Heterointerface promoted trifunctional electrocatalysts for all temperature high-performance rechargeable Zn–air batteries

Abstract

The rational design of wide-temperature operating Zn–air batteries is crucial for their practical applications. However, the fundamental challenges remain; the limitation of the sluggish oxygen redox kinetics, insufficient active sites, and poor efficiency/cycle lifespan. Here we present heterointerface-promoted sulfur-deficient cobalt-tin-sulfur (CoS_1−δ/SnS_2−δ) trifunctional electrocatalysts by a facile solvothermal solution-phase approach. The CoS_1−δ/SnS_2−δ displays superb trifunctional activities, precisely a record-level oxygen bifunctional activity of 0.57 V (E_1/2 = 0.90 V and E_j=10 = 1.47 V) and a hydrogen evolution overpotential (41 mV), outperforming those of Pt/C and RuO₂. Theoretical calculations reveal the modulation of the electronic structures and d-band centers that endorse fast electron/proton transport for the hetero-interface and avoid the strong adsorption of intermediate species. The alkaline Zn–air batteries with CoS_1−δ/SnS_2−δ manifest record-high power density of 249 mW cm⁻² and long-cycle life for >1000 cycles under harsh operations of 20 mA cm⁻², surpassing those of Pt/C + RuO₂ and previous state-of-the-art catalysts. Furthermore, the solid-state flexible Zn–air battery also displays remarkable performance with an energy density of 1077 Wh kg⁻¹, >690 cycles for 50 mA cm⁻², and a wide operating temperature from +80 to −40 °C with 85% capacity retention, which provides insights for practical Zn–air batteries.