Lead-Based Flow Battery Based on New Pb-Based Anolyte Chemistry

Abstract

Aqueous metal-based batteries are very promising for energy storage applications, owing to their high energy density and high safety. However, the plating of metal in the anode suffers from dendrite growth, which results in low areal capacity and poor reliability of the battery. Here, we design a PbBr(H 2 O) n + -based anolyte with solubility up to 2.4 mol L −1 , fast metal ion transport, and excellent kinetic properties to construct a lead-based flow battery that demonstrates an areal capacity far beyond the state-of-theart, together with long cycling life and excellent power performance. The coordination between Pb 2+ and Br − and the specific adsorption of Br − on the anode significantly weaken the concentration gradient near the electrode interface and realize unique under-potential deposition on the anode. The flow battery achieves an ultrahigh areal capacity of 433 mAh cm −2 with a Coulombic efficiency of 95.22% and an energy efficiency of 87.37% at 40 mA cm −2 , and long-term stability for over 2500 cycles at 200 mA cm −2 , along with energy efficiency exceeding 80%.