全浓度梯度高镍正极材料的可控制备及性能

Controllable Preparation and Performance of Full Concentration-Gradient High Nickel Cathode Material

针对全浓度梯度高镍正极材料批次一致性控制问题,采用Ni、Co、Mn三种溶液单独配制,各自通过程序精确控制流量进入反应釜的新思路和梯度降温烧结方式,实现可控制备。制备的全浓度梯度LiNi0.82Co0.08Mn0.10O2的0.1 C放电比容量为210.9 mAh/g,制作成的18650电池比能量为240 Wh/kg和669 Wh/L,具有较好的大电流充放电能力,适用于-20~55℃,1 000次循环后容量保持率为85.2%。高镍正极材料的浓度梯度化设计,显著提高了材料表面结构的稳定性,与商业化的高镍正极材料相比,在循环性能、倍率和安全性能等方面都具有明显优势。

Aiming at the batch consistency control problem of full concentration-gradient(FCG) high nickel cathode materials,a new idea is presented,in which Ni,Co,and Mn solutions are separately prepared and their flow amounts into the reactor are precisely controlled by a program. Along with the gradient cooling sintering method,controllable preparation can be achieved. The specific discharge capacity of the prepared FCG LiNi0.82Co0.08Mn0.10O2 is 210.9 mAh/g at 0.1 C. The 18650-type battery made with such cathode materials has the specific energy of 240 Wh/kg and 669 Wh/L,and has a good high-current charge/discharge capability. It is suitable for operations at the temperature range from-20℃ to 55℃. After 1 000 cycles,its capacity retention rate is 85.2%. The concentration-gradient design of high nickel cathode materials significantly improve the stability of the surface structure. Compared with commercial high nickel cathode materials,the high nickel cathode materials prepared by the concentration-gradient design have significant advantages in cycle performance,rate,safety,etc.