Nanocatalyzed PtNi Alloy Intact @3D Graphite Felt as an Effective Electrode for Super Power Redox Flow Battery

A zinc-bromine redox flow battery (RFB) is highly suitable for high-energy storage due to its decoupled energy and power generation. However, the poor kinetics and poor reversible behavior of Br-2/Br- redox activity are some of the significant barriers, and as a result, the flow system delivers low power density. To increase the efficiency of the flow cell, in the present work, bimetallic catalysts are deposited on 3D graphite felt network and are used in the positive electrode for enhancing the kinetics of the Br-2/Br- redox reaction. The platinum-nickel (PtNi) bimetallic composition is optimized, and the highly improved performances are investigated using half-cell and flow-cell assembly. The redox kinetics parameters are improved due to the high electro-catalytic nature of the heat-treated Ni-rich PtNi coating on the graphite felt (GF) and the flow cell is operated up to 140 mA cm(-2). The flow cell with Pt0.5Ni1@GF delivers an impressive ever-best power density of around 1550 mW cm(-2). The cycle life shows excellent stability up to 300 cycles with coulombic, voltage, and energy efficiency of 97%, 86%, and 83%, respectively. Thus, the present work offers a promising approach to developing effective electrode materials for obtaining a superpower RFB system.

Automated summary

A zinc-bromine redox flow battery with bimetallic catalysts deposited on a graphite felt network shows improved kinetics and power density. The use of the PtNi bimetallic composition enhances the redox reaction kinetics, resulting in a power density of 1550 mW cm(-2). The flow cell also demonstrates excellent stability with 97% coulombic efficiency, 86% voltage efficiency, and 83% energy efficiency over 300 cycles.