Facile synthesis of mesoporous 0.4Li2MnO3·0.6LiNi2/3Mn1/3O2 foams with superior performance for lithium-ion batteries

Abstract

Mesoporous 0.4Li₂MnO₃·0.6LiNi_2/3Mn_1/3O₂ foams with a pore diameter of ca. 3 nm have been fabricated by a gel-combustion method. The sintering temperature is optimized to as low as 600 °C by considering the balance of crystallization and particle size. The as-obtained mesoporous 0.4Li₂MnO₃·0.6LiNi_2/3Mn_1/3O₂ foams show excellent rate capability and cyclability. At a current density of 15 mA g⁻¹, the specific discharge capacity is 291 mA h g⁻¹ for the first cycle and the capacity retention is 92.3% over 100 cycles. Even at 200 mA g⁻¹, the capacity is as high as 208 mA h g⁻¹. The improved rate capability and cyclability can be ascribed to the mesoporous structure. The mesoporous structure has a large contact surface between the electrode and electrolyte, which facilitates the Li⁺-ion diffusion and enhances the ability of accommodation for continuous structural transition during charge and discharge cycling.