Power generation device, preparation method thereof and electric equipment

Abstract

The invention belongs to the technical field of power generation devices, and particularly discloses a power generation device, a preparation method thereof and electric equipment, and the power generation device comprises a positive electrode which comprises a positive electrode material; the negative electrode comprises a negative electrode material; the diaphragm is arranged between the positive electrode and the negative electrode; the positive electrode, the negative electrode and the diaphragm are soaked in the electrolyte; wherein the initial electrode potentials of the positive electrode material and the negative electrode material are different. The power generation device is formed by self-evaporation at room temperature, and is extremely low in energy consumption, green, safe, environment-friendly, small in size and wide in application range.

Description

Technical Field

[0001] The present application belongs to the technical field of power generation devices, and specifically relates to a power generation device, a preparation method thereof, and power-consuming equipment. Background Art

[0002] Capturing different forms of energy (such as light energy, heat energy, mechanical energy, radio frequency energy, etc.) from the surrounding environment and converting it into electrical energy is a new energy harvesting technology that is of great significance to the development of low-power and self-powered systems such as IoT devices, wearable devices, and wireless sensor networks. Traditional power sources such as batteries and wire connections have problems such as large size, limited life, and environmental pollution, while energy harvesting technology can provide a sustainable, low-maintenance, and highly adaptable power supply solution. By utilizing renewable and distributed energy sources in the environment, such as sunlight, wind energy, vibration, and thermal differences, energy harvesting devices can power devices for a long time without the need to replace batteries or connect to a power source.

[0003] However, existing energy harvesting devices are heavily dependent on the surrounding environment, such as solar power generation depends on sunlight, hydroelectric power generation depends on water droplets or ambient humidity, and wind power generation depends on ambient wind with considerable strength. In addition, it is difficult to manufacture efficient energy harvesting devices in a tiny size, especially when ensuring its sensitivity and response speed while ensuring its structural stability and controlling its manufacturing cost.

[0004] Therefore, there is an urgent need to develop a new type of power generation device that is not affected by light, wind, humidity, etc. in the surrounding environment and can stably output high-density electrical energy. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the present application proposes a power generation device with small size, stable structure, wide application range or low manufacturing cost, a preparation method and a power generation device.

[0006] In a first aspect, the present application proposes a power generation device, comprising:

[0007] A positive electrode, the positive electrode comprising a positive electrode material;

[0008] A negative electrode, the negative electrode comprising a negative electrode material;

[0009] A separator, the separator being disposed between the positive electrode and the negative electrode;

[0010] An electrolyte, in which the positive electrode, the negative electrode and the separator are immersed;

[0011] Wherein, the positive electrode material and the negative electrode material have different initial electrode potentials.

[0012] The above-mentioned power generation device is tiny in size and can be applied to a variety of microelectronic devices. It is self-formed at room temperature, has extremely low energy consumption, is green, safe and environmentally friendly, and is suitable for large-scale promotion.

[0013] In some embodiments, the power generation device further comprises a positive electrode current collector connected to the positive electrode and a negative electrode current collector connected to the negative electrode, thereby playing a role in transmitting electrons.

[0014] In some embodiments, the positive electrode current collector is a fibrous positive electrode current collector partially inserted into the positive electrode, and the negative electrode current collector is a fibrous negative electrode current collector partially inserted into the negative electrode; in other embodiments, the fibrous positive electrode current collector and the fibrous negative electrode current collector each independently include at least one of conductive carbon fiber and conductive metal wire; in some specific examples, the diameter of the positive electrode current collector or the negative electrode current collector is independently 50μm to 200μm. The diameter within the above range is conducive to the insertion of the positive electrode current collector and the negative electrode current collector into the positive electrode and the negative electrode, thereby improving the power generation performance of the power generation device.

[0015] In some embodiments, the positive electrode material and the negative electrode material independently include at least one of graphene hard particles, MXene hard particles, graphene / MXene composite hard particles, graphene / carbide composite hard particles, graphene / carbon-based material composite hard particles, graphene / metal oxide composite hard particles, graphene / nitride composite hard particles, graphene / sulfide composite hard particles, and graphene / conductive polymer composite hard particles. Thus, the material source is wide and the cost is low.

[0016] In some embodiments, the separator includes at least one of a cellulose membrane, a non-woven film, a polytetrafluoroethylene hydrophilic separator, a polyvinylidene fluoride hydrophilic separator, and a glass fiber separator. Thus, the material source is wide, and the positive and negative electrodes of the power generation device can be isolated to prevent short circuit.

