Innovative Approaches to Utilizing High-Entropy Oxide Materials in Lithium-Ion Batteries

Electrode materials of conventional lithium-ion batteries (LIBs) have limited capacity, and their energy density approaches their theoretical limits. In addition, issues such as the formation of a solid electrolyte interface, structural collapse of the electrodes, and lithium metal deposition (dendrite formation) during fast charging result in reduced electrode durability, efficiency, and safety. Furthermore, the increased use of rare metals such as nickel and cobalt exacerbates resource depletion, price volatility, and environmental problems. To overcome these limitations, researchers have focused on high-entropy oxides (HEOs) with diverse elemental compositions. HEOs provide high energy density and stability, and their excellent thermal stability and chemical versatility make them promising candidates for next-generation LIBs. This review discusses the definitions, characteristics, and synthesis methods of HEOs and analyzes their performance improvements as electrode materials. It also explores structural stability, charge transfer mechanisms, and performance optimization through theoretical calculations and simulations. In addition, this review addresses the significant barriers to high production costs for commercialization and proposes potential solutions. With advancements in synthesis technologies and compositional optimization, HEOs are expected to become commercially feasible and provide innovative solutions to energy and environmental challenges.