Durable and temperature-adapted flexible rechargeable zinc-air batteries enabled by in-situ encapsulated FeMo alloy nanoparticles within nitrogen-doped carbon particles cathode

Abstract

Flexible rechargeable zinc-air batteries (FRZABs) are highly desirable for portable and wearable electronics due to their high energy density and safety. However, achieving reliable performance of FRZABs across a broad temperature range remains challenging due to inherent cathode limitations. These challenges include not only insufficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics at high and low temperatures but also poor structural and interfacial stability across temperature. Herein, we report a novel self-growth strategy to synthesize a composite cathode catalyst comprising FeMo alloy nanoparticles embedded on nitrogen-doped porous carbon particles (FeMo/NCPs). Notably, benefiting from rapid electron transfer, a protective structural framework of the carbon matrix, and abundant active sites of the FeMo/NCPs, the FRZABs exhibit excellent ORR performance with an E_1/2 as high as 0.85 V, and an OER overpotential of 390 mV at a current density of 10 mA cm⁻², as well as good structural stability and flexibility in a wide temperature range. As a proof of concept, FeMo/NCPs-based aqueous RZABs exhibit a cycling life exceeding 2720 h with a peak power density of 139 mW cm⁻². FRZABs exhibit a low charge-discharge voltage gap and a discharge lifespan of 170 h at 5 mA cm⁻², and remarkable tolerance to both high and low temperatures, showcasing immense application potential in wearable and portable electronic devices.