[0017] In some embodiments, the electrolyte includes an ion-containing liquid; in other embodiments, the ion-containing liquid includes at least one of tap water, river water, lake water, seawater, laboratory salt solution, acid solution, alkaline solution, and ionic liquid. Thus, the material source is wide, the cost is low, and it plays the role of conducting electrons between the positive electrode and the negative electrode of the power generation device.

[0018] In some embodiments, the volume of the power generation device is 0.0001 cm 3 ~0.006cm 3 In other embodiments, the volume of the power generation device is 0.001cm 3 ~0.003cm 3 Therefore, the power generation device is small in size and can be applied to a variety of microelectronic devices.

[0019] In some embodiments, the power generation device further comprises an outer package, in which the positive electrode, the negative electrode, the separator and the electrolyte are contained, and the packaging method of the outer package comprises at least one of a heat shrink tube, a hot melt adhesive and a photocuring agent.

[0020] The second aspect of the present application proposes a method for preparing a power generation device, comprising: stacking a positive electrode, a separator and a negative electrode in sequence to obtain an electrode assembly; and soaking the electrode assembly in an electrolyte to obtain the power generation device. The preparation method described in the present application is simple to operate, spontaneously dehydrates and shrinks at room temperature, has extremely low energy consumption, and is green, safe and environmentally friendly.

[0021] In some embodiments, the electrode assembly is prepared by the following steps:

[0022] (1) mixing positive electrode raw materials to prepare positive electrode hydrogel;

[0023] (2) mixing negative electrode raw materials to prepare negative electrode hydrogel;

[0024] (3) The positive electrode hydrogel, the separator and the negative electrode hydrogel are stacked in sequence, and the obtained intermediate product is dehydrated to obtain the electrode assembly.

[0025] When the electrode assembly is prepared by the above method, the water inside the hydrogel will evaporate spontaneously at room temperature, which is not only simple to operate but also effectively reduces energy consumption.

[0026] In some embodiments, the positive electrode hydrogel and the negative electrode hydrogel independently include at least one of graphene hydrogel, MXene hydrogel and composite hydrogel, the composite hydrogel includes graphene and composite materials, the composite materials include at least one of metal oxides, carbides, nitrides, sulfides, conductive polymers and carbon-based materials; and the positive electrode hydrogel and the negative electrode hydrogel are different. Thus, the source of materials is wide, and the difference between the positive electrode hydrogel and the negative electrode hydrogel can make the positive electrode material and the negative electrode material show different initial electrode potentials, thereby generating an initial potential difference, which is beneficial to the power generation of the power generation device.

[0027] In some embodiments, in the composite hydrogel, the mass ratio of the graphene to the composite material is 1:1 to 1:5. Within the above ratio range, the composite hydrogel can be better formed, which is conducive to the power generation effect of the power generation device.

[0028] In some embodiments, before dehydrating the intermediate product, the process further includes: inserting the fibrous positive electrode current collector into the positive electrode hydrogel, and inserting the fibrous negative electrode current collector into the negative electrode hydrogel, thereby achieving the function of electron transmission.

[0029] In some embodiments, soaking the electrode assembly in an electrolyte includes: dripping the electrolyte into the electrode assembly, thereby allowing electrons to be conducted between the positive electrode and the negative electrode of the power generation device.

[0030] In some embodiments, the dehydration includes placing the intermediate product on a hydrophobic surface and leaving it in an air environment for 1 hour to 8 hours, thereby facilitating the hydrogel to fully dehydrate and shrink to form, and finally obtaining a power generation device with a regular structure.

[0031] In some embodiments, the size of the positive electrode hydrogel and the negative electrode hydrogel are independently 2mm×2mm to 10mm×10mm, and the thickness of the positive electrode hydrogel and the negative electrode hydrogel are independently 1mm to 3mm. This is conducive to accelerating the electron and ion transmission rate, thereby improving the power generation performance of the power generation device.

[0032] In some embodiments, the thickness of the separator is 10 μm to 30 μm. Within the above thickness range, it is beneficial for the separator and the hydrogel to shrink together, thereby manufacturing a complete power generation device.

[0033] The third aspect of the present application provides a power generation device, comprising the power generation device described in the first aspect of the present application or the power generation device prepared by the method described in the second aspect of the present application. Thus, the power generation device is not affected by light, wind, humidity, etc. in the surrounding environment, and can stably output high-density electrical energy.

[0034] In some embodiments, the power-consuming device further includes a switch, an external circuit and a load; the power generating device, the switch, the external circuit and the load are connected in series to form a loop. Thus, the external circuit can be continuously closed and opened by the switch control to realize power generation and recovery of the power generating device, and the cycle is continuously cyclic to realize cyclic power generation.

