Binder-free carbon-coated nanocotton transition metal oxides integrated anodes by laser surface ablation for lithium-ion batteries

Abstract

In this paper, an efficient laser surface ablation strategy for producing binder-free carbon-coated nanocotton CoO-Co integrated anode is reported. The fabrication process introduces in-situ growing nanocotton-like CoO on the surface of Co foil via ablating with a nanosecond laser. After that, coated with dopamine as carbon source, the CoO-Co composite foil is heated in Argon atmosphere to form a CoO@C-Co foil as an anode of LIB. The laser surface ablation exhibits high fabrication speed (~10 minutes) and significantly reduces the processing time. The obtained binder-free CoO@C-Co integrated anode shows a unique cotton-like villous structure with large specific surface area and an active material/current collector integrated architecture, which provides a stabilized rapid electronic conduction path. When tested as an anode for LIBs, the CoO@C-Co integrated anode possesses superior performance: First discharge capacity of 1301.5 mAh g⁻¹ is achieved at a current density of 0.1 A g⁻¹. Also at a high current density of 1.5 A g⁻¹, the second discharge capacity of 791.7 mAh g⁻¹ is achieved. After 800 cycles, reversible capacities of 799.8 mAh g⁻¹ can still be achieved with an average coulombic efficiency of nearly 100%. In addition, this strategy is suitable for the production of other carbon coated transition metal oxides integrated anodes, such as NiO@C-Ni, Fe<inf>2</inf>O<inf>3</inf>/Fe<inf>3</inf>O<inf>4</inf>@C-Fe, and CuO/Cu<inf>2</inf>O@C-Cu integrated anodes.