Wireless charging and micro-supercapacitor integrated electronic skin device and preparation method thereof

Abstract

The application relates to a wireless charging and micro-supercapacitor integrated electronic skin device and a preparation method thereof, and belongs to the technical field of energy storage devices. The device comprises a substrate, electrodes, an outer coil and an inner coil which are located on the upper surface of the substrate and are fixedly connected with the substrate, the inner coil is located in the inner part of the outer coil, the electrodes are located between the outer coil and the inner coil and are electrically connected with the outer coil and the inner coil respectively, an electrolyte is covered on the electrodes and the inner coil and is fixedly connected therewith, and a packaging material is at least covered on the outer coil and is fixedly connected therewith. The device is characterized by close connection of each part to form an integrated structure, lightness, thinness, softness, superconformality and wireless charging, and can be directly used as a micro energy source for electronic skin. The device is an integrated structure prepared by combining a solidified liquid precursor and laser etching, the preparation process is simple, the operability is high, and the device can be prepared on a large scale.

Description

Technical Field

[0001] This invention relates to an electronic skin device integrating wireless charging and a micro supercapacitor, and its fabrication method, belonging to the field of energy storage device technology. Background Technology

[0002] The rapid development of the Internet of Things (IoT) has spurred demand for microelectronic devices in wearable devices, electronic skin, digital health, and implantable electronics. Corresponding energy storage devices are essential for energy supply and need to be flexible, thin, and easily conform to the skin. Miniature supercapacitors (MSCs) are promising micro-energy storage devices with characteristics such as fast charging and discharging speeds, long cycle life, and high power density, possessing enormous energy storage potential in the field of microelectronics. In practice, MSCs need to be connected to an external power source via wires for periodic charging, which implies additional human intervention. Furthermore, charging devices are typically bulky and prone to damage to the MSC due to physical electrode contact. Therefore, MSCs with adaptive advantages such as wireless charging must be replenished with timely and sufficient power even without a wired external power connection.

[0003] Many studies have integrated MSCs with wireless charging coils in pursuit of integrated wireless charging devices. For example, Shen fabricated a seamless, all-MXene integrated system with a wireless charging coil, a micro-supercapacitor, and a photodetector, using a wireless charging MSC to drive a surface-modified (dodecyltriethoxysilane)DCTES MXene photodetector. Mousavi constructed an integrated wireless charging, energy storage, and sensing system using laser-scribed graphene, including a near-field communication (NFC) antenna, a micro-supercapacitor, a humidity sensor, and a resistor. Previous work by the inventors combined wireless charging coils and micro-supercapacitors using graphite / activated carbon materials. While most previous research has focused on building wireless charging devices with uniform structures and materials, constructing a flexible, skin-adherent, integrated wireless charging micro-supercapacitor remains a challenge, requiring it to adapt to the local details of an uneven surface like skin while maintaining aesthetic appeal. Current integrated wireless charging micro-supercapacitors have limited flexibility, allowing only partial bending and a limited bending angle. Furthermore, the weak contact between the substrate, wireless charging coil, supercapacitor electrodes, and electrolyte in these integrated wireless charging micro supercapacitors makes them prone to wrinkling and disassembly during human movement. These problems severely limit the application of wireless charging micro supercapacitors as skin-like power sources in human-machine interfaces, virtual reality / augmented reality platforms, and artificial robots. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an electronic skin device integrating wireless charging and a micro supercapacitor, along with its fabrication method. By selecting appropriate materials, the various parts of the device are tightly connected to form an integrated structure. This structure is not only lightweight, flexible, and ultra-conformal, adapting to various curved and uneven surfaces, but also features wireless charging capabilities, allowing it to be directly used as a micro energy source for electronic skin. The device is an integrated structure fabricated by combining a solidified liquid precursor with laser etching. The fabrication process is simple, highly operable, and suitable for large-scale production.

[0005] The objective of this invention is achieved through the following technical solutions.

