Single-Crystal vs Polycrystalline Cathodes for Lithium-Ion Batteries

As various applications increasingly demand Li-ion batteries (LIBs) with higher energy densities, cathode materials with extensively high Ni contents have been developed for LIBs. However, commercially available polycrystalline (PC) cathodes struggle to maintain structural stabilities due to severe cracking. In this regard, single-crystal (SC) cathode materials have gained significant attention owing to their inherent structural integrities and resistances to intergranular cracking. This review comprehensively examines nanoscale-to-microscale degradation mechanisms, challenges in the synthesis, and characteristic electrochemical behaviors of SC cathodes, in comparison with PC cathodes. By elucidating the distinct structural and kinetic characteristics of SC and PC cathodes, this review offers strategic insights into the rational design of durable, high-energy LIB cathode materials.