Application Of Carbon Fiber Loaded Sn-Zn Bimetal Flexible Electrode Material In Supercapacitors

Energy is an important material foundation for the survival and development of human society.In order to meet the rapid growth of energy demand,the improvement of the performance of representative new energy devices such as supercapacitors has become an urgent problem in the energy storage field.The electrode material is the core component of supercapacitors,which has a major impact on the performance of supercapacitors,and is the key to research.Tin-based materials with high theoretical capacity and low cost are attractive candidates for efficient electrochemical energy storage systems,due to their unique physicochemical properties such as cyclic stability.In this paper,one-dimensional carbon nanofibers?CNFs?with good electrical conductivity are used as supporter,carbon fibers and tin salts are combined to form composites by electrospinning,high-temperature carbonization,and the electrochemical performance of composite electrode materials as pseudocapacitor electrode materials is explored.In addition,from the perspective of adjusting the composition of the composite material,the influence on the electrochemical performance was examined.The main content is divided into the following three parts:1. A series of Sn O_x/CNFs composite materials were prepared by using electrospinning and high-temperature carbonization technologies.By changing the carbonization temperature and conditions,tin-based carbon nanofiber composite electrode materials?Sn/CNFs,Sn O/Sn O₂/CNFs,Sn O₂/CNFs?systematically investigated the influence of Sn valence state on the performance of supercapacitors.Electrochemical tests show that the Sn/CNFs composite has the best electrochemical performance.The specific capacitance value is 761 F g^-1at a current density of 0.5 A g^-1,and the retention rate was 114%after10,000 cycles at 5 A g^-1.2. Due to the synergistic effect of bimetals,the electrochemical performance of supercapacitors can be further improved.Therefore,based on the previous step,a series of porous carbon nanofiber tin-zinc bimetal?Sn O_x-Zn O/MCNFs?composite electrode materials were prepared by introducing Zn salt and polystyrene?PS?porogen,and applied to supercapacitors.The electrochemical performance tests show that the electrochemical performance of the composites is optimal when the impregnated Zn?CH₃COOH?₂is 10mmol L^-1,and the specific capacitance value is 783 F g^-1at a current density of 0.5 A g^-1,and the retention rate was 87%after 5,000 cycles at 5 A g^-1.3. On the basis of the above experiments,by modifying the cyano functional group on the surface of PAN,the amidoxime functional group is formed.The introduction of amidoxime group not only increases the coordination ability of the composite to Zn²⁺,but also increases the content and type of nitrogen,and improves the wettability of the composite electrode material.By changing the calcination temperature and conditions,four different ratios of nitrogen were obtained,and the effects of different types of nitrogen on the electrochemical performance of the composites were explored.The experimental results show that pyridine nitrogen and pyrrole nitrogen are considered to be electrochemically active in alkaline aqueous solutions and provide additional rubidium capacitance;the presence of quaternary ammonium salt nitrogen and pyrrole nitrogen oxide effectively promotes electron transport and improves the conductivity of carbonaceous materials active surface.The composite material has a specific capacitance value of 810 F g^-1at a current density of 0.5 A g^-1;and the retention rate was 119%after5,000 cycles at 5 A g^-1.