[0006] An electronic skin device integrating wireless charging and a micro supercapacitor, the device comprising:

[0007] The substrate is made of polyvinylidene fluoride-hexafluoropropylene copolymer;

[0008] The device comprises an electrode, an outer coil, and an inner coil, all made of a cured composite of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) or 1-ethyl-3-methylimidazolium tetrafluoroborate. The electrode, outer coil, and inner coil are all located on and fixedly connected to the substrate. The inner coil is located inside the outer coil, and the electrode is located between the outer coil and the inner coil, and is electrically connected to both the outer coil and the inner coil.

[0009] The electrolyte is a cured gel mixture of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid (or 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid) and polyvinylidene fluoride-hexafluoropropylene copolymer; the electrolyte covers the corresponding areas of the electrode and the inner coil and is fixedly connected to the electrode and the inner coil, note that the electrolyte does not cover the corresponding area of ​​the outer coil at this time;

[0010] The encapsulation material is made of polyvinylidene fluoride-hexafluoropropylene copolymer; the encapsulation material covers at least the corresponding area of ​​the outer coil and is fixedly connected to the outer coil.

[0011] It should be noted that the electrode, the outer coil, and the inner coil are all fixedly connected to the substrate, which can be achieved by directly curing the electrode, the outer coil, and the inner coil onto the substrate to form a fixed connection; the electrolyte is fixedly connected to the electrode and the inner coil, which can be achieved by directly curing the electrolyte onto the corresponding areas of the electrode and the inner coil to form a fixed connection; the encapsulation material is fixedly connected to the outer coil, which can be achieved by directly curing the encapsulation material onto the corresponding area of ​​the outer coil to form a fixed connection; the encapsulation material at least covers the corresponding area of ​​the outer coil, meaning that the encapsulation material must cover the corresponding area of ​​the outer coil, but it is not limited to only covering the corresponding area of ​​the outer coil, and can also cover the surface of the electrolyte and be fixedly connected to the surface of the electrolyte.

[0012] Preferably, the electrode has an interdigitated structure, with one or more electrodes connected in parallel between the outer coil and the inner coil, and the interdigitated fingers in each electrode are alternately connected to the outer coil and the inner coil. More preferably, each electrode has 6 to 18 interdigitated fingers, each interdigitated finger has a width of 150 μm to 800 μm, each interdigitated finger has a length of 2 mm to 5 mm, and the spacing between two adjacent interdigitated fingers is 150 μm to 800 μm.

[0013] Preferably, the outer coil is a rectangular or circular coil arranged in a spiral, and the inner coil is a single, unclosed coil. More preferably, the width of the center line of the outer coil is 0.6mm to 1.2mm, the spacing between the center lines of the outer coil is 0.6mm to 1.2mm, the maximum length and maximum width of the rectangular outer coil are each 1cm to 10cm, the maximum diameter of the circular outer coil is 1cm to 10cm, and the width of the center line of the inner coil is 0.6mm to 1.2mm.

[0014] Preferably, the electrode, the outer coil, and the inner coil are an integrated structure formed by laser etching.

[0015] Preferably, the thicknesses of the electrode, the outer coil, and the inner coil are 1 μm to 150 μm, respectively.

[0016] Preferably, the thicknesses of the substrate, the electrolyte, and the encapsulation material are 1 μm to 300 μm, respectively.

[0017] Preferably, the overall thickness of the device is 3μm to 600μm.

[0018] The device works as follows: the outermost coil's wire port is denoted as point a, any point in the innermost coil is denoted as point c, and any point in the inner coil is denoted as point b. When the device is charging, points a and b are connected to the positive and negative terminals of an external rectifier diode via wires to achieve wireless charging. When the device is discharging, points b and c are connected to the positive and negative terminals of an external electrical appliance via wires to provide power to the appliance.

[0019] A method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor specifically includes the following steps:

[0020] (1) Mix polyvinylidene fluoride-hexafluoropropylene copolymer and acetone evenly to prepare a substrate precursor solution; then coat the substrate precursor solution evenly on the plane, and after curing and removing the acetone, form a substrate on the plane.

