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作为锂离子电池阳极材料的铁酸镍及其相关材料,由于其具有较高的理论比容量,近来受到广泛关注。为了克服在充放电过程中的较低导电性与较大的体积膨胀等不良因素,通过水热法合成了纳米铁酸镍钉扎在石墨表面而形成的复合物。该纳米铁酸镍/石墨复合物表现出了较高的比容量以及优异的循环性能。其初始放电容量接近1478 mAh·g~(-1),并且在100 mA·g~(-1)的电流密度下循环50周之后,其可逆容量依然高达1109 mAh·g~(-1)。在1000 mA·g~(-1)的充电电流情况下,该复合材料的充电容量也能保持750 mA·g~(-1)。这优异的电化学性能主要归功于纳米铁酸镍能够稳定的钉扎在石墨表面上,这种特殊的结构增强了材料的导电性同时也增大了材料的表面比容量。
As the anode material for lithium-ion battery, nickel ferrite and its related materials have drawn much attention recently because of their high specific theoretical capacity. In order to overcome the adverse effects of lower conductivity and larger volumetric expansion in the process of charge and discharge, a composite formed by hydrothermal deposition of NiFe2O4 onto the graphite surface was synthesized. The nano-nickel-iron / graphite composite exhibits higher specific capacity and excellent cycling performance. Its initial discharge capacity is close to 1478 mAh · g -1, and its reversible capacity is still as high as 1109 mAh · g -1 after 50 cycles at a current density of 100 mA · g -1. The charge capacity of the composite can be kept at 750 mA · g -1 at the charge current of 1000 mA · g -1. This excellent electrochemical performance is mainly due to the nano-nickel ferrite can be pinned firmly on the graphite surface, this special structure enhances the conductivity of the material and also increases the surface specific capacity of the material.