长寿命高镍无钴锂离子正极材料的制备

通过调整不同配锂量、不同焙烧温度以及包覆改性对高镍无钴二元材料性能的影响因素进行了研究。对不同原样和其改性后的材料进行了X射线粉末衍射(XRD)分析和首次充放电性能和倍率性能、循环性能等电化学性能测试。其中过锂量(质量分数)为5%,焙烧温度为820℃的材料性能优异,其首次放电比容量为171.6 mAh·g^-1,1C和3C的放电比容量分别为147.8、129.8 mAh·g^-1。对材料进行锰化合物(质量分数1.0%)包覆处理后,材料的残碱量下降明显,加工性能优异,倍率性能得到明显改善,1C和3C的放电比容量分别提升为156.5、141.8 mAh·g^-1。2Ah软包电池常温循环830周容量保持率为80%,高温循环345周容量保持率为80%。

Preparation of Long-Life Nickel-Rich and Cobalt-Free Layered LiNi0.75Mn0.25O2 Cathode Materials

The nickel-rich and cobalt-free binary cathode materials were prepared,and the effects of lithium content,calcination temperature and coating modification on the properties of samples were studied.X-ray diffraction(XRD)analyses and electrochemical properties such as first charge-discharge performance,rate performance and cycling performance of different samples and modified materials were investigated.Among them,the material with excess lithium content of 5%(w/w)and calcination temperature of 820℃had excellent performance.Its first discharge specific capacity was 171.6 mAh·g^-1,and the discharge specific capacities of 1C and 3C were 147.8 and 129.8 mAh·g^-1,respectively.After coating the material with 1.0%(w/w)manganese compound,the residual alkali content of the material decreased obviously.The processing performance was excellent,the rate performance was improved obviously,and the discharge specific capacities of 1C and 3C were increased to 156.5,141.8 mAh·g^-1,respectively.The capacity retention rate of 2Ah soft-packed battery was 80%after 830 cycles at room temperature and 80%after 345 cycles at high temperature.