Petal-like metal-organic framework stabilized Si@C with long cycle life and excellent kinetics.

Poor electrochemical kinetics caused by the unstable structure for the dramatically volumetric expansion (>300%) hinders the application of silicon in rechargeable lithium ion batteries. Si@C-Ni-MOF composites with petal-like Ni-MOFs as the skeleton and Si@C nanoparticles as the active center were synthesized via facile solvothermal process. The resulting Ni-MOF-Si@C material maintains admirable stability on cycling, and its capacity remains 1545.3 mAh g with a high capacity retention rate of 99.79% after 300 cycles at the current density of 200 mA g. The enhancement on the kinetics is obtained, attributing to the porous structure created by the petal-like Ni-MOFs and the strong interface bonding between Si@C and Ni-MOFs.