[0021] (2) Poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) or 1-ethyl-3-methylimidazolium tetrafluoroborate are mixed evenly to prepare an electrode precursor solution; then the electrode precursor solution is uniformly coated on the surface of the substrate, and after curing, an electrode layer is formed on the substrate; then the electrode layer is laser etched to etch an integrated outer coil, electrode and inner coil on the electrode layer, that is, an outer coil, electrode and inner coil are formed on the substrate;

[0022] (3) Mix 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid or 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid, polyvinylidene fluoride-hexafluoropropylene copolymer and acetone evenly to prepare an electrolyte precursor solution; coat the electrolyte precursor solution evenly on the corresponding areas of the electrode and the inner coil, and after curing and removing the acetone, form a gel electrolyte in the corresponding areas of the electrode and the inner coil; the outermost wire port of the outer coil, any point of the innermost coil of the outer coil and any point of the inner coil are electrically connected to one end of the three wires respectively.

[0023] (4) Mix polyvinylidene fluoride-hexafluoropropylene copolymer and acetone evenly to prepare an encapsulation precursor solution; then coat the encapsulation precursor solution evenly on the corresponding area of ​​the outer coil, and after curing and removing the acetone, encapsulation material is formed at least in the corresponding area of ​​the outer coil, thus completing the preparation of the electronic skin device integrating wireless charging and micro supercapacitor.

[0024] Preferably, the ratio of polyvinylidene fluoride-hexafluoropropylene copolymer to acetone in both the substrate precursor solution and the encapsulation precursor solution is (1-4g):20mL.

[0025] Preferably, in the electrode precursor solution, the ratio of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) to 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (or 1-ethyl-3-methylimidazolium tetrafluoroborate) is 80 mL:(1-4 mL).

[0026] Preferably, the power of laser etching is 1W to 20W.

[0027] Preferably, in the electrolyte precursor solution, the ratio of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid or 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid, polyvinylidene fluoride-hexafluoropropylene copolymer, and acetone is (1-16 mL):(1-16 g):80 mL.

[0028] In step (3), conventional wires can be selected, such as strip copper foil, strip aluminum foil, gold wire, silver wire, platinum wire, copper wire, etc. Preferably, in order to avoid contact reaction between the wire and the electrolyte and the outer coil, wires encapsulated with encapsulation material can be electrically connected to the corresponding points of the outer coil and the inner coil.

[0029] Beneficial effects:

[0030] (1) The high capacity of the device described in this invention mainly comes from the uniform mixing of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (chemical formula abbreviation PEDOT:PSS) and ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) or 1-ethyl-3-methylimidazolium tetrafluoroborate (chemical formula abbreviation [EMIM][TFSI]). The ionic liquid and PEDOT:PSS are cross-linked together through electrostatic interaction, resulting in ion exchange and greatly improving its conductivity. This is because the conductive hydrophobic PEDOT is locked in place by excessive insulating hydrophilic PSS chains, which inhibits the formation of the PEDOT conductive network. Therefore, PEDOT:PSS itself exhibits poor electrical transport properties. The introduction of ionic liquids replaces the PSS in PEDOT:PSS with [TFSI]- counterions and induces a fibrillary structure in the PEDOT chains, thereby shortening the π-π chain distance. The delocalization of π electrons on the PEDOT conjugated polymer backbone leads to faster charge carrier mobility, thus improving the conductivity of PEDOT:PSS. The capacitance of the device described in this invention can reach up to 11.39 F / cm. 3 Its volumetric capacity is far greater than that of other planar micro supercapacitors;

[0031] (2) The device described in this invention can achieve wireless charging after being connected to a rectifier diode. When placed in an alternating magnetic field, the outer coil can receive magnetic field energy to charge the micro supercapacitor. During the charging process, the magnetic field energy is first converted into alternating current electrical energy, which is then rectified into direct current by the rectifier diode and stored in the micro supercapacitor.

[0032] (3) The device described in this invention optimizes the types of materials for the substrate, electrodes, outer coil, inner coil and packaging materials, and achieves its thin, soft and ultra-conformal characteristics while ensuring high capacity, so that it can fit perfectly with human skin.

