Magnetic field-induced thermal regulation in composite phase change materials for lithium-ion battery

Abstract

High-energy-density lithium-ion batteries (LIBs) encounter substantial thermal management challenges, especially during high-rate charge-discharge operations. Phase change materials (PCMs), known for their exceptional latent heat storage and temperature regulation properties, are widely used to mitigate thermal risks and enhance safety. In this study, we introduce an innovative strategy utilizing magnetic field-assisted alignment to regulate thermally conductive magnetic additives in composite phase change materials (CPCMs), enabling their self-assembly into ordered, continuous heat conduction networks. This aligned microstructure markedly enhances the thermal conductivity and operational stability of the CPCMs. Compared to non-aligned CPCMs, the magnetically aligned variants show a significant improvement in phase change reliability, with heat absorption and release profile similarity rising from 89.3 % to 95.8 % after 30 thermal cycles. Under stringent 3 C discharge conditions, the peak battery temperature decreases by 40.7 °C, and temperature fluctuations are limited to 0.3 °C, with no detectable phase change medium leakage. Additionally, multiphysics simulations confirm that a highly ordered, interconnected thermally conductive framework significantly improves effective heat transfer. This study proposes a scalable and promising strategy to enhance CPCM thermal management performance through magnetic field-guided structural engineering, providing a novel approach for safer next-generation high-power lithium-ion battery operation.