화학공학소재연구정보센터
Applied Surface Science, Vol.463, 132-140, 2019
Facile synthesis of 2D graphene oxide sheet enveloping ultrafine 1D LiMn2O4 as interconnected framework to enhance cathodic property for Li-ion battery
Cubic spinel lithium manganese oxide (LiMn2O4) has been able to attract a great deal of attention over the years as a promising cathode material for large-scale lithium-ion batteries. Here a facile hydrothermal route followed by solid state reaction is developed using as grown ultrafine alpha-MnO2 nanorods to prepare 1D LiMn2O4 with 10-50 nm diameters. To enhance the cathodic property of these nanorods, a unique synthesis technique of heat treatment is developed to grow 2D graphene oxide sheet enveloping 1D LiMn2O4 as interconnected framework. This nanocomposite 3D porous cathode exhibits a high specific charge capacity of 130 mAh g(-1) at 0.05 C rate and Coulombic efficiency of similar to 98% after 100 cycles in the potential window of 3.5 to 4.3 V vs Li/Li+ with promising initial charge capacity retention of similar to 87%, and outstanding structural stability even after 100 cycles. Enhancement in the lithiation and de-lithiation processes leading to improved performance is likely to have its origin in the 2D conducting graphene oxide sheets. It allows for decreasing the Mn dissolution, improve the electron conductivity and reduce the Li-ion path diffusion inside the favourable morphology and crystallinity of the ultrafine 1D LiMn2O4 nanorods, giving rise to a promising cathode nanocomposite.