Submicron silica as high−capacity lithium storage material with superior cycling performance

Abstract

Submicron silica (SiO2) is prepared via directly milling bulk SiO2, which is the major constituent of the abundant sand on the earth. The electrochemical lithium storage performance of SiO2 is found to be strongly associated with the ball milling treatment. The reversible capacity of SiO2 gradually increases from 163 to 803mAhg−1 as the milling time is extended from 0 to 72h. For the SiO2 milled for 24h, it exhibits excellent cycling performance with a discharge capacity of 602mAhg−1 over 150 cycles, corresponding to the capacity retention of 99.8% relative to the 2nd cycle. The different particle sizes distribution and electrochemical activity of SiO2 are responsible for the effect of ball milling on its electrochemical lithium storage performance such as reversible capacity, cycling stability, electrode polarization and initial Coulombic efficiency.