安全型电解液对锂离子电池性能的影响

Effect of security electrolyte to the performance of Li-ion battery

对比使用常规电解液1 mol/L LiPF_6/EC＋DMC＋EMC和添加磷酸三苯酯、甲基氟代丁基醚的安全型电解液的锂离子电池的性能。使用安全型和常规电解液的电池,直流内阻分别为90 mΩ、70 mΩ,以0.4 A在3.0~4.2 V充放电的首次库仑效率分为90.60%、89.96%。使用安全型电解液的电池,倍率放电性能较差,8.0 A放电容量与0.4 A时相比降低了42.5%;搁置120 d,容量保持率为85.89%;以0.50 C在3.0~4.2 V循环150次的容量衰减率约为11.1%。在4.2 V满电状态下的针刺实验结果表明：使用安全型电解液的电池,表面最高温度为109℃,且不燃烧、不起火、不爆炸;使用常规电解液的电池,表面温度高于350℃,并伴随有燃烧、起火,但不爆炸。

Performance of Li-ion battery using conventional electrolyte（ 1 mol / L LiPF_6/ EC ＋ DMC ＋ EMC） and safety electrolyte which added phosphoric acid three phenyl ester and methyl butyl fluoride was compared. The direct current impedance resistances of battery using conventional electrolyte and safety electrolyte were 90 mΩ and 70 mΩ,respectively,when charged-discharged in 3. 0 ~4. 2 V with 0. 4 A,the initial Columbic efficiencies were 90. 60% and 89. 96%,respectively. The battery using safety electrolyte had poor rate discharge performance,the 8. 0 A discharge capacity was reduced by 42. 5% compared with 0. 4 A,when stored for 120 d,the capacity retention was 85. 89%,the capacity fading was about 11. 1% when cycled 150 times with 0. 50 C in 3. 0 ~ 4. 2 V. The experiment result of acupuncture test by 4. 2 V full of electricity showed that the highest surface temperature of the battery using safety electrolyte was 109 ℃,no burning,no fire,no explosion; the highest surface temperature of the battery using conventional electrolyte was higher than 350 ℃,burning and fire appeared,but no explosion.