[0035] In some embodiments, the switch includes at least one of a mechanical control switch, a light control switch, a temperature and heat control switch, an electrical control switch, a timing control switch, and a cycle time relay. Thus, the types of switches and control methods are rich, and the range of choices is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the preparation process of the power generation device of an embodiment of the present application.

[0037] Figure 2 This is an electronic photograph of the power generation device prepared in Example 1 of the present application.

[0038] Figure 3 It is a curve diagram of voltage and current output of the power generation device prepared in Example 1 of the present application in a cycle in which the circuit is closed for 1 second and opened for 20 minutes.

[0039] Figure 4 This is a curve diagram of the voltage and current output of the power generation device prepared in Example 2 of the present application in a cycle in which the circuit is closed for 1 second and opened for 20 minutes.

[0040] Figure 5 This is a curve diagram of the voltage and current output of the power generation device prepared in Example 3 of the present application in a cycle in which the circuit is closed for 1 second and opened for 30 minutes. DETAILED DESCRIPTION

[0041] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0042] In a first aspect, the present application proposes a power generation device, comprising:

[0043] A positive electrode, the positive electrode comprising a positive electrode material;

[0044] A negative electrode, the negative electrode comprising a negative electrode material;

[0045] A separator, the separator being disposed between the positive electrode and the negative electrode;

[0046] An electrolyte, in which the positive electrode, the negative electrode and the separator are immersed;

[0047] Wherein, the positive electrode material and the negative electrode material have different initial electrode potentials.

[0048] It should be noted that the power generation device proposed in this application has an initial non-conductive external circuit (no conductive loop is formed between the positive and negative electrodes). In the electrolyte, the two different electrode materials exhibit different initial electrode potentials, so there is an initial potential difference between the positive and negative electrodes. There is no specific requirement for the initial potential difference, as long as it is greater than 0; when the external circuit is closed, due to the potential difference, electrons flow from the negative electrode to the positive electrode, the potential difference between the positive and negative electrodes decreases (equipotential), and the external circuit generates current. At the same time, the ionic state of the interface between the positive and negative electrodes and the electrolyte changes, that is, the ions that generate the initial electrode potential migrate away from the surface of the electrode material. When the external circuit is disconnected again, due to the intrinsic characteristics of the two different materials, the ions in the electrolyte are rearranged again, and the electrode potential of the electrode material is restored to the inherent initial electrode potential. By continuously closing and disconnecting the external circuit through switch control, the power generation and recovery of the power generation device can be realized, and it is continuously cycled to achieve cyclic power generation.

[0049] In some embodiments, the power generation device further includes a positive electrode current collector connected to the positive electrode and a negative electrode current collector connected to the negative electrode.

[0050] In some embodiments, the positive electrode current collector is a fibrous positive electrode current collector partially inserted into the positive electrode, and the negative electrode current collector is a fibrous negative electrode current collector partially inserted into the negative electrode; in other embodiments, the fibrous positive electrode current collector and the fibrous negative electrode current collector each independently include at least one of conductive carbon fibers and conductive metal wires; in some specific examples, the diameters of the positive electrode current collector and the negative electrode current collector are each independently 50μm to 200μm, for example, 50μm, 100μm, 150μm or 200μm, etc.

[0051] It can be understood that the conductive fiber used as the positive electrode current collector or the negative electrode current collector can be various conductive metal wires and conductive carbon fibers. The diameter is within the above range, which is conducive to the positive electrode current collector and the negative electrode current collector being inserted into the positive electrode and the negative electrode respectively, thereby improving the power generation performance of the power generation device. If the diameter is too small, the conductive fiber is easy to break and cannot be inserted into the positive electrode and the negative electrode, and the contact area with the electrode material is small, which affects the performance of the power generation device; if the diameter is greater than 200μm, it will be thicker than the thickness of the electrode material after shrinkage, and the electrode material will be destroyed by the current collector, and a complete power generation device cannot be prepared.

[0052] In some embodiments, the positive electrode material and the negative electrode material independently include at least one of graphene hard particles, MXene hard particles, graphene / MXene composite hard particles, graphene / carbide composite hard particles, graphene / carbon-based material composite hard particles, graphene / metal oxide composite hard particles, graphene / nitride composite hard particles, graphene / sulfide composite hard particles, and graphene / conductive polymer composite hard particles. Wherein, the hard particles are obtained by spontaneous dehydration of the positive electrode hydrogel and the negative electrode hydrogel at room temperature. As a result, the material source is wide and the cost is low.

[0053] In some embodiments, the separator includes at least one of a cellulose membrane, a non-woven film, a polytetrafluoroethylene hydrophilic separator, a polyvinylidene fluoride hydrophilic separator, and a glass fiber separator. Thus, the material source is wide, and the positive and negative electrodes of the power generation device can be isolated to prevent short circuit.

