Abstract: High-entropy materials (HEMs), an innovative class of materials with complex stoichiometry, have recently garnered considerable attention in energy storage applications. While their multi-element compositions (five or more principal elements in nearly equiatomic proportions) confer unique advantages such as high configurational entropy, lattice distortion, and synergistic cocktail effects, the fundamental understanding of structure-property relationships in battery systems remains fragmented across existing studies. This review addresses critical research gaps by proposing a multidimensional design paradigm that systematically integrates synergistic mechanisms spanning cathodes, anodes, electrolytes, and electrocatalysts. We provide an in-depth analysis of HEMs' thermodynamic/kinetic stabilization principles and structure-regulated electrochemical properties, establishing quantitative correlations between entropy-driven phase stability and charge transport dynamics. Through performance benchmarking across lithium/sodium/potassium-ion battery components, we reveal how entropy-mediated structural tailoring enhances cycle stability and ionic conductivity. Notably, we pioneer the mapping of high-entropy effects to electrochemical interfaces, demonstrating their unique potential in stabilizing solid-electrolyte interphases and suppressing transition metal dissolution. Emerging opportunities in machine learning-driven composition screening and sustainable manufacturing are discussed alongside critical challenges, including performance variability metrics and cost-benefit analysis for industrial implementation. This work provides both fundamental insights and practical guidelines for advancing HEMs toward next-generation battery technologies.