Direct synthesis of ACo2O4 (A= Ni, Cu, Fe, Zn) nanowires on carbon cloth as an oxygen electrode catalyst for rechargeable lithium-oxygen batteries

Abstract Developing a low-cost, stable and efficient oxygen electrode catalyst for use in lithium-oxygen batteries with a long cycling stability and a high discharge/charge capacity is very important for solving the energy crisis and reducing environmental pollution. In this study, ACo2O4 (A= Ni, Cu, Fe, Zn) nanowires grown on carbon cloth (CC) were readily synthesized via a hydrothermal method with a subsequent heat treatment. NiCo2O4 nanowires grew and crossed each other to randomly form many hedges with a three-dimensional network structure. The NiCo2O4/CC electrode has the higher specific surface area and more mesopores than the other ACo2O4/CC (A= Cu, Fe, Zn) electrodes. The NiCo2O4/CC electrode can cycle over 200 times under a limited capacity of 0.3 mA h cm−2 (500 mA h g−1) at 0.2 mA cm−2 (340 mA g−1) and show a discharge capacity of up to 6.2 mA h cm−2 (10541 mA h g−1) at 0.12 mA cm−2 and 4.75 mA h cm−2 (8076 mA h g−1) at 0.24 mA cm−2, reaching 2861.8 and 2674.5 Wh kg-1 at 0.12 and 0.24 mA cm−2, respectively.