Fabrication of C@Si@G for flexible lithium-ion batteries

The commercial application of silicon is still impeded by poor conductivity and significant volume change. In this work, a C@Si@G composite was synthesized by a facile chemical solution reaction and carbonization procedure with cocoon silk as a natural carbon source. This composite has a sandwich structure, where Si nanoparticles as a sandwich middle layer and graphene (G) as an out layer. And it possesses the advantages of flexible, nitrogen-doped and is environmentally friendly. The optimized C@Si@G-15 composite is used as a self-supporting anode without a current collector, and it shows a reversible discharge capacity of 972 mAh g(-1) after 120 cycles at 1 A g(-1) and a relatively high capacity of 1070 mAh g(-1) after 300 cycles at 200 mA g(-1), demonstrating the effect of coating the N-doped carbonized silk and the graphene synergistically to improve electrical connectivity and to constrain the pulverization of Si nanoparticles. Hence, it delivers great potential for application on wearable devices. (C) 2021 Elsevier B.V. All rights reserved.