[0054] In some embodiments, the electrolyte includes an ion-containing liquid; in other embodiments, the ion-containing liquid includes at least one of tap water, river water, lake water, seawater, laboratory salt solution, acid solution, alkaline solution, and ionic liquid. In some specific examples, the electrolyte is sodium chloride or lithium chloride. As a result, the material source is wide and the cost is low, and it can play the role of conducting electrons between the positive electrode and the negative electrode of the power generation device.

[0055] In some embodiments, the volume of the power generation device is 0.0001 cm 3 ~0.006cm 3In other embodiments, the volume of the power generation device is 0.001cm 3 ~0.003cm 3 In some specific examples, the volume of the power generation device can be 0.0001cm 3 、0.0005cm 3 , 0.001cm 3 , 0.002cm 3 、0.0025cm 3 、0.003cm 3 、0.005cm 3 or 0.006cm 3 Etc. Therefore, the power generation device is small in size and can be applied to a variety of microelectronic devices.

[0056] In some embodiments, the power generation device further includes an outer package, in which the positive electrode, the negative electrode, the diaphragm and the electrolyte are contained. It should be noted that the electrolyte can be an aqueous, gel-based or solid electrolyte, as long as it is conductive. If it is a solid electrolyte, the electrode material-solid electrolyte-electrode material forms a sandwich structure and does not require packaging; if it is a gel and aqueous electrolyte, whether to encapsulate or not depends on the usage scenario. The electrolyte is adsorbed and filled into the entire power generation device, and can be encapsulated with heat shrink tubing, hot melt adhesive, light curing agent, etc. It can also be replenished or not encapsulated for a short time in a high humidity environment or a fixed environment.

[0057] The second aspect of the present application provides a method for preparing a power generation device, comprising:

[0058] S1: stacking the positive electrode, separator and negative electrode in sequence to obtain an electrode assembly.

[0059] In some embodiments, the electrode assembly is prepared by the following steps:

[0060] (1) mixing positive electrode raw materials to prepare positive electrode hydrogel;

[0061] (2) mixing negative electrode raw materials to prepare negative electrode hydrogel;

[0062] (3) The positive electrode hydrogel, the separator and the negative electrode hydrogel are stacked in sequence, and the obtained intermediate product is dehydrated to obtain the electrode assembly.

[0063] In some embodiments, the positive electrode hydrogel and the negative electrode hydrogel each independently include at least one of a graphene hydrogel, a MXene hydrogel and a composite hydrogel, the composite hydrogel includes graphene and a composite material, the composite material includes at least one of a metal oxide, a carbide, a nitride, a sulfide, a conductive polymer and a carbon-based material; and the positive electrode hydrogel and the negative electrode hydrogel are different.

[0064] In some embodiments, in the composite hydrogel, the mass ratio of the graphene to the composite material is 1:1 to 1:5, for example, 1:1, 1:2, 1:3, 1:4 or 1:5, etc. It is understood that if the amount of the composite material added is too much, the hydrogel cannot be formed in the hydrothermal process, and if the amount of the composite material added is too little, it cannot produce electricity when used as an electrode material for a power generation device in the subsequent process.

[0065] It should be noted that after the positive electrode hydrogel and the negative electrode hydrogel are prepared, they need to be cut by laser to obtain hydrogel sheets of the same size. Depending on the different geometric structures of the hydrogel sheets obtained during the laser cutting process, the prepared micro-granular power generation device can present different three-dimensional geometric shapes.

[0066] In some embodiments, the size of the positive electrode hydrogel and the negative electrode hydrogel are independently 2mm×2mm~10mm×10mm, and the thickness of the positive electrode hydrogel and the negative electrode hydrogel are independently 1mm~3mm. For example, the size of the hydrogel can be 2mm×2mm, 4mm×4mm, 6mm×6mm, 8mm×8mm or 10mm×10mm, etc., and the thickness can be 1mm, 1.5mm, 2mm, 2.5mm or 3mm, etc. It can be understood that if the size of the hydrogel is too large, the distance between the electrode material and the current collector in the final granular power generation device increases, the ion and electron transmission distance increases, and the power generation performance deteriorates; if the size is too small, the interaction area between the positive electrode, the negative electrode and the diaphragm is reduced, and an integrated device cannot be formed; if the thickness is too small, the laser cutting accuracy cannot be achieved; if the thickness is too large, it will affect the internal ion transmission rate of the electrode material, and ultimately affect the performance of the power generation device.

[0067] In some embodiments, before dehydrating the intermediate product, the process further includes: inserting the fibrous positive electrode current collector into the positive electrode hydrogel, and inserting the fibrous negative electrode current collector into the negative electrode hydrogel, so that the current collector can play a role in transmitting electrons.

