Toward High Energy Density Redox Targeting Flow Batteries With a Mushroom-Derived Electrolyte

Abstract Among several types of redox flow batteries (RFBs) under development, non-aqueous (NRFBs) have the potential to approach energy density lithium-ion batteries, while maintaining advantages systems, including ability decouple power and ratings, thermal stability. Despite their promise, NRFBs suffer from low densities because solubility limitation species in solvents remains relatively lower compared water. One promising concept for drastically improving is utilization solid charge storage materials, which are reversibly oxidized or reduced electrolyte tanks upon interaction with active (mediators) dissolved (i.e., redox-targeting battery (RTFB)). Herein, we demonstrate a RTFB using highly stable, bio-inspired mediator, vanadium(IV/V)bis-hydroxyiminodiacetate (VBH), coupled cobalt hexacyanoferrate (CoHCF) as material. Based on charge/discharge cycling experiments, capacity was found be enhanced by ∼5x when CoHCF pellets were added into tank case without CoHCF. With pellet approach, up ∼70% theoretical utilized at 10 mA cm−2 current density. Sufficient evidence has indicated that this utilizing reactions makes it possible surpass limitations material, allowing unprecedented improvements RFBs.