Hierarchical CuCo carbonate hydroxide nanowires/graphitic carbon nitride composites as high-performance anode materials for fast-charging and long-life lithium-ion batteries

Transition metal carbonate hydroxides (TMCHs)/sulfides (TMSs) have been attracting great interest in energy storage systems owing to their versatile electrochemical characteristics. Copper cobalt carbonate hydroxide (CuCo-CH) nanowires and their hybrids with graphitic carbon nitride nanosheets (CuCo-CH/g-C3N4) were prepared in this study using a hydrothermal method, and their electrochemical performance as anodes for Lithiumion batteries (LIBs) were explored for the first time. The existence of a unique CuCo-CH nanowires-penetrated-gC3N4 nanosheet architecture effectively contributing to fast ion/electron transport channels for high electrolyte diffusion. The synergetic effect of the g-C3N4 nanosheets alleviating the volume changes of the CuCo-CH nanowires and preventing their self-stacking/structural collapse during (de)-lithiation processes. As a result, LIBs employing the CuCo-CH/g-C3N4 hybrid exhibited a high discharge capacity of -394 mA h g- 1 at 100 mA g- 1 after 100 cycles, superior rate capability, and long-term cyclic stability as compared with CuCo-CH nanowires (-242 mA h g- 1 at 100 mA g- 1). Moreover, CuCo-CH/g-C3N4 delivered a high capacity of -171 mA h g- 1 over 100 cycles at a fast charging rate (1 A g- 1) and slow discharging rate (0.2 A g- 1). The ex-situ XPS studies demonstrated that the various redox-active centers (i.e., metal-oxides, metal-carbonyls, metal-hydroxyls, surface carbon hydroxyls, carbonyls, and abundantly accessible defects of the g-C3N4 frameworks) were participated in the electrochemical redox reactions, leading to the high pseudocapacitance contribution effect and an outstanding Li+ storage capability. This study provides new insights and demonstrates the significant implications for the practical application of CuCo-CH-nanostructured high-performance LIBs.