添加磷、硼、硅和铝的锂离子电池材料LiNiO_2研究

Study on LiNiO_2 materials with additive elements P,B,Si and Al used in lithium ion battery

研究了添加元素磷、硼、硅和铝对锂离子蓄电池材料LiNiO2 的影响 .添加磷、硼、硅和铝的目的是提高LiNiO2 的放电平台和充放电稳定性 ,增加循环寿命并且提高充放电能量 .在n(LiOH)∶n(Ni(OH) 2 )为 1 1∶1 0的材料中分别加入P2 O5;H3 BO3 ,SiO2 ,Al2 O3 ,保持 4种元素与锂的摩尔比值分别为 0 0 1,0 0 2 ,0 0 3,0 0 4和 0 0 5 .分析测定了样品的充放电曲线和循环伏安曲线 ,并采用XRD对样品的放电过程和合成产品进行了结构分析 .结果证明 ,当n(P) /n(Ni) =0 0 2 ,n(B) /n(Ni) =0 0 3,n(Si) /n(Ni) =0 0 2 ,n(Al) /n(Ni) =0 0 2时 ,LiNiO2 的放电电压提高 .添加元素使LiNiO2 在充放电过程中的晶型转变过程发生改变 ,使六方晶系向单斜晶系转变的趋势变小 ,这将改善LiNiO2 的循环性能 ,但没有影响锂离子的嵌入和脱嵌机理 .XRD分析表明 ,添加磷和铝使LiNiO2 的层状结构更完善 ,同时增加了活性 .但添加硼和硅以后 ,LiNiO2 的XRD图上的衍射峰 (0 0 3)强度度减弱 ,衍射峰 (0 18)和 (0 19)峰也有改变 ,这证明B和Si影响了LiNiO2 性能 .

The effect of additive elements P,B,Si and Al on liNiO 2 materials used in lithium ion battery was studied.The aim of adding P,B,Si and Al were to improve the discharge plateau and the charge/discharge stability of LiNiO 2 as well as to increase its cycle life and charge/discharge energy.P 2O 5,H 3BO 3,SiO 2 and Al 2O 3 were added into the powder of LiOH and Ni(OH) 2 with their mole ratio n( LiOH)∶ n (Ni(OH) 2)=1.1∶1 0,and their mole ratio were kept 0.01,0.02,0.03,0.04 and 0.05 respectively,The charge/discharge curves and cyclic voltammogram of the sample were determined and the XRD patterns of the samples were tested.The results showed that the discharge voltage of LiNiO 2 were increased when n (P)/ n (Ni)=0.02, n (B)/ n (Ni)=0.03, n (Si)/ n (Ni)=0.02, n /(Al)/ n (Ni)=0.02 and the process of crystal-form transformation from hexagonal syst to monoclinic system was decreased.It was obvious to improve cycle properties LiNiO 2.Through testing of the cyclic voltammogram of liNiO 2 samples,adding elements did not affect the intercalation and extraction of Lithium ion.The XRD analysis showed that lamellar structure of LiNiO 2 was improved and its electrochemical action was increased adding elements P and Al.It was also found that when elements B and Si were added,the strength of (003)peak in XRD pattern of LiNiO 2 damps and those of the (018) peak and (010)peak also change.It roved that elements B and Si affected property of LiNiO 2.