Catalytic production of impurity-free V<sup>3.5+</sup> electrolyte for vanadium redox flow batteries.

Heo, Jiyun; Han, Jae-Yun; Kim, Soohyun; Yuk, Seongmin; Choi, Chanyong; Kim, Riyul; Lee, Ju-Hyuk; Klassen, Andy et al. · Nat Commun · 2019

basic_science · Level V

Where this comes from

Abstract

The vanadium redox flow battery is considered one of the most promising candidates for use in large-scale energy storage systems. However, its commercialization has been hindered due to the high manufacturing cost of the vanadium electrolyte, which is currently prepared using a costly electrolysis method with limited productivity. In this work, we present a simpler method for chemical production of impurity-free V<sup>3.5+</sup> electrolyte by utilizing formic acid as a reducing agent and Pt/C as a catalyst. With the catalytic reduction of V<sup>4+</sup> electrolyte, a high quality V<sup>3.5+</sup> electrolyte was successfully produced and excellent cell performance was achieved. Based on the result, a prototype catalytic reactor employing Pt/C-decorated carbon felt was designed, and high-speed, continuous production of V<sup>3.5+</sup> electrolyte in this manner was demonstrated with the reactor. This invention offers a simple but practical strategy to reduce the production cost of V<sup>3.5+</sup> electrolyte while retaining quality that is adequate for high-performance operations.