氢氧化钠/尿素体系中纤维素改性制备锂离子电池隔膜的研究

Study on the Preparation of Lithium Ion Battery Membrane by Modified Cellulose in NaOH/Urea System

采用无纺布作为支撑底材,利用Na OH/尿素水溶液初步制备了无纺布基改性纤维素锂电池隔膜,对隔膜的机械性能、热稳定性能进行分析和优化,进一步添加聚乙烯吡咯烷酮(PVP K-30)调控隔膜微孔结构来改善膜的性能,讨论了PVP的致孔作用对膜的机械强度、吸液率、纯水通量及孔结构的影响,并对隔膜进行SEM、XRD表征分析。研究结果表明:当纤维素含量为4%时,隔膜的变形率最高(27.55%),并且纤维素隔膜具有较高的机械强度、吸液率和热稳定性。PVP的添加量为3%时,吸液率达到最大值,隔膜的整体性能最佳,机械强度达到40.15MPa,吸液率为239%,纯水通量为122.4 L·m-2·h-1,吸液率和纯水通量比未添加时分别提高了40%和72.6 L·m-2·h-1。

Using non -woven fabric as base, modified cellulose lithium battery membrane was prepared by using aqueous solution of NaOH/urea as the casting solvent. The mechanical properties and thermal stability of the dia- phragm is analyzed and optimized. Adding polyvinylpyrrolidone （PVP K30） to control the microporous structure and improve the performance of the membrane. The effects of PVP pore formation on the tensile strength of membrane , electrolyte uptake, pure water flux and the influence of pore structure were discussed. The membrane was respectively characterized by scanning electron microscopy （SEM） and X- ray diffraction （XRD）. The results showed that when the concentration of fiber was 4%, the strain rate of the highest （27.55%）, and cellulose mem- brane has high tensile strength, electrolyte uptake and thermal stability. When the concentration of PVP was 3%, the electrolyte uptake of the membrane is up to its maximum and the membrane owns the best integrity. Under those conditions, the tensile strength is 40. 15 MPa, the electrolyte uptake and pure water flux can reach 239% and 122.4L·m^-2·h^-1 ,increased 40% and 72. 6 L·m^-2·h^-1 ,respectively.