[0033] (4) All materials in the device of the present invention are obtained by solidifying a liquid precursor. Adjacent parts can be tightly connected through dissolution and penetration, thus facilitating the formation of an integrated device. Moreover, the thickness of each part prepared by the liquid precursor is controllable. Specifically, the electrodes, outer coil, and inner coil are first solidified into a uniform layer by the liquid precursor and then obtained by laser etching. The preparation method of the device of the present invention is simple, highly operable, and less prone to open circuits during preparation. It can be mass-produced and has good application prospects in the fields of electronic skin, microrobots, and sensing systems for irregular human organs.

[0034] (5) In the device described in this invention, the substrate, electrolyte and encapsulation layer all use acetone as solvent, which facilitates mutual penetration and bonding between the layers under liquid conditions. Acetone is also volatile, and after evaporation, the layers solidify to form a tight interconnected structure. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the integrated structure of the outer coil, electrode and inner coil obtained by laser etching in Example 1.

[0036] Figure 2 This is a cross-sectional scanning electron microscope (SEM) image of the electronic skin device integrating wireless charging and a micro supercapacitor in Example 1.

[0037] Figure 3 for Figure 2 Cross-sectional scanning electron microscope image of the interface between the electrolyte and the electrode layer.

[0038] Figure 4 This is a photograph of the electronic skin device, which integrates wireless charging and a micro supercapacitor, prepared in Example 1, after bending.

[0039] Figure 5 The graphs show the charge-discharge curves of the electronic skin device integrating wireless charging and micro supercapacitor prepared in Example 1 at different current densities.

[0040] Figure 6 This is a graph showing the relationship between the volumetric specific capacitance and current density of the electronic skin device integrating wireless charging and micro supercapacitor prepared in Example 1.

[0041] Figure 7 This is a schematic diagram of the integrated structure of the outer coil, electrode and inner coil obtained by laser etching in Example 2.

[0042] Figure 8 The graph shows the charge-discharge curves of the electronic skin device integrating wireless charging and micro supercapacitor prepared in Example 2 at different current densities. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Unless otherwise specified, the methods described are conventional methods, and the raw materials described are available from publicly available commercial sources.

[0044] In the following embodiments:

[0045] Scanning electron microscope (SEM): SUPRA 55;

[0046] Laser instrument: LAJAMIN LASER (LM-YLP-20F-III);

[0047] The charge-discharge curves were tested using the chronovoltammetry and cyclic voltammetry methods. The instrument used was the Shanghai Chenhua CHI 760E electrochemical workstation. During the test, the working electrode of the electrochemical workstation was connected to any point b or c on the outer and inner coils of the prepared integrated micro supercapacitor electronic skin device. The counter electrode and reference electrode of the electrochemical workstation were both connected to the other point c or b.

[0048] Example 1

[0049] (1) Dissolve 4g of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) in 40mL of acetone and stir at room temperature for 3 hours to obtain a uniformly mixed substrate precursor solution; then coat the substrate precursor solution uniformly on the surface of a clean glass plate, cure at room temperature to remove acetone, and form a 24μm thick substrate on the surface of the glass plate.

[0050] (2) Mix 150 μL of [EMIM][TFSI] ionic liquid and 6 mL of PEDOT:PSS together and stir vigorously for 10 minutes to obtain a homogeneous electrode precursor solution; then uniformly coat the electrode precursor solution onto the surface of the substrate, and cure it in air at 120°C for 3 minutes to form an 11.7 μm thick electrode layer on the substrate; then use a 10W laser to laser etch the electrode layer, etching an integrated outer coil, electrode, and inner coil on the electrode layer. Three parallel interdigitated electrodes are located between the outer coil and the inner coil, and the interdigitated fingers in each electrode are alternately connected to the outer coil and the inner coil (e.g., ...). Figure 1 As shown in the figure, that is, an outer coil, an electrode, and an inner coil are formed on the substrate;

[0051] like Figure 1 As shown, in this embodiment, each electrode has 14 interdigitated fingers, each finger is 200 μm wide, each finger is 3.8 mm long, and the spacing between two adjacent interdigitated fingers is 200 μm. The outer coil is a rectangular coil arranged in a spiral shape. The outermost end of the outer coil is denoted as point a, and any point in the innermost coil is denoted as point c. The width of the center line of the outer coil is 1 mm, the spacing between the lines in the center line of the outer coil is 0.8 mm, the maximum length of the rectangular coil is 35.4 mm, and the maximum width of the rectangular coil is 34.5 mm. The inner coil is a non-closed coil. Any point in the inner coil is denoted as point b, and the width of the center line of the inner coil is 1 mm.

