Materials design for thermally improved safety in lithium-ion batteries.

With the ever-increasing demand for high-energy-density lithium-ion batteries (LIBs) in multiscale energy storage, safety concerns have emerged as critical obstacles hindering their widespread application. The excess heat generated during the electrochemical process, if not properly managed, can accumulate and accelerate the aging of key cell components, potentially leading to catastrophic thermal runaway events such as fires and explosions. Thus far, considerable attention has been devoted to alleviating intense thermal runaway through fire-safe materials and energy-intensive thermal management technologies. However, the stabilization of the electrochemical environment through intrinsic thermal dissipation and temperature regulation governed by key material design has received comparatively little consideration. This paper aims to summarize the mechanism of thermal runway and highlight material advances for safer LIBs, with particular emphasis on the thermal-electrochemical synergy in mitigating localized overheating, stabilizing the electrochemical environment, and improving electrochemical performance. Subsequently, recent research progress in thermal management materials and strategies for dynamic temperature regulation is reviewed. Finally, current challenges are discussed, and future directions are proposed for material innovations that can be applied to high-energy-density and high-safety LIBs.