摘要
采用溶剂热法成功制备了富锂锰基正极材料Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)(LLO),通过铈离子掺杂和Nb_(2)O_(5)包覆,获得新型改性富锂锰基正极材料CNLLO。与LLO相比,比镍、钴、锰离子半径更大的铈离子的掺入增加了CNLLO的层间距,提高了锂离子扩散速率;Nb_(2)O_(5)包覆层抑制了CNLLO表面的副反应,限制了晶体结构的转变,提高了CNLLO的稳定性。在10 C倍率下,CNLLO的放电比容量(128.0 mAh·g^(-1))高于LLO(85.6 mAh·g^(-1))。此外,CNLLO还表现出优异的循环性能,1 C下循环200次后容量保持率和平均放电电压衰减值分别为80.2%和415.3 mV。因此,所制备的CNLLO正极材料具有优异的电化学性能,在锂离子电池中具有广阔的应用前景。
Li-rich Mn-based cathode material Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)(LLO)was successfully prepared by a solvothermal method.Then,a novel modified Li-rich Mn-based cathode material CNLLO was obtained through being doped with cerium ions and coated with Nb_(2)O_(5).Compared with LLO,cerium ions with larger radius than nickel,cobalt and manganese ions increase the interlayer spacing of CNLLO,and the diffusion rate of lithium ions is increased.Nb_(2)O_(5) coating inhibits the side reaction on the surface of CNLLO,restricts the transformation of crystal structure and improves the stability of CNLLO.At the rate of 10 C,the specific discharge capacity of CNLLO(128.0 mAh·g^(-1))is higher than that of LLO(85.6 mAh·g^(-1)).Besides,CNLLO shows excellent cycle performance.The capacity retention rate and average discharge voltage attenuation value are 80.2%and 415.3 mV after 200 cycles at 1 C,respectively.As a result,the as-prepared CNLLO cathode material has excellent electrochemical performance,which has a broad application prospect in lithium-ion battery.
作者
罗欢
李豪
袁盛旭
张亚萍
李劲超
LUO Huan;LI Hao;YUAN Sheng-xu;ZHANG Ya-ping;LI Jin-chao(School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Engineering Research Center of Biomass Materials,Ministry of Education,Southwest University of Science and Technology,Mianyang 621010,China)
出处
《化学研究与应用》
CAS
CSCD
北大核心
2022年第8期1862-1871,共10页
Chemical Research and Application
基金
射洪经济技术开发区管理委员会基金(21zh0226)资助
西南科技大学博士研究基金(18zx7133)资助。
关键词
锂离子电池
富锂锰基正极材料
掺杂
包覆
lithium-ion battery
Li-rich Mn-based cathode material
doping
coating