氧化镍柔性自支撑电极材料的电化学性能研究

Electrochemical Performance of Flexible and Free-standing NiO Carbon Composite Nanofiber as Negative Electrodes

摘要:

制备具有优异界面结构和电子/离子传质能力的柔性电极材料是解决高性能电化学活性物质由体积膨胀引起材料粉化和从集流体剥落难题的关键。一种独特的工艺实现了高性能过渡金属氧化物（氧化镍）内嵌碳纤维柔性织物电极的一步制备，所制备的活性物质免于使用导电剂、粘结剂和集流体直接用于锂离子电池负极材料的组装。得益于氧化镍超高的理论比容量，活性碳纤维基体材料低维特性和良好的内应力分散率，制备的复合织物电极展现出良好的电化学性能，一维氧化镍/碳纳米纤维（NiO-CNF）复合柔性电极较纯氧化镍（NiO NF）纤维电极材料具有更卓越的循环耐久性和倍率性能，NiO-CNF和NiO NF在0.5C倍率循环200次分别具有418 mAh·g-1和242 mAh·g-1的可逆容量，良好的电化学性质归因于复合柔性电极的交联结构提供的优异扩散动力学和应力缓冲。

Abstract:

The key to solving pulverization and stripping from collector caused by volume expansion of high performance electrode lies in flexible electrode was prepared, which has excellent interface structure and electron/ion mass transfer capacity. A unique process has been used to prepare high performance transition metal oxide (nickel oxide) coupled carbon fiber mat flexible electrode. When directly applied such a flexible negative electrode for lithium-ion battery, due to the high theoretical specific capacitance of nickel oxide, unique low dimensional characteristics and huge draw ratios for internal stress dispersion of carbon fiber mat, NiO carbon nanofiber (NiO-CNF) deliver excellent cyclic characteristic and better rate electrochemical performance simultaneously much higher than NiO nanofiber (NiO NF) without carbon. NiO-CNF and NiO NF have reversible capacities of 418 mAh.g_-1 and 242 mAh.g_-1 after 200 cycles at 0.5C, respectively. These electrochemical properties can be attribute to the cross-linked structures provide diffusion kinetics and external stress buffering.