One-Dimensional Nano-structured Copper Sulfide Electrodes for Efficient Energy Storage by Surface Activation and Corrosion

Abstract Transition metal sulfide electrodes subjected to structural and morphological engineering are promising options for advancing electrochemical energy storage technology owing to their high surface areas, favorable ion diffusion kinetics, and stable cycling. Synthesis approaches involving direct-solution exposure (metal precursor-free) on metal substrates are expected to have several benefits, such as attaining high conductivity of the metal substrate and reducing the contact resistance of electrode materials. However, the widespread utilization of this approach remains a challenge due to unintended growth that may occur during direct-solution exposure. Here, one-dimensional (1D) CuxS electrodes are developed efficiently by using surface activation and corrosion methods on cost-effective copper metal substrates. Metal precursor-free conditions, which enable the alteration of surface characteristics of transition metal sulfides, represent crucial steps towards modifying the corresponding sulfide structures and achieving favorable electrochemical kinetics. Proper manipulation of diverse growth conditions verified the formation of various 1D diameters in the range of 500 nm to 3.0 µm. The 1D configurations of the CuxS electrodes ensured large energy storage capacity and stable electrochemical performance. Therefore, we anticipate that both surface activation and corrosion processes as a synthetic approach will foster progress towards the realization of 1D CuxS frames.