[0052] (3) First, dissolve 1.5g PVDF-HFP in 15mL acetone and stir for 3 hours. Then add 2mL [EMIM][TFSI] ionic liquid and continue stirring at room temperature for 2 hours to obtain a uniformly mixed electrolyte precursor solution. Coat the electrolyte precursor solution uniformly on the corresponding areas of the electrode and the inner coil. After curing at room temperature and removing the acetone, a 30μm thick gel electrolyte is formed in the corresponding areas of the electrode and the inner coil. Connect one end of the three wires (strip copper foil) to the outer coil and the three points a, b, and c on the inner coil respectively through conductive silver paste. The two wires connected to b and c are encapsulated with the substrate precursor solution to avoid contact reaction between the wires and the outer coil and the electrolyte.

[0053] (4) Dissolve 4g of PVDF-HFP in 40mL of acetone and stir at room temperature for 3 hours to obtain a uniformly mixed encapsulation precursor solution; then uniformly coat the encapsulation precursor solution on the corresponding area of ​​the outer coil and the surface of the electrolyte. After curing and removing the acetone at room temperature, a 30μm thick encapsulation material is formed on the corresponding area of ​​the outer coil and the surface of the electrolyte, thus obtaining an electronic skin device integrating wireless charging and micro supercapacitor with a total thickness of 96μm.

[0054] In practical application, the other ends of the two wires connected to a and b are connected to the positive and negative terminals of a rectifier diode (model 1N4148) respectively during charging, and placed in an alternating magnetic field (parallel to the transmitting coil of the alternating magnetic field, at a distance of 0.5cm). During static placement, the outer coil collects the magnetic field energy of the alternating magnetic field, converts it into alternating current, and then into direct current after passing through the rectifier diode. This direct current charges the prepared device, thereby realizing the device's own wireless charging function. After charging for 1400 seconds, the device's voltage reaches 2V. The other ends of the two wires connected to b and c are connected to the positive and negative terminals of an external electrical appliance respectively during discharging, thereby providing electrical energy to the appliance.

[0055] according to Figure 2 and Figure 3 SEM characterization results show that the electrolyte, electrode layer (referring to the integrated structure of outer coil, electrode, and inner coil formed after laser etching), and substrate layer are tightly bonded, ensuring the structural stability of the device for use as electronic skin. It is important to note that... Figure 2 The layer below the middle basal layer is the sample stage for the scanning electron microscope.

[0056] The fabricated device has a macroscopic appearance similar to a thin film, is very flexible, and possesses excellent mechanical properties. Different regions of the device can be bent at different angles and to varying degrees, achieving a perfect fit with human skin. An image of the device after bending is shown below. Figure 4 As shown.

[0057] The device prepared in Example 1 was tested using a chronopotentiometric method on an electrochemical workstation, with a maximum voltage limited to 2V. Figure 5 The charge-discharge curves show that the fabricated device operates at 128.5 mA / cm². 3 192.8 mA / cm 3 257.1 mA / cm 3 and 321.3 mA / cm 3 It exhibits good charge and discharge capabilities when charged and discharged under constant current.

[0058] In addition, according to Figure 5 The relationship between the volumetric capacity and current density of the fabricated device, calculated from the test results, is shown in the graph below. Figure 6 As shown. From Figure 6 As can be seen, the prepared device exhibits good rate capability.

[0059] According to equation (1), the volume capacitance C under different current densities is obtained. v , drawing Figure 6 The curve in the image.

[0060]

[0061] In the formula, C v I is the area capacitance; Δt is the constant charging / discharging current set in the chronopotential method; Δt is the discharge time; ΔV is the maximum limiting voltage; and V is the volume of the capacitor electrodes.

