On ways of conversion of silicon dioxide SiO2 in lithium battery systems: a review

Abstract

Silicon and silicon oxide compounds SiO, SiO2, SiOx and SiOC are considered as a promising family of materials for high-energy lithium batteries due to their high theoretical capacity, widespread in nature, low cost, environmental safety and ease of synthesis. Silicon oxide compounds have replaced silicon in the hope of improving the discharge characteristics of lithium batteries. Oxides of silicon show excellent stability during cycling after structure optimization. However, they suffer from the problem of low Coulomb efficiency and high voltage hysteresis (difference in charge and discharge voltage), which prevents their practical application. Significant bulk expansion of silicon oxides during cycling and irreversible loss of capacity in the initial cycles are an obstacle to their large-scale practical use. This review pays attention to the peculiarities of the conversion of SiO2 and its hybrid compounds into the redox reaction with lithium and ways to overcome existing problems. Silicon dioxide is more resistant to bulk expansion than silicon. Various structural formats of nanometer SiO2 have been developed and tested for lithium batteries, such as nanotubes, nanorods, nanowires, nanoparticles, thin films. To solve problems in the SiO2/Li system, a number of SiO2 composites with carbon, graphene, active and inactive metals, etc. have also been proposed and studied. Analyzing the results of the studies, we found a significant role of the solid electrolyte interphase film in the efficient conversion of SiO2. In turn, the formation of a film on silicon dioxide depends on the method of synthesis of dioxide, which introduces impurities into the final synthesis product. Impurities contribute to the distortion of the solid electrolyte interphase film during the cycling of the SiO2/Li system, and the loss of discharge capacity. SiO2 dioxide obtained in a dry environment of a ball mill differs favorably from that obtained from solutions. Many efforts have been made to overcome the problems in Si-containing electrode materials, however, they have to go a certain way for large-scale practical application.