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In this work, we demonstrated an accessible and facile method to prepare hierarchically porous carbon (HPC)/Co 3 O 4 nanocomposites (HPCC). Biomaterials-derived HPC was used as the appropriate carrier to load Co 3 O 4 nanoparticles due to its hierarchically porous structure and high surface area of 163 m 2 g −1 . The HPCC nanocomposites were used as an anode material for lithium-ion batteries (LIBs) and showed good electrochemical performance, delivering an initial discharge of 1566 and charge capacity of 1314 mA h g −1 with a initial coulombic efficiency of 83.9%. Additionally, it could still maintain a high reversible capacity of 1215 mA h g −1 after 100 cycles at a specific current of 100 mA g −1 , which is much better than that of HPC, and Co 3 O 4 and some Co 3 O 4 -based nanocomposites. The good electrochemical performance was mainly attributed to the good distribution of small Co 3 O 4 on HPC, the high surface area and hierarchical pores of HPC to effectively load a number of small Co 3 O 4 , alleviate the severe volume expansion during cycling and improve the electrical conductivity of nanocomposites, and the synergistic effects from the HPC and Co 3 O 4 . Therefore, the HPCC nanocomposites were expected to be an advanced anode material for LIBs. [ABSTRACT FROM AUTHOR]

Novel porous cage-like carbon (C)/nano-Si nanocomposites as anode materials for lithium-ion batteries (LIBs) was prepared based on nano-Si@zeolitic imidazolate frameworks (ZIF-8)-templated method. In this strategy, p-aminobenzoic acid was initially grafted onto nano-Si to form benzoic acid-functionalized nano-Si, and then nano-Si@ZIF-8 was constructed by alternately growing Zn(NO 3 ) 2 ·6H 2 O and 2-methylimidazolate on benzoic acid-functionalized nano-Si under ultrasound. The novel porous cage-like nano-Si/C nanocomposites were fabricated by pyrolyzing the resulted nano-Si@ZIF-8 and washing with HCl to remove off ZnO. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Raman spectra and N 2 adsorption/desorption isotherms were employed to characterize the porous cage-like nano-Si/C nanocomposites. The resulted nano-Si/C nanocomposites as anode materials for LIBs showed a high reversible capacity of ∼1168 mA h g −1 at 100 mA g −1 after 100 cycles, which was higher than many previously reported Si/C nanocomposites. The porous nanostructure, high specific surface area and good electrical conductivity of the cage-like nano-Si/C nanocomposites contributed together to the good performance for LIBs. It might open up a new way for application of silicon materials. [ABSTRACT FROM AUTHOR]