Water-activated power supply device and preparation method and application thereof

Abstract

The application discloses a water-activated energy supply device and a preparation method and application thereof. The water-activated energy supply device comprises a negative electrode layer, a hydrophilic diaphragm layer and a positive electrode layer which are sequentially stacked. The negative electrode layer comprises a negative electrode metal layer and a hydrophilic coating layer arranged on the surface of the negative electrode metal layer. The hydrophilic diaphragm layer is formed in situ on the surface of the hydrophilic coating layer of the negative electrode layer. The hydrophilic coating layer comprises a first hydrophilic polymer. The hydrophilic diaphragm layer comprises a polyamide and a second hydrophilic polymer. The positive electrode layer comprises a positive electrode active material and an electrolyte salt. The water-activated energy supply device has the advantages of simple activation mode, rapid voltage response, rapid rebound of pulse discharge voltage, long storage time and good flexibility, and has a good application prospect in emergency rescue microsystems, deep sea environment monitoring equipment, environment detection equipment, flexible medical monitoring equipment, wearable devices or beauty care equipment.

Description

Technical Field

[0001] This invention belongs to the field of energy supply technology, and in particular relates to a water-activated energy supply device, its preparation method and application. Background Technology

[0002] Water-activated power supply devices, as a special type of on-demand responsive energy supply unit, possess significant advantages in ultra-long steady-state storage lifetime and on-demand activation characteristics due to their unique power supply mechanism (using water as an energy excitation source). This makes them an ideal choice for applications requiring long-term dormancy, constant readiness, and ultra-fast response. Typical application areas include emergency rescue microsystems, deep-sea environmental monitoring, special environment exploration, and flexible medical monitoring equipment. As microelectronics technology evolves towards flexibility and high integration, these power supply devices face more stringent comprehensive performance requirements, including: 1) ultra-fast response characteristics with instantaneous activation upon contact with water; 2) dynamic load capacity to support high-current pulse output and rapid voltage rebound; 3) mechanical flexibility to adapt to wearable devices or complex curved surface integration scenarios; and 4) electrochemical stability with continuous and stable power output after activation.

[0003] Traditional water-activated power supply device technologies (such as magnesium-silver chloride, magnesium-cuprous chloride, aluminum-silver oxide, and aluminum-oxygen systems) have certain advantages in terms of storage life and power supply device capacity, but they still have significant limitations in meeting the aforementioned comprehensive performance requirements. These limitations include slow activation response speed, poor pulse discharge performance, severe self-discharge, high manufacturing cost, and complex structure and manufacturing process. These shortcomings greatly restrict the development and application of water-activated power supply devices.

[0004] In recent years, despite some progress in electrode materials and electrolytes, there is still significant room for improvement in the complexity of the fabrication process and the looseness of the internal structure of power supply devices. For example, existing processes include, but are not limited to: precursor inert atmosphere protection, centrifugal spray drying, printing coating, rolling, water inlet setting, opening, and sealing. These water-activated power supply device fabrication processes are all quite complex and rely on a stacked structure requiring external clamping for pressurization to ensure normal operation. Further breakthroughs are needed in optimizing diaphragm performance and electrode-electrolyte interface characteristics, as well as optimizing the structure and fabrication process of water-activated power supply devices to achieve low cost, long shelf life, rapid activation, excellent pulse discharge performance, and good flexibility. Summary of the Invention

[0005] In order to overcome at least one of the problems of traditional water-activated batteries in the prior art, such as complex assembly, high interface impedance, slow response speed, poor mechanical flexibility, poor pulse discharge performance, and poor long-term dry storage performance, one of the objectives of the present invention is to provide a water-activated power supply device that has the comprehensive advantages of simple activation method, rapid voltage response, rapid pulse discharge voltage rebound, long storage time, and good flexibility.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned water-activated energy supply device.

[0007] The third objective of this invention is to provide an application of the above-mentioned water-activated energy supply device.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides a water-activated power supply device, comprising a negative electrode layer, a hydrophilic membrane layer and a positive electrode layer stacked sequentially; the negative electrode layer includes a negative electrode metal layer and a hydrophilic coating disposed on the surface of the negative electrode metal layer; the hydrophilic membrane layer is formed in situ on the surface of the hydrophilic coating of the negative electrode layer; The hydrophilic coating comprises a first hydrophilic polymer; the hydrophilic membrane layer comprises polyamide and a second hydrophilic polymer; and the positive electrode layer comprises a positive electrode active material and an electrolyte salt.

[0009] This invention employs a hydrophilic coating on the surface of the negative electrode layer to protect the negative electrode metal layer and prevent oxidation of the metal negative electrode during storage. A high-performance hydrophilic membrane layer is prepared using a specific polymer combination of polyamide and hydrophilic polymers, optimizing the membrane's hydrophilicity, ionic conductivity, and mechanical flexibility. The positive electrode layer composition is optimized to include pre-placed electrolyte salts, promoting rapid electrochemical reactions and ion migration for rapid water activation. The device does not undergo electrochemical reactions in a dry state and can be stored long-term. Upon contact with water, water rapidly penetrates the hydrophilic membrane layer and dissolves the pre-placed electrolyte salts inside the device, activating the electrochemical reaction and providing power. This invention simplifies the production process through an integrated fabrication process, effectively solving the problems of complex assembly and poor membrane wettability leading to activation delays in traditional water-activated power devices. Furthermore, it offers good flexibility, adjustable operating voltage, and adaptability to voltage requirements in different application scenarios.

