One-step synthesis method of flower-like Si@NiO/rGO composites as high-performance anode for lithium-ion batteries

Si-based materials are the most potential high-capacity anode material for lithium-ion batteries due to their theoretical specific capacity of 4200 mAh g −1 , significantly higher than the current commercial graphite anode (372 mAh g −1 ). However, the significant volume change (>300%) of Si-based materials during the embedding of lithium ions into Si NPs results in various issues, such as short cycle life and low electrical conductivity , which significantly restricts their commercial development. This study introduces a new flower-like Si@NiO/reduced graphene oxide (rGO) ternary composite synthesized using a straightforward and low-pollution one-step synthesis technique. A distinctive composite flower-like structure is created by wrapping Si NPs in NiO nanoflowers and embedding the rGO nanosheets in the NiO "petal" structure. This structure can shorten the lithium-ion transport path, provide a superb conductive network, effectively reduce the electrode's bulk effect and improve the structural stability of the anode material. Additionally, the structure provides more capacity for the electrodes. At a current density of 1 A g −1 and after 700 cycles, the Si@NiO/rGO anode displays a discharge-specific capacity of 1081.34 mAh g −1 thanks to its one-of-a-kind flower-like structure. At various current densities, the Si@NiO/rGO anode likewise demonstrates outstanding electrochemical performance. Additionally, the volume growth of the flower-like Si@NiO/rGO anode material after 700 cycles is approximately 15.08%, substantially less than that of Si NPs. The new flower-shaped Si@NiO/ rGO ternary composite, synthesized in a simple and cost-effective way, offers not only an alternative for the preparation of Si-based electrode materials that can alleviate their drastic volume expansion but also an effort to create new renewable green energy storage devices.