工程科学学报.第43卷.第8期：1012-1018.2021年8月 Chinese Journal of Engineering,Vol.43,No.8:1012-1018,August 2021 https://doi.org/10.13374/j.issn2095-9389.2020.11.30.004;http://cje.ustb.edu.cn 硼掺杂镍酸锂的改性研究 张 宁1,2)，厉英2)区，倪培远1,2 1)东北大学冶金学院.沈阳1108192)辽宁省冶金传感器及技术重点实验室，沈阳110819 ☒通信作者，E-mail:liying@mail.neu.edu.cn 摘要采用共沉淀法制备了N(Oh前驱体材料，通过高温固相法制备了LNiO2和B掺杂LiNO2(B的摩尔分数为1%)， 利用X射线衍射(XRD)、里特维尔德(Rietveld)精修、扫描电子显微镜(SEM)、恒流充放电测试、循环伏安(CV)和电化学阻 抗谱(EIS)对材料的晶体结构、表面形貌和电化学性能进行了系统性表征.XRD和Rietveld精修结果表明，LNiO,和B掺杂 LO2均具有良好的层状结构，B因为占据在过渡金属层和锂层的四面体间隙位而导致掺杂后略微增大材料的晶格参数和 晶胞体积，同时增大了LiO6八面体的间距，进而促进锂离子运输.由于掺杂的B的摩尔分数仅为1%，LNO2和B掺杂 LNO2均表现为直径10um左右的多晶二次颗粒，且一次颗粒晶粒尺寸没有明显区别.长循环数据表明B掺杂可以有效提 高材料的循环容量保持率，经100次循环后，B掺杂样品在40mAg电流下的容量保持率为77.5%，优于未掺杂样品（相同条 件下容量保持率为66.6%).微分容量曲线和EIS分析表明B掺杂可以有效抑制循环过程中的阻抗增长， 关键词硼：掺杂：镍酸锂：正极材料：锂离子电池 分类号TM912.9 Enhanced electrochemical performance of LiNiO2 by B doping ZHANG Ning2,LI Ying2),NI Pei-yuan2 1)School of Metallurgy,Northeastern University,Shenyang 110819.China 2)Liaoning Key Laboratory for Metallurgical Sensor and Technology,Shenyang 110819,China Corresponding author,E-mail:liying@mail.neu.edu.cn ABSTRACT The application markets for portable electronics,battery-operated electric vehicles,and large-scale energy-storage grids have been expanding rapidly for the past ten years,which has attracted massive attention to the investigation and development of batteries with high energy density,long cycle life,high safety,and low cost.A commonly used lithium-ion battery consists of intercalation-type materials,such as LiCoO2 as cathode and graphite as an anode.Owing to technical difficulties,including high cost, low stability,and the poor safety of Li,the large-scale application of the high-energy Li anode is still premature.A more common strategy than the one mentioned above for improving the energy density of Li-ion batteries is to develop a cathode material with high specific capacity and low cost,such as LiNiCo,Mn,O2(NCM)and LiNiCo,Al,O2(NCA).Among the NCMs and NCAs,Co is more expensive and less abundant than Ni,Mn,and Al.Presently,high-nickel,low-cobalt NCMs,and NCAs have attracted huge attention as suitable cathodes for both academic and industrial purposes.LNiO,can be regarded as the Ni content increasing to 100%for NMCs and NCAs,which stood as the "holy grail"of layered cathodes.This study aims to investigate the structural and electrochemical stability of LiNiO and B-doped LiNiO.In this study,Ni(OH)was synthesized by a coprecipitation method using a continuous stirred tank reactor (CSTR).LiNiO,and B-doped LiNiO2 were synthesized by high-temperature solid-state sintering.The crystal structure, surface morphology,and electrochemical performance were investigated by X-ray diffraction(XRD),Rietveld refinement,scanning electron microscopy(SEM),constant current charge-discharge,cyclic voltammetry (CV),and electrochemical impedance spectroscopy 收稿日期：2020-11-30 基金项目：国家自然科学基金资助项目(51834004.51774076.51704062)硼掺杂镍酸锂的改性研究 张    宁1,2)，厉    英1,2) 苣，倪培远1,2) 1) 东北大学冶金学院，沈阳 110819    2) 辽宁省冶金传感器及技术重点实验室，沈阳 110819 苣通信作者，E-mail：liying@mail.neu.edu.cn 摘    要    采用共沉淀法制备了 Ni(OH)2 前驱体材料，通过高温固相法制备了 LiNiO2 和 B 掺杂 LiNiO2（B 的摩尔分数为 1%）， 利用 X 射线衍射（XRD）、里特维尔德（Rietveld）精修、扫描电子显微镜（SEM）、恒流充放电测试、循环伏安（CV）和电化学阻 抗谱（EIS）对材料的晶体结构、表面形貌和电化学性能进行了系统性表征. XRD 和 Rietveld 精修结果表明，LiNiO2 和 B 掺杂 LiNiO2 均具有良好的层状结构，B 因为占据在过渡金属层和锂层的四面体间隙位而导致掺杂后略微增大材料的晶格参数和 晶胞体积，同时增大了 LiO6 八面体的间距，进而促进锂离子运输. 