Particle-aggregation induced instability of flow electrodes in electrochemical lithium extraction

Abstract

Electrochemical lithium extraction using flow electrodes offers great potential due to its high selectivity, environmental sustainability, and scalability. In this work, we find that lithium iron phosphate flow electrodes would inevitably suffer rapid capacity degradation under dynamic flowing conditions. Experimental and simulation analyses identified flow-induced particle aggregation as the primary factor behind this instability. To address this challenge, salt-responsive zwitterionic polymers were grafted onto particle surfaces, introducing steric repulsion that effectively mitigated aggregation, ensuring stable operation of flow electrodes. These findings highlight the importance of controlling interparticle forces and aggregation dynamics in optimizing flow electrode functionality, providing valuable insights for the development of advanced lithium extraction systems.