Molten salt induced formation of chitosan based carbon nanosheets decorated with CoNx for boosting rechargeable Zn-air batteries

Abstract

The earth-abundant, low-cost, and efficient oxygen electrode materials offer a potential opportunity to satisfy the large-scale production and application of metal-air batteries. Herein, a molten salt-assisted strategy is developed to anchor transition metal-based active sites via in-situ confining into porous carbon nanosheet. As a result, a chitosan-based porous nitrogen-doped nanosheet decorated with the well-defined CoNx (CoNx/CPCN) was reported. Both structural characterization and electrocatalytic mechanisms demonstrate a prominent synergetic effect between CoNx and porous nitrogen-doped carbon nanosheets forcefully accelerates the sluggish reaction kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Interestingly, the Zn-air batteries (ZABs) equipped with CoNx/CPCN-900 as an air electrode shows outstanding durability for 750 discharge/charge cycles, a high power density of 189.9 mW cm−2, and a high gravimetric energy density of 1018.7 mWh g−1 at 10 mA cm−2. Furthermore, the assembled all-solid cell displays exceptional flexibility and power density (122.2 mW cm−2).