由于掺杂的 B 的摩尔分数仅为 1%，LiNiO2 和 B 掺杂 LiNiO2 均表现为直径 10 μm 左右的多晶二次颗粒，且一次颗粒晶粒尺寸没有明显区别. 长循环数据表明 B 掺杂可以有效提 高材料的循环容量保持率，经 100 次循环后，B 掺杂样品在 40 mA·g−1 电流下的容量保持率为 77.5%，优于未掺杂样品（相同条 件下容量保持率为 66.6%）. 微分容量曲线和 EIS 分析表明 B 掺杂可以有效抑制循环过程中的阻抗增长. 关键词    硼；掺杂；镍酸锂；正极材料；锂离子电池 分类号    TM912.9 Enhanced electrochemical performance of LiNiO2 by B doping ZHANG Ning1,2) ，LI Ying1,2) 苣 ，NI Pei-yuan1,2) 1) School of Metallurgy, Northeastern University, Shenyang 110819, China 2) Liaoning Key Laboratory for Metallurgical Sensor and Technology, Shenyang 110819, China 苣 Corresponding author, E-mail: liying@mail.neu.edu.cn ABSTRACT    The application markets for portable electronics, battery-operated electric vehicles, and large-scale energy-storage grids have  been  expanding  rapidly  for  the  past  ten  years,  which  has  attracted  massive  attention  to  the  investigation  and  development  of batteries  with  high  energy  density,  long  cycle  life,  high  safety,  and  low  cost.  A  commonly  used  lithium-ion  battery  consists  of intercalation-type materials, such as LiCoO2 as cathode and graphite as an anode. Owing to technical difficulties, including high cost, low  stability,  and  the  poor  safety  of  Li,  the  large-scale  application  of  the  high-energy  Li  anode  is  still  premature.  A  more  common strategy than the one mentioned above for improving the energy density of Li-ion batteries is to develop a cathode material with high specific capacity and low cost, such as LiNi1–x–yCoxMnyO2 (NCM) and LiNi1–x–yCoxAlyO2 (NCA). Among the NCMs and NCAs, Co is more  expensive  and  less  abundant  than  Ni,  Mn,  and  Al.  Presently,  high-nickel,  low-cobalt  NCMs,  and  NCAs  have  attracted  huge attention as suitable cathodes for both academic and industrial purposes. LNiO2 can be regarded as the Ni content increasing to 100% for NMCs and NCAs, which stood as the “holy grail” of layered cathodes. This study aims to investigate the structural and electrochemical stability of LiNiO2 and B-doped LiNiO2 . In this study, Ni(OH)2 was synthesized by a coprecipitation method using a continuous stirred tank  reactor  (CSTR).  LiNiO2 and  B-doped  LiNiO2 were  synthesized  by  high-temperature  solid-state  sintering.  The  crystal  structure, surface  morphology,  and  electrochemical  performance  were  investigated  by  X-ray  diffraction  (XRD),  Rietveld  refinement,  scanning electron microscopy (SEM), constant current charge–discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy 收稿日期: 2020−11−30 基金项目: 国家自然科学基金资助项目（51834004，51774076，51704062） 工程科学学报，第 43 卷，第 8 期：1012−1018，2021 年 8 月 Chinese Journal of Engineering, Vol. 43, No. 8: 1012−1018, August 2021 https://doi.org/10.13374/j.issn2095-9389.2020.11.30.004; http://cje.ustb.edu.cn