Pore size-controlled synthesis of 3D hierarchical porous carbon materials for lithium-ion batteries

摘要

3D hierarchical porous carbons (3DCs) with different pore size distributions are prepared by using Ni(OH)(2) as template. The morphology, crystalline features, pore structure and surface composition of the hierarchical porous carbons are characterized using various analytic techniques including scanning electron microscopy, transmission electron microscopy, N-2 physical adsorption, powder X-ray diffraction and X-ray photoelectron spectroscopy. It is found that the pore size distributions of the 3DCs play an important role in the lithium-storage capacity when they are used as anode materials for rechargeable lithium-ion batteries. The typical sample 3DC-20 has a specific reversible capacity of 630 mAh g(- 1) in the first cycle and and 363 mAh g(- 1) after 50 cycles. The high capacity of 3DC-20 can be attributed to the existence of the largest amount of micropores with 0.6-0.9 nm pore width, which increase the lithium storage capacity; in addition, the existence of mesoporous and macroporous effectively shortens the distance for charge diffusion, the turbostratic graphite structure low resistance for electron conduction.