Review of thermal management strategies for cylindrical lithium-ion batteries: Active, passive, and hybrid approaches

The increasing adoption of lithium-ion batteries (LIBs) in electric vehicles and renewable energy systems necessitates effective thermal management to ensure safety, reliability, and extended lifespan. This review provides a comprehensive analysis of battery thermal management systems (BTMS) for cylindrical LIBs, covering active cooling, passive techniques, and hybrid configurations. Recent studies demonstrate peak temperature reductions of up to 25 °C, enhancements in thermal conductivity from 0.2 to over 10 W/m.K, and temperature uniformity improvements exceeding 40 %. Key design strategies, including the use of composite PCMs, advanced fin geometries, and nano-enhanced coolants, are evaluated in terms of performance and feasibility. The paper also discusses challenges related to weight, cost, energy efficiency, and system integration, particularly in the context of scalable applications. By highlighting current advancements and limitations, this review offers valuable insights into promising directions for developing high-performance BTMS suited for modern energy storage and electric mobility systems.