Preparation Of Polypyrrole Matrix Composites And Construction Of Aqueous System High Voltage Planar Micro Supercapacitor

Since entering the new century,the rapid development of wearable electronic devices means that the following energy storage devices must not only meet the excellent electrochemical performance,but also have good flexibility.Supercapacitor is a new energy storage device with long cycle life,high power density,environmental protection and many other advantages.Micro-supercapacitors have great potential to supply and replace tiny batteries.Compared with traditional sandwich supercapacitors,planar supercapacitors have the advantage of narrow electrode spacing,which eliminates the need for septa,facilitates electrolyte ion diffusion,and allows easy integration with other components.Although planar micro-supercapacitors have been extensively studied,they still face many challenges such as low energy storage density,large internal resistance,cycle stability to be improved,and complex miniaturization preparation process.In view of the above problems,the following work has been carried out:1.Herein,we constructed flexible symmetrical pseudocapacitive micro-supercapacitors with hybrid PPy and reduced graphene oxide(PPy@rGO)nanosheets as electrochemically active materials working in WIS electrolyte of 20 M(mol-salt in kg-solvent)Li Cl gel electrolyte.The PPy@rGO composite was prepared via a chemical oxidation method and the planar interdigital PPy@rGO based MSCs(PPy@rGO-MSCs)was constructed by one-step mask-assisted filtration.The as-fabricated symmetrical PPy@rGO-MSCs showed a high voltage window of 1.6 V in 20 M Li Cl electrolyte.Notably,the PPy@rGO-MSCs in 20 M Li Cl electrolyte showed a higher areal capacitance of 44.5 m F/cm~2 at 5 m V/s than that in 20 M Li TFSI electrolyte.In addition,PPy@rGO-MSCs also exhibited high areal and volumetric energy density of 15.8μWh/cm~2and 8.89 m Wh/cm~3,respectively.Moreover,PPy@rGO-MSCs displayed excellent flexibility at the bending angle of 180~o,and robust modular integration to boost voltage and current output.2.Asymmetric micro-supercapacitors(VN//PPy@rGO-MSCs)based on PPy@rGO and VN were prepared by using the same one-step mask assisted filtration method with PPy@rGO as the positive electrode and VN as the negative electrode.The electrolyte of micro-supercapacitor is 20 M Li Cl electrolyte which is more matched with PPy@rGO.By adjusting the ratio of positive and negative electrodes to find suitable matching quality,the voltage window of the device prepared under this condition can reach 2.0 V.VN//PPy@rGO-MSCs can reach 31.9 m F/cm~2 and the energy density can reach 17.6μWh/cm~2.In addition,VN//PPy@rGO-MSCs can maintain almost stable capacity and integrability under very large bending angles.