Grafting of hyperbranched polysiloxane on carbon nanofiber by the electrospinning method for an effective anode in lithium-ion batteries

Lithium-ion batteries (LIBs) have drawn interest in silicon-based anodes because of their remarkably high theoretical specific capacity. Nonetheless, the substantial volumetric expansion during cycling limits their practical application, causing severe capacity decay and compromised cycling performance. This work describes the highly stable and effective anode based on a novel hyperbranched polysiloxane@carbon nanofibers (HBPSi@CNFs) composite for stable and high-performance LIBs. HBPSi@CNFs composite was prepared through an in-situ controlled electrospinning method using freshly synthesized HBPSi and polyacrylonitrile (PAN) as precursors. The wrapping of the HBPSi layer over CNFs offers various advantages, including the formation of HBPSi@CNFs composite structures, which can boost ion and electron transfer at the interfaces. The prepared HBPSi@CNFs as anode exhibited a significantly improved specific capacity of ∼729 mAh.g⁻¹ at a current density of 0.1 A.g⁻¹ after 60 cycles, which was nearly twice that of CNFs (∼376 mAh.g⁻¹). Cycle testing revealed that HBPSi@CNFs demonstrated remarkable cycling performance at high current density of 2 A.g⁻¹, retaining a capacity of approximately 223.87 mAh g⁻¹ (∼92 % capacity retention) after 100 cycles with a coulombic efficiency of 100 %. Thus, a unique and structurally stable HBPSi@CNFs composite, produced via the controlled electrospinning method, makes a promising and cost-effective silicon-anode material for developing next-generation, high-performance batteries.