Advancing silicon-based Li-ion batteries: enhanced stability and performance through carbon-coated Si and rGO linkage

Silicon (Si), which is the most promising anode material for lithium-ion batteries (LIBs), faces critical obstacles in responding to the demand for high-energy-density LIBs, owing to its poor electrical conductivity and large-volume pulverization property during the lithiation/delithiation process. To solve this problem, we introduced electrostatically reinforced polydiallyldimethylammonium chloride (PDDA) Si nanoparticles, double coated with reduced graphene oxide (rGO) and a carbon coating derived from the carbonization of polyvinylpyrrolidone (PVP). Prior to the rGO encapsulation of Si@C, PDDA was introduced on the surface of Si@C to enhance the positive polarization and attract the negatively charged rGO. This resulted in the improvement of the Si coverage, linkage between each Si@C, and electroconductivity. Consequently, the carbon-rGO double-encapsulated Si exhibited a highly improved battery performance, with demonstrating a remarkable capacity retention of 808.1 mAh g −1 at 0.2 A g −1 over the course of 100 cycles, accompanied by a reasonable initial coulombic efficiency of 82.4%. Graphical abstract