Cobalt selenide with ordered cation vacancies for efficient oxygen reduction and frigostable Al–air batteries

Abstract

Aluminum–air batteries are still inhibited by the sluggish cathodic oxygen reduction reactions, especially in low temperature conditions. Thus, it is urgent to develop efficient electrocatalysts for Al–air batteries to allow their use in extreme weather conditions. In this work, hexagonal Co_0.85Se-decorated N,Se co-doped carbon nanofibers (Co_0.85Se@N,Se-CNFs) were synthesized via facile carbonization/selenization of electrospun ZIF-67 nanocubes. The as-prepared metallic Co_0.85Se with ordered structural cation vacancies endows Co_0.85Se@N,Se-CNFs with remarkable oxygen reduction reaction activity, including high onset and half-wave potentials (0.93 V and 0.87 V vs. RHE, respectively). Consequently, the corresponding Al–air battery exhibits superior performance in a wide range of operating temperatures (−40–50 °C). For instance, this Al–air battery exhibits a voltage from 0.15–1.2 V with a peak power density of about 0.7 mW cm⁻² at −40 °C. It is expected that TMSe-decorated N,Se co-doped carbon nanofibers could be applied in extensive energy fields.