The Construction Of Anode Materials For Lithium And Sodium Ion Batteries Based On Electrospinning And Their Electrochemical Performance

With the rapid development of science and technology,and continuous consumption of non-renewable fossil energy,the human society is suffering from serious energy problem,pushing people to develop low cost,environment-friendly,and renewable energy,such as wind power,solar energy,tidal energy and nuclear energy,etc.However,the intermittent nature of new energy also increases the requirement for various energy storage equipment.Lithium-ion batteries?LIBs?have great application potential in portable electronic devices,electric vehicles,medical research,and aerospace,owing to high energy density,high operation voltage,and environment-friendly,but the limited lithium source impede its future large-scale application.Rechargeable sodium-ion batteries?SIBs?have recently attracted great interest for large-scale energy storage in renewable energy and smart grid applications,owing to the favorable energy density,natural abundance,and low cost.For LIBs and SIBs,exploring the anode materials with high energy density,safety,low-cost and flexible structure is the key step toward meeting the growing requirements for next-generation energy storage device.Electrospinning is a facile and controllable method to prepare one-dimensional?1D?nanomaterials,and the nanomaterials with large specific area can enlarge the contact area with electrolyte and shorting the diffusing paths for ion/electron.Through electrospinning technology,our study is focused on enhancing the electrochemical performance of anode materials for LIBs and SIBs.The main content of the study are as follows:?1?Preparation of 1D In_1-xZn_xO_y heterogeneous nanofibers as anode materials for LIBs.The 1D In_1-xZn_xO_y heterogeneous nanofibers were synthesized by electrospinning method and calcination.The influence of Zn contents on In₂O₃ microstructure and electrochemical performances has been systematically investigated.As a result,pure In₂O₃ possess cubic bixbyite-type?c-In₂O₃?,while the phase transition from c-In₂O₃ to rhombohedral?or hexagonal?corundunm-type In₂O₃?rh-In₂O₃?can be realized through simply introduction of Zn²⁺.Furthermore,the phase compositions can be controllably tuned with the changing of Zn²⁺content.In_1-xZn_xO_y nanofibers with mixed phase of c-In₂O₃ and rh-In₂O₃ present outstanding electrochemical performance.Impressively,the optimal In_0.5Zn_0.5O_1.25 NFs electrodes exhibit a high specific capacity of 704 mA h g^-1 after 200 cycles at a current density of 100 mA g^-1,and superior reversible capacity of 440 mA h g^-11 and 358 mA h g^-1can be still retained at 1 A g^-1 and 2 A g^-1 upon 800 cycles,respectively,demonstrating the ultralong cyclic stability.?2?Fabrication of three-dimensional?3D?hierarchical Sn/NS-CNFs@rGO flexible anodes for sodium-ion batteries.Using a facile electrospinning technique followed by filtration and calcination treatment.1D Sn/NS-CNFs as building blocks were wrapped by graphene oxide?GO?on the surfaces,which can prepare 3D flexible and free-standing Sn/NS-CNFs@rGO network.This 3D network can be directly used as binder-and current-free anode for sodium-ion batteries.As a result,based on the optimized structure and synergistic effects between the individual component,the 3D flexible Sn/NS-CNFs@rGO electrodes exhibit excellent electrochemical performance,including ultralong cycling life(373 mA h g^-1 after 5000 cycles at 1 A g^-1),and excellent high-rate capability(189 mA h g^-1 at 10 A g^-1).