WN-CoS2 nanoparticles encapsulated into carbon nanotubes enable a stable and high-performance rechargeable zinc air battery

The battery performance associated with longevity are the priorities for the industrialization of rechargeable zinc air battery (ZAB). Herein, we have reported the construction of WN-CoS2 heterostructure enveloped by nitrogen and phosphorus co-doped carbon nanotubes (WN-CoS2@NPCNT). WN-CoS2@NPCNT performs a superior oxygen evolution reaction (OER) catalytic activity of 279 mV overpotential to reach 10 mA cm(-2), lowered by 85 mV with relative to CoS2@NCNT attributing to the heterostructure efficiently modulating the electronic structure of active sites. Besides, the half-wave potential reaches 0.875 V vs. RHE for WN-CoS2@NPCNT under oxygen reduction reaction (ORR) condition, corresponding to a 3.2-time higher kinetic current density compared to commercial Pt/C. Due to the exceptional bifunctionality, the battery performance is 205 mW cm(-2) for WN-CoS2@NPCNT, 1.54 times higher than commercial counterpart, Pt/C + IrO2. Impressively, the battery performance sustains for 1000 h for WN-CoS2@NPCNT stemming from the confinement effect caused by NPCNT. In addition, the all-solid-state ZAB shows a high-power density of 55 mW cm(-2).