Aquatic self-recharging hydrogen battery

Abstract

This disclosure provides an aqueous self-charging hydrogen battery, belonging to the field of electrochemical energy storage technology. The battery includes a negative electrode, a positive electrode, and an electrolyte. A catalyst is supported on the negative electrode for reacting H2 to H2O or H2O at the interface with the electrolyte during discharge. + The oxidation reaction occurs; the positive electrode includes a redox-active positive electrode material, which undergoes a reduction reaction at its interface with the electrolyte during discharge; after discharge, the battery is charged with oxygen, and under the condition of oxygen presence, the reduction products of the positive electrode material are oxidized through self-charging. The aqueous self-charging hydrogen battery of this disclosure involves only the generation of water during self-charging and discharge cycles, avoiding the generation of solid byproducts and improving the cycle stability of the self-charging battery during self-charging.

Description

Technical Field

[0001] This disclosure relates to the field of electrochemical energy storage technology, specifically to an aqueous self-charging hydrogen battery. Background Technology

[0002] Rechargeable batteries are considered promising candidates for portable electronic devices and grid-scale energy storage applications. However, in certain special circumstances, such as harsh environments, remote areas, and emergency power needs, battery recharging and reuse are often limited by power shortages. To facilitate energy acquisition, various intelligent self-powered systems, including photovoltaic power generation, piezoelectric nanogenerators, and thermoelectric power, have been integrated into rechargeable batteries. However, the intermittency and low energy density of these self-powered systems hinder their further application. Therefore, developing a simple and low-cost self-powered system is crucial for the application of batteries in harsh environments.

[0003] Oxygen in the air is considered an abundant and cost-free resource, and its redox reactions have attracted widespread attention in the energy storage field. Therefore, integrating additional energy by introducing oxygen into batteries is a relatively effective method for achieving battery self-charging. Recently, various chemically self-charging aqueous metal-based batteries have been developed using the chemical effects of oxygen in the air. Related technologies have reported self-charging aqueous zinc-based batteries based on the spontaneous oxidation of inorganic metal electrodes (such as Prussian blue and manganese oxides) and organic electrodes (mainly conductive polymers) by oxygen. However, the self-charging batteries developed above typically generate a large amount of OH- during the self-charging process. - During the subsequent discharge process, the metal anode material oxidizes, generating a large number of metal ions. Therefore, the metal ions and OH- produced in the electrolyte... - The tendency to form solid metal hydroxide byproducts on the electrodes hinders further electrode reactions and leads to rapid failure of the self-rechargeable battery.

[0004] Therefore, there is a strong desire to explore novel self-rechargeable battery systems that do not form any solid byproducts in order to achieve excellent self-recharging capabilities. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides an aqueous self-charging hydrogen battery that utilizes oxygen from the air to self-charge itself. The self-charging / discharging cycle process only involves OH groups. - and H + The generation of this process eliminates the formation of solid byproducts, thereby improving the cycle stability of the battery.

[0006] To achieve the above objectives, as one aspect of this disclosure, an aqueous self-charging hydrogen battery is provided, comprising: a negative electrode, a positive electrode, and an electrolyte; wherein, a catalyst is supported on the negative electrode for reacting H2 to H2O or H2O at the interface between the negative electrode and the electrolyte during discharge. + The oxidation reaction; the positive electrode includes a positive electrode material with redox activity, which is used to carry out a reduction reaction at the interface between the positive electrode and the electrolyte during discharge; wherein, after the discharge is completed, the battery is filled with oxygen, and the reduction products of the positive electrode material are oxidized by self-charging in the presence of oxygen.

[0007] In the embodiments of this disclosure, the self-charging method includes one of chemical self-charging, short-circuit induced self-charging, and energy input induced self-charging;

[0008] When the battery's self-charging method is chemical self-charging, the reduction products of the positive electrode material can be spontaneously oxidized by oxygen.

