Fabrication Of Flexible Electrode Based On Carbonized Cotton Textile And Its Research In Electrochemical Performance

With the development of science and technology,people's demand for portable electronic devices has gradually increased,such as:electronic devices implanted in the human body,display screens that can be repeatedly bent.Therefore,the development and research of lightweight and high-performance flexible energy storage devices has become a hot spot in current research.Flexible supercapacitors,with fast charge and discharge rates,high power density values,and long cycle life,are considered to be one of the potential energy storage devices.Among them,the synthesis and preparation of flexible substrates is undoubtedly very important.Carbonized cotton fabric?CCT?consists of micron-sized hollow carbon fiber and also exhibits excellent hydrophilicity with electrical conductivity.All these advantages make CCT a promising substrate.In this paper,a flexible electrode?CCT-0.5PPY₄?of carbonized cotton fabric and polypyrrole,a composite flexible electrode of carbonized cotton fabric and manganese dioxide?MCCT-5?with excellent electrochemical performance and good mechanical properties were prepared by an easy-to-operate and low-cost method.The flexible electrode CCT-0.5PPY₄ was prepared by a simple low temperature polymerization method based on carbonized cotton textile in an ice bath,which greatly improved the cycle performance of PPY.The electrode prepared by the experimental optimization showed good electrical conductivity,which was 625.28 S m^-1 by the four-probe test;it has high mechanical ductility and tensile strength of0.56 MPa,together with excellent hydrophilicity and excellent electrochemical performance.With the composite as the working electrode,the areal capacitance is1245 mF cm^-2 at a current density of 1 mA cm^-2 in a three-electrode system,and the cycle performance loss rate of 3,000 cycles is only 8.8%.After assembled into a symmetrical device,the capacitance is 520.34 mF cm^-2 at a current density of 1 mA cm^-2,and the high areal capacitance of 154.62 mF cm^-22 is maintained at a current density of 50 mA cm^-2.In addition,the device has a maximum power density of25.18 mW cm^-2 and a maximum energy density of 0.074 mWh cm^-2.A CCT-based MnO₂ composite?MCCT?flexible electrode was prepared by a simple low temperature in situ hydrothermal method.For manganese dioxide composites,the voltage window is typically limited to 1.0 V.In the composite MCCT prepared in this paper,the voltage window?OPW?is extended to-0.8 V under low potential conditions.The absolute value of the overall voltage window is1.6 V.More importantly,in the three-electrode system,MCCT-5 has a high specific capacitance of 526.25 mF cm^-2(751.78 F g^-1)at 1 mA cm^-2 and has good rate performance(with a capacitance of 237.6 mF cm^-2 at 50 mA cm^-2)and excellent cycle retention?loss rate of 0.3%after 10,000 cycles?.The assembled symmetrical supercapacitors showed a high power density of 5.71 mWh cm^-3(0.057 mWh cm^-2)and 3.97 W cm^-3(39.71 mW cm^-2).