Synthesis and electrochemical performance of three-dimensionally ordered macroporous CoCr2O4 as an anode material for lithium ion batteries

Three-dimensionally ordered macroporous (3DOM) CoCr2O4 was synthesized by a colloidal crystal templating route and used as an anode material for lithium ion batteries. Benefiting from the porous structure and smaller particle size, the 3DOM-CoCr2O4 anode exhibits a high specific capacity and excellent rate capability. After an initial specific capacity decrease from 1588 to 709 mAh g−1 during the first three cycles at 50 mAh g−1, the capacity exhibits an increasing trend in subsequent cycles. After 100 cycles, a high specific capacity of 1218 mAh g−1 is achieved, which is much higher than that of non-templated n-CoCr2O4 (499 mAh g−1). Even at a very high current density of 3000 mA g−1, a specific capacity of 328 mAh g−1 could be obtained. The impact of calcination temperature for 3DOM-CoCr2O4 composites on electrochemical performance is also explored, and possible electrochemical processes involving CoCr2O4 during charging and discharging are proposed in this work. During the charge process, oxidation may occur not only from Co0 to Co2+, but also partly from Co2+ to Co3+. It is also found that the 3DOM architecture of the CoCr2O4 compounds can be preserved even after 100 charge and discharge cycles.

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