A Versatile Polymeric Precursor to High-Performance Silicon Composite Anode for Lithium-Ion Batteries

Silicon is a promising anode material for lithium-ion batteries due to its very high theoretical capacity. Herein, a Si/SiOx@C composite anode is prepared from a polymeric precursor, and the performance of the anode is optimized by controlling the composition of the polymeric precursor. The precursor is produced by cross-linking divinyl benzene (DVB) and polymethylhydrosiloxane (PMHS). Silicon nanoparticles are formed from the precursor via a molten-salt reduction process, and a conductive SiOx@C matrix is produced through a subsequent pyrolysis process. As the ratio between DVB and PMHS is adjusted to 2:1, the specific capacity and rate performances of the resulting Si/SiOx@C composite reach the optima. Both the composition and the microstructure of the composite are affected by the composition of the precursor, and, in turn, they determine the performance of the composite anode.