Preparation And Application In Supercapacitor Of Ti₃C₂T_x Based Composite

Recently,the rapidly development of electronic skin,smart wearable devices and flexible electronic devices have been widely applied in the fields of medical health and sports.The exploitation of micro energy storage devices with light weight,flexibility,long life and high energy storage is the key to these equipment.How to design micro energy storage devices with high energy density,high flexibility and high stability has drawn the researchers'attention.The research on new electrode materials with high capacity and high flexibility has important scientific significance for the development of advanced micro energy storage devices.In this thesis,we choosed a typical MXene material?Ti₃C₂T_x?as the research object,and the controllable preparation,supercapacitor performance and planar microsupercapacitor?MSC?preparation of Ti₃C₂T_x based composites have been explored and investigated.The main contents are as follows:?1?ZIF-67 crystals were synthesized on Ti₃C₂T_x nanosheets by co-precipitation method.The size of the ZIF-67 crystal and its distribution on Ti₃C₂T_x were regulated by controlling the synthesis conditions.The effects of etching conditions on the morphology and structure of Ti₃C₂T_x/CoNi-LDH composites were investigated.In particular,the relationship between the different concentrations of metal salts?nickel nitrate hexahydrate?and morphology and distribution uniformity of CoNi-LDH on Ti₃C₂T_x nanosheets were investigated.When tested on supercapacitor,Ti₃C₂T_x/CoNi-LDH displays the high specific capacity(656.2 F g^-11 at 0.5 A g^-1),excellent cycle stability and good rate performance?with⁹7.7%retention of initial specific capacity after 9000 charge/discharge cycles?.The Ti₃C₂T_x/CoNi-LDH composites exhibit such excellent performance could be benefit from that the loading of CoNi-LDH increases the specific surface area of the material and provides an additional pseudo-capacitance,a strong interface between the CoNi-LDH and the highly conductive Ti₃C₂T_x.?2?A simple scratch method was developed to achieve the controllable preparation of Ti₃C₂T_x based flexible planar supercapacitors.The Ti₃C₂T_x based all-solid-state planar MSC exhibits a high area capacitance of 25.5 mF cm^-22 with good cycle stability and flexibility.On this basis,MSC with graphene?PANI/EG?composite film prepared by polyaniline?PANI?/electrochemically exfoliated method shows a high areal capacitance of 220.6 mF cm^-22 in 1 M H₂SO₄ electrolytes,which higher than that of most reported PANI-based MSCs.The device showed a good cycling stability with⁹0%retention of initial areal capacitance after 8000 charge/discharge cycles.