( 1. 成都理工大學(xué) 材料與生物工程學(xué)院, 成都 610059；
2. 成都雷靂高科技公司, 成都 610045)
摘 要: 在空氣氣氛中合成了LiCo0.3Ni0.7-xSrxO2二元摻雜鋰離子電池正極材料， 研究了不同摻Sr2+量對(duì)材料的結(jié)構(gòu)與電化學(xué)性能的影響， 用XRD、 SEM及電性能測(cè)試考察了材料的結(jié)構(gòu)、 形貌及其電化學(xué)性能。 結(jié)果表明： Sr2+的摻入量對(duì)材料的結(jié)構(gòu)與電化學(xué)性能影響較大， 隨著摻Sr2+量的增加， X射線衍射圖中材料的特征峰向低角度飄移， 晶胞參數(shù)a和c增大， 晶胞體積增大； 電性能測(cè)試結(jié)果表明： 適量的摻Sr2+有利于提高材料中Li+的擴(kuò)散能力， 抑制John-Teller效應(yīng)， 降低陽離子混排現(xiàn)象， 提高材料的電化學(xué)穩(wěn)定性， 當(dāng)x=0.003， LiCo0.3Ni0.697-Sr0.003O2顯示出較優(yōu)的電化學(xué)性能， 首次放電容量為162mA·h·g-1， 首次放電效率為90.6%； 40次循環(huán)后其放電容量仍為153mA·h·g-1， 容量損失為7%， 顯示出較好的循環(huán)穩(wěn)定性。
關(guān)鍵字: 鋰離子電池； 正極材料； LiCo0.3Ni0.7-xSrxO2；合成
cathode material for lithium ion batteries
（ 1. School of Material and Bioengineering,
Chengdu University of Technology,Chengdu 610059, China;
2. LeiLi High-tech. Development Ltd Co.,
Chengdu 610045, China）
Abstract: The layered LiCo0.3Ni0.7-xSrxO2 cathode materials for lithium ion batteries were synthesized in air. The influence on the structure and electrochemical properties of the materials caused by different contents of Sr2+ was investigated, and XRD analysis, SEM and electrochemical tests were used to study the physical and the electrochemical performances of the materials. With increasing value of x, the characteristic peaks of LiCo0.3Ni0.7-xSrxO2 shift to a lower degree and the lattice parameters increase. The results of electrochemical tests indicate that small content of Sr2+ can stabilize the structure of the material and make the electrochemical properties of the material better. The sample LiCo0.3Ni0.697Sr0.003O2 with doping Sr2+ (x=0.003) has the best electrochemical properties, which has an initial discharge capacity of 162mA·h·g-1 and an initial discharge efficiency of 90.6%. After 40 cycles, this sample remains 153mA·h·g-1 of discharge capacity and the loss ratio of capacity is just 7%, showing perfect cyclic stability.
Key words: lithium-ion battery； cathode material； LiCo0.3Ni0.7-xSrxO2; synthesis
