一维纳米导电剂对低温18650锂离子电池性能的影响  

Effect of one-dimensional nano conductive agent on performance of low-temperature 18650 lithium ion batteries

作　　者：李中原 张健 张航 梁建权 王磊 张家伟 刘倩 LI Zhongyuan;ZHANG Jian;ZHANG Hang;LIANG Jianquan;WANG Lei;ZHANG Jiawei;LIU Qian(Electric Power Research Institute,State Grid Heilongjiang Electric Power Company Limited,Harbin Heilongjiang 150030,China;School of Electrical and Electronic Engineering,Harbin University of Science and Technology,Harbin Heilongjiang 150080,China)

机构地区：[1]国网黑龙江省电力有限公司电力科学研究院,黑龙江哈尔滨150030 [2]哈尔滨理工大学电气与电子工程学院,黑龙江哈尔滨150080

出　　处：《电源技术》2025年第2期337-346,共10页Chinese Journal of Power Sources

基　　金：国网黑龙江省电力有限公司科技项目(522437240003);国家自然科学基金项目(52377206)。

摘　　要：针对低温下锂离子电池性能下降严重甚至无法工作的问题,开发了一种NCA/C体系低温18650锂离子电池。通过膜片电阻、倍率性能、高低温性能及循环性能的对比分析,研究了一维纳米导电剂多壁碳纳米管(MWCNT)、气相生长碳纤维(VGCF)对电池性能的影响。研究发现,一维纳米导电剂的加入可以有效降低极片电阻,改善电池的倍率性能,降低发热量,提升循环性能,提升低温倍率性能。对比分析表明,MWCNT相比VGCF在循环寿命的提升上有显著优势,但在倍率性能、高低温性能等方面优势并不明显。采用MWCNT+超级碳黑(SP)复合导电剂制备的2.5 Ah低温18650锂离子电池具备10 C持续放电、20 C脉冲放电能力,并且-40℃下1 C放电容量保持率为76.2%,常温循环1000次后,容量保持率达94.5%。Aim at the problem of severe performance degradation or even failure of lithium-ion batteries at low temperature,a low-temperature NCA/C based 18650 lithium-ion battery was developed.The impact of one-dimensional nanofiber conductive additives such as MWCNT and VGCF on the battery performance was studied through the comparative analysis of the electrode sheet resistance,rate capability,high/low-temperature performance and cycling performance.It’s found that the addition of one-dimensional nanofiber conductive additives can effectively reduce the electrode resistance,enhance the battery rate capability,decrease the heat generation,prolong the cycle life and improve the low-temperature rate performance.The comparative analysis shows that compared with VGCF,MWCNTs have a significant advantage in improving cycle life,but have no obvious advantage in terms of rate capability or high/low-temperature performance.The 2.5 Ah low-temperature 18650 lithium-ion battery prepared by MWCNT+SP composite conductive agents exhibits the capability of 10 C sustained discharge and 20 C pulse discharge,the discharge capacity retention is 76.2%at-40℃and 1 C,and the capacity retention is 94.5%after 1000 cycles at room temperature.

关 键 词：低温 一维导电剂 多壁碳纳米管 气相生长碳纤维 锂离子电池 

分 类 号：TM912.9[电气工程—电力电子与电力传动]