Fabrication Of Flexible Electrode Based On Sliver Nanowires And Its Application In Skin-Like Supercapacitors

With the rapid development of soft and elastic materials,skin electronics have received extensive attention from researchers.These electronics not only have various functional properties,but also have soft mechanical properties like human skin.Skin-like supercapacitors are indispensable energy storge devices in skin electronics,which have shown wide potential applications in implanted electronics,health monitoring,soft robots,and many emerging research fields.As we all know,the development of electrodes with high electrical conductivity and high mechanical flexibility is the key to construction high-performance skin-like supercapacitors,and it is also a major scientific problem which needs to be solved in this field.At present,the electrode materials for the preparation of skin-like supercapacitors mainly include metal nanowires,conductive polymers,carbon nanotubes,graphene,etc.In contrast,silver nanowires（AgNWs）,which have the characteristics of high conductivity,high transparency,and outstanding flexibility,have been one of the best electrode materials for constructing high-performance skin-like supercapacitors.However,AgNWs networks have many problems such as large junction contact resistance,poor mechanical,and low environmental stability,which limit their application in skin electronics.Therefore,a microwave-welded technique was developed to fabricate AgNWs transparent electrodes with high conductivity and high mechanical flexibility embedded structure by combing stable flexible photopolymers in this work.Based on the AgNWs transparent electrode,skin-like supercapacitors with high mechanical stability and high electrochemical performance have been obtained,and their application in driving circuits was carried out.The main research contents are as follows:（1）This work proposed a facile microwave-welded method,so that AgNWs can realize self-limiting welding and solve the problem of large contact resistance at their junctions,which used the basic principle of AgNWs absorbing microwaves to generate Joule heat.In this study,the effects of welding time and welding power on AgNWs electrodes are systematically studied and analyzed.Through optimization,the square resistance of the obtained AgNWs electrode is as low as 13.5?/sq,and the transmittance is as high as 87.2%.Compared with high-temperature heating,laser welding and other methods,the welding process of this technology is efficient and compatible with flexible substrates.（2）In this study,microwave-welded technology is further combined with flexible photopolymers to fabricate AgNWs flexible transparent electrodes with embedded structure,so that AgNWs have both high conductivity and high mechanical flexibility.By systematically characterizing the parameters of various flexible polymer materials such as Young’s modulus,adhesion,and resistance of AgNWs electrodes before and after peeling.It is found that high-performance flexible transparent electrodes can be fabricated by embedding AgNWs in photopolymer NOA63.Through testing,the prepared AgNWs flexible electrodes show high mechanical stability（2000 bending cycles）and great environmental stability（can be placed in air for more than one month）.（3）Based on the AgNWs flexible transparent electrode with high conductivity and high mechanical flexibility,combined with polyvinyl alcohol（PVA）/phosphoric acid（H₃PO₄）electrolyte,this work constructed skin-like supercapacitors by all solution method.The skin-like supercapacitors exhibit outstanding mechanical flexibility and electrochemical performance,with the areal capacitance up to 2.09 mF cm^-2.After 2000 bending cycles,the areal capacitance maintains 98%,and the supercapacitor can still work normally after conforming to the human body,demonstrating their application potential in skin electronics.