[0010] In this invention, the first hydrophilic polymer may be the same as or different from the second hydrophilic polymer.

[0011] In some embodiments of the present invention, the first hydrophilic polymer includes at least one of sodium polyacrylate, polyacrylamide, polyvinyl alcohol, or polyethylene glycol; in some specific embodiments of the present invention, the first hydrophilic polymer is selected from polyvinyl alcohol (PVA).

[0012] In some embodiments of the present invention, the second hydrophilic polymer includes at least one of polyacrylamide, polyvinyl alcohol, or polyethylene glycol; in some specific embodiments of the present invention, the second hydrophilic polymer is selected from polyvinyl alcohol (PVA).

[0013] In some embodiments of the present invention, the number-average molecular weights of the first hydrophilic polymer and the second hydrophilic polymer are each independently 10. 6 ~10 8 g / mol; In some specific embodiments of the present invention, the number-average molecular weights of the first hydrophilic polymer and the second hydrophilic polymer are each independently 6 × 10⁻⁶ g / mol. 6 ~8×10 7 g / mol.

[0014] In some embodiments of the present invention, the polyamide has a melt index of 5-15 g / 10 min at 240°C and 2.16 kg; in some specific embodiments of the present invention, the polyamide has a melt index of 8-12 g / 10 min at 240°C and 2.16 kg.

[0015] In some embodiments of the present invention, the negative electrode metal layer comprises an active metal; the active metal includes at least one of zinc, magnesium, or aluminum; in some specific embodiments of the present invention, the active metal is selected from zinc.

[0016] In this invention, the active metal in the negative electrode metal layer is selected from electrochemically active metals such as zinc, magnesium, and aluminum, or their alloys, as an electron supply source.

[0017] In some embodiments of the present invention, the negative electrode metal layer may be a metal foil or a composite foil; specifically, the metal foil is a foil or film composed of an active metal; the composite foil is a foil or film composed of an active metal, a conductive additive and a binder, wherein the mass percentage of the active metal is 60-90%.

[0018] In some embodiments of the present invention, the electrolyte salt includes at least one of potassium salt, sodium salt, lithium salt, or zinc salt; specifically, the potassium salt includes at least one of potassium chloride, potassium nitrate, potassium sulfate, or potassium carbonate; the sodium salt includes at least one of sodium chloride, sodium nitrate, sodium sulfate, or sodium carbonate; the lithium salt includes at least one of lithium chloride, lithium nitrate, or lithium sulfate; and the zinc salt includes at least one of zinc chloride, zinc nitrate, or zinc sulfate. In some specific embodiments of the present invention, the electrolyte salt is selected from potassium chloride.

[0019] In some embodiments of the present invention, the electrolyte salt is a dried electrolyte salt.

[0020] Dry electrolyte salts are non-conductive in the absence of water, keeping the device in a dormant state. When in contact with water, the electrolyte salts dissolve rapidly and induce the diaphragm to wet, which can cause the working voltage of the water-activated power supply device to jump rapidly, achieving rapid activation.

[0021] In some embodiments of the present invention, the positive electrode active material is selected from manganese-based oxides; in some embodiments of the present invention, the positive electrode active material is selected from manganese dioxide.

[0022] In some embodiments of the present invention, the positive electrode layer further comprises a conductive agent and a binder.

[0023] In some embodiments of the present invention, the conductive agent in the positive electrode layer includes at least one of conductive carbon black, graphite, carbon nanotubes, or graphene.

[0024] In some embodiments of the present invention, the mass ratio of the conductive agent to the positive electrode active material in the positive electrode layer is (0.1~0.3):1.

[0025] In some embodiments of the present invention, the binder in the positive electrode layer includes at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene, sodium polyacrylate, carboxymethyl cellulose, or styrene-butadiene rubber.

[0026] In some embodiments of the present invention, the mass ratio of the binder to the positive electrode active material in the positive electrode layer is (0.1~0.2):1.

[0027] In some embodiments of the present invention, the mass ratio of the polyamide to the second hydrophilic polymer in the hydrophilic membrane layer is 1:(0.1~1); in some specific embodiments of the present invention, the mass ratio of the polyamide to the second hydrophilic polymer is 1:(0.25~0.7).

[0028] In some embodiments of the present invention, the mass ratio of the positive electrode active material to the electrolyte salt in the positive electrode layer is 1:(0.1~1); in some specific embodiments of the present invention, the mass ratio of the positive electrode active material to the electrolyte salt is 1:(0.25~0.8).

