锂离子电池三元正极材料残碱测试影响因素  

Factors of residual alkali test in ternary cathode materials for Li-ion battery

作　　者：王裕生 柳春月 吴珊珊 孙伟丽 WANG Yu-sheng;LIU Chun-yue;WU Shan-shan;SUN Wei-li(Ningbo Ronbay New Energy Technology Co.,Ltd.,Ningbo,Zhejiang 315400,China)

机构地区：[1]宁波容百新能源科技股份有限公司,浙江宁波315400

出　　处：《电池》2022年第4期475-478,共4页Battery Bimonthly

摘　　要：残碱是三元正极材料生产过程中的一项重要控制指标。通过电位滴定法,研究三元正极材料中残碱测试的影响因素,包括水质、温度、CO_(2)、过滤方式和静置时间等,其中,空气中的CO_(2)对残碱测试的影响最大。三元正极材料及残碱溶液敞口放置0.5 h后,Li_(2)CO_(3)含量升高约22%,LiOH含量降低约15%。这说明材料暴露在空气中,极易吸收CO_(2),导致LiOH转化为Li_(2)CO_(3),因此,测试残碱的材料应密封包装,测试过程中应减少材料、溶液与空气的接触。材料体相内的Li会不断溶出,搅拌结束后,应尽快测试或过滤到烧杯中,用保鲜膜密封,避免长时间静置导致残碱测试结果偏高。由于上述因素影响面较广,三元正极材料中残碱的测试过程需要严格控制。Residual alkali was an important control index in the production of ternary cathode materials.The influcing factors of residual alkali test in ternary cathode materials were studied by potentiometric titration method,including water quality,temperature,CO_(2),filtration method and standing time,among which CO_(2)in air had the greatest influence to the test of residual alkali.The content of Li_(2)CO_(3)increased by 22%and the content of LiOH decreased by 15%when ternary cathode materials and residual alkali solutions were exposed for 0.5 h,indicating that the materials were easy to absorb CO_(2)when exposed in the air,resulting in the conversion of LiOH to Li_(2)CO_(3).Therefore,the materials for testing residual alkali should be sealed and packaged.During testing process,the exposure of materials and solutions in the air should be reduced.The Li in the bulk phase of materials would constantly dissolve out,after mixing,it should be tested as soon as possible or filtered into the beaker and sealed with plastic wrap to avoid high residual alkali test results due to long-term standing.Due to the wide influence of these factors,it was necessary to strictly control the testing process of residual alkali in ternary cathode materials.

关 键 词：电位滴定法 三元正极材料 残碱 CO_(2) Li_(2)CO_(3) LiOH 

分 类 号：TM912.9[电气工程—电力电子与电力传动]