Three-dimensional BiVO4-based semiconductor photocathode for high efficiency photo-assisted Zn-iodine redox flow batteries

Maolin Dong; Yijie Wang; Aoshuang Li; Chuanwei Cheng

doi:10.1088/1361-6528/ac5f83

Three-dimensional BiVO₄-based semiconductor photocathode for high efficiency photo-assisted Zn-iodine redox flow batteries

Nanotechnology. 2022 Apr 7;33(26). doi: 10.1088/1361-6528/ac5f83.

Authors

Maolin Dong¹, Yijie Wang¹, Aoshuang Li¹, Chuanwei Cheng¹

Affiliation

¹ Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China.

PMID: 35313297
DOI: 10.1088/1361-6528/ac5f83

Abstract

Aqueous Zn-iodine redox flow batteries have aroused great interest for the features of high capacity, excellent stability, low cost, and high safety, yet the dissatisfying energy efficiency still limits their future advancement. In this work, three-dimensional semiconductor BiVO₄nanoparticles decorated hierarchical TiO₂/SnO₂arrays (BiVO₄@TiO₂/SnO₂) were applied as photocathode in Zn-iodine redox flow batteries (ZIRFBs) for the realization of efficient photo-assisted charge/discharge process. The photogenerated carriers at the solid/liquid interfaces boosted the oxidation process of I^-, and thus contributed to a significant elevation in energy efficiency of 14.9% (@0.5 mA cm^-2). A volumetric discharge capacity was extended by 79.6% under light illumination, owing to a reduced polarization. The photocathode also exhibited an excellent durability, leading to a stable operation for over 80 h with a maintained high energy efficiency of ∼90% @0.2 mA cm^-2. The research offers a feasible approach for the realization of high-energy-efficiency aqueous Zn-iodine batteries towards high-efficiency energy conversion and utilization.

Keywords: Zn-iodine redox flow batteries; energy efficiency; hierarchical structure; photoelectrode.