静电纺PMMA/EVOH-SO3Li锂离子电池隔膜复合材料的制备及性能

以聚甲基丙烯酸甲酯（PMMA）和聚乙烯-乙烯醇磺酸锂（EVOH-SO₃Li）为原料，通过高压静电纺丝法进行交替纺丝，制备PMMA/EVOH-SO₃Li锂离子电池隔膜复合材料。通过FTIR、SEM、万能拉伸试验仪、TGA、IM6型电化学工作站和电池循环测试设备对PMMA/EVOH-SO₃Li隔膜复合材料的性能进行检测表征。结果表明：PMMA/EVOH-SO₃Li隔膜复合材料具有清晰的三维网状结构，与EVOH-SO₃Li隔膜材料相比，改性后PMMA/EVOH-SO₃Li隔膜复合材料的孔隙率、吸液率和拉伸强度分别提高至80%、340%和3.18 MPa，起始热分解温度升高至294℃，热收缩率也有所降低，并表现出良好的电化学性能。其中电化学稳定窗口由5.0V增加到5.6 V，界面阻抗由420.69 Ω降低至262.31 Ω，离子电导率则由1.560×10^-3 S/cm提高至2.089×10^-3 S/cm，并且经过100次循环充放电后，容量保持率仍高达93.7%。

Preparation and properties of PMMA/EVOH-SO3Li Li-ion battery separator composite by electrospinning

Polymethylmethacrylate (PMMA)/lithium ethylene-vinyl alcohol copolymer sulfate (EVOH-SO₃Li) Li-ion battery separator composite was prepared by means of electrostatic spinning alternated, PMMA and EVOH-SO₃Li as raw materials. The performance of PMMA/EVOH-SO₃Li separator composite was characterized by FTIR, SEM, universal tensile tester, TGA, IM6 electrochemical workstation and battery cycler. The results show that PMMA/EVOH-SO₃Li separator composite has a clear three-dimensional network structure. Compared with EVOH-SO₃Li separator, the porosity, absorption rate and tensile strength of modified PMMA/EVOH-SO₃Li separator composite are increased to 80%, 340% and 3.18 MPa, respectively. The initial thermal decomposition temperature is also rised to 294℃. The thermal shrinkage rate is reduced. The excellent electrochemical performance is exhibited. The electrochemical stability window is increased from 5.0 V to 5.6 V. The interfacial impedance is reduced from 420.69 Ω to 262.31 Ω. The ionic conductivity is increased from 1.560×10^-3 S/cm to 2.089×10^-3 S/cm. The coulombic efficiency is 93.7% after 100 cycles of charge and discharge.