Performance enhancement of rechargeable zinc-air battery through synergistic ex-solution of multi-component Pt/CoWO4-x catalysts

Advancing zinc-air battery (ZAB) technology necessitates the development of air cathode electrocatalyst systems that demonstrate high reactivity and stability. We introduce a novel method to fabricate a robust catalyst-support hybrid. This hybrid comprises Co-doped Pt nanoparticles (NPs) anchored on metal oxide (Ex-PtCoWO) nanofibers (NFs), synthesized via electrospinning followed by selective metal ex-solution. Controlling the ex-solution of metal NPs leads to a highly active and stable oxygen reduction reaction (ORR). Moreover, the three-dimensional CoWO4-x NFs network enhances the surface exposure of ex-solved metal NPs, thereby aiding both selective ex-solution and the provision of active sites for the oxygen evolution reaction (OER) during ZAB recharge. The Ex-PtCoWO NF exhibits an ORR half-wave potential of 0.89 V and an OER potential of 1.69 V at 10 mA cm−2 in alkaline media. ZABs utilizing Ex-PtCoWO NF show an extended cycle life of over 240 h with reduced charge-discharge polarization, compared to commercial catalysts. [Display omitted] •Co doped Pt nanoparticles are thermally ex-solved onto the Co and W-based metal oxide (CoWO4-x) nanofibers.•The mechanism of selective metal ex-solution from the multi-component matrix is demonstrated by using DFT calculations.•The developed Ex-PtCoWO NF shows outstanding ORR and OER activities in alkaline media.•A zinc-air battery using Ex-PtCoWO NF demonstrates outstanding cell performance over 240 hours cycling tests.