Carbon-based Composite Nano-electrode Materials Are Prepared Based On The Electrospinning Method And Applied To Supercapacitors

The reduction of non-renewable energy sources and the increasing environmental problems require the development of clean,efficient and sustainable new energy materials and devices.As a new type of energy storage devices,supercapacitors have attracted great attention,due to the advantages such as fast charge and discharge speed,large power density,long cycle life,low cost,and environmental protection.The performance of supercapacitors is affected by many factors,among which the choice of electrode materials is crucial.One-dimensional nanostructures as electrodes can increase the contact area with the electrolyte,shorten the transport pathways of ions and electrons,and thereby increase the capacitance of the electrode.Electrospinning is a simple,fast and efficient method for preparing continuous and uniform one-dimensional nanomaterials?controllable size,large specific surface area,high porosity,and good flexibility?,which makes it widely used in energy,wearable equipment,filtration and other fields.In addition to the inherent advantages of carbon materials,electrospun carbon nanofibers?CNFs?have a controllable pore structure and strong processability,and are easily compounded with other materials,so they are considered to be good conductive substrates.Multi-component composite fibers obtained by modifying and designing carbon nanofibers can be well controlled in the chemical composition and morphology in order to prepare high-performance supercapacitor electrode materials.?1?Activated porous carbon nanofibers/tin dioxide?APCNFs/SnO₂?composite electrode materials.First,CNFs/Cu O_x composites were prepared by electrospinning and high-temperature calcination technology;then,activated porous CNFs?APCNFs?were obtained by nitric acid treatment;finally,SnO₂ nanoparticles were evenly deposited on the surface of APCNFs at room temperature,resulting in the formation of a flexible APCNFs/SnO₂composite membrane.Compared with pure CNFs and activated CNFs/Sn O₂ electrodes,APCNFs/SnO₂ single electrodes with a certain mass of SnO₂ showed larger specific capacitance and higher rate capacity.Moreover,the assembled quasi-solid-state symmetrical supercapacitor possessed good flexibility and excellent electrochemical performance.The maximum energy density was 10.3 Wh kg^-1 at a power density of 325 W kg^-1.After 2500 charge/discharge cycles,the device exhibited no capacitance loss,which indicated the great potential in practical applications.?2?Hierarchical C/NiCoO_x/MnO₂ nanotube electrode materials.Hierarchical C/NiCoO_x/MnO₂ fiber-in-tube?CNCM-FiT?and particle-in-tube?CNCM-PiT?nanostructures have been designed and constructed with the electrospun C/NiCoO_x nanofibers as self-templates through redox reactions and controlled pyrolysis process.These hollow nanofibers with complex architectures as electrode materials delivered excellent electrochemical performance.Furthermore,when used as the positive electrodes,the assembled asymmetric button-type devices gave rise to high capacity,energy density and good cycle stability.This work not only provides a simple method for the controllable preparation of multi-component hollow composite materials,but also offers more feasible ways to improve the performance of supercapacitors.