High power lithium-ion battery based on a LiMn2O4 nanorod cathode and a carbon-coated Li4Ti5O12 nanowire anode

Abstract

Lithium-ion batteries have been widely applied to power various devices because of their high energy density. However, their power performance is generally limited by the Li⁺ diffusion in the bulk of electrode-active materials and is much lower than that of a supercapacitor. Herein, nano-structured cathode (spinel LiMn₂O₄ nanorods) and anode materials (carbon-coated Li₄Ti₅O₁₂ nanowires) are prepared by hydrothermal approaches with subsequent heat treatments or a chemical vapor deposition treatment. Electrochemical investigation demonstrates that the nano-size and one-dimensional structure of the prepared electrode materials can efficiently shorten Li⁺ diffusion length and reduce interface impedance, and thus they exhibit much higher rate capability than that of the micro-sized LiMn₂O₄ and Li₄Ti₅O₁₂. The LiMn₂O₄ nanorods and carbon-coated Li₄Ti₅O₁₂ nanowires were then used to build a full cell that exhibits supercapacitor-like power performance (a maximum power density of 6880 W kg⁻¹), long life (500 cycles with a capacity retention of 81%) and high energy density (a maximum energy density of 140 W h kg⁻¹).