Heterojunction Engineering of Electrodes and Membranes in Redox Flow Batteries

Redox flow batteries (RFBs) have demonstrated considerable potential for application prospects in the domain of large-scale energy storage. This potential can be attributed to their notable advantages, which include the decoupling of power and capacity, a prolonged cycle life, and a high level of safety. However, the enhancement of their energy efficiency and power density remains significantly constrained by critical issues, including sluggish reaction kinetics, the shuttle effect of active species, and inadequate interfacial stability. In recent years, heterojunctions have emerged as an efficient interfacial engineering strategy, providing novel solutions for enhancing the key performance of RFBs. This enhancement is achieved through the reconstruction of the interfacial electronic structure and modulation of the built-in electric field. This study provides a comprehensive review of the research progress related to heterojunctions in RFBs. The study focuses on summarizing the construction strategies and action mechanisms of heterojunction electrodes and heterojunction ion exchange membranes. It also discusses the regulatory effects of these materials on redox reaction kinetics, ion transport behavior, and cycling stability of RFBs. Additionally, the development trend of machine learning-assisted rational design of heterojunctions is discussed in detail. The objective of this work is to establish a theoretical framework and to elucidate the research insights pertinent to the precision design and engineering application of heterojunction materials in high-performance RFBs.