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.
Nickel ferrite and related materials have recently received considerable attention as potential anode in lithium-ion batteries for their high theoretical specific capacities.To overcome low intrinsic electronic conductivity and large volume expansion during the Li insertion/extraction process,in this work,nano-NiFe2O4 pinning on the surface of the graphite composite was prepared by a hydrothermal method.As the superior anode material,the as-obtained nano-NiFe2Odgraphite composite demonstrates high capacity and excellent cycle stability.An initial specific discharge capacity of approximate 1478 mAh·gq and a reversible specific capacity of approximate 1109 mAh·g-1 after 50 cycles at a current density of 100 mA·g1 are reached.When the charging current is increased to 1000 mA·g-1,it also delivers a charge capacity of 750 mAh·g-1.The excellent performances are attributed to the special structure of NiFe2O4 nanoparticles pinning on the surface of the graphite,especially the enhanced electronic conductivity and area specific capacitance during the cycling process.
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