[0068] In some embodiments, the dehydration comprises: placing the intermediate on a hydrophobic surface and leaving it to stand in an air environment for 1 to 8 hours. For example, the standing time may be 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours or 8 hours. The standing time is related to the size of the hydrogel. In order to allow the hydrogel to fully dehydrate and shrink, the standing time may be extended accordingly as the size of the hydrogel increases.

[0069] In some embodiments, the hydrophobic surface may be a hydrophobic substrate, such as a polytetrafluoroethylene plate, a hydrophobic plastic plate or a hydrophobic glass, etc. The hydrophobic substrate can effectively reduce the interaction force between the hydrogel-based electrode material and the substrate during the shrinkage process, so that the shrinkage rates of the upper and lower surfaces of the sandwich structure hydrogel device are consistent, and finally a micro-granular power generation device with a regular structure is obtained.

[0070] In some embodiments, the thickness of the diaphragm is 10 μm to 30 μm. For example, the thickness of the diaphragm can be 10 μm, 20 μm or 30 μm. It can be understood that if the thickness of the diaphragm is too thin, the electrode material is easy to pierce the diaphragm during the contraction of the hydrogel electrode, causing a short circuit in the power generation device; if the thickness is too thick, the diaphragm cannot wrinkle and shrink with the electrode material, and ultimately cannot form an integrated micro-granular power generation device.

[0071] S2: Immersing the electrode assembly in an electrolyte to obtain the power generation device.

[0072] In some embodiments, soaking the electrode assembly in the electrolyte includes: dripping the electrolyte into the electrode assembly, wherein the electrolyte is adsorbed and filled in the entire power generation device, so that electrons are conducted between the positive electrode and the negative electrode of the power generation device.

[0073] Specifically, refer to Figure 1 , the preparation method of the power generation device comprises the following steps:

[0074] (1) At a concentration of 2.5 mg mL -1 ~4 mg mL -1 Graphene oxide aqueous solution and other composite materials are used as raw materials, and graphene-based composite hydrogel is prepared by hydrothermal method at 160℃~200℃;

[0075] (2) At a concentration of 10 mg mL -1 ~20mg mL -1 MXene aqueous solution was used as raw material to prepare MXene hydrogel by replacement method;

[0076] (3) Using laser to cut graphene composite hydrogel and MXene hydrogel to obtain hydrogel sheets of the same size;

[0077] (4) The graphene composite hydrogel sheet is used as the positive electrode, the MXene hydrogel sheet is used as the negative electrode, and a cellulose membrane of the same size and thickness of 10 μm to 30 μm is assembled into a sandwich structure, and conductive fibers are inserted into the positive electrode hydrogel and the negative electrode hydrogel respectively as current collectors;

[0078] (5) The assembled device is placed on a hydrophobic substrate and shrinks spontaneously at room temperature to a volume 1 / 100 of that before shrinkage. Electrolyte is added dropwise to obtain a power generation device with a size of 0.0001 cm 3 ~0.006cm 3 , connect the positive electrode current collector, the negative electrode current collector to the switch and the load in the external circuit to generate electricity in a cycle.

[0079] It can be understood that the positive electrode material and negative electrode material of the power generation device prepared in this application are obtained by the spontaneous evaporation casting process of the hydrogel. Under room temperature, the water inside the hydrogel evaporates spontaneously, and under the influence of capillary force, the water molecules interact with the graphene sheets, and the graphene sheets shrink, wrinkle, and reduce in size. The macroscopic size of the hydrogel is about 1 / 100 of that before evaporation casting, and the size of the prepared micro-granular power generation device is as small as 0.0001cm 3 , which can be applied to a variety of microelectronic devices.

[0080] The third aspect of the present application provides a power generation device, including the power generation device described in the first aspect of the present application or the power generation device prepared by the method described in the second aspect of the present application.

[0081] In some embodiments, the electrical equipment further includes a switch, an external circuit and a load; the power generation device, the switch, the external circuit and the load are connected in series to form a loop.

[0082] In some embodiments, the switch includes at least one of a mechanical control switch, a light control switch, a temperature and heat control switch, an electrical control switch, a timing control switch, and a cycle time relay. Among them, the mechanical control switch includes a rotary and selector switch, a wave switch, and a slide switch.

[0083] It can be understood that the power generation process of the power generation device described in the present application does not require external stimulation such as light and heat, and only generates and recovers the power by switching the device on and off. During the cyclic power generation process, the closed power generation time of each cycle is 0.1s to 10s, and the circuit breaker recovery time is 1min to 30min; if the closed power generation time is too short, the power generation in one cycle will be too small, and the practical value will be reduced. If the closed power generation time is too long, the electrode material will be deeply discharged each time, and the recovery time will be greatly increased, which will also affect the power generation performance. If the circuit breaker recovery time of each cycle is too short, the electrode material cannot be fully recovered after discharge, affecting the power generation performance. If the circuit breaker recovery time is too long, the power generation cycle will be lengthened, the power generation will be reduced, and the practicality will be reduced.