[0029] In some embodiments of the present invention, the thickness of the negative electrode layer is 15~100μm; in some specific embodiments of the present invention, the thickness of the negative electrode layer is 50~90μm.

[0030] In some embodiments of the present invention, the thickness of the negative electrode metal layer is 10~70μm; in some specific embodiments of the present invention, the thickness of the negative electrode metal layer is 40~60μm.

[0031] In some embodiments of the present invention, the thickness of the hydrophilic coating in the negative electrode layer is 5~30μm; in some specific embodiments of the present invention, the thickness of the hydrophilic coating is 10~30μm.

[0032] In some embodiments of the present invention, the thickness of the hydrophilic membrane layer is 5~100μm; in some specific embodiments of the present invention, the thickness of the hydrophilic membrane layer is 50~90μm.

[0033] In some embodiments of the present invention, the thickness of the positive electrode layer is 5~100μm; in some specific embodiments of the present invention, the thickness of the positive electrode layer is 70~95μm.

[0034] In some embodiments of the present invention, the total thickness of the water-activated power supply device is 25~300μm; in some specific embodiments of the present invention, the total thickness of the water-activated power supply device is 170~275μm.

[0035] In some embodiments of the present invention, the water-activated power supply device retains a discharge efficiency of ≥95% after 200 cycles of 180° bending; and its performance degradation rate is ≤3% after 30 days of storage in an environment of -20~60℃.

[0036] In some embodiments of the present invention, the open-circuit voltage of the water-activated power supply device tends to be 0V before activation, and jumps to the working voltage within 5 seconds after contact with the activation liquid.

[0037] In some embodiments of the present invention, the water-activated power supply device has an internal resistance of 90 ohms, a capacity of 6mAh, and can withstand more than 2000 pulse discharge cycles with a current intensity of 5mA, a duration of 5 seconds, and an interval of 5 seconds.

[0038] The water-activated power supply device has an integrated structure of negative electrode-diaphragm-positive electrode with no physical bonding interface between the layers.

[0039] In some embodiments of the present invention, the activating liquid of the water-activated power supply device is an activating liquid containing water molecules; specifically, the activating liquid includes at least one of deionized water, seawater, or physiological saline. The activating liquid is used to trigger the activation of the water-activated power supply device.

[0040] A second aspect of the present invention provides a method for preparing a water-activated power supply device as described in the first aspect of the present invention, comprising the following steps: applying a hydrophilic coating to the surface of a negative electrode metal layer, and drying it to obtain a negative electrode layer having a hydrophilic coating; applying a hydrophilic membrane slurry to the surface of the hydrophilic coating of the negative electrode layer, and drying it to form the hydrophilic membrane layer in situ; applying a positive electrode slurry to the surface of the hydrophilic membrane layer, and drying it to form the positive electrode layer; The hydrophilic coating comprises a first hydrophilic polymer; the hydrophilic membrane slurry comprises polyamide and a second hydrophilic polymer; and the positive electrode slurry comprises a positive electrode active material and an electrolyte salt.

[0041] This invention establishes a continuous ion transport network through solvent interpenetration between its internal layers. Specifically, a hydrophilic coating is applied to the surface of the negative electrode metal layer. After the solvent evaporates, a dense protective hydrophilic coating forms on the negative electrode surface, preventing oxidation of the metal negative electrode during storage. A hydrophilic membrane slurry is directly applied to the surface of the negative electrode layer, achieving molecular-level anchoring through the micro-dissolution effect of the solvent at the interface. A positive electrode slurry containing electrolyte salt is applied to the dried hydrophilic membrane layer surface, achieving solid-state integration of the overall structure through solvent permeation between the interfaces. The production process is simple, achieving integrated fabrication. Furthermore, by simplifying the additive deposition process, the construction cost of the energy release unit is significantly reduced, and the system integration is improved, expanding its application range in precision microsystems. It is suitable for long-term storage, ultra-fast response, high-pulse discharge, and flexible deformation scenarios.

[0042] In some embodiments of the present invention, the content of the first hydrophilic polymer in the hydrophilic coating is 1-15 wt%; in some specific embodiments of the present invention, the content of the first hydrophilic polymer in the hydrophilic coating is 8-12 wt%.

[0043] In some embodiments of the present invention, the solvent in the hydrophilic coating is water.

[0044] In some embodiments of the present invention, the drying temperature of the hydrophilic coating is 40~80°C.

[0045] In some embodiments of the present invention, the negative electrode metal layer is pretreated before applying the hydrophilic coating to the surface of the negative electrode metal layer; the pretreatment may be physical polishing or cleaning to remove the oxide layer on the surface, which is beneficial for the subsequent preparation of the hydrophilic coating.

[0046] In some embodiments of the present invention, the polyamide content in the hydrophilic membrane slurry is 5-15 wt%; in some specific embodiments of the present invention, the polyamide content in the hydrophilic membrane slurry is 7-11 wt%.

[0047] In some embodiments of the present invention, the solvent in the hydrophilic membrane slurry includes solvent A and solvent B; solvent A includes one of formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 2-hydroxypropionic acid or oxalic acid; solvent B includes one of toluene, benzene, dichloromethane, chloroform, 1,2-dichloroethane, carbon tetrachloride, trichloroethane, acetone or petroleum ether.

