添加剂联用改善4.5V锂离子电池的循环性能

Enhancing cycle performance of 4.5 V Li-ion battery by combination of electrolyte additives

将电解液添加剂甲烷二磺酸亚甲酯（MMDS）和三（三甲基硅烷）硼酸酯（TMSB）联用,改善4.5 V石墨/Li Ni1/3Co1/3Mn1/3O2锂离子电池的循环性能。用电化学阻抗谱测试阻抗特性,透射电子显微镜和X射线光电子谱对电极表面进行分析。单独添加1.0%MMDS或1.0%TMSB的电池,以1.00 C在3.0~4.5 V循环200次的容量保持率分别为59.5%和10.9%;0.5%MMDS与0.5%TMSB联用,容量保持率提高至90.6%,原因是电极表面形成了更好的界面膜,抑制阻抗的增加。

The combination effects of functional electrolyte additives, including methylene methanedisulfonate （ MMDS ） and tris （trimethylsilyl） borate （ TMSB ）, on the cycle performance of 4. 5 V graphite/LiNil/3 Col/3 Mnl/3 02 Li-ion battery was investigated. The impedance behaviors of the battery were measured by electrochemical impedance spectroscopy. The morphology, compositions of the LiNil/3Col/3Mnl/3 02 cathode and graphite anode interface film were measured by transmission electron microscopy and X-ray photoelectron spectroscopy. The combination of 0. 5% MMDS and 0. 5% TMSB in electrolyte additive improved the capacity retention form 59. 5% or 10. 9% to 90. 6% by 200 cycles in 3.0 -4. 5 V compared to the addition of 1.0% MMDS or 1.0% TMSB into the electrolyte. The combination of MMDS and TMSB facilitated the formation of better interface film on both LiNi1/3C%/3Mnl/3 02 and graphite electrode,suppress impedance growth,thus improving the cycle performance.