Thermodynamics-informed design in electrochemical systems: Entropy generation as a performance metric

Entropy Generation Analysis (EGA) and Entropy Generation Minimization (EGM) provide insightful thermodynamic lenses through which the hidden inefficiencies of electrochemical energy systems can be revealed and addressed. Far more than diagnostic tools, these frameworks provide a pathway toward principled and physically grounded design—where performance gains are achieved not by trial and error, but by understanding the fundamental sources of irreversibility. This review weaves together a broad and evolving body of work that applies EGA and EGM across diverse electrochemical technologies. Spanning analytical models, computational fluid dynamics, and topology optimization (TO), the reviewed studies expose how entropy generation is governed by flow field architecture, mass and heat transfer mechanisms, and complex multiphysics couplings. This review offers a vision for advancing the field: one in which EGA and EGM are integrated with full transport coupling, geometric complexity, and operational realism. Ultimately, we assert that to approach the thermodynamic limits of electrochemical systems, entropy must be embraced not just as a consequence, but as a core principle of design.