NCM811正极材料的高能量密度体系软包电池评价  

Evaluation of NCM811 cathode materials for pouch cell with high energy density

作　　者：谭显艳 高旭光 张志平 TAN Xianyan;GAO Xuguang;ZHANG Zhiping(Hunan Semicore Thermal Intelligent Equipment Co.,Ltd.,Changsha Hunan 410111,China;Greenway Technology Co.,Ltd.,Dongguan Guangdong 523749,China)

机构地区：[1]湖南烁科热工智能装备有限公司,湖南长沙410111 [2]广东博力威科技股份有限公司,广东东莞523749

出　　处：《电源技术》2023年第3期294-297,共4页Chinese Journal of Power Sources

摘　　要：因高镍三元锂离子电池具有高能量密度而成为海内外中高端车企共同选择的对象。然而,三元正极在循环过程中会经历从H2到H3的相变而导致较大的晶格体积变化,造成二次球三元材料在循环过程中容易发生颗粒破碎,导致电池阻抗增加和衰减严重。而单晶三元材料几乎由一次颗粒构成,循环过程颗粒保持较好。通过将市售的单晶NCM811和二次球NCM811分别制作成5 Ah软包叠片电池,研究对比发现:二次球NCM811在室温25℃下经过2000次循环容量保持率为84.2%,而单晶NCM811电芯容量保持率90.5%;在45℃下,二次球样品经过1300次循环,容量衰减到80%,而单晶样品经过2000次循环容量保持率仍有86.3%,具有更优的循环性能。其他关键指标,如存储、产气等方面单晶优势明显。The high-nickel NCM lithium ion battery with high energy density has become the main technical route chosen by middle and high-end electrical auto companies in the domestic and overseas.However,NCM cathode undergoes a phase transition from H2 to H3 during the charge/discharge cycle,which will cause a large lattice volume change and lead to the particle crack of the secondary sphere,resulting in the increase of cell impedance and accelerated cycle fading.The monocrystal NCM is almost composed of primary particles,and the particle integrity can be maintained during the cycling.The commercial NCM811 monocrystal cathode material and secondary sphere NCM811 cathode material were compared by making 5 Ah pouch laminated battery.The results show that the capacity retention ratio of the secondary sphere NCM811 cell is 84.2%after 2000 cycles at 25℃,while that of the single crystal NCM811 cell is 90.5%.At high temperature of 45℃,the capacity of secondary sphere NCM811 decreases to 80%after 1300 cycles,while the capacity retention ratio of monocrystal NCM811 remains 86.3%after 2000 cycles.Monocrystal NCM811 shows excellent cycling performance.In other key performance indicators,such as high temperature storage,gas evolution,monocrystal NCM811 also demonstrates outstanding performance.

关 键 词：锂离子电池 高镍 NCM811 单晶 

分 类 号：TM912[电气工程—电力电子与电力传动]