[0062] Example 2

[0063] (1) Dissolve 3g PVDF-HFP in 40mL acetone and stir at room temperature for 3 hours to obtain a uniformly mixed substrate precursor solution; then coat the substrate precursor solution uniformly on the surface of a clean glass plate, and cure at room temperature to remove acetone to form a 30μm thick substrate on the surface of the glass plate.

[0064] (2) Mix 100 μL of [EMIM][TFSI] ionic liquid and 6 mL of PEDOT:PSS together and stir vigorously for 5 minutes to obtain a homogeneous electrode precursor solution; then uniformly coat the electrode precursor solution onto the surface of the substrate, and cure it in air at 120°C for 3 minutes to form a 94.5 μm thick electrode layer on the substrate; then use a 5W laser to laser etch the electrode layer, etching an integrated outer coil, electrode, and inner coil on the electrode layer. Three parallel interdigitated electrodes are located between the outer coil and the inner coil, and the interdigitated fingers in each electrode are alternately connected to the outer coil and the inner coil (e.g., ...). Figure 7 As shown in the figure, that is, an outer coil, an electrode, and an inner coil are formed on the substrate;

[0065] like Figure 7 As shown, in this embodiment, each electrode has 13 interdigitated fingers, each finger is 700 μm wide, each finger is 4.7 mm long, and the spacing between two adjacent interdigitated fingers is 300 μm. The outer coil is a rectangular coil arranged in a spiral shape. The outermost end of the outer coil is denoted as point a, and any point in the innermost coil is denoted as point c. The width of the center line of the outer coil is 1 mm, the spacing between the lines in the center line of the outer coil is 0.8 mm, the maximum length of the rectangular coil is 35.4 mm, and the maximum width of the rectangular coil is 34.5 mm. The inner coil is a non-closed coil. Any point in the inner coil is denoted as point b, and the width of the center line of the inner coil is 1 mm.

[0066] (3) First, dissolve 1g of PVDF-HFP in 15mL of acetone and stir for 3 hours. Then add 1mL of [EMIM][TFSI] ionic liquid and continue stirring at room temperature for 3 hours to obtain a uniformly mixed electrolyte precursor solution. Coat the electrolyte precursor solution uniformly on the corresponding areas of the electrode and the inner coil. After curing at room temperature to remove acetone, a 30μm thick gel electrolyte is formed in the corresponding areas of the electrode and the inner coil. Connect one end of the three wires (strip copper foil) to the outer coil and the three points a, b, and c on the inner coil respectively through conductive silver paste. The two wires connected to b and c are encapsulated with the substrate precursor solution to avoid contact reaction between the wires and the outer coil and the electrolyte.

[0067] (4) Dissolve 3g of PVDF-HFP in 40mL of acetone and stir at room temperature for 3 hours to obtain a uniformly mixed encapsulation precursor solution; then uniformly coat the encapsulation precursor solution on the corresponding area of ​​the outer coil and the surface of the electrolyte. After curing at room temperature and removing the acetone, a 30μm thick encapsulation material is formed on the corresponding area of ​​the outer coil and the surface of the electrolyte, thus obtaining an electronic skin device integrating wireless charging and micro supercapacitor with a total thickness of 184.5μm.

[0068] In practical applications, the other ends of the two wires connected to a and b are connected to the positive and negative terminals of a rectifier diode (model 1N4148) respectively during charging, and placed in an alternating magnetic field (parallel to the transmitting coil of the alternating magnetic field, at a distance of 0.2cm). During static placement, the outer coil collects the magnetic field energy of the alternating magnetic field, converts it into alternating current, and then into direct current after passing through the rectifier diode. This direct current charges the prepared device, thereby realizing the device's own wireless charging function. After charging for 3000 seconds, the device's voltage reaches 2V. The other ends of the two wires connected to b and c are connected to the positive and negative terminals of an external electrical appliance respectively during discharging, thereby providing electrical energy to the appliance.

[0069] The device prepared in Example 2 was tested using a chronopotentiometric method on an electrochemical workstation, with a maximum voltage limited to 2V. According to... Figure 8 The test results show that the prepared device operates at 66.8 mA / cm². 3 100.1 mA / cm 3 133.5 mA / cm 3 and 166.9 mA / cm 3 It exhibits good charge and discharge capabilities when charged and discharged under constant current.

