Multiscale Magnetic Field Engineering for Advanced Lithium‐Based Batteries

Lithium battery performance remains limited by sluggish kinetics, interfacial instability, and mass transport constraints. The application of magnetic fields as a non-invasive physical modulation tool offers a promising paradigm to fundamentally circumvent these pervasive bottlenecks. This review first outlines the fundamental physical principles of magnetic fields to establish the theoretical basis for their functionality in electrochemical systems. Building upon this foundation, we systematically elucidate the role of the magnetic field in addressing multiscale scientific challenges within lithium-based batteries, specifically regarding interfacial dynamics, bulk phase transport, and chemical reactions. Regarding the electrode/electrolyte interface, the magnetic field effectively inhibits lithium dendrite proliferation and stabilizes the solid electrolyte interphase through the homogenization of ionic flux. Within the bulk phase, macroscopic convection induced by the magnetohydrodynamic effect mitigates concentration polarization, while magnetic force facilitates the directional transport of paramagnetic molecules such as oxygen and the targeted capture of detrimental ions. At the reaction level, magnetic modulation inhibits cation mixing via spin-state regulation and accelerates sluggish multielectron reactions. The objective of this review is to clarify the transformative potential of magnetic fields as multiscale and multifunctional regulatory tool for advancing the development of next-generation lithium-based batteries, including lithium-sulfur, lithium-oxygen, and all-solid-state batteries.