A　high-performance　silicon-carbon　nanocomposite　facilely　prepared　by　one-step　magnetoelectric　plasma　pyrolysis　of　the　mixture　of　methane,　silane,　and　hydrogen　is　proposed　for　lithium-ion　batteries.　The　ratio　of　silane,　methane,　and　hydrogen　was　studied　to　optimize　the　properties　of　the　composite.　When　the　ratio　of　hydrogen/silane/methane　is　1:1:3,　the　composite　is　composed　of　spherical　Si　nanoparticles　that　uniformly　attach　to　the　surface　of　the　tremelliform　carbon　nanosheets　framework,　in　which　the　tremelliform　carbon　nanosheets　can　effectively　resist　the　volumetric　change　of　the　Si　nanoparticles　during　the　cycles　and　serve　as　electronic　channels.　The　silicon-carbon　nanocomposite　exhibits　a　high　reversible　capacity　(1007　mAh　g(-1)　after　50　cycles),　a　low　charge　transfer　resistance,　and　an　excellent　rate　performance.　In　addition,　the　proposed　process　for　synthesizing　silicon-carbon　nanocomposite　without　expensive　materials　or　toxic　reagents　is　an　environmentally　friendly　and　cost-effective　method　for　mass　production.