[0048] The hydrophilic separator slurry employs two solvents with different evaporation rates. Solvent A dissolves the polyamide backbone and weakly wets the surface of the negative electrode layer to enhance adhesion, while solvent B has a lower evaporation rate than solvent A. This gradient evaporation of the two solvents creates a porous network structure within the separator. This invention utilizes the difference in solvent evaporation rates to allow the material to naturally form a porous structure during the drying process, resulting in a hydrophilic separator layer with a porous structure.

[0049] In some embodiments of the present invention, the mass ratio of solvent A to solvent B is 1:(0.1~3); in some specific embodiments of the present invention, the mass ratio of solvent A to solvent B is 1:(0.3~2.5).

[0050] In some embodiments of the present invention, the application rate of the hydrophilic membrane slurry is 5~100 mm / min, and the thickness of the formed wet film is 100~500 μm; in some specific embodiments of the present invention, the application rate of the hydrophilic membrane slurry is 20~40 mm / min, and the thickness of the formed wet film is 200~300 μm.

[0051] In some embodiments of the present invention, the drying temperature of the hydrophilic membrane slurry is 40~80°C.

[0052] In some embodiments of the present invention, the content of positive electrode active material in the positive electrode slurry is 10-40%; in some specific embodiments of the present invention, the content of positive electrode active material in the positive electrode slurry is 15-33%.

[0053] In some embodiments of the present invention, the positive electrode slurry is obtained by mixing each component with a positive electrode solvent and then stirring; specifically, the stirring speed of the positive electrode slurry is 500~3000 r / min, and the stirring time is 2~24 hours; further, the stirring speed of the positive electrode slurry is 1500~2500 r / min, and the stirring time is 4~12 hours.

[0054] In some embodiments of the present invention, the positive electrode solvent is selected from N-methylpyrrolidone (NMP).

[0055] In some embodiments of the present invention, the mass ratio of the positive electrode solvent to the positive electrode active material is (3~7):1.

[0056] In some embodiments of the present invention, the application rate of the positive electrode slurry is 2~20 mm / min, and the thickness of the formed wet film is 100~500 μm; in some specific embodiments of the present invention, the application rate of the positive electrode slurry is 5~10 mm / min, and the thickness of the formed wet film is 200~400 μm.

[0057] In some embodiments of the present invention, the drying temperature of the positive electrode slurry is 50~120°C; in some specific embodiments of the present invention, the drying temperature of the positive electrode slurry is 70~90°C.

[0058] During the drying process, the positive electrode slurry also solidifies the entire device, allowing the three layers of material—the negative electrode layer, the hydrophilic separator layer, and the positive electrode layer—to bond in situ, forming a tightly connected battery core without physical gaps.

[0059] In some embodiments of the present invention, the drying time of the positive electrode slurry is 30-90 min; in some specific embodiments of the present invention, the drying time of the positive electrode slurry is 50-60 min.

[0060] In some embodiments of the present invention, the hydrophilic coating, hydrophilic membrane slurry, and positive electrode slurry may be applied by printing or coating processes.

[0061] A third aspect of the present invention provides an application of the water-activated power supply device as described in the first aspect of the present invention in emergency rescue microsystems, deep-sea environmental monitoring equipment, environmental detection equipment, flexible medical monitoring equipment, wearable devices, or beauty care devices.

[0062] The beneficial effects of this invention are: The water-activated power supply device of this invention is constructed from a negative electrode layer, a hydrophilic membrane layer, and a positive electrode layer through an in-situ integration process. A hydrophilic coating is applied to the surface of the negative electrode layer to protect the negative electrode metal layer and prevent oxidation during storage. The hydrophilic membrane layer, made of polyamide and hydrophilic polymer, separates the positive and negative electrode layers and possesses excellent hydrophilic properties. The positive electrode layer contains a pre-placed electrolyte salt, enabling the device to achieve rapid water activation. This water-activated power supply device offers a combination of advantages, including simple activation, rapid voltage response, rapid pulse discharge voltage rebound, good long-term static storage stability, strong pulse load capacity, and good flexibility. It shows promising application prospects in emergency rescue microsystems, deep-sea environmental monitoring equipment, environmental detection equipment, flexible medical monitoring equipment, wearable devices, and beauty care devices. Attached Figure Description

[0063] Figure 1 This is a physical image of the water-activated power supply device in Example 1.

[0064] Figure 2 This is a bending photograph of the water-activated power supply device of Example 1.

[0065] Figure 3 This is a cross-sectional SEM image of the water-activated power supply device in Example 1.

[0066] Figure 4This is a cross-sectional SEM image of the water-activated power supply device in Example 2.

[0067] Figure 5 This is a cross-sectional SEM image of the water-activated power supply device in Example 3.

[0068] Figure 6 The diagram shows the voltage change of the water-activated power supply device in Example 1 before and after it comes into contact with water.

