High performance Si/MgO/graphite composite as the anode for lithium-ion batteries

The Si/MgO/graphite composite was synthesized by high energy ball-milling and evaluated as a durable anode for lithium-ion batteries. EDX mapping indicated that Si was dispersed homogeneously in the MgO matrix. The composite delivered an initial capacity of similar to 700 mAh/g and maintained a capacity of 630 mAh/g after 74 cycles at 0.5 mA/cm(2); even at 8 mA/cm(2) it delivered more than 85% of its capacity. Its volumetric capacity is double that of carbon. The coulombic efficiency climbed from 77% in the first cycle to above 99.5% after 20 cycles, and retained that value. (C) 2011 Elsevier B.V. All rights reserved.