摘要
本文采用溶胶-凝胶法制备了钴和钛共掺杂的层状LiNi_(0.82)Co_(0.15)Ti_(0.03)O_(2)正极材料,研究了离子掺杂对LiNiO_(2)材料电化学性能的影响。XRD和XPS分析显示,钴和钛共掺杂可以抑制Li+和Ni2+离子在Li层的混排现象。电化学测试结果表明,钴单元素掺杂可以显著提高LiNiO_(2)材料的倍率性能,而钛单掺杂则提高了材料的循环稳定性。进一步地,通过钴钛共掺杂的协同作用,可以使LiNiO_(2)材料的倍率性能和循环稳定性同时得到极大的提高。在200 mA/g的电流密度下循环200次,LiNi_(0.82)Co_(0.15)Ti_(0.03)O_(2)材料的容量保持率高达94.4%,而未掺杂的LiNiO_(2)材料容量保持率仅为57.1%;且在1000 mA/g的电流密度下,放电比容量仍能维持在100 mAh/g左右。
In this paper,we have synthesized Co-Ti co-doped layered LiNi_(0.82)Co_(0.15)Ti_(0.03)O_(2) cathode material by a sol-gel method.The effects of the element-doping on the structure and electrochemical properties of the layered LiNiO_(2)cathode material were studied.XRD and XPS analyses showed that the cation mixing of Li^(+)and Ni^(2+)ions in the Li layer in the LiNiO_(2)crystal lattice can be effectively suppressed by a Co-Ti co-doping.By measuring the electrochemical properties of different as-synthesized LiNiO_(2)based materials,it is found that the rate performance of LiNiO_(2)cathode materials can be significantly improved by single element Co-doping,while the cycle stability of LiNiO_(2)cathode materials can be enhanced by single element Ti-doping.Furthermore,the rate capability and cycle stability of LiNiO_(2)were improved through the synergistic effect of Co-Ti co-doping.The capacity retention of LiNi_(0.82)Co_(0.15)Ti_(0.03)O_(2) cathode material was still as high as 94.4%after 200 cycles at the current density of 200 mA/g,while the capacity retention of undoped LiNiO_(2)material was only 57.1%.At the same time,the discharge capacity of Co and Ti co-doped LiNiO_(2)cathode materials can still be maintained at 100 mAh/g under the current density of 1000 mA/g.
作者
张佩琪
李东林
王子匀
李童心
任旭强
孔祥泽
ZHANG Peiqi;LI Donglin;WANG Ziyun;LI Tongxin;REN Xuqiang;KONG Xiangze(School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2021年第4期4166-4173,共8页
Journal of Functional Materials
基金
国家自然科学基金资助项目(21473014)。
