Study On Preparation And Performance Of Polylactic Acid-based Polyaniline Flexible Biodegradable Supercapacitor

Flexible biodegradable supercapacitors have promising prospects in transient electronics,such as wearable electronic devices and implantable medical devices.In this study,flexible and biodegradable supercapacitors were prepared by combining biodegradable polylactic acid with conductive polymer polyaniline.The PANI-PLA//PANI-PLA)and asymmetric supercapacitor PANI-PLA//PANI-SS were prepared by in-situ growth of PANI on the substrate of PLA film obtained by solution casting.Foamed PLA（fo-PLA）was further prepared by non-solvent induced phase separation（NIPS）method to improve the flexibility and the loading of the active electrode materials.Using fo-PLA as the substrate,symmetrical supercapacitor of PANI-fo-PLA/PANI-fo-PLA was preparedThe physical properties and structure of the electrodes were characterized,and the electrochemical workstation was used to evaluate the energy storage properties of the assembled supercapacitors:（1）The maximum area specific capacitance of PANI-PLA can reach 5.00 m F·cm^-2(@0.10 m A·cm^-2)in the three-electrode system.In the two electrode system,using polyvinyl alcohol/surfuric acid（PVA//H₂SO₄）as the gel electrolyte,the areal specific capacitance of the symmetrical solid supercapacitor of PANI-PLA//PANI-PLA is 0.20 m F·cm^-2,and the power density is 3.60μW·cm^-2,and the corresponding energy density is 0.02μWh·cm^-2(@0.02 m A·cm^-2).The areal specific capacitance of PANI-PLA//PANI-SS asymmetrical solid state supercapacitors is 23.33 m F·cm^-2,and the maximum power density is 30.09μW·cm^-2,and the corresponding energy density is 1.17μWh·cm^-2(@0.05 m A·cm^-2).（2）PNAI-fo-PLA electrode not only has good flexibility（fracture strain is 34.70%）,but also has excellent mechanical properties（the fracture strength is 77.80 MPa）.The areal specific capacitance of PNAI-fo-PLA//PNAI-fo-PLA is 27.73 m F·cm^-2,the power density is2.465μW·cm^-2,and the corresponding energy density is 45.72 m Wh·cm^-2(@0.05 m A·cm^-2).At the same time,the device also shows excellent flexibility,and the areal specific capacitance will not change much even bent at different bending angles.In addition,PNAI-fo-PLA electrode can be completely degraded in 1 mol/L Na OH solution under ultrasonic condition within 2 hours,demonstrating good degradation capability.