Direct amination of Si nanoparticles for the preparation of Si@ultrathin SiOx@graphene nanosheets as high performance lithium-ion battery anodes†
Abstract
NH2-terminated Si nanoparticles with an ultrathin silica shell have been efficiently obtained by a one-step reaction in ammonia–water–ethanol solution. Graphene nanosheet (GNS) encapsulated Si@ultrathin SiOx has been fabricated by self-assembly and thermal treatment. Because of the uniform ultrathin SiOx shell and superior GNS encapsulation structure, this material shows a reversible capacity of 2391.3 mA h g−1, maintaining 1844.9 mA h g−1 after 50 cycles at a current density of 200 mA g−1, and good rate and long cycle performance (∼700 mA h g−1 at 2000 mA g−1 after 350 cycles) as well.