Research progress on nanoparticles applied in redox flow batteries

Abstract

In recent years, the focus on the utilization of renewable energy has continued to heat up. However, renewable energy has the drawbacks of intermittency and mismatch between power generation and electricity consumption in time and space, thus the energy storage system is indispensable. Redox flow batteries (RFBs), as an electrochemical energy storage system, have attracted widespread attention with the nature of flexible design and long service life. The components of RFB and the efficient combination of components play a key role in battery performance. Due to the size effect and physicochemical properties of nanoparticles, the ionic conductivity, thermal conductivity, and mechanical effects are improved in RFBs with the addition of nanoparticles, thus improving the power performance and charge–discharge cycle life of the battery. In this review paper, we mainly report the application and research progress of nanoparticles applied in RFBs. The applications of nanoparticles in electrode, electrolyte, and proton (ion) exchange membranes in aqueous and nonaqueous RFBs are briefly introduced, with emphasis on adjusting the type, size, surface treatment, loading method, and loading quality of nanoparticles. The transport property and electrochemical reaction rate of active species and charges in RFBs can be improved after the inclusion of nanoparticles, leading to the improvement of the power density, energy efficiency, and stability of the battery. The applications and research progress of nanoparticles in RFBs can be systematically and comprehensively understood via the analyses and discussions in this review. It also provides a new technical idea to promote the commercial development and deployment of high-performance RFB.