[0069] Figure 7 The diagram shows the voltage change of the water-activated power supply device in Example 2 before and after it comes into contact with water.

[0070] Figure 8 The diagram shows the voltage change of the water-activated power supply device in Example 3 before and after contact with water.

[0071] Figure 9 This is a charge-discharge curve of the water-activated power supply device in Example 1 after water activation.

[0072] Figure 10 This is a charge-discharge curve of the water-activated power supply device in Example 2 after water activation.

[0073] Figure 11 This is a charge-discharge curve of the water-activated power supply device in Example 3 after water activation.

[0074] Figure 12 This is a photograph of the water-activated power supply device from Example 1 actually driving an LED light.

[0075] Figure 13 This is a photograph of the water-activated power supply device of Example 2 actually driving the electronic display screen.

[0076] Figure 14 This is a bending photograph of the water-activated power supply device for Comparative Example 1.

[0077] Figure 15 This is a comparison chart of the pulse discharge curves of the water-activated power supply devices in Example 1 and Comparative Example 1.

[0078] Figure 16 The image shows a comparison of the electrochemical impedance spectroscopy of the power supply devices in Example 1 and Comparative Example 2.

[0079] Figure 17 This is a physical image of the interface peeling that occurred in the power supply device of Comparative Example 3.

[0080] Figure 18 This is a graph showing the voltage change of the power supply device in Comparative Example 4 before and after it comes into contact with water.

[0081] Figure 19 The discharge curve of the power supply device in Comparative Example 4 is shown. Detailed Implementation

[0082] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0083] Example 1 A water-activated power supply device, which is an integrated structure, is fabricated using the following steps: 1) Raw material preparation: Metal anode: Pure zinc foil with a thickness of 50μm. Anode protective solution: 10% polyvinyl alcohol (PVA, number average molecular weight 10). 6 Aqueous solution (g / mol). Hydrophilic membrane components: Polyamide 1212 (PA1212, melt index of 10 g / 10 min at 240℃ and 2.16 kg), polyvinyl alcohol (PVA, number average molecular weight of 10 g / mol). 6 (g / mol), acetic acid, acetone. Positive electrode components: manganese dioxide particles, conductive carbon black, potassium chloride, PVDF, NMP.

[0084] 2) Construction steps: Step 1: Surface modification and protection of the negative electrode The zinc foil surface was activated by physical polishing to remove surface oxides. A 20μm scraper was used to uniformly cover the activated zinc foil surface with a negative electrode protective liquid (10% PVA aqueous solution by mass). The surface was dried at 60℃ to form a 20μm hydrophilic coating with antioxidant properties, resulting in a pretreated zinc foil (negative electrode layer) with a total thickness of 70μm.

[0085] Step 2: Preparation of hydrophilic membrane slurry Acetic acid and acetone were mixed at a mass ratio of 2:1 to prepare a solvent as a pore-forming system. PA1212 (10% by mass of the solvent) and PVA (4% by mass) were added to the above system. The components were completely dissolved by mechanical shearing to obtain a uniform and transparent hydrophilic membrane slurry.

[0086] Step 3: Preparation of positive electrode slurry Manganese dioxide granules, conductive carbon black, PVDF, and potassium chloride were blended at a mass ratio of 7:2:1:5. After adding 30 parts by mass of NMP, the mixture was stirred under high shear force for 5 hours at a speed of 2000 r / min to obtain a positive electrode slurry with suitable viscosity. Specifically, the ratio of manganese dioxide granules, conductive carbon black, PVDF, potassium chloride, and NMP was 7:2:1:5:30.

[0087] Step 4: In-situ integration of power supply devices Pretreated zinc foil is fixed, and the hydrophilic separator slurry is deposited in situ on its surface at a deposition rate of 30 mm / min, controlling the wet film thickness to be 300 μm. Pretreatment is performed at 60°C, and microphase separation is triggered by the selective evaporation of the pore-forming solvent to construct a porous ion transport network, forming a 75 μm hydrophilic separator layer. Subsequently, a positive electrode slurry is deposited in situ on the surface of the hydrophilic separator layer at a deposition rate of 10 mm / min, controlling the wet film thickness to be 300 μm. Overall curing is performed at 80°C for 60 min, and the interlayer physical interface is eliminated by the interpenetration effect of the solvent, forming a 90 μm positive electrode layer, resulting in an integrated water-activated power supply device that can be used as a battery core.

[0088] Example 2 A water-activated power supply device differs from Example 1 in that the solvent in the diaphragm slurry is replaced with acetic acid and toluene in a mass ratio of 1:2, while the other conditions are the same as in Example 1.

[0089] Example 3 A water-activated power supply device differs from Example 1 in that the amounts of PA1212 and PVA added are 8% and 5% of the solvent mass, respectively, while the other conditions are the same as in Example 1.

[0090] Comparative Example 1 A water-activated power supply device is a discrete, multilayered, non-integrated structure, used to compare and demonstrate the impact of an integrated structure on the power supply device. The specific preparation steps are as follows, referring to the preparation method in Example 1: 1) Preparation of the membrane layer: The same hydrophilic membrane slurry as in Example 1 was independently deposited on the release substrate, dried and cured, and then peeled off to obtain independent discrete membrane sheets.

