CAJ | 학술논문

分别以 LiPF6、LiBOB 和 LiPF6/LiBOB 混合盐为电解质,研究了不同电解液对 LiFePO4/石墨动力电池高温循环性能的影响。结果表明,LiBOB 盐抑制了正极溶铁行为,并提高了正极高温循环充放电效率；由于 LiBOB基电解液对正极的保护及在负极表面良好的成膜作用,使得LiFePO4/石墨电池高温循环性能得到明显改善,但是增大了电池阻抗。LiPF6/Li-BOB混合盐可以发挥 LiBOB盐的优点增加正极稳定性,在石墨表面形成致密的 SEI 膜并能够有效改善电池高温循环性能,同时避免了单纯使用 LiBOB盐时阻抗较高的缺点。使用 LiPF6/LiBOB 混合盐,利用LiPF6盐低阻抗特性及 LiBOB盐对正、负电极的保护作用,可以有效提高电池电化学性能。
분별이 LiPF6、LiBOB 화 LiPF6/LiBOB 혼합염위전해질,연구료불동전해액대 LiFePO4/석묵동력전지고온순배성능적영향。결과표명,LiBOB 염억제료정겁용철행위,병제고료정겁고온순배충방전효솔；유우 LiBOB기전해액대정겁적보호급재부겁표면량호적성막작용,사득LiFePO4/석묵전지고온순배성능득도명현개선,단시증대료전지조항。LiPF6/Li-BOB혼합염가이발휘 LiBOB염적우점증가정겁은정성,재석묵표면형성치밀적 SEI 막병능구유효개선전지고온순배성능,동시피면료단순사용 LiBOB염시조항교고적결점。사용 LiPF6/LiBOB 혼합염,이용LiPF6염저조항특성급 LiBOB염대정、부전겁적보호작용,가이유효제고전지전화학성능。
LiPF6 ,LiBOB and LiPF6/LiBOB blend salt-based electrolytes were investigated for improving cycling performances of LiFePO4/graphite lithium-ion batteries at elevated temperature.It was demonstrated that dis-solution of Fe from LiFePO4 was depressed in LiBOB based electrolyte,and columbic efficiency of LiFePO4/Li cell at elevated temperature was increased;LiBOB was reduced earlier on anode surface,forming compact SEI layer;and the capacity retention of LiFePO4/graphite cells at 55℃ increases with LiBOB concentration due to protective depositions of LiBOB on cathode surface and the SEI layer on anode surface,while the impedance of the cell is increased.LiPF6/LiBOB blend salt-based electrolyte combines the advantages of the different salts and maximizes the performance of cells.When electrolytes with LiPF6/LiBOB blend salt was used,the LiFe-PO4/graphite cells have excellent capacity retention at 55℃,while the impedance was dramatically decreased.