Design,Construction And Applications Of Stretchable Energy Storage Devices

With the continuous progress of wearable medical devices,electronic skin,artificial muscles,the rapid development of stretchable electronics has been promoted.Stretchable energy storage devices,such as high-capacity lithium ion batteries and supercapacitors,are essential components of stretchable electronic devices,which are of great significance to the development of stretchable technology and the development of the stretchable electronic market.As the core component of the energy storage devices,the traditional rigid electrode is an important challenge hindering the development of current stretchable energy storage devices.Aiming at above problems,our work designs stretchable electrodes,transparent and stretchable electrodes,then constructs stretchable lithium ion batteries,stretchable supercapacitors,transparent and stretchable supercapacitors,and explores the application of our supercapacitors in the sensor field.The main innovations are as follows:1.Taking advantage of the stretchability of poly?dimethylsiloxane??PDMS?elastomer and the conductivity of single-wall carbon nanotube?SWCNT?,the stretchable 3D porous PDMS/SWCNT frameworks are obtained by using sugar cubes as templates,which solves the rigidity and unstretchability of metal foils,as well as the low mass load and detachment of active materials during repeated stretch-release cycles.The maximum tensile strain is up to62%.It exhibits the stable conductivity when stretched in different axes.After 500stretch-release cycles of 50%tensile strain,the normalized resistance can return to its original value and remain stable.Based on the 3D porous PDMS/SWCNT-based electrode,poly?vinylidene fluoride-co-hexafluoropropylene??PVDF-HFP?gel separator and PDMS packing shell,an all-stretchable-component lithium ion battery with excellent electrochemical performance and mechanical deformation was obtained.The fabricated all-stretchable-component lithium ion battery achieves a high areal capacity of 0.81 m Ah cm^-2 at 0.069 C.The full cell delivers a high capacity of 0.66 m Ah cm^-2 even after 100stretch-release cycles of 50%tensile strain at 0.075 C,and shows the stable power supply during various extreme deformations.This work opens a feasible route to construct all-stretchable-component lithium ion batteries with high electrochemical performance and high stretchability,presenting promising potential for application in new-generation wearable and portable energy storage devices.2.Based on the excellent mechanical stretchability of Ecoflex elastomer,3D porous Ecoflex?1:3.5?/SWCNT/poly?3,4-ethylenedioxythiophene?-poly?styrenesulfonate??PEDOT:PSS?-based supercapacitor and Ecoflex?1:1.5?/SWCNT/PEDOT:PSS-based strain sensor with excellent stretchability and high performance were fabricated combined with the conductivity of SWCNT and electrochemical performance of PEDOT:PSS.The 3D porous Ecoflex/SWCNT/PEDOT:PSS frameworks are obtained by using white granulated sugar as templates and mixing with Ecoflex elastomer at different mass ratios.The supercapacitor exhibits a specific capacitance of 29.63 m F cm^-2,an energy density up to 2.08?W h cm^-2,and a power density up to 618.12?W cm^-2.The supercapacitor exhibits stable electrochemical performance under various deformation?bending and 160%tensile strain?.The Ecoflex?1:1.5?/SWCNT/PEDOT:PSS-based strain sensor delivers excellent stretchability?60%?and high sensitivity?gauge factor of 14.7 and 80.6 in strain of 0-25%and 25-60%,respectively?.The stretchable supercapacitor-strain sensor integrated system can successfully detect the strain caused by various movements when it is fixed on the finger joint,wrist and elbow joint.Our work demonstrates the great potential of the Ecoflex/SWCNT/PEDOT:PSS based integrated system in the field of wearable devices.3.By using the transparent and conductivity of PEDOT:PSS and stretchability of SWCNT network,the large-area transparent and stretchable SWCNT/PEDOT:PSS hybrid electrode was designed via simple and low cost all-solution process,which solves the rigid and opaque of traditional metal foils.Based on transparent stretchable SWCNT/PEDOT:PSS hybrid electrode,combined with transparent stretchable polyvinyl alcohol?PVA?/H₃PO₄ gel electrolyte,the transparent stretchable supercapacitor is obtained.The fabricated transparent and stretchable supercapacitor achieves an areal capacitance of 0.12 m F cm^-2 and high transparency of?72%.Under 50%tensile strain,the specific capacitance of the supercapacitor can still maintain 98%of the initial capacitance.The supercapacitor-pressure sensor integrated system is obtained by using transparent stretchable supercapacitor as power unit and high sensitive pressure sensor.The integrated system successfully detects biosignals generated from hands,arms and leg movements.This work demonstrates the feasibility of transparent stretchable supercapacitor-wearable pressure sensor integrated system for real-time human motion detection in wearable devices.