Aiming at the shortcomings of traditional graphite negative electrode,such as low specific capacity,large volume expansion of charging, resulting in instability of electrode structure and poor rate performance, it is proposed to use nickel graphene nanosheet(Ni-Gns)composite coating as a cathode electrode material for lithium-ion battery. To verify the performance of this material, a new ultrasonic assisted jet electrodeposition experiment device is developed,and the Ni-Gns composite coating is prepared under different process conditions. Then, the battery negative electrode is fabricated based on such composite materials.. An orthogonal experimental method is employed to measure the discharge capacity of the electrode over 50 charge/discharge cycles, and the electrodeposition process parameters are optimized. The results show that the dominant electrodeposition parameters sequences:added amount of Gns m > coating thickness h > current density D > bath temperature T;optimized process parameters:m =0.75 g·L-1,h = 30 μm,D = 33 A·dm-2,T = 35 ℃. The surface morphology and microstructure of the optimized coating are observed, which show the Ni - Gns composite coating has a compact structure and a good interface bonding. For transition metal-carbon composite materials, the mechanism model for the electrodeposition process of carbon nanofibers(whiskers)as reinforcement in this composite is proposed. The study suggests that the ultrasonic wave can improve the efficiency of electrodeposition and the structure of the coating. Under the synergistic action of power ultrasonic and electrodeposition, Ni(matrix)and Gns(reinforcing phase)connected by"nickel bridge"between the overlapping form dense and uniform distribution of"percolation conductive network". Combined with Gns' s multilayer thin honeycomb lamella structure and its excellent mechanical and electrochemical properties, the material has excellent conductivity and stable structure, and is suitable for lithium ion battery cathode material.%针对传统的石墨负极存在着比容量低、充电时体积膨胀大导致电极结构不稳定、倍率性能差等缺点,提出采用镍-石墨烯纳米薄片(Ni-Gns)复合镀层作为锂离子电池负极材料的解决方案.为验证该材料的性能,创新研制超声辅助喷射电沉积实验装置,在不同的工艺条件下制得Ni-Gns复合镀层,并制成电池负极.采用正交实验法,以电极充放电循环50次后的放电容量为评价指标,测定最优的电沉积工艺参数组合.结果表明,电沉积参数显著性顺序为:Gns的掺量m > 镀层厚度h > 电流密度D > 镀液温度T,最优数值组合为:m = 0.75 g·L-1,h = 30 μm,D = 33 A·dm-2,T = 35℃.观察在此条件下制得的镀层的表面形貌和微观结构,发现Ni-Gns复合镀层结构致密,界面结合良好,Gns在其中弥散分布;给出碳族纳米纤维(晶须)作为增强相的过渡族金属-碳族复合材料电沉积过程机理模型.研究认为:超声波起到提升电沉积效率、改善镀层组织结构的作用;在功率超声和电沉积的协同作用下,Ni (基体相)和Gns(增强相)之间形成由"镍桥"搭接构成的密集且分布均匀的"逾渗导电网络",结合Gns的多层细密蜂窝状薄片结构和自身优异的力学、电化学性能,因此该材料的导电性能优异、结构稳定,适合用作锂离子电池负极材料.
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