Partial carbonization strategy to prepare Si@C composite and its lithium storage performance

Silicon is the most attractive anode material due to its higher theoretical specific capacity (~3 579 mAh/g, Li₁₅Si₄). To solve the problems of volume expansion (300%) and poor electrical conductivity of silicon materials, Si@C_AS electrode materials are prepared in one step by simple partial carbonizing the slurry of polyacrylic acid (PAA), sericin (Sericin) and Si NPs. The effects of Carbonization temperatures and polyacrylic acid/sericin ratios on the electrochemical properties of the tlectrode are systematically investigated. Results demonstrate that the Si@C_AS composite with polyacrylic acid (A)/sericin (S) ratio of 1∶1 and carbonization temperature of 450 ℃ shows excellent lithium storage performance, superior to those of Si@C_A and Si@C_S anode. The Si@C_AS anode can deliver a specific capacity of 1 404.2 mAh/g after 200 cycles at a current density of 0.5 A/g and exhibits excellent rate performance, with a specific capacity of 1 452.8 mAh/g at a current density of 4 A/g, suggesting its promising applications in lithium-ion battery.