Sea Urchin-like Si@MnO₂@rGO as Anodes for High-Performance Lithium-Ion Batteries

Abstract

Si is a promising material for applications as a high-capacity anode material of lithium-ion batteries. However, volume expansion, poor electrical conductivity, and a short cycle life during the charging/discharging process limit the commercial use. In this paper, new ternary composites of sea urchin-like Si@MnO2@reduced graphene oxide (rGO) prepared by a simple, low-cost chemical method are presented. These can effectively reduce the volume change of Si, extend the cycle life, and increase the lithium-ion battery capacity due to the dual protection of MnO2 and rGO. The sea urchin-like Si@MnO2@rGO anode shows a discharge specific capacity of 1282.72 mAh g−1 under a test current of 1 A g−1 after 1000 cycles and excellent chemical performance at different current densities. Moreover, the volume expansion of sea urchin-like Si@MnO2@rGO anode material is ~50% after 150 cycles, which is much less than the volume expansion of Si (300%). This anode material is economical and environmentally friendly and this work made efforts to develop efficient methods to store clean energy and achieve carbon neutrality.

Keywords

• Si
• MnO₂
• rGO
• sea urchin-like structure
• lithium-ion battery
• high performance