导电剂对锂离子电池正极性能的影响

Effect of conductive agent on performance of positive electrode for Li-ion battery

将科琴黑（KB）、碳纳米管（CNT）、导电石墨KS-6等3种导电剂分别与导电炭黑SP混合,组成锂离子电池用双组分导电剂。以KB＋SP、CNT＋SP和KS-6＋SP为导电剂的电池以1.0 C在3.0~4.2 V循环400次,容量保持率分别为94.15%、93.07%和92.30%;以KB＋SP作为导电剂的电池,内阻最低（28.2 mΩ）,化成容量最高（1 756.8 m Ah）,-40℃低温下以0.5 C放电到2.5 V时,输出容量为1.31 Ah,达到常温容量的80%以上;以5.0 C高倍率放电（3.0~4.2 V）时,电压平台最高（3.32 V）,输出容量最大（1 458.3 m Ah）。

Three kinds of conductive agent,such as Ketjen Black（KB）,carbon nanotube（CNT） and conductive graphite KS-6 were mixed with conductive carbon black SP to compose two-component conductive agent for Li-ion battery,respectively. The battery using KB ＋ SP,CNT ＋ SP and KS-6 ＋ SP as conductive agent were cycled 400 times with 1. 0 C in 3. 0 ~ 4. 2 V,the capacity retention rate was 94. 15%,93. 07% and 92. 30%,respectively. The battery using KB ＋ SP conductive agent had the lowest internal resistance（28. 2 mΩ）,the highest formation capacity（1 756. 8 m Ah）. When discharged to 2. 5 V with 0. 5 C at- 40 ℃,its output capacity was 1. 31 Ah,which exceeded 80% of that at room temperature. When discharged with high rate 5. 0 C（3. 0 ~ 4. 2V）,it had the highest working voltage platform（3. 32 V） and the highest output capacity（1 458. 3 m Ah）.