EVOH-SO3Li/P(VDF-HFP)/HAP锂离子电池隔膜的制备及电化学性能EI北大核心CSCD

以聚偏氟乙烯-六氟丙烯(P(VDF-HFP))、纳米羟基磷灰石(HAP)和聚乙烯-乙烯醇共聚物的磺化物(EVOH-SO3Li)为原料进行高压共混静电纺丝,制备出EVOH-SO3Li/P(VDF-HFP)/HAP锂离子电池隔膜。利用FTIR,SEM,电化学工作站和电池检测系统对隔膜进行测试分析。结果表明:EVOH-SO3Li隔膜为粗细均匀的三维网络结构,加入P(VDF-HFP)和HAP后,EVOH-SO3Li/P(VDF-HFP)/HAP复合隔膜呈现出树枝形状的三维网状结构,提高了隔膜的孔隙率和吸液率,与纯EVOH-SO3Li隔膜相比,分别提高了37.5%和91.6%。同时表现出良好的电化学性能,组装的锂离子电池的电化学稳定窗口为5.65V,界面阻抗降至184.24Ω,离子电导率则提高至2.686×10^-3 S·cm^-1;在0.5 C放电电流下循环100次后容量保持率为96.69%,与EVOH-SO3Li隔膜相比各项性能均有所提高。

Preparation and electrochemical propertiesof EVOH-SO 3Li/poly(vinylidene fluoride-hexafluoropropylene)/hydroxyapatitelithium-ion battery separator

EVOH-SO3Li/P(VDF-HFP)/HAP lithium ion battery separator was prepared by high-pressure blending electrospinning using polyethylene-vinyl alcohol sulfonate(EVOH-SO3Li),poly(vinylidene fluoride-hexafluoropropylene)(P(VDF-HFP))and nano hydroxyapatite(HAP)as raw materials.The performance of the separator was characterized by FTIR,SEM,electrochemical workstation and battery detection system.The results show that the EVOH-SO3Li/P(VDF-HFP)composite separator forms an uniform and dense three-dimensional network structure,and the EVOH-SO3Li/P(VDF-HFP)/HAP composite separator presents a three-dimensional network of dendritic shapes after adding P(VDF-HFP)and HAP,which improves the porosity and liquid absorption rate of the separator.Compared with the pure EVOH-SO3Li separator,the porosity and liquid absorption rate of the EVOH-SO3Li/P(VDF-HFP)/HAP composite separator are increased by 37.5%and 91.6%,respectively.Meanwhile,the excellent electrochemical performance is also exhibited.The electrochemical stability window of the assembled lithium-ion battery is 5.65 V,and the interfacial impedance is decreased to 184.24Ω,and the ionic conductivity is increased to 2.686×10^-3 S·cm^-1;Lithium-ion batteries assembled with EVOH-SO3Li/P(VDF-HFP)/HAP composite separator have a capacity retention rate of 96.69%after 100 cycles at 0.5 C discharge current,the properties of EVOH-SO3Li/P(VDF-HFP)/HAP composite separator are improved compared with EVOH-SO3Li.