Thermal management of supercapacitors: a review of thermal challenges, management strategies, future directions

Supercapacitors (SCs) have emerged as critical energy storage devices for high-power applications including electric vehicles, renewable energy systems, and power grid stabilization. However, their performance is significantly influenced by temperature variations, with lifespan reducing by 50% for every 10K increase above 298K. This comprehensive review analyzes the thermal challenges facing supercapacitors and evaluates current thermal management strategies. The study examines temperature effects on key SC components including electrolytes, electrodes, and separators, revealing that ionic conductivity increases with temperature while high temperatures accelerate degradation through Joule heating, pressure evolution, and increased equivalent series resistance. Performance analysis shows that extreme temperatures severely impact self-discharge rates, aging mechanisms, and overall efficiency. Current thermal management approaches are categorized into passive systems (heat pipes, phase change materials, natural convection) and active systems (forced air cooling, liquid cooling). Comparative analysis demonstrates that liquid cooling offers superior temperature control with up to 35% lower maximum temperatures in SC-specific experimental studies, while PCM-based systems provide excellent temperature uniformity. Heat pipe cooling shows 7.5%–11.7% temperature reduction and 2.1% improvement in capacity retention compared to natural convection. The review identifies critical research gaps including limited understanding of molecular-level degradation mechanisms, lack of standardized testing protocols, and insufficient development of cost-effective thermal interface materials. Future directions emphasize hybrid thermal management systems, advanced materials with enhanced thermal stability, and integrated design approaches for optimizing both device architecture and thermal control strategies.