[0091] 2) Discrete preparation of positive electrode: The positive electrode slurry is deposited independently on the surface of the current collector and dried to obtain discrete electrode sheets.

[0092] 3) Physical stacking assembly: The metal negative electrode, discrete film and discrete electrode sheet are physically stacked in sequence by mechanical external pressure, and the assembly is completed by mechanical contact between the interfaces.

[0093] Comparative Example 2 A power supply device without hydrophilic modifier is provided to demonstrate the effect of hydrophilic modifier on power supply devices. The difference between this example and Example 1 is that no hydrophilic modifier was added to the hydrophilic diaphragm slurry in this example; the other conditions are the same as in Example 1.

[0094] The hydrophilic membrane slurry in this example is prepared as follows: Acetic acid and acetone are mixed at a mass ratio of 2:1 to prepare a solvent as a pore-forming system; only PA1212 accounting for 10% of the total mass of the solvent is added to the above system, without adding any hydrophilic modifier, and the components are completely dissolved by mechanical shearing to obtain a uniform and transparent hydrophilic membrane slurry.

[0095] Comparative Example 3 A power supply device with a hydrophilic coating removed is used to demonstrate the effect of the hydrophilic coating on the power supply device. The difference between this example and Example 1 is that: in this example, no hydrophilic coating is set on the surface of the zinc foil negative electrode. Instead, after the zinc foil is fixed after grinding, the hydrophilic membrane slurry is deposited directly on its surface in situ and the subsequent treatment is carried out. The other conditions are the same as in Example 1.

[0096] Comparative Example 4 A power supply device for removing electrolyte salts is provided to demonstrate the effect of electrolyte salts on power supply devices. The difference between this example and Example 1 is that no electrolyte salts are added to the positive electrode slurry in this example; the other conditions are the same as in Example 1.

[0097] The cathode slurry preparation process in this example is as follows: Manganese dioxide particles, conductive carbon black, and PVDF are blended in a mass ratio of 7:2:1. After adding 30 parts by mass of NMP, the mixture is stirred under high shear force for 5 hours at a speed of 2000 r / min to obtain a cathode slurry with suitable viscosity. That is, the ratio of manganese dioxide particles, conductive carbon black, PVDF, and NMP is 7:2:1:30.

[0098] Performance testing 1. Morphological characterization: Physical images and scanning electron microscopy (SEM) were performed on each power supply device.

[0099] 2. Activation rate test: This is mainly reflected by the open-circuit voltage of each power supply device. The testing instrument used is an electrochemical workstation with a sampling frequency of 10Hz. The positive and negative electrodes of the device are connected to the corresponding electrodes on the workstation, and the voltage changes of the device before and after contact with water are tested.

[0100] 3. Electrochemical impedance spectroscopy test: Characterized by an electrochemical workstation, the test range is from 100,000 Hz to 0.1 Hz, and the perturbation voltage is 10 mV.

[0101] 4. Pulse discharge performance test: Characterized by the Blue Battery test system. During the test, a 10-minute resting time is set before the constant current discharge step to ensure that the power supply device is fully activated. The pulse discharge operation is to cycle through 30 seconds of discharge and 30 seconds of rest, with a current of 0.1 mA.

[0102] 5. Charge / Discharge Test: Characterized using the Blue Battery Testing System; each power supply device was cut into 16mm diameter circular pieces using a battery cutting machine and assembled into a button cell casing. After adding an appropriate amount of deionized water, the casing was sealed using a battery packaging machine. The charge / discharge conditions were both 0.1C.

[0103] Figure 1 This is a physical image of the water-activated power supply device in Example 1. Figure 1 The macroscopic appearance of the water-activated power supply device prepared in Example 1 is shown, and its potential for large-scale preparation is demonstrated.

[0104] Figure 2 This is a bending photograph of the water-activated power supply device of Example 1. According to... Figure 2 As can be seen, the water-activated power supply device prepared in Example 1 has good flexibility and bending resistance.

[0105] Figure 3 This is a cross-sectional SEM image of the water-activated power supply device in Example 1. Figure 4 This is a cross-sectional SEM image of the water-activated power supply device in Example 2. Figure 5 This is a cross-sectional SEM image of the water-activated power supply device in Example 3. Figures 3-5 The internal morphology of the water-activated power supply devices prepared in Examples 1-3 is shown respectively. They have similar layered morphology sections, which are arranged from bottom to top as a negative electrode metal layer, a hydrophilic coating layer, a hydrophilic membrane layer and a positive electrode layer.

