Constructing quasi-2D amorphous MnSiO3@C toward stable and high lithium storage

Abstract

Featuring of high theoretical capacity, non-toxic, low-cost, and environmental benignity, metal silicates attract great attention as viable alternative anodes of lithium-ion battery. But, they show serious electrochemical irreversibility during cycle due to large volume variation and low conductivity. Herein, a novel and facile method is developed to synthesize a quasi-2 dimensional (2D) amorphous MnSiO3/C composite (A-MnSiO3@C), consisting of ultra-thin conformal carbon coated amorphous MnSiO3 quasi-nanosheets. Therefore, the A-MnSiO3@C innovatively integrates the structural characteristics of amorphous structure, 2D nanostructure and ultra-thin conformal carbon coating through a simple process. The structure-property correlations of the A-MnSiO3@C during lithium storage have been expounded systematically. The findings indicate that these structural characteristics offer A-MnSiO3@C enhanced electrical conductivity, improved Li+ transport kinetics, high capacitive contribution and good structural stability during cycle, and hence alleviate the issues MnSiO3 suffered from. As a result, the A-MnSiO3@C demonstrates outstanding lithium storage properties such as high capacity, good rate capability and long cycle durability, with 511.2 and 416.5 mAh g−1 after 400 and 600 cycles at 200 and 1000 mA g−1, respectively. Finally, this work offers a constructive reference for improving electrochemical performance of the other promising metal silicate anodes.