Bioinspired interfacial engineering of a CoSe2 decorated carbon framework cathode towards temperature-tolerant and flexible Zn–air batteries

Abstract

A high-performance air electrode is essential for the successful application of flexible Zn–air batteries in wearable devices. However, endowing the electrode–electrolyte interface with high stability and fast electron/ion transportation is still a great challenge. Herein, we report a bioinspired interfacial engineering strategy to construct a cactus-like hybrid electrode comprising CoSe₂ nanoparticles embedded in an N-doped carbon nanosheet arrays penetrated with carbon nanotubes (CoSe₂-NCNT NSA). Associated with the synergistic effect of highly active CoSe₂ nanoparticles and N-doped carbon moieties and a stable 3D interconnected CNT network, the obtained self-standing electrode exhibits satisfactory catalytic activities towards oxygen evolution/reduction and hydrogen evolution, as well as an enhanced electrode–electrolyte interaction/interface area, and thus delivers superior performance for flexible Zn–air batteries. Remarkably, the fabricated flexible Zn–air battery with this CoSe₂-NCNT NSA cathode achieves a high peak power density (51.1 mW cm⁻²), considerable mechanical flexibility, and excellent durability in a wide temperature range of 0 to 40 °C. Furthermore, the assembled Zn–air batteries can efficiently power a water-splitting device that adopts the CoSe₂-NCNT NSA as both the anode and cathode, demonstrating promising potential in energy conversion and portable electronic applications.