## 1 Introduction
The electrostatic spinning method is not efficient enough for mass production, while the fibers spun by centrifugal spinning have good orientation, a uniform diameter distribution, and the advantages of no voltage, a high yield, a simple structure, no pollution, and low production costs [14; 15]; therefore, providing a good alternative to electrostatic spinning. [PERSON] et al. [16] prepared polymethyl methacrylate/polyacrylamideonitrile (PMMA/PAN) films with different blending ratios by centrifugal spinning, which possessed a high porosity and wicking rate. For PMMA/PAN (50/50) membranes, the porosity and wicking rate are 73% and 370%, respectively. [PERSON] et al. [17] prepared poly(vinylidene fluoride) (PVDF)/polyacrylamideonitrile (PAN) blended nanofiber diaphragms by centrifugal spinning, and the cells possessed excellent cycling stability and multiplicative performance, but their diaphragms still had problems, such as poor electrochemical stability, and therefore the preparation of lithium-ion battery diaphragms by a centrifugal spinning method still needs to be improved. The development of high-performance composite diaphragms for lithium-ion batteries is being actively studied. [PERSON] et al. [18] prepared oxide aluminum-coated films by a physico-chemical wet dipping method using aluminum oxide nanoparticles with a poly(vinylidene fluoride-hexafluoropropylene) trilayer polymer. The electrolyte affinity of the diaphragm, the absorption rate, and the thermal dimensional stability of the diaphragm were significantly improved. [PERSON] et al. [19] coated both sides of a PE diaphragm with aminated silica particles by immersion to give a higher ionic conductivity with better wettability and cycling stability than the conventional PE diaphragm. [PERSON] et al. [20] used the non-solvent induced phase separation (NIPS) technique to prepare polyvinylidene fluoride (PVDF)/vermiculite nanosheet (VNs) lithium battery (LIB) diaphragms. When the VNs content reached 7.0 wt%, the ionic conductivity of the separator increased from 0.300 mS/cm to 1.679 mS/cm, and the PVDF/VNs composite films exhibited better performance due to their suitable pore structure and uniformly distributed VNs fillers, and the cells using PVDF/VNs The cells using PVDF/VNs spacer films exhibit excellent cycling stability, better multiplicative performance, and wider electrochemical window. [PERSON] et al. [21] successfully fabricated a new type of Poly (vinylidene fluoride-co-hexafluoropropylene)/polyimide (PVDF-HFP/PI) diaphragm for lithium-ion batteries, which combined the excellent properties of PVDF-HFP and PI, while maintaining a high porosity and thermal dimensional stability, and its porosity was 85.9%. [PERSON] et al. [22] prepared a Poly(vinylidene fluoride)/polyacrylonitrile (PVDF/PAN) co-blended porous membrane by thermally induced phase separation (TIPS), which had an improved electrolyte uptake and ionic conductivity. [PERSON] et al. [23] successfully prepared polyacrylamide/Polyvinylalcohol/malonic acid (PAN/PVA/MA) lithium-ion battery diaphragms. Due to the excellent hydrophilic properties of PVA, the thermal shrinkage, wettability, and ionic conductivity of the diaphragms were significantly improved, and with a wide chemical stability window of 5.2 V. A polyacrylamide/styrene-isoprene-styrene (SIS) composite fiber membrane was prepared by [PERSON] et al. [24] The battery assembled by this composite diaphragm had a good charge and discharge performance, the initial discharge capacity of the cell assembled with this composite fiber film was 146.4 mAh/g at 0.2 C rate. From the above study, it was found that the composite diaphragm had the advantages of good heat resistance and high safety, but due to the increase in the thickness of the diaphragm, the internal resistance of the battery increased, and the diaphragm production cost also increased accordingly. Polyacrylonitrile (PAN) is a popular material for lithium-ion battery diaphragms with strong polar organic groups (-CN) on its side chains.