Preparation And Properties Of Supercapacitor Paper-based Separator

Supercapacitor is a new type of green energy storage equipment with high power density,high charge and discharge efficiency,long cycle life and wide working temperature range.As a key component of supercapacitors,the main function of the separator is to isolate the positive and negative electrodes,and to conduct electrons as a channel for ion transport during charge and discharge.In this paper,a supercapacitor paper-based separator is prepared by using the fiber having a sheath-core structure as a main raw material.By researching the effects of low concentration,high consistency refining method and beating degree on the preparation of microfibers,it was found that the beating action promoted the improvement of the mechanical strength of the paper-based separator,and the low-concentration beating could score.The fine fiber slurry with better silking effect,but the fine fiber curling deformation is serious,the fiber splitting effect after high-concentration refining treatment is good,no obvious curling phenomenon,and the strength property of the prepared paper separator is also greatly improved.Based on the comprehensive comparison,the fiber A microfibers with a high degree of refining and a beating degree of 85°SR were selected as the main raw materials for the preparation of supercapacitor paper separators.The raw materials of the fiber microfibers were compared by comparing the Elongthesia fiber,the bamboo pulp fiber,the hemp fiber and the para-aramid chopped fiber having a higher aspect ratio.The experimental comparison found that the fiber microfibers and the Elongthesia fiber with a beating degree of 40°SR can effectively improve the tensile strength(0.67 kN/m)and porosity(69%)of the paper separator.The introduction of MFC fiber,by comparing the different ways of MFC,found that the paper separator prepared by the modified Eulaliopsis fiber @ MFC composite and fiber microfiber can effectively control the pore structure,optimize the pore distribution and reduce the average pore size.When a 6%(mass fraction)MFC paper separator sample was added,the tensile strength before and after the modification of Eulaliopsis binata increased by 11.7% to 0.76 kN/m,and the average pore diameter decreased by 16.7% to 0.60 ?m.The tensile strength of the paper separator produced by the modified.sinensis fiber @ MFC composite and the fiber microfibers was also increased by 10.1% compared to the paper separator which the coated MFC fiber.By studying the influence of paper separator thickness and pore structure on the electrochemical performance of supercapacitor,it is found that the equivalent series internal resistance of supercapacitor increases with the increase of the thickness of paper separator.The porosity,pore size and distribution of the paper separator have a significant effect on the electrical performance of the supercapacitor.When the diaphragm thickness is the same,as the porosity of the diaphragm decreases,the internal resistance of the supercapacitor increases significantly,and the energy density and power density decrease significantly.