3D NiCo2S4 nanorod arrays as electrode materials for electrochemical energy storage application

It is essential to develop new electrode materials for electrochemical energy storage to meet the increasing energy demands, reduce environmental pollution and develop low-carbon economy. In this work, binder-free NiCo₂S₄ nanorod arrays (NCS NRAs) on nickel foam electrodes are prepared by an easy and low energy-consuming route. The electrodes exhibit superior electrochemical properties both for alkaline and Li-ion batteries. In 3 M KOH electrolyte, the NCS NRAs achieve a specific capacity of 240.5 mA h g^?1 at a current density of 0.2 A g^?1, and 105.7 mA h g^?1 after 1500 cycles at the current density of 5 A g^?1 with capacity retention of 87.3%. As the anode for LIBs, it shows a high initial capacity of 1760.7 mA h g^?1 at the current density of 100 mA g^?1, corresponding coulombic efficiency of 87.6%, and a rate capacity of 945 mA h g^?1 when the current density is improved 10 times. Hence, the NiCo₂S₄ nanorod arrays are promised as electrode materials with competitive performance.