEMs) offer unique advantages for batteries, including high configurational entropy, lattice distortion, and synergistic cocktail effects, which enhance structural stability, electronic conductivity, and ionic transport.
• The review proposes a multidimensional design paradigm that integrates synergistic mechanisms across cathodes, anodes, electrolytes, and electrocatalysts, addressing fragmented knowledge in structure–property relationships.
• Entropy-mediated structural tailoring improves cycle stability and ionic conductivity in lithium, sodium, and potassium-ion batteries, with high-entropy effects stabilizing solid-electrolyte interphases and suppressing transition metal dissolution.
• Machine learning-driven composition screening and sustainable manufacturing present emerging opportunities, while performance variability and cost-benefit analysis remain critical challenges for industrial implementation.