Preparation And Application Of Multi-level Adjustable Micro-nano Array Modified Flexible Nickel Cathod

With the rapid development of intelligent wearable technology,flexible energy storage devices have attracted extensive attention in the application of intelligent wearable.Nickel zinc battery,which has the advantages of high energy density,high power density,wide source of raw materials,safety,environmental protection and low price,has become the best choice for flexible energy storage devices.In recent years,in order to better match the capacity of positive and negative electrodes of nickel zinc batteries and solve the problems of poor conductivity and cycle stability of nickel positive materials,it is urgent to develop a flexible nickel positive electrode with high capacity,high energy density and high cycle durability.Compared with planar electrode,the linear design of electrode is easier to adapt to complex deformation,such as bending,torsion and extrusion,so it is more suitable for flexible devices.How to realize the controllable preparation of high load active materials on the fiber fluid collection,meanwhile solve the reaction kinetics of active materials,achieve high electrochemical performance and maintain ultra-high cycle stability,has always been the focus of the research of yarn energy storage devices.In this paper,SCNF@Ni@MOF@Ni Co LDHs electrode was prepared by electroplating,aqueous phase and chemical synthesis.The electrode is composed of silver coated Nylon Fibers（SCNF）as the core,nickel（Ni）as the intermediate layer.The hierarchical structure of micron"triangular"and nano"corrugated"nickel cobalt double hydroxide was prepared on the Ni layer.The electrochemical properties of nickel anode of yarn can be greatly changed by adjusting the morphology of Ni interlayer,MOF and Ni Co LDHs.When the Ni plating time is 1200s,not only can improve the electrode conductivity,but also conducive to the attachment of active substances,greatly improve the electrochemical performance and mechanical properties of the yarn nickel electrode.The electrode has a large capacity of 290 m Ah g^-1 and excellent cycling performance（75%after cycling for 400times）.Furthermore,by adjusting the morphology of MOF and Ni Co LDHs,the performance of yarn nickel electrode can be greatly improved.Length specific capacity reaches 23.1μAh cm^-1(equivalent to 352 m Ah g^-1),and has good cycle stability（60%after cycling for 1000 times）.The maximum energy density and power density of the aqueous nickel-zinc battery can reach 572.52 m Wh g^-1and 62.81 W g^-1 respectively.The maximum energy density and power density of the solid nickel-zinc battery can reach381.68 m Wh g^-1and119.08 W g^-1 respectively.Subsequently,we also proposed the design and application of one-dimensional flexible nickel-zinc battery.The charging and discharging performance of the battery does not decrease much under bending,twisting and extruding conditions,and it can supply energy for various electronic devices.