Recent Advances in Sensing Materials for Monitoring Thermal Runaway in Lithium-Ion Batteries

Lithium-ion batteries (LIBs) play a critical role in modern energy technologies, powering portable electronics, electric vehicles, and renewable energy storage systems due to their high energy density, long cycle life, and lightweight properties. However, their high energy storage capacity presents intrinsic safety challenges posed by thermal runaway, a potentially catastrophic failure mode. Recent advances in safety monitoring leverage detectable thermal runaway precursors, including temperature fluctuations, pressure variations, and gas evolution. Although significant efforts have focused on developing smart materials for early-stage thermal runaway detection, limited reviews have systematically addressed these material innovations. This review seeks to fill this gap by providing a concise overview of the mechanisms underlying thermal runaway in LIBs and the corresponding smart monitoring strategies. It also examines recent progress in smart materials tailored for temperature, pressure, and gas sensing applications. The primary objective of this survey is to offer valuable insights and guidance for enhancing thermal runaway safety management in battery systems.