摘要
为了研究高镍三元前驱体和高镍三元正极材料之间的“构效”关系,采用共沉淀法合成不同结构的前驱体Ni_(0.92)Co_(0.05)Mn_(0.03)(OH)_(2),将前驱体与氢氧化锂高温固相烧结后合成高镍正极材料。实验发现在低pH与低氨条件下合成的前驱体(101)峰与(001)峰的强度比值(I_(101)/I_(001))更大,一次堆积粒子较小并且表面疏松,所得正极材料一次晶粒细长,具有更好的放射结构。实验结果表明,I_(101)/I_(001)大的前驱体制备的正极材料在2.7~4.3V、0.1C测试条件下,首次放电比容量为232.3mAh/g,首次放电效率达到92.3%。该材料不仅具有良好的循环和倍率性能,而且热稳定性能提高了4.6℃,证明了前驱体优先沿(101)晶面生长能够有效提高正极材料的结构稳定性和电化学性能。
In order to study the“structure-activity”relationship between high-nickel ternary precursors and cathode materials,Ni_(0.92)Co_(0.05)Mn_(0.03)(OH)_(2)precursors with different structures were designed and synthesized by coprecipitation method,and then a series of high-nickel cathode materials were prepared by high-temperature solid-phase sintering of the precursors with lithium hydroxide.It was found that the peak intensity ratio of the precursor I_(101)/I_(001) was larger under the conditions of low pH and low ammonia concentration,the primary crystal grains were smaller,and the secondary accumulation particles were looser.The primary crystal grains of the obtained cathode materials were elongated with better radiation structure.The experimental results showed that the initial discharge capacity was 232.3mAh/g and the first discharge efficiency was 92.3%under the conditions of 2.7~4.3V and 0.1C when the cathode material obtained from the precursors with a large I_(101)/I_(001) peak intensity ratio.The obtained cathode materials not only had excellent cycling and rate performance,but also had improved thermal stability performance by 4.6℃.It.was confirmed that the preferential growth of the precursors along the(101)plane could effectively improve the structure stability and electrochemical performance of the cathode materials.
作者
王继锋
屈涛
陈微微
张诚
李宇
Wang Jifeng;Qu Tao;Chen Weiwei;Zhang Cheng;Li Yu(Jinghe New City Shaanxi Coal Technology Research Institute New Energy Materials Co.,Ltd.,Xi’an 713700)
出处
《化工新型材料》
CAS
CSCD
北大核心
2023年第S02期357-362,共6页
New Chemical Materials
基金
陕煤基金(2022YJY-Y-ZZ-XS-JH003)
关键词
前驱体结构
正极材料
倍率性能
循环稳定性
锂离子电池
precursor structure
cathode material
rate capability
cycling stability
lithium-ion battery
