Structural, Electronic, and Interfacial Pathways Governing the Stability of LiMn ₂ O ₄ Spinel Cathodes

LiMn 2 O 4 spinel cathodes, with their low cost, environmental benignity, and promising voltage profile, serve as a cornerstone of next‐generation Li‐ion batteries. Yet, its commercial viability is impeded by structural degradation and surface instabilities that arise during extended cycling. This review infers how intrinsic (thermodynamic, kinetic, electronic, magnetic, and mechanical) properties and extrinsic factors converge to govern the stability of LiMn 2 O 4 , providing a unified framework that correlates atomic‐scale processes and electrochemical performance. Particular emphasis is placed on the mechanistic pathways of lithiation/delithiation, where Jahn–Teller distortions, phase transitions, and strain evolution interplay with oxygen release, Mn dissolution, and electrolyte decomposition. By dissecting these coupled processes, this review clarifies how surface instabilities arise and how they propagate across length scales. Doping, coating, and electrolyte additives are critically examined not only as stabilization strategies but also as practical avenues that reveal fundamental degradation drivers. Unlike prior reviews, this work integrates cross‐disciplinary insights spanning thermodynamics to mechanics and methodically correlates them with electrochemical outcomes, presenting a comprehensive and causally connected picture of spinel degradation. The perspectives outlined here highlight design principles and interfacial engineering strategies that can expedite the rational development of durable LiMn 2 O 4 cathodes and inform broader efforts toward sustainable, high‐performance rechargeable batteries.