[0009] When the battery's self-charging method is short-circuit induced self-charging, the negative electrode is used as an oxygen electrode to carry out the reduction reaction under the short circuit between the positive and negative electrodes, and the positive electrode is used to oxidize the reduction products of the positive electrode material under the short circuit between the positive and negative electrodes.

[0010] When the battery's self-charging method is energy input-induced self-charging, the negative electrode is used as an oxygen electrode to carry out the reduction reaction under the action of an external voltage, and the positive electrode is used to oxidize the reduction products of the positive electrode material under the action of an external voltage.

[0011] In the embodiments of this disclosure, when the oxidation potential of the positive electrode material is lower than the reduction reaction potential of oxygen, the self-charging method of the battery is chemical self-charging or short-circuit induced self-charging; when the oxidation potential of the positive electrode material is higher than the reduction reaction potential of oxygen, the self-charging method of the battery is energy input induced self-charging.

[0012] In embodiments of this disclosure, the oxygen filling pressure is 1-100 atm.

[0013] In the embodiments of this disclosure, the electrolyte is one of acidic, neutral, or alkaline.

[0014] In the embodiments of this disclosure, the positive electrode material is selected from inorganic or organic materials. Inorganic materials include halogens, Prussian blue analogues, manganese oxides, vanadium oxides, cobalt oxides, and polyanionic compounds. Organic materials include conductive polymers, carbonyl compounds, imine compounds, and organosulfides. The conductive polymers include, but are not limited to, polyaniline, polypyrrole, polythiophene, and polyacetylene.

[0015] In embodiments of this disclosure, the negative electrode is a current collector, which is a carrier for the catalyst.

[0016] In embodiments of this disclosure, the catalyst includes one or more of a first metal catalyst, a second metal catalyst, a third metal catalyst, and a carbon material.

[0017] In embodiments of this disclosure, the first metal catalyst comprises one or more of Pt, Pd, Ir, Ru, PtNi, PtCo, PtMo, PtW, PtNiCo, PtNiMo, PdNi, PdCo, ​​PdMo, PdW, PdNiCo, PdNiMo, IrNi, IrCo, IrMo, IrW, IrNiCo, IrNiMo, RuNi, RuCo, RuMo, RuW, RuNiCo, and RuNiMo; the second metal catalyst comprises PtO2, PtOH, and PtC. One or more of the following: IrO2, IrC, IrN, IrS, IrP, RuO2, RuC, RuN, RuS, RuP; the third metal catalyst includes one or more of the following: Ni, NiMo, NiCoMo, MoC, MoC2, MoO2, MoS2, MoP, WC, WC2, WO2, WS2, WP, NiN, NiS, NiP, NiPS; the carbon material includes one or more of the following: microspheres, nanospheres, microparticles, nanoparticles, microsheets, nanosheets, microwires, nanowires, microtubes, nanotubes.

[0018] In embodiments of this disclosure, the battery further includes a separator disposed between the positive and negative electrodes.

[0019] As can be seen from the above technical solution, the water-based self-charging hydrogen battery provided in this disclosure has at least one or a portion of the following beneficial effects:

[0020] According to embodiments of this disclosure, in the aqueous self-charging battery provided by this disclosure, the negative electrode undergoes hydrogen evolution and hydrogen oxidation reactions upon the addition of hydrogen gas. The negative electrode is used during discharge to facilitate the H2 to H2O or H2O reaction at its interface with the electrolyte. + The oxidation reaction is carried out; the positive electrode includes a positive electrode material with redox activity, which is used to better facilitate the reduction reaction during discharge; wherein, after discharge, the battery is charged with oxygen, and in the presence of oxygen, the reduction products of the positive electrode material are oxidized through self-charging. The self-charging hydrogen battery involves only water production during self-charging and discharge cycles, making it environmentally friendly. It also completely avoids the generation of solid byproducts in traditional self-charging metal-based batteries, thus ensuring excellent cycle stability. This disclosure opens up new avenues for the development of high-performance self-charging batteries, showing promising application prospects in special situations such as harsh environments, remote areas, and emergency power needs.

