Fabrication Of Flexible Transparent Metal Micromesh Electrodes And Their Application In Energy Storage

Flexible electronics is a subversive science and technology based on the high degree of interdisciplinary integration,and it is also an important strategic opportunity for my country’s independent innovation to lead the future industrial development.Flexible electronics are developing in the direction of thinning,integration and intelligence,and have achieved disruptive innovations in the fields of wearable/implantable electronic devices,wearable intelligent health monitoring systems,flexible displays and intelligent electronic sensors.Application Showcase.The flexible transparent energy supply unit plays a crucial role as the”heart”of flexible electronics.The development of high-performance flexible transparent energy storage devices（FTESDs）is extremely challenging due to the mutual constraints of light transmittance and energy density.As the core part of energy storage devices,flexible transparent conductive electrodes are composed of current collectors that transfer and gather electrons and active materials for electrochemical energy storage.Among them,the functional characteristics and quality factor of the current collector are particularly important,which greatly determine the performance of the device functionality and energy storage characteristics.Commercial indium-doped tin oxide（ITO）has poor mechanical toughness,and traditional metal foil current collectors are thick and non-transparent,which cannot meet the development needs of flexible and transparent electronic devices.Therefore,designing and developing lightweight current collectors with high electrical conductivity,high mechanical flexibility,and high transparency for high-performance flexible transparent energy storage devices is particularly important,but at the same time challenging.Aiming at the above bottleneck problem,this paper realizes the reliable manufacture of a highly transparent,highly conductive flexible self-supporting metal microgrid current collector by developing advanced micro-nano processing technology combined with conformal filling electroplating,and further combines electroplating,physical impregnation and other technologies to process material-structure-function integrated high-performance transparent electrodes,and finally realize the development of multi-functional flexible transparent energy storage devices.The main researches are as follows:（1）Combining micro-nano lithography and conformal electroplating technology to prepare flexible,transparent and ultra-light random micro-metal meshes.The random mesh can effectively eliminate the Moiréinterference effect.The random nickel micromesh（NM）has up to 92.1%The light transmittance and low square resistance of 0.7Ωsq^-1 show excellent optoelectronic properties and mechanical robustness.The integrated fabrication of nickel microgrids and high-capacity NiCoP active materials was further achieved by electrodeposition technology,and an NM@NiCoP integrated electrode was fabricated,which exhibited high specific capacity,excellent rate capability,and long cycle life.Finally,by matching the active carbon anode supported by flexible transparent nickel microgrids and the NM@NiCoP cathode,the development of all-solid-state flexible transparent supercapacitor devices with both high energy density and high light transmittance is realized.（2）By designing a stretchable sine wave microgrid structure,a flexible,transparent and stretchable nickel microgrid was prepared by micro-nanolithography and conformal electroplating technology.The nickel microgrid supported NiCoP cathode and the nickel microgrid supported Zn anode were prepared respectively.The as-prepared NM@NiCoP cathode and NM@Zn anode can achieve an effective stretch rate of 50%at high optical transmittances of 81.4%and 70.2%,respectively.The final integrated transparent and stretchable all-solid-state alkaline Zn-ion battery still has a capacity retention rate of 57.14%after 6000 cycles at a current density of 5 m A cm^-2.