Study On The Preparation Of High-Performance One-Dimensional Anode Materials For Flexible Lithium-Ion Batteries By Electro-Blown Spinning

In recent years,with the rapid development of flexible electronic devices,flexible lithium-ion batteries have entered people’s field of vision,and anode materials that play an important role in flexible lithium-ion batteries have become a hot spot in the field of energy storage research.For the requirements of high cycle performance,stable rate performance and low manufacturing cost of flexible lithium ion battery anode materials,the preparation method is simple and easy to operate,this paper uses self-built gas-electricity spinning equipment to efficiently prepare lithium ion battery anode materials with Flexible nitrogendoped/silicon porous carbon nanofiber cloth.The thesis systematically studied the effect of ammonia activation time,the amount of polymethyl methacrylate(PMMA)and the amount of melamine and nano-silicon on the electrochemical performance of carbon nanofibers,and determined the optimal ratio and process parameter.In this paper,polyacrylonitrile(PAN)is used as the carbon source,and the fiber cloth is obtained by the electro-blown Spinning technology,and then pre-oxidized and carbonized to study the effect of different ammonia activation time on carbon fiber.Experimental studies show that the carbon fiber exhibits the best electrochemical performance and flexibility when the ammonia activation time is 30 minutes.Before studying the amount of nitrogen doped,a certain amount of polyacrylonitrile was used as a carbon source,and then a certain amount of graphene and melamine were added to study the effect of different PMMA additions on battery performance.When the amount is 100% of the PAN mass,the electrochemical performance of the material is optimal.After determining the optimal ammonia activation time and the amount of PMMA added,the amount of melamine was studied.The results showed that when the amount of melamine was 100% of the PAN mass,the flexible nitrogen-doped porous carbon fiber lithium ion battery negative electrode material The reversible capacity is 1108.9 m Ah/g,which can be maintained at 954.3 m Ah/g after 100 cycles.The cycle and rate performance exhibited is the best among all nitrogen doping ratios.In order to make the reversible capacity of carbon fiber higher,this article chooses nanosilicon material as a substitute for melamine.The theoretical capacity of the silicon material is 4200 m Ah/g,which is the highest capacity among the negative electrode materials,but the volume expansion of 300% limits the application of the silicon material.Therefore,it is the key to provide prefabricated expansion space for silicon material.From the flexible nitrogen-doped porous carbon fiber,it can be seen that there are a large number of micropores and mesopores in the fiber,which effectively provides prefabricated expansion space for silicon material.Before investigating the amount of silicon doped,a certain amount of polyacrylonitrile was used as a carbon source,and then a certain amount of graphene and nano-silicon was added to study the effect of different PMMA additions on battery performance.The results showed that when PMMA When the added amount is 150% of the mass of PAN,the electrochemical performance of the material is optimal.After determining the optimal amount of PMMA,the amount of nano-silicon was studied.The results show that when the amount of nano-silicon is 10% of the mass of PAN,the negative electrode material of flexible silicon-doped porous carbon fiber lithium ion battery shows 1737.2 m Ah The ultra-high reversible capacity of g for the first time can be maintained at 985.3 m Ah/g after 100 cycles.The cycle and rate performance exhibited is the best among all silicondoped ratios.But the cycle stability is not as good as the negative electrode material of flexible nitrogen-doped porous carbon fiber lithium ion battery.