[0084] The embodiments of the present application are described in detail below.

[0085] In the following examples, the graphene oxide dispersion was prepared by the following method:

[0086] (1) Prepare a 0°C ice water bath, place 260mL of concentrated sulfuric acid (98wt%) in a 3000mL beaker, add 10g of 200-mesh flake graphite powder during mechanical stirring, and continue stirring for 2h. Then slowly add 30g of potassium permanganate, measure the temperature at any time, and ensure that the temperature does not exceed 5°C during the whole process. Then transfer the beaker to a 50°C water bath and stir for 8h to 12h to obtain graphite oxide slurry.

[0087] (2) Slowly pour the obtained graphite oxide slurry into the stirred excess ice water, and keep the temperature rise no more than 5°C during the water addition process. Cool to room temperature, then add excess hydrogen peroxide (30wt%), and stop adding hydrogen peroxide when the dispersion changes from dark brown to golden yellow and no bubbles are generated. Continue to stir the solution for 20 minutes to allow it to fully mix and react, and then let it stand to settle. Pour off the upper clear liquid, take 3000mL of deionized water and add it to the lower sediment, stir for 20 minutes and let it stand to settle, pour off the upper clear liquid, take another 3000ml of deionized water and add it to the lower sediment, stir, let it stand to settle and pour off the upper clear liquid. This process is repeated once or twice a day for 7 to 10 times. The sediment obtained at the last time is placed in a dialysis bag for dialysis, and the water is changed every day until the pH of the solution is 7. Then the sediment is dialyzed at 10000rpm min -1 Centrifuge at a speed of 30 min to remove impurities in the lower layer and the supernatant to obtain 3 mg mL -1 ~15mg mL -1 The graphene oxide dispersion is calibrated to a certain concentration and set aside.

[0088] Example 1

[0089] (1) Preparation of positive electrode hydrogel: Take 60 ml of 3 mg mL -1 The graphene oxide aqueous solution was mixed with 0.5 g RuO2, stirred for 30 min, and then placed in a hydrothermal reactor and hydrothermal at 180 ° C for 6 h to prepare a graphene / RuO2 composite hydrogel;

[0090] (2) Preparation of negative electrode hydrogel: Take 1 ml of 20 mg mL -1 The MXene aqueous solution was placed in a volume of 1 cm 3 Place the MXene block in an excess 5M HCl solution, allow to react for 6 hours, and then wash repeatedly with excess secondary water to obtain a MXene hydrogel.

[0091] (3) Preparation of hydrogel electrode sheets: Using laser cutting, graphene / RuO2 composite hydrogel and MXene hydrogel were obtained to obtain hydrogel sheets with a size of 6 mm × 6 mm × 1.5 mm;

[0092] (4) Preliminary assembly of power generation devices: The graphene / RuO2 composite hydrogel sheet is used as the positive electrode, the MXene hydrogel sheet is used as the negative electrode, and carbon fibers with a diameter of 100 μm are inserted into the positive electrode hydrogel sheet and the negative electrode hydrogel sheet as current collectors, and then assembled with a cellulose membrane with a size of 6 mm × 6 mm × 20 μm into a sandwich structure;

[0093] (5) Shrinkage and self-assembly of power generation device: The assembled device was placed on a polytetrafluoroethylene hydrophobic plate and allowed to shrink spontaneously for 5 h at room temperature. The device volume shrank by dehydration. A 0.1 M sodium chloride electrolyte was added dropwise to obtain a volume of 0.001 cm 3 The power generation device (structural diagram refers to Figure 2 ), connect the positive electrode current collector, the negative electrode current collector to the switch and the load in the external circuit, and then the cycle power generation can be carried out.

[0094] In this embodiment, the positive current collector and the negative current collector of the power generation device are connected to a control switch and a voltmeter and an ammeter for testing the power generation signal in an external circuit. The switch is used to control the open / closed state of the circuit, thereby controlling the generation and recovery of the electrical signal. The voltmeter and ammeter test the open circuit voltage and short circuit current of the power generation device respectively.

