Thermal management system and its impact on <scp>PEMFC</scp> performance: Review

Abstract Polymer electrolyte membrane fuel cells (PEMFCs) are prominent green energy sources that generate power 50%–60% more efficiently than internal combustion engines. They emit only heat and water, avoiding carbon emissions, but their operating temperatures are limited by membrane hydration, flooding prevention, and material deterioration. A good heat management system boosts PEMFC's performance and flexibility. Most systems use air cooling under 2 kW and liquid cooling beyond 5 kW. Conventional air‐ and liquid‐cooled systems have parasitic power, cost, maintenance, leakage, reliability, and portability concerns. We aim to solve air‐ and liquid‐cooled system problems with innovative passive and hybrid solutions. This study explores innovative thermal management systems (TMS) like heat pipes, heat spreaders, PCMs, metal foam thermal management, microchannel heat sinks, and integrated cooling technologies for mid‐range power applications (10–100 W and up). The presented work articulates both active and passive cooling systems in detail, followed by phase change materials (PCMs) and metal foam‐based cooling systems. Thermal management systems incorporating PCMs minimize coolant pump requirements, improve water removal, and distribute reactants. PCMs cause system design, flow instability, working fluid leaks, and durability concerns. On the other hand, metal foam flow fields improve PEMFC performance over other cooling systems, but their pressure dips, humidity balance, electrolyte dehydration, and complexity make them challenging to deploy. Hybrid nanofluids, PCMs, metal foams, and hybrid cooling systems may increase application‐specific cooling. This report advises more investigation in these areas. Understanding PEMFC thermal dynamics enhances system efficiency and longevity, enabling fuel cell commercialization and mainstream use.