A Review of Fin Geometry and Design for Performance Enhancement in Latent Heat Thermal Energy Storage Systems

The low thermal conductivity of phase change materials (PCMs) remains a primary constraint on the performance of latent heat thermal energy storage (LHTES) systems. This review critically analyzes the extensive body of research dedicated to overcoming this limitation through the application of various fin geometries and designs. It delves into the geometrical parameters, dimensionless numbers, and placement strategies of fins, including rectangular, annular, spiral, plate, and novel biomimetic designs, evaluating their impact on thermal behavior through both numerical and experimental investigations. The analysis demonstrates that fin configuration fundamentally dictates the balance between conductive and convective heat transfer mechanisms. While longitudinally finned structures often provide the most practical enhancement due to their manufacturing simplicity, innovative designs like tree‐shaped and spiral fins offer superior thermal performance at the cost of increased complexity. Key trade‐offs are identified, notably between thermal performance gains and the concomitant reduction in PCM storage volume. The review concludes by highlighting critical research gaps, particularly the need for multi‐objective optimization frameworks that concurrently consider thermal performance, energy density, and economic viability, and calls for long‐term stability studies to assess the practicality of advanced fin designs.