[0021] According to embodiments of this disclosure, operation using the self-charging method provided by this disclosure is more convenient. Specifically, when the battery's self-charging method is chemical self-charging, the reduction products of the positive electrode material can be spontaneously oxidized by oxygen; when the battery's self-charging method is short-circuit induced self-charging, the self-charging process can begin through a short circuit after the introduction of oxygen; and when the battery's self-charging method is energy input induced self-charging, only a small amount of energy input is needed to output more energy. Aqueous self-charging hydrogen batteries hold promise for providing more durable and stable power in areas without sunlight or other energy sources, in remote areas without grid coverage, or in areas with power shortages. Attached Figure Description

[0022] Figure 1 This schematic diagram illustrates the reaction mechanism of the self-charging and discharging process of an aqueous self-charging hydrogen battery according to an embodiment of the present disclosure.

[0023] Figure 2 This schematic diagram illustrates the reaction mechanism of an aqueous chemical self-charging I2-H2 battery according to an embodiment of the present disclosure.

[0024] Figure 3 This schematic diagram illustrates the reaction mechanism of the PBA-H2 battery induced by short circuit in water according to an embodiment of the present disclosure.

[0025] Figure 4 This schematic diagram illustrates the reaction mechanism of a water-based energy input-induced self-charging PbO2-H2 battery according to an embodiment of the present disclosure.

[0026] Figure 5 The schematic diagram illustrates the charge-discharge test results curves of the chemical self-charging iodine-hydrogen battery of Embodiment 1 of this disclosure at different self-charging times;

[0027] Figure 6 The rate test results curves of the chemically self-charging I2-H2 battery of Embodiment 1 of this disclosure at different current densities are illustrated schematically.

[0028] Figure 7 The diagram illustrates the self-charge-discharge cycle performance test results curve of the chemically self-charging I2-H2 battery of Example 1 of this disclosure;

[0029] Figure 8 The schematic diagram illustrates the charge-discharge test results curves of the short-circuit induced self-charging PBA-H2 battery of Embodiment 2 of this disclosure at different self-charging times;

[0030] Figure 9 The diagram illustrates the rate test results curves of the short-circuit induced self-charging PBA-H2 battery of Embodiment 2 of this disclosure at different current densities;

[0031] Figure 10The diagram illustrates the self-charge-discharge cycle performance test results curve of the short-circuit induced self-charging PBA-H2 battery of Embodiment 2 of this disclosure;

[0032] Figure 11 The schematic diagram illustrates the charge-discharge test results curves of the energy input-induced self-charging PbO2-H2 battery of Embodiment 3 of this disclosure under different self-charging current densities;

[0033] Figure 12 The diagram illustrates the self-charge-discharge cycle performance test curves of the energy input-induced self-charging PbO2-H2 battery of Embodiment 3 of this disclosure. Detailed Implementation

[0034] Due to its abundant source and rapid participation in electrochemical oxidation and reduction reactions, hydrogen shows excellent potential as a battery electrode. Especially during the oxidation reaction of hydrogen, only H₂ is produced in the electrolyte. + This is significantly different from metal-based electrodes. In realizing this disclosure, it was discovered that by adding oxygen and hydrogen, during self-charge / discharge cycles, the hydrogen oxidation reaction producing H₂ during discharge... + OH- reacts with oxygen during the self-charging process - The combination produces pollution-free water, which helps the self-rechargeable battery operate for a long time.

[0035] In view of this, this disclosure proposes utilizing oxygen from the air to integrate additional energy. Through different self-charging methods, combined with the products of the hydrogen oxidation reaction at the hydrogen negative electrode, a self-charging and discharging process can be achieved. Specifically, chemical self-charging requires the introduction of oxygen to begin the charging process; short-circuit induced self-charging first introduces oxygen, then initiates the self-charging process through a short circuit; and energy input induced self-charging requires less energy input to output more energy. Using these self-charging methods avoids the problem of solid byproducts generated in traditional metal-based self-charging batteries, while further enhancing the battery's cycle life and stability.

