NiCo Alloy Anchored Self-supporting Carbon Foam as Bifunctional Oxygen
Electrode for Rechargeable and Flexible Zn-air Batteries
Abstract
The design and fabrication of flexible, porous, conductive electrodes
with customizable functions become the prime challenge in the
development of new-generation wearable electronics, especially for
rechargeable batteries. Here, NiCo bi-alloy particulate catalysts loaded
self-supporting carbon foam framework (NiCo@SCF) as a flexible electrode
has been fabricated through one facile adsorption-pyrolysis method using
a commercial melamine foam. Compared with the electrode with Pt/C and
Ir/C benchmark catalysts, the NiCo@SCF electrode exhibited superior
bifunctional electrocatalytic performance in alkaline media with a
half-wave potential of 0.906V for oxygen reduction reaction, an
overpotential of 286 mV at j=10 mA cm−2 for oxygen evolution reaction,
and stable bifunctional performance with a small degradation after
20,000 voltammetric cycles. The as-assembled aqueous zinc-air battery
(ZAB) with NiCo@SCF as a self-supporting air cathode demonstrated a high
peak power density of 178.6 mW cm-2 at a current density of 10 mA cm−2
and a stable voltage gap of 0.94V a 540 h charge-discharge operation.
Remarkably, the as-assembled flexible solid-state ZAB with
self-supporting NiCo@SCF as air cathode presented an engaging peak power
density of 80.1 mW cm-2 and excellent durability of 95 h undisrupted
operation, showing promise for the design of wearable ZAB.