Preparation And Performance Study Of Ultra-electric/lithium Battery Diaphragm Based On Polyester Electrospun Membrane

Poly(ethylene terephthalate)(PET)is macromolecule that is a polycondensation of a polyol and a polybasic acid Widely used in synthetic fibers and engineering plastics.It has a large number of rigid benzene rings in its molecular chain and the molecular chain has a high degree of symmetry.Keratin extracted from animal hair is a biological material with renewable?green and non-polluting properties.Its surface contains a large number of polar groups,such as-NH2?-OH?etc,which can improve the affinity of the separator to the electrolyte.In this paper,Using PET polyester as the matrix and adding keratin to the polyester spinning solution,using electrospinning technology to make blended nanofiber membranes,afterwards modified separator to meet the requirements of the battery separator.Further improving its macro performance and electrochemical performance.Besides,a PVA/PET/PVA composite film was fabricated and its physical and chemical properties and electrochemical properties were preliminarily tested.1?Crosslinking modification of polyester/keratin blend film with glutaraldehyde and assembled into a supercapacitor for electrochemical performance testing.After cross-linking,the strength of the separator is increased and the liquid absorption rate is slightly lowered.The cross-linked blend membrane has a decomposition temperature of 387 ? and the cycle performance of the supercapacitor after cross-linking is increased to 9000 times compared to uncross-linking,which greatly increases the durability,the specific capacity retention after the cycle can reach 88.42%.Crosslinking membrane has a symmetric charge and discharge curve at each magnification.2?A composite film with a sandwich structure was fabricated by electrospinning PVA nanofibers on both sides of an electrospun film using PET as a matrix.It is assembled into a lithium-ion battery to test electrochemical performance.The composite membrane has a first charge capacity of 112 mAh/g at 0.2 C,which can reach 75.6%of the theoretical capacity of lithium manganate.Capacity decreased by 14%with cycling 100 times at 0.5C.The discharge capacity at 3C current density is 70.60%compared to the current density of 0.2 C,which is higher than 59.8%of the PP film.3?Modification of polyester keratin blend membrane with SiO2 greatly increases the thermal stability of the separator,no obvirous shrinkage at 200 ? for 30 min,ensuring safe operation of lithium-ion batteries at high temperatures.The strength is 2.37 times higher than that of the blend membrane.It has high affinity for organic electrolysis and the liquid absorption rate is as high as 525%.it meet the macro requirements for lithium ion battery separators.A button-type lithium ion battery was assembled for electrochemical testing and its ionic conductivity was 1.46 ms/cm.The first discharge capacity was 111.4 mAh/g and the Coulomb efficiency was 94.4%.The capacity at the 3C rate is 80.89%compared to the rate of 0.5 C,the rate performance is excellent.