[0036] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0037] In embodiments of this disclosure, an aqueous self-charging hydrogen battery is provided, comprising: a negative electrode, a positive electrode, and an electrolyte; wherein, a catalyst is supported on the negative electrode for reacting H2 to H2O or H2O at the interface between the negative electrode and the electrolyte during discharge. +The oxidation reaction; the positive electrode includes a positive electrode material with redox activity, which is used to carry out a reduction reaction at the interface between the positive electrode and the electrolyte during discharge; wherein, after the discharge is completed, the battery is filled with oxygen, and the reduction products of the positive electrode material are oxidized by self-charging in the presence of oxygen.

[0038] Figure 1 This schematic diagram illustrates the reaction mechanism of the self-charging and discharging process of an aqueous self-charging hydrogen battery according to an embodiment of the present disclosure, as shown below. Figure 1 As shown, during self-charging and discharging cycles, the self-charging hydrogen battery generates H2O through the hydrogen oxidation reaction. + OH produced from the reduction of oxygen - This invention combines the generation of pollution-free water with the conversion of chemical energy into electrical energy stored in the battery through a redox reaction, achieving a self-charging process that is environmentally friendly. It also completely avoids the generation of solid byproducts found in traditional self-charging metal-based batteries, thus ensuring excellent cycle stability. This disclosure opens up new avenues for the development of high-performance self-charging batteries, showing promising applications in special situations such as harsh environments, remote areas, and emergency power needs.

[0039] Based on the above embodiments, the battery disclosed herein may further include a separator disposed between the positive and negative electrodes. The separator disposed between the positive and negative electrodes can separate the positive and negative electrode materials of the battery, preventing short circuits caused by contact between the two electrodes, thereby improving the battery's cycleability and safety.

[0040] Based on the above embodiments, the battery's self-charging method includes one of chemical self-charging, short-circuit induced self-charging, and energy input induced self-charging. When the battery's self-charging method is chemical self-charging, the reduction products of the positive electrode material can be spontaneously oxidized by oxygen. When the battery's self-charging method is short-circuit induced self-charging, the negative electrode is used as an oxygen electrode to perform the reduction reaction under a short circuit between the positive and negative electrodes, and the positive electrode is used to oxidize the reduction products of the positive electrode material under a short circuit between the positive and negative electrodes. When the battery's self-charging method is energy input induced self-charging, the negative electrode is used as an oxygen electrode to perform the reduction reaction under the action of an external voltage, and the positive electrode is used to oxidize the reduction products of the positive electrode material under the action of an external voltage.

[0041] Based on the above embodiments, when the oxidation potential of the positive electrode material is lower than the reduction reaction potential of oxygen, the battery self-charging method is chemical self-charging or short-circuit induced self-charging; when the oxidation potential of the positive electrode material is higher than the reduction reaction potential of oxygen, the battery self-charging method is energy input induced self-charging.

[0042] Figure 2This schematic diagram illustrates the reaction mechanism of an aqueous chemical self-charging I2-H2 battery according to an embodiment of the present disclosure. Figure 3 This schematic diagram illustrates the reaction mechanism of the PBA-H2 battery induced by short circuit in water according to an embodiment of the present disclosure. Figure 4 This diagram schematically illustrates the reaction mechanism of an aqueous energy input-induced self-charging PbO2-H2 battery according to an embodiment of this disclosure. In the case of chemical self-charging, the reduction products of the cathode material can be spontaneously oxidized by oxygen. Please refer to... Figure 2 This self-charging method is suitable when the oxidation reaction potential of the positive electrode material is lower than the reduction reaction potential of oxygen, allowing oxygen to oxidize the discharge products at a faster rate. Short-circuit induced self-charging refers to the process where, after the introduction of oxygen, the original hydrogen electrode is replaced by an oxygen electrode. A short circuit between the positive and negative electrodes causes the potentials of the two electrodes to converge, thereby accelerating the self-charging reaction process. Please see [link to relevant documentation]. Figure 3 This self-charging method is suitable when the oxidation reaction potential of the cathode material is lower than the reduction reaction potential of oxygen, and the potential difference is 0-0.4V. Energy input-induced self-charging refers to the process where, after the introduction of oxygen, the battery still needs to replenish a small amount of electrical energy to drive the self-charging process. Please refer to [link to relevant documentation]. Figure 4 This self-charging method is suitable when the oxidation reaction potential of the cathode material is higher than the reduction reaction potential of oxygen, so additional energy is required to enable self-charging.

