单晶与多晶超高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)动力学研究  

Kinetics of single crystal and polycrystalline for ultra-high nickel LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)

作　　者：金光 田小龙[2] 马松花 JIN Guang;TIAN Xiaolong;MA Songhua(Henan Intelligent Safety Engineering Research Center for Rail Transit,Zhengzhou Henan 450018,China;Zhengzhou Railway Vocational Technical College,Zhengzhou Henan 450052,China)

机构地区：[1]河南省轨道交通智能安全工程技术研究中心,河南郑州450018 [2]郑州铁路职业技术学院,河南郑州450052

出　　处：《电源技术》2023年第12期1555-1558,共4页Chinese Journal of Power Sources

基　　金：国家自然基金青年基金资助项目(62003313);郑州市机器人与智能装备工程研究中心资产项目(2021101369)。

摘　　要：高镍正极因其高容量和高工作电压,在高能量密度锂离子电池中具有很大的前景。然而,随着镍含量的增加,高镍正极出现了阳离子混排、结构退化、副反应和微裂纹等关键问题。制备了单晶和多晶LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)正极材料,并比较了它们在扣式电池中的性能和容量衰减行为,结合相应的XRD、SEM、HRTEM、EIS分析相应的机理演变。结果显示单晶正极的循环稳定性明显优于多晶正极,单晶颗粒的强晶体结构缓解内应力的积累,抑制循环过程中的微裂痕的形成。单晶正极展现出优异的电化学性能,在2.8~4.6 V(Li^(+)/Li)之间,在0.5 C时500次容量保持率是多晶正极2倍。这项工作为单晶和多晶材料在高电压下的应用及发展提供了借鉴。High nickel cathode has a great prospect in high energy density for lithium-ion batteries due to its high capacity and high operating voltage.However,with the increase of nickel content,the cation disorder,structural degradation,side reactions and microcracks of high nickel cathode become more and more serious.In this paper,single crystal and polycrystal LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2) cathode materials were prepared,the performance and capacity attenuation behavior in the coin-cell were compared,and the corresponding mechanism evolution was analyzed by XRD,SEM,HRTEM and EIS.The results show that the cyclic stability of the single crystal cathode is obviously better than that of the polycrystal positive electrode.The strong crystal structure of the single crystal particles alleviates the accumulation of internal stress and inhibits the formation of microcracks during the cyclic process.The single crystal cathode shows excellent electrochemical performance between 2.8 V and 4.6 V(Li^(+)/Li),the capacity retention is 2 times higher than that of the polycrystalline positive electrode at 0.5 C after 500 cycles.This work provides reference for the application and development of crystalline and polycrystalline materials at high voltage.

关 键 词：锂离子电池 超高镍正极 单晶和多晶 高电压 

分 类 号：TM912.9[电气工程—电力电子与电力传动]