NaCl-Assisted electrospinning of bifunctional carbon fibers for High-Performance flexible zinc-air batteries

Release time:2025-07-14 Hits:

Key Words:OXYGEN REDUCTION; DOPED GRAPHENE; ELECTROCATALYSTS

Abstract:With the increasing demand for flexible, rechargeable zinc-air batteries (ZABs), developing efficient oxygen electrocatalysts is challenging. A large specific surface area and porous structure are critical for electrochemical performance but can compromise mechanical strength and flexibility. Herein, a novel strategy with NaCl-assisted electrospinning and pyrolysis has been proposed to fabricate self-supported carbon fibers with a solid core and mesoporous shell as bifunctional oxygen electrocatalysts for flexible ZABs. The fibers incorporate NaCl and ZnCoZIFs via coaxial electrospinning. NaCl enhances both the electrospinning process and ZIF carbonization, creating a porous surface on robust carbon fibers that balances surface exposure with structural stability. Experimental data and density functional theory calculations confirm that cobalt atoms anchored on the carbon surface are the primary active sites, boosting electrocatalytic performance. Zinc facilitates the formation of structural defects and porosity during volatilization at high temperatures, promoting NaCl molten salt infiltration, ZIF decomposition, and large pore formation. The resulting cross-linked porous structure increases active site exposure, enhancing catalytic efficiency. The synthesized ZN3-CNFs-900 exhibit remarkable catalytic activity, achieving an oxygen reduction reaction half-wave potential of 0.834 V and an oxygen evolution reaction overpotential of 1.695 Vat 10 mA cm-2. ZABs assembled with these carbon fibers demonstrate an open-circuit voltage of 1.43 V, a peak power density of 111 mW cm-2, and cycling stability beyond 400 h. The carbon fiber-based solid-state ZABs show a high open circuit voltage of 1.39 V, a power density of 81.7 mW cm-2 and a cycle life of 33 h.

Volume:690

Issue:

Translation or Not:no