[0106] Figure 6 The voltage change diagram of the water-activated power supply device in Example 1 before and after encountering water is shown. The period before the 5th second is before encountering water, and the period from the 5th second onwards is after encountering water. Figure 7 The voltage change graph of the water-activated power supply device in Example 2 before and after encountering water is shown. The graph shows the voltage change before encountering water before the 5th second and the voltage change after the 5th second. Figure 8 The graph shows the voltage change of the water-activated power supply device in Example 3 before and after contact with water. The period before 20 seconds represents the period before contact with water, and the period from 20 seconds onwards represents the period after contact with water. According to... Figures 6-8 It can be seen that the water-activated power supply devices prepared in Examples 1 to 3 all have the characteristic of rapid activation, and can be activated rapidly within 5s to 10s.

[0107] Figure 9 This is a charge-discharge curve of the water-activated power supply device in Example 1 after water activation. Figure 10This is a charge-discharge curve of the water-activated power supply device in Example 2 after water activation. Figure 11 This is a charge-discharge curve of the water-activated power supply device in Example 3 after water activation. According to... Figures 9-11 It can be seen that the water-activated power supply devices prepared in Examples 1-3 can achieve good charge and discharge performance after water activation.

[0108] Figure 12 This is a photograph of the water-activated power supply device from Example 1 actually driving an LED light. Figure 13 This is a photograph of the water-activated power supply device from Example 2 actually driving an electronic display screen. According to... Figures 12-13 It is evident that the water-activated energy supply device prepared in the embodiments of the present invention can provide energy and has practical application value.

[0109] The methods described in Examples 1 to 3 of this invention can all be used to prepare water-activated power supply devices, demonstrating good process versatility.

[0110] Figure 14 This is a bending photograph of the water-activated power supply device in Comparative Example 1. Figure 2 compared to, Figure 14 The interfaces of the device are clearly separated, demonstrating the defects of the non-integrated structure of the water-activated power supply device in Comparative Example 1.

[0111] Figure 15 This is a comparison chart of the pulse discharge curves of the water-activated power supply devices in Example 1 and Comparative Example 1. According to... Figure 15 As can be seen, the pulse curve shape of Example 1 is close to a square wave, while the pulse curve shape of Comparative Example 1 is like an ocean wave. This indicates that the concentration polarization inside Example 1 dissipates rapidly the moment the current is removed, while Comparative Example 1 requires a certain amount of time buffer. This demonstrates that the integrated structure adopted in Example 1 of this invention has better electrochemical performance and interface advantages.

[0112] A comparison between Comparative Example 1 and Example 1 reveals the following: 1) Differences in interfacial mechanical properties: During dynamic bending, Comparative Example 1, due to the lack of molecular-level permeation and anchoring between layers (only physical contact), is prone to interlayer dislocations and physical stripping, leading to interruption of charge transport paths. 2) Differences in kinetic efficiency: The integrated in-situ structure of Example 1 eliminates interfacial contact resistance through solvent interpenetration, and its voltage rise rate and pulse load capacity after water activation are significantly better than the discrete stacked non-integrated structure in Comparative Example 1.

[0113] In Comparative Example 2, because no hydrophilic agent was added to the diaphragm layer, the diaphragm had extremely low hydrophilicity, resulting in extremely high internal resistance of the power supply device, making charge-discharge testing impossible. To quantitatively compare its internal resistance, an electrochemical impedance spectroscopy test was performed, and the results are shown below. Figure 16 .

[0114] Figure 16 This is a comparison of the electrochemical impedance spectroscopy (EIS) of the power supply devices in Example 1 and Comparative Example 2. According to... Figure 16 It is evident that the internal resistance of Example 1 is much smaller than that of Comparative Example 2, indicating that the hydrophilic modifier has a crucial impact on the performance of the power supply device, and the performance of Comparative Example 2, which lacks the hydrophilic modifier, is significantly worse.

[0115] In Comparative Example 3, the device was difficult to form an integrated structure after removing the hydrophilic polymer protective coating. This was due to the corrosive effect of acetic acid on the zinc foil surface (zinc is a reactive metal that readily reacts with acids to generate byproducts, which severely affect interfacial bonding). A physical image of the power supply device after the reaction is shown below. Figure 17 .

[0116] Figure 17 This is a physical image of the interface delamination that occurred in the power supply device of Comparative Example 3. According to... Figure 17 As can be seen, in Comparative Example 3, the diaphragm layer and zinc foil side of the water-activated power supply device showed obvious interfacial peeling, and the zinc foil also exhibited severe corrosion. This was caused by the corrosive effect of the acid in the casting solution on the zinc foil. This illustrates the importance of setting a hydrophilic coating on the surface of the negative electrode zinc foil in the embodiments of the present invention; the internal structure of the water-activated power supply device lacking a hydrophilic coating is extremely fragile.

[0117] Figure 18 The graph shows the voltage change of the power supply device in Comparative Example 4 before and after encountering water. The period before the 5th second is before encountering water, and the period from the 5th second onwards is after encountering water. Figure 19 This is the discharge curve of the power supply device in Comparative Example 4. According to... Figures 18-19 As can be seen, the power supply device lacking electrolyte salt in Comparative Example 4 completely loses its activation characteristics and has almost no capacity, which also demonstrates the crucial role of electrolyte salt in the normal operation of the device. Electrolyte salt is the core raw material for water-activated power supply devices. Power supply devices without electrolyte added to the positive electrode slurry do not have water activation characteristics, the open circuit voltage of the device is always maintained at about 1.4V (i.e., the potential difference between manganese dioxide and zinc), and the discharge capacity of the device approaches 0.

