Research On Manganese Dioxide-Based Micro-Energy Storage Devices With High Performance

With the rapid development of electronic information technology,the consumer electronics market represented by portable and wearable electronic devices is growing,and flexible,integrable and miniaturized energy storage devices has become the research focus of researchers.Despite the fact that many on-chip microsupercapacitors?MSCs?and microbatteries?MBs?have been reported,the development of high performance active electrode materials and advanced micro-device manufacturing technology are urgently needed.The micro-energy storage devices still have a better choice in electrode material,electrolyte and preparation technology.Relying on the merits of abundant reserves,security,non-toxic,environmentally friendly,high theoretical specific capacity,manganese dioxide?MnO₂?as the electrode material has been researched for a long time.High conductivity active materials and metal current collector can be introduced to improve the conductivity of manganese dioxide.In this thesis,manganese dioxide-based micro-energy storage devices with high performance were researched.The composite?rGO/MnO_x?prepared by a solution based redox reaction and hydrazine vapor reduction method has a large specific surface and highly porous network structure.And it reveals excellent capacity and ultrahigh cycle life,with 106%capacitance retention after 115000 charge/discharge cycles.MnO₂ with a nanofiber structure was grown on the nickel nanocone arrays?NCAs?current collector by electrochemical deposition technology.Based on this unique framework,MnO₂ can display excellent electrochemical properties.The highest volumetric capacitance of the electrode can reach 28.3 mAh cm^-3 at 0.03 A cm^-3,and81.5%of the initial capacity can be preserved after 1000 charge/discharge cycles.Based on the rGO/MnO_x composite electrode,flexible and tailorable MnO₂ based MSCs could be prepared by slurry dispensing technique,stencil printing technique and hot pressing technology.The device system has a good flexibility,with the function of tailorability.The surface mountable and integratable MnO₂ based MSCs could be prepared by hole drilling,electroplating,and etching technique,on the epoxy glass fibre board.This preparation technology is fully compatible with industrial integration manufacturing,which can be integrated directly into printed circuit board.Based on the MnO₂@NCA composite structure,flexible and integratable Zn//MnO₂ MBs could be prepared by laser etching technology,electrochemical deposition technology and stencil printing technique,with the characteristics of ultrathin,lightweight,miniaturization and security.Moreover,it can be used with radio frequency identification tags.Based on the three kinds of preparation techniques of micro-energy storage devices,the as-obtained device systems can not only display an excellent electrochemical performance,but effectively avoid the leakage and short circuit,with a great application potential in portable and wearable electronic devices and Internet of Things?IoT?.