| Lithium ion batteries have become the most potential chemical energy since their commercial introduction in the early 1990s, which have been widely used in portable electronic devices. And searching for better electrode materials is critical for improving the electrochemical performance of lithium ion batteries.Three dimensionally ordered macroporous ( 3DOM ) electrode materials with inverse-opal structure show unique advantages. The connected channels and nano-scaled walls can provide lithium ions with more sites on their surface and shorten the diffusion distances of lithium ions markedly, which can reduce the charge transfer resistance, decrease the polarization and improve the rate capability. So it shows great promising to enhance the performance of rechargeable lithium-ion batteries by preparing 3DOM materials.In this paper, 3DOM NiFe2O4 cathode material was prepared by crystal templates. The morphology, crystal structure and electrochemical performance of the products synthesized under various calcination temperatures and duration were systematically discussed and optimized. And the 3DOM NiFe2O4 synthesized under the optimum condition was compared with the SS-NiFe2O4 synthesized at the same condition by traditional solid state reaction. The 3DOM NiFe2O4 showed higher capacity and better cyclability. The initial discharge capacity of 3DOM NiFe2O4 could reach to 1370 mAh/g, while the discharge capacity decreased gradually untill 20th cycle and retained 660 mAh/g after 50 cycles, which was much higher than the commercial graphite.3DOM ZnFe2O4 anode material was prepared through similar method. The morphology, crystal structure and electrochemical performance were discussed. It showed the discharge capacity of 3DOM ZnFe2O4 was 1088 mAh/g at the first cycle, while it exhibited a gradually decreasing trend and retained only 210 mAh/g after 50 cycles, because of the existense of impurity and the unproper calcination condition.Crystal templates were used to prepare 3DOM LiCoO2 anode materials. The morphology, crystal structure and electrochemical performance of the products synthesized under various calcination temperatures was discussed and optimized. The 3DOM LiCoO2 synthesized under the optimum condition was compared with the commercial LiCoO2 powder. The 3DOM LiCoO2 showed high capacity and good rate capability with the discharge capacity of 151, 126 and 90 mAh/g at the rate of 1C, 2C and 5C, respectively. |
