Anode material with Li-Si nano-domains in three-dimensional carbon network

Abstract

A micro-nano combined composite with Li-Si alloy nano-domains in three-dimensional carbon network was prepared as a novel electrode material. The carbon network constrained the volume contraction and promoted effectively charge transfer of the whole active material. Meanwhile, the abundant interfaces between Li-Si alloy and carbon bound by Li-C ionic bonds, not only enhanced the delithiation at interface but also ensured the structural integrity. The present composite exhibited excellent electrochemical performance. The specific capacity at the first lithiation was as high as 1133 mAh g−1 at a current density of 0.1 A g−1, which is superior to those reported for the core-shell structured nanoparticles. The Coulombic Efficiency at the first cycle was 90.4% and kept stable at more than 99.0% after only 10 cycles. The capacity retention was nearly twice as that of the incompact mixture of Li-Si nanoparticles and carbon. The energy density of the full cell constructed by the present composite and sulfur was evaluated to be 3 times as high as that of the commercial lithium-ion batteries. This work provides a new universal strategy for developing Li-rich anode materials with high combination properties and low cost.