[0095] In the open circuit state, the initial potential difference between the graphene / RuO2 positive electrode and the MXene negative electrode in a 0.1M sodium chloride solution is about 0.42-0.46V. When the switch is closed, due to the potential difference, electrons flow from the negative electrode to the positive electrode, the potential difference between the positive and negative electrodes decreases (equipotential), and the external circuit generates a current of about 3mA. At the same time, the ion state at the interface between the positive and negative electrodes and the solution changes, that is, the ions that generate the initial electrode potential migrate away from the surface of the electrode material. At this time, the potential difference between the graphene / RuO2 positive electrode and the MXene negative electrode is 0V through the external circuit. When the external circuit is disconnected again, due to the intrinsic characteristics of the two different materials, the ions in the solution are rearranged again, and the electrode potential of the electrode material is restored to the inherent initial electrode potential. The potential difference of the power-generating device gradually recovers from 0 to the initial potential difference of 0.42-0.46V. Through switch control, the circuit is closed for 1 second and opened for 20 minutes, and the external circuit is closed and opened continuously, so that the power generation and recovery of the power generation device can be realized, and the cycle can be continuously realized to achieve cyclic power generation. Figure 3 As shown, the open circuit voltage of the graphene / RuO2-MXene power generation device is about 0.45V, the peak short-circuit current when the switch is closed is about 3mA, and it shows good stability during multiple cycles of power generation.

[0096] Example 2

[0097] The difference from Example 1 is that the electrolyte is replaced with a 0.01 M lithium chloride solution.

[0098] Figure 4 The current and voltage performance of the power generation device using 0.01M lithium chloride solution as the electrolyte is shown, which proves that the power generation device of the embodiment of the present application can show excellent power generation performance in different types and concentrations of electrolyte systems.

[0099] Example 3

[0100] (1) Preparation of positive electrode hydrogel: Take 60 ml of 3 mg mL -1 The graphene oxide aqueous solution was mixed with 0.2 g PtC powder, stirred vigorously for 30 min, and then placed in a hydrothermal reactor and hydrothermal at 180 ° C for 6 h to prepare the graphene / PtC composite hydrogel;

[0101] (2) Preparation of negative electrode hydrogel: same as Example 1.

[0102] (3) Preparation of hydrogel electrode sheets: Using laser cutting, graphene / PtC composite hydrogel and MXene hydrogel were obtained to obtain hydrogel sheets with a size of 8 mm × 8 mm × 2 mm;

[0103] (4) Preliminary assembly of power generation devices: The graphene / PtC composite hydrogel sheet is used as the positive electrode, the MXene hydrogel sheet is used as the negative electrode, and a gold wire with a diameter of 150 μm is inserted into the positive and negative electrode hydrogel sheets as current collectors, and then assembled with a cellulose membrane with a size of 8 mm × 8 mm × 20 μm into a sandwich structure;

[0104] (5) Shrinkage and self-assembly of power generation device: The assembled device was placed on a polytetrafluoroethylene hydrophobic plate and allowed to shrink spontaneously for 6 h at room temperature. The device volume shrank by dehydration. A 0.1 M sodium chloride electrolyte was added dropwise to obtain a volume of 0.0025 cm 3 The power generation device can generate electricity in a cycle by connecting the positive electrode collector, the negative electrode collector, the switch and the load in the external circuit.

[0105] In the open circuit state, the initial potential difference between the graphene / PtC positive electrode and the MXene negative electrode in a 0.1M sodium chloride solution is about 0.55-0.6V. When the switch is closed, due to the potential difference, electrons flow from the negative electrode to the positive electrode, the potential difference between the positive and negative electrodes decreases (equipotential), and the external circuit generates a current of about 5mA. At the same time, the ion state at the interface between the positive and negative electrodes and the solution changes, that is, the ions that generate the initial electrode potential migrate away from the surface of the electrode material. At this time, the potential difference between the graphene / PtC positive electrode and the MXene negative electrode is 0V through the external circuit. When the external circuit is disconnected again, due to the intrinsic characteristics of the two different materials, the ions in the solution are rearranged again, and the electrode potential of the electrode material is restored to the inherent initial electrode potential. The potential difference of the power-generating device gradually recovers from 0 to the initial potential difference of 0.55-0.6V. Through switch control, the circuit is closed for 1 second and opened for 30 minutes, and the external circuit is continuously closed and opened to realize the power generation and recovery of the power generation device, and to realize cyclic power generation. Figure 5 As shown, the open circuit voltage of the graphene / PtC-MXene power generation device is about 0.56V, the peak short-circuit current when the switch is closed is about 5.2mA, and it shows good stability during multiple cycles of power generation.

[0106] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0107] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A power generation device, characterized in that: include: A positive electrode, the positive electrode comprising a positive electrode material; A negative electrode, the negative electrode comprising a negative electrode material; A separator, the separator being disposed between the positive electrode and the negative electrode; An electrolyte, in which the positive electrode, the negative electrode and the separator are immersed; Wherein, the positive electrode material and the negative electrode material have different initial electrode potentials.