[0118] In summary, the water-activated power supply device of the present invention is constructed from a negative electrode layer, a hydrophilic membrane layer, and a positive electrode layer through an in-situ integration process. The surface of the negative electrode layer is coated with a hydrophilic coating to protect the negative electrode metal layer and prevent oxidation of the metal negative electrode during storage. The hydrophilic membrane layer, made of polyamide and hydrophilic polymer, separates the positive and negative electrode layers and possesses excellent hydrophilic properties. The positive electrode layer contains a pre-placed electrolyte salt, enabling the device to achieve rapid water activation. The water-activated power supply device of the present invention offers comprehensive advantages, including simple activation, rapid voltage response, rapid pulse discharge voltage rebound, long storage time, and good flexibility. It shows promising application prospects in emergency rescue microsystems, deep-sea environmental monitoring equipment, environmental detection equipment, flexible medical monitoring equipment, wearable devices, and beauty care devices.

Claims

1. A water-activated energy supply device, characterized in that, It includes a negative electrode layer, a hydrophilic membrane layer, and a positive electrode layer stacked sequentially; the negative electrode layer includes a negative electrode metal layer and a hydrophilic coating disposed on the surface of the negative electrode metal layer; the hydrophilic membrane layer is formed in situ on the surface of the hydrophilic coating of the negative electrode layer; The hydrophilic coating comprises a first hydrophilic polymer; the hydrophilic membrane layer comprises polyamide and a second hydrophilic polymer; and the positive electrode layer comprises a positive electrode active material and an electrolyte salt.

2. The water-activated energy supply device according to claim 1, characterized in that, The first hydrophilic polymer includes at least one of sodium polyacrylate, polyacrylamide, polyvinyl alcohol, or polyethylene glycol; And / or, the second hydrophilic polymer includes at least one of polyacrylamide, polyvinyl alcohol, or polyethylene glycol; And / or, the number-average molecular weights of the first hydrophilic polymer and the second hydrophilic polymer are each independently 10. 6 ~10 8 g / mol.

3. The water-activated energy supply device according to claim 1, characterized in that, The negative electrode metal layer contains an active metal; the active metal includes at least one of zinc, magnesium, or aluminum. And / or, the electrolyte salt includes at least one of potassium salt, sodium salt or lithium salt; And / or, the positive electrode layer further comprises a conductive agent and a binder.

4. The water-activated energy supply device according to claim 1, characterized in that, In the hydrophilic membrane layer, the mass ratio of the polyamide to the second hydrophilic polymer is 1:(0.1~1). And / or, in the positive electrode layer, the mass ratio of the positive electrode active material to the electrolyte salt is 1:(0.1~1).

5. The water-activated energy supply device according to claim 1, characterized in that, The thickness of the negative electrode layer is 15~100μm; And / or, the thickness of the hydrophilic membrane layer is 5~100μm; And / or, the thickness of the positive electrode layer is 5~100μm; And / or, the total thickness of the water-activated power supply device is 25~300μm.

6. A method for preparing a water-activated energy supply device as described in any one of claims 1 to 5, characterized in that, Includes the following steps: A hydrophilic coating is applied to the surface of the negative electrode metal layer, and after drying, a negative electrode layer with a hydrophilic coating is obtained; a hydrophilic membrane slurry is applied to the surface of the hydrophilic coating of the negative electrode layer, and after drying, the hydrophilic membrane layer is formed in situ; a positive electrode slurry is applied to the surface of the hydrophilic membrane layer, and after drying, the positive electrode layer is formed. The hydrophilic coating comprises a first hydrophilic polymer; the hydrophilic membrane slurry comprises polyamide and a second hydrophilic polymer; and the positive electrode slurry comprises a positive electrode active material and an electrolyte salt.

7. The preparation method according to claim 6, characterized in that, The content of the first hydrophilic polymer in the hydrophilic coating is 1~15wt%; And / or, the polyamide content in the hydrophilic membrane slurry is 5-15 wt%; And / or, the content of positive electrode active material in the positive electrode slurry is 10~40%.

8. The preparation method according to claim 6, characterized in that, The solvent in the hydrophilic membrane slurry includes solvent A and solvent B; solvent A includes one of formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 2-hydroxypropionic acid or oxalic acid; solvent B includes one of toluene, benzene, dichloromethane, chloroform, 1,2-dichloroethane, carbon tetrachloride, trichloroethane, acetone or petroleum ether.

9. The preparation method according to claim 8, characterized in that, The mass ratio of solvent A to solvent B is 1:(0.1~3).

10. The application of a water-activated power supply device as described in any one of claims 1 to 5 in emergency rescue microsystems, deep-sea environmental monitoring equipment, environmental detection equipment, flexible medical monitoring equipment, flexible wearable devices, or beauty care devices.

Images