Microstructural engineering of high-power redox flow battery electrodes via non-solvent induced phase separation

Abstract

Redox flow batteries (RFBs) are emerging as viable options for grid-scale energy storage, but their elevated costs hamper commercialization. Enhancing the porous carbon electrode performance to improve power density and reduce system costs is an effective strategy toward widespread deployment; however, the porous carbon electrode must satisfy multiple contradictory roles, including providing high surface area, low pressure drop, and facile mass transport, thus motivating electrode engineering efforts. In this work, we systematically explore the non-solvent induced phase separation (NIPS) technique as a platform to synthesize a family of distinct microstructures for use in RFBs. Flow cell studies in commercially relevant redox pairs (i.e., Fe 2+/3+ , V 2+/3+ , and V 4+/5+ ) are performed, revealing diverse performance profiles, synthesis-structure-performance relationships, and opportunities for high-power electrode materials. We anticipate that, with further refinement and customization, NIPS electrodes can broadly benefit electrode engineering efforts for electrochemical energy storage and conversion applications. • Non-solvent induced phase separation as a versatile and facile synthetic platform • Porous electrodes with tunable microstructure • Synthesis-property-performance relationships for flow battery electrodes • High power density redox flow batteries Jacquemond et al. develop a versatile synthetic approach, based on non-solvent induced phase separation, to manufacture porous electrodes for redox flow batteries. Through a systematic study of synthetic conditions, the authors elucidate manufacturing-microstructure-performance relationships and demonstrate high power density operation in redox flow batteries using the novel electrodes.