2. The power generating device according to claim 1, characterized in that: Also includes: a positive electrode current collector connected to the positive electrode and a negative electrode current collector connected to the negative electrode; Preferably, the positive electrode current collector is a fibrous positive electrode current collector partially inserted into the positive electrode; Preferably, the negative electrode current collector is a fibrous negative electrode current collector partially inserted into the negative electrode; Preferably, the fibrous positive electrode current collector and the fibrous negative electrode current collector each independently include at least one of conductive carbon fibers and conductive metal wires; Preferably, the diameter of the positive electrode current collector and the diameter of the negative electrode current collector are independently 50 μm to 200 μm.

3. The power generation device according to claim 1, characterized in that: in, The positive electrode material and the negative electrode material independently include at least one of graphene hard particles, MXene hard particles, graphene / MXene composite hard particles, graphene / carbide composite hard particles, graphene / carbon-based material composite hard particles, graphene / metal oxide composite hard particles, graphene / nitride composite hard particles, graphene / sulfide composite hard particles, and graphene / conductive polymer composite hard particles; and / or The separator includes at least one of a cellulose membrane, a non-woven fabric film, a polytetrafluoroethylene hydrophilic membrane, a polyvinylidene fluoride hydrophilic membrane, and a glass fiber separator.

4. The power generating device according to claim 1, characterized in that: The electrolyte includes a liquid containing ions; Preferably, the ion-containing liquid includes at least one of tap water, river water, lake water, sea water, laboratory salt solution, acid solution, alkaline solution, and ionic liquid.

5. The power generating device according to claim 1, characterized in that: The volume of the power generation device is 0.0001cm 3 ~0.006cm 3 , preferably 0.001 cm 3 ~0.003cm 3 ; Optionally, the power generation device further comprises an outer package, in which the positive electrode, the negative electrode, the separator and the electrolyte are contained, and the packaging method of the outer package comprises at least one of a heat shrink tube, a hot melt adhesive and a light curing agent.

6. A method for preparing the power generation device according to any one of claims 1 to 5, characterized in that: include: The positive electrode, the separator and the negative electrode are stacked in sequence to obtain an electrode assembly; The electrode assembly is immersed in an electrolyte to obtain the power generation device.

7. The method according to claim 6, characterized in that The electrode assembly is prepared by the following steps: (1) mixing positive electrode raw materials to prepare positive electrode hydrogel; (2) mixing negative electrode raw materials to prepare negative electrode hydrogel; (3) The positive electrode hydrogel, the separator and the negative electrode hydrogel are stacked in sequence, and the obtained intermediate product is dehydrated to obtain the electrode assembly.

8. The method according to claim 7, characterized in that The positive electrode hydrogel and the negative electrode hydrogel each independently include at least one of a graphene hydrogel, a MXene hydrogel and a composite hydrogel, the composite hydrogel includes graphene and a composite material, the composite material includes at least one of a metal oxide, a carbide, a nitride, a sulfide, a conductive polymer and a carbon-based material; and the positive electrode hydrogel and the negative electrode hydrogel are different; Preferably, in the composite hydrogel, the mass ratio of the graphene to the composite material is 1:1 to 1:

5.

9. The method according to claim 7, characterized in that: Before dehydrating the intermediate product, the method further includes: inserting the fibrous positive electrode current collector into the positive electrode hydrogel, and inserting the fibrous negative electrode current collector into the negative electrode hydrogel.

10. The method according to claim 6, characterized in that Immersing the electrode assembly in an electrolyte includes: dripping the electrolyte into the electrode assembly.

11. The method according to claim 7, characterized in that The dehydration comprises: placing the intermediate product on a hydrophobic surface and leaving it to stand in an air environment for 1 hour to 8 hours.

12. The method according to claim 7, characterized in that The sizes of the positive electrode hydrogel and the negative electrode hydrogel are independently 2 mm×2 mm to 10 mm×10 mm, and the thicknesses of the positive electrode hydrogel and the negative electrode hydrogel are independently 1 mm to 3 mm; and / or The thickness of the separator is 10 μm to 30 μm.

13. An electrical equipment, characterized in that: The invention comprises the power generation device according to any one of claims 1 to 5 or the power generation device prepared by the method according to any one of claims 6 to 12.

14. The electrical equipment according to claim 13, characterized in that: The electrical equipment further comprises a switch, an external circuit and a load; the power generation device, the switch, the external circuit and the load are connected in series to form a loop; Preferably, the switch includes at least one of a mechanical control switch, a light control switch, a temperature and heat control switch, an electrical control switch, a timing control switch, and a cycle time relay.

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