The Study Of New-Generation Three-Dimensional Composite Electrodes For Flexible Energy Storage Devices And Flexible Integrated Multifunctional System

After nearly 20 years of rapid development,electronic devices have become an indispensable part of everyone's life.Their future development trend is miniaturization,flexibility and integration.The driving power supply of electronic equipment should also meet the requirements of this development trend.Currently used energy storage devices are big volume,do not bend,low energy/power density,poor miniaturization and integration.New type of energy storage devices need to be develop,with new battery structure,clever designed device structure for the preparation of a new generation of flexibility,with small volume,high energy density,and can match the other functional devices as flexible multi-function integrated system.Based on the above objectives,this paper studied flexible planar/linear supercapacitors and ionic batteries based on novel 3D nano-structured electrode materials,flexible multi-functional systems integrating sensors and energy storage units,etc.The specific research contents are as follows:?1?Here,we proposed a rational design of branched CoMoO₄@CoNiO₂ core/shell nanowire arrays on Ni foam as supercapacitors electrode by two steps of hydrothermal processing,with high areal specific capacitance and superior cycling stability.The all-solid-state asymmetric supercapacitors composed of such electrode and activated carbon?AC?exhibited an areal specific capacitance of 1.54 F/cm² at10mA/cm² and a rate capability?59.75 Wh/kg at 1464 W/kg?comparable with Li-ion batteries,demonstrating advances in energy storage,scalable integrated applications and promising commercial potential.?2?Herein,we reported the fabrication of wire-supercapacitors with the length of longer than 1 m,based on CoNiO₂-nanowires@carbon-fibers electrodes.The device shows no obvious performance degradation when suffering cycling,bending,pulling,tying and weaving.After weaving as Chinese knot,watchband,belt and clothes textile,the wire-supercapacitors work well as the wearable energy-storage units to power the personal electronics.?3?The rechargeable aluminium-ion battery is a promising candidate for next-generation high-performance batteries,demonstrated herein is the growth of MoSe₂ three-dimensional helical nanorod arrays?HNRAs?on a Ti/polyimides?PI?substrate to form novel cathodes for AIBs.The binder-free,3D MoSe₂-based AIB shows a high specific capacity of 1563 mAh/g at a current density of 0.5 A/g and an ultralong cycling life of at least 1000 times.Further exploratory work on interdigital flexible AIBs and stretchable AIBs was demonstrated,exhibiting a steady output capacity under different bending and stretching states.This method provides a new and controllable strategy for selenide nanostructure-based AIBs for use in future applications of energy-storage devices in flexible and wearable electronics.?4?In this study,we report the fabrication of a flexible film-shaped resistive-type pressure sensor with high performance and versatile applications by sandwiching a polystyrene ball@reduced graphene-oxide?PS ball@rGO?core-shell nanomaterial film layer between two thin flexible polydimethylsiloxane?PDMS?sheets.In addition,different applications of our flexible sensor in detecting blood pulse,swallowing,skin pulling,and articular activities were demonstrated when the sensor was attached to the human body.Furthermore,by an efficient scalable fabrication process,a large-area integrated pressure sensor array was demonstrated,and it enabled patterning of the mapped spatial pressure distribution as well as large-area monitoring of body pressure,pulses,and human actions.?5?Multifunctional integrated devices which can integrate many functions in one device and miniaturize their volume,are constantly evolving in recent years.Herein,four kinds of planar devices namely micro-supercapacitors,pressure sensor,photodetector and gas sensor were modularly manufactured,all with the reduced graphene oxide?rGO?encapsulated poly?vinylidene fluoride-trifluoroethylene?[P?VDF-TrFE?]?PVDF?nanofibers?NFs?as the functional materials.They were integrated into a single pixel to form a self-powered multifunctional electronic skin system,where the micro-supercapacitors could drive the three sensors to detect the change of the environment conditions and physiological signs of health,like the functions of human skins and sense organs.The technology is quite simple and efficient,which can in principle be scaled-up to fabricate more compact and higher performance e-skins for applications in wearable electronics or bionics field,demonstrated the great application potential of flexible energy storage devices and flexible multi-functional systems.