Research On Nickel-based Flexible Energy Storage Devices With High Performance

With bloom of portable electronic products,ultra-thin,ultra-light as well as flexibility gradually become important indicators of the next generation of electronic products.Among them,how to solve the problem of high performance energy storage devices turns out as a major challenge to the above problems.The electrode of traditional energy storage devices is mainly prepared by slurry coating,which is difficult to realize the flexibility of the device due to its intrinsic structure.Current collectors holding active material could enhance the electron transfer of the electrode caused of binder-free.Meanwhile the electrode built on flexible current collectors could achieve the flexible electrode.These advantages make it possible to realize the high performance and flexibility of energy storage devices.Compared with carbon material current collectors,the metallic current collectors?Ni,Ag,Cu?,especially Ni current collectors have advantages over its hydrophilic property and high electron transfer efficiency and electrochemical stability.It has been widely studied and applied in various types of energy storage devices.Therefore,this thesis focuses on the study of the preparation of nickel based current collectors and its application in the energy storage devices.Cloth-like electronic devices are of great interest for the rapid development of wearable electronics.Herein we report a flexible and high-performance supercapacitor constructed on conductive cloth.In order to improve the electrochemical capacity,nickel nanocone arrays were electrodeposited onto a piece of conductive cloth?nickel plated polyester plain cloth?for the nickel current collector?NCC?.The NCC@MnO₂ and NCC@polypyrrole were prepared as binder-free electrodes via a facile electro-deposition process for both cathode and anode.The NCC contributes to enhance electron transport/collection and makes it easy to release stress generated in the charge-discharge cycles of the active materials.Due to the design of highly ordered array electrode architecture,our NCC electrodes display excellent capacitive performance with high gravimetric and areal capacitances,excellent rate capability and outstanding cycling stability.Furthermore,the as-obtained pseudo-supercapacitor shows unique mechanical property of flexibility due to the presence of conductive cloth.The present study provides an alternative strategy for the development of cost effective,flexible,and high-performance energy storage devices.Electrospinning,magnetron sputtering and electrochemical deposition are commonly used in industry.Based on the above methods,a new type of nickel nanotube membrane current collector was prepared.A new kind of flexible high performance aqueous Zn/MnO₂ rechargeable battery was prepared by electrodeposition of manganese dioxide on nickel nanotube membrane.Experimental results show that the Ni nanotube membrane structure has unique structure advantages and efficient electron transfer efficiency.The application of nickel nanotube membrane greatly improve the specific capacity of the MnO₂ cathode and energy density;Furthermore the performance on device level has also been improved.Sandwich packaging for aqueous Zn/MnO₂ rechargeable battery based on nickel nanotube membrane material has shown that the flexibility of the device.The flexible battery can work stably under the condition of bending 180 degrees.In addition,Ni nanotube films are access to industrial scalable production.We believe this preparation route of nickel nanotube membrane could make contribution to the large-scale production of flexible electrode in the energy storage devices for portable electronics.