Phase Change Materials for Thermal Management in Lithium-Ion Battery Packs: A Review

In the continuous demand for high-performance lithium-ion batteries (LIBs), thermal management control is, these days, crucial with respect to safety, performance, and longevity. As a promising passive solution, Phase Change Materials (PCMs) have been implemented to overcome the conventional battery thermal management (BTM) approaches, including air cooling, liquid cooling, or refrigerant-based systems. Their ability to transfer the heat during phase change processes makes them ideal candidates for further thermal buffers, thus allowing compact and energy-efficient temperature control without extra power consumption. This work encompasses the recent progress in PCM-based battery thermal management systems, with a particular focus on material selection, structural design, and experimental validation. Current advances in composite PCMs, including the use of high-conductivity additives, porous supports, and encapsulation methods, are here appraised in terms of their thermal conductivity, cycling stability, leakage prevention, and overall safety. Comparisons between organic, inorganic, and hybrid PCM types demonstrate the benefits and drawbacks of each class. Ongoing discussion is also directed towards challenges that include low thermal conductivity, limited heat storage capacity, scalability, cost, and flammability. Future development opportunities are also identified in the areas of multifunctional PCMs, hybrid passive–active cooling approaches, scalable processing, and life-cycle considerations.