Flexible Supercapacitors Based On Polymer Membranes

Supercapacitor,also known as electrochemical capacitor,is one new kind of environmental friendly and irreplaceable energy storage devices,between the traditional capacitors and rechargeable batteries.It has caused the wide attentions of sciencific researchers,for its high power density,fast charge-discharge time,long cycle life and safe operation.In recent years,with the rapid development of portable electronic devices and wearable electronics,the flexible energy storage device as an important functional component is required to have easy portability,safe and large energy storage.Nowadays,flexible supercapacitor as one type of flexible energy storage devices has become one of the hot research topics.And the flexible electrode as the most important part of flexible supercapacitor becomes the key to solove the present questions of supercapacitor.In this paper,we design and prepare a simple and effective,high-energy and low-cost flexible supercapacitor membrane electrode material,and study the relationships between the membrane structures and its electrochemical performances.(1)Activated carbon membrane electrode: One kind flexible membrane electrode was prepared by a phase inversion technology,where PES was just as scaffold material for its high flexibility;and activated carbon was used as active material.The results indicated: The PCM prepared at the PES/AC mass ratio of 4:11(wt: wt)presented a high specific capacitance and excellent flexibility,the specific capacitance can reach to 169.4 F/g.(2)Nickel hydroxide membrane electrode: One kind nickel hydroxide(Ni(OH)2)flexible membrane electrode was prepared,where PES was just as flexible substrate;and Ni(OH)2 was used as active material,and the influences of the conductivity and hydrophilic on the electrochemical performances of electrode materials were further studied.The results indicated: well electrical conductivity and hydrophilic can significantly improve the electrochemical performances of electrode materials.(3)The influences of membrane structure on its electrochemical performances: The influences of flexible membrane thickness and hydrophilicity on the electrochemical performances of electrode materials were further studied.The results indicated: when the thickness of membrane is 60 ?m,modified with hydrophilic –PAA,the membrane electrode(FME-PAA-60)shows an optimal electrochemical performance.Finally,a flexible asymmetric supercapacitor was assembled,where FME-PAA-60 was used as positive electrode and activated carbon flexible membrane as negative electrode.