[0070] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor, characterized in that... Specifically, it includes the following steps: (1) Mix polyvinylidene fluoride-hexafluoropropylene copolymer and acetone evenly to prepare a substrate precursor solution; then coat the substrate precursor solution evenly on the plane, and after curing and removing the acetone, form a substrate on the plane. (2) Poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) or 1-ethyl-3-methylimidazolium tetrafluoroborate are mixed evenly to prepare an electrode precursor solution; then the electrode precursor solution is uniformly coated on the surface of the substrate, and after curing, an electrode layer is formed on the substrate; then the electrode layer is laser etched to etch an integrated outer coil, electrode and inner coil on the electrode layer, that is, an outer coil, electrode and inner coil are formed on the substrate; wherein, the inner coil is located inside the outer coil, the electrode is located between the outer coil and the inner coil, and the electrode is electrically connected to the outer coil and the inner coil respectively; (3) Mix 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt or 1-ethyl-3-methylimidazolium tetrafluoroborate, polyvinylidene fluoride-hexafluoropropylene copolymer and acetone evenly to prepare an electrolyte precursor solution; coat the electrolyte precursor solution evenly on the corresponding areas of the electrode and the inner coil, and after curing and removing the acetone, form a gel electrolyte in the corresponding areas of the electrode and the inner coil; the outermost wire port of the outer coil, any point of the innermost coil and any point of the inner coil are electrically connected to one end of the three wires respectively. (4) Mix polyvinylidene fluoride-hexafluoropropylene copolymer and acetone evenly to prepare an encapsulation precursor solution; then coat the encapsulation precursor solution evenly on the corresponding area of ​​the outer coil, and after curing and removing the acetone, encapsulation material is formed at least in the corresponding area of ​​the outer coil, thus completing the preparation of the electronic skin device integrating wireless charging and micro supercapacitor.

2. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 1, characterized in that: In both the substrate precursor solution and the encapsulation precursor solution, the ratio of polyvinylidene fluoride-hexafluoropropylene copolymer to acetone is (1-4g):20mL.

3. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 1, characterized in that: In the electrode precursor solution, the ratio of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) to 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonylimide) or 1-ethyl-3-methylimidazolium tetrafluoroborate is 80 mL:(1-4 mL).

4. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 1, characterized in that: In the electrolyte precursor solution, the ratio of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid or 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid, polyvinylidene fluoride-hexafluoropropylene copolymer, and acetone is (1-16 mL):(1-16 g):80 mL.

5. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 1, characterized in that: Electrical connections are made between the wires, which are encapsulated with encapsulation material, and the corresponding points of the outer and inner coils.

6. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 1, characterized in that: The electrodes have an interdigitated structure, with one or more electrodes connected in parallel between the outer coil and the inner coil. The interdigitated fingers of each electrode are alternately connected to the outer coil and the inner coil. The outer coil is a rectangular or circular coil arranged in a spiral shape; The inner coil is a single, unclosed coil.

7. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 6, characterized in that: Each electrode has 6 to 18 interdigitated fingers, each interdigitated finger has a width of 150 μm to 800 μm, each interdigitated finger has a length of 2 mm to 5 mm, and the spacing between two adjacent interdigitated fingers is 150 μm to 800 μm. The width of the outer coil center line is 0.6mm to 1.2mm, the spacing between the outer coil center lines is 0.6mm to 1.2mm, the maximum length and maximum width of the rectangular outer coil are 1cm to 10cm respectively, and the maximum diameter of the circular outer coil is 1cm to 10cm. The width of the center line of the inner coil is 0.6mm to 1.2mm.

8. A method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 1, 6, or 7, characterized in that: The thicknesses of the electrodes, outer coil, and inner coil range from 1 μm to 150 μm.

9. The method for fabricating an electronic skin device integrating wireless charging and a micro supercapacitor according to claim 8, characterized in that: The thicknesses of the substrate, electrolyte, and encapsulation material range from 1 μm to 300 μm. The overall thickness of the device is 3μm to 600μm.

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