添加剂对三元和锰酸锂混合正极体系的影响  

Effect of additives on ternary and lithium manganate composite cathode system

作　　者：乔顺攀 彭鸣 张和平 卢胜娟 孙春胜 QIAO Shunpan;PENG Ming;ZHANG Heping;LU Shengjuan;SUN Chunsheng(Xianghe Kunlun New Energy Co.,Ltd.,Langfang 065400,Hebei,China)

机构地区：[1]香河昆仑新能源材料股份有限公司,河北廊坊065400

出　　处：《电池》2025年第1期104-110,共7页Battery Bimonthly

摘　　要：电解液添加剂对电池性能起着关键的作用。分析碳酸乙烯亚乙酯(VEC)或碳酸亚乙烯酯(VC)作为添加剂,对三元和锰酸锂混合正极体系电池电化学性能的影响。通过密度泛函理论,计算添加剂的成膜性,发现VC具有更好的正极成膜性,而VEC则具有更好的负极成膜性。添加质量分数为0.5%的VC的电池具有较小的交流内阻和直流内阻,分别为25.0 mΩ和62.1 mΩ。该体系的Li+迁移数较高,在3.00~4.20 V充放电,常温25℃下3.00 C放电容量与1.00 C充电容量之比为86.4%,高温60℃存储后的容量残余率为96.7%,容量恢复率为99.6%。25℃1.00 C循环650次的容量保持率为94%,45℃1.00 C循环500次的容量保持率为77%。The electrolyte additive plays a crucial role in the performance of batteries.Vinyl ethylene carbonate(VEC)or vinylene carbonate(VC)is selected as an additive to explore its effect on the electrochemical performance of ternary and lithium manganate composite cathode system batteries.The film-forming capacity of the additives is evaluated by using density functional theory,revealing that VC exhibits better film-forming property at the cathode,whereas VEC demonstrates better film-forming property at the anode site.The battery with mass fraction of 0.5%of VC has smaller AC internal resistance and DC internal resistance values,which are 25.0 mΩand 62.1 mΩ,respectively.This system exhibits a heightened Li+migration number.When charged-discharged in 3.00-4.20 V,the ratio of 3.00 C discharge capacity to 1.00 C charge capacity at room temperature of 25℃is 86.4%;the capacity residual rate after storage at high temperature of 60℃is 96.7%,the capacity recovery rate is 99.6%;the capacity retention rate after 650 cycles at 25℃and 1.00 C is 94%,the capacity retention rate after 500 cycles at 45℃and 1.00 C is 77%.

关 键 词：锂离子电池 复合正极 电解液 碳酸乙烯亚乙酯(VEC) 碳酸亚乙烯酯(VC) 三元材料 锰酸锂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]