[0043] Based on the above embodiments, the negative electrode is the current collector, which is a carrier supporting the catalyst, such as... Figure 2 As shown, the catalyst is attached to the substrate surface of the gas diffusion layer, which serves as the current collector. The current collector has the advantage of being able to rapidly undergo three-phase interfacial reactions and can support catalysts for the hydrogen evolution reaction and hydrogen oxidation reaction.

[0044] Based on the above embodiments, the catalyst includes one or more of a first metal catalyst, a second metal catalyst, a third metal catalyst, and a carbon material. Catalysts for the hydrogen evolution reaction and the hydrogen oxidation reaction are of various types, and the reactions are promoted at the three-phase interface through active sites exposed on the catalyst surface.

[0045] Based on the above embodiments, the first metal catalyst includes one or more of Pt, Pd, Ir, Ru, PtNi, PtCo, PtMo, PtW, PtNiCo, PtNiMo, PdNi, PdCo, ​​PdMo, PdW, PdNiCo, PdNiMo, IrNi, IrCo, IrMo, IrW, IrNiCo, IrNiMo, RuNi, RuCo, RuMo, RuW, RuNiCo, and RuNiMo; the second metal catalyst includes PtO2, PtOH, and PtC. The catalyst comprises one or more of the following: IrO2, IrC, IrN, IrS, IrP, RuO2, RuC, RuN, RuS, and RuP; the third metal catalyst comprises one or more of the following: Ni, NiMo, NiCoMo, MoC, MoC2, MoO2, MoS2, MoP, WC, WC2, WO2, WS2, WP, NiN, NiS, NiP, and NiPS; and carbon materials comprise one or more of the following: microspheres, nanospheres, microparticles, nanoparticles, microsheets, nanosheets, microwires, nanowires, microtubes, and nanotubes. The first and second metal catalysts exhibit relatively high catalytic activity, while the third metal catalyst shows only a slight difference in catalytic activity compared to the former two and is significantly cheaper. Carbon materials have the advantage of low cost, but their catalytic activity is relatively poor.

[0046] Based on the above embodiments, the oxygen filling pressure is 1-100 atm. Preliminary experiments conducted according to this disclosure found that oxygen pressure within this range is favorable for oxygen reduction reactions.

[0047] Based on the above embodiments, the hydrogen charging pressure is 1-100 atm. Preliminary experiments related to this disclosure have shown that hydrogen pressure within this range is favorable for oxidation reactions at the hydrogen negative electrode.

[0048] Based on the above embodiments, the electrolyte is one of acidic, neutral, or alkaline. The electrolyte provides a reaction site for the redox reaction between the positive and negative electrode materials.

[0049] Based on the above embodiments, the cathode material is selected from inorganic or organic materials. Inorganic materials include elemental halogens, Prussian blue analogues, manganese oxides, vanadium oxides, cobalt oxides, and polyanionic compounds; organic materials include conductive polymers, carbonyl compounds, imine compounds, and organosulfides. The aforementioned conductive polymers include, but are not limited to, polyaniline, polypyrrole, polythiophene, and polyacetylene. These inorganic and organic materials are all well-established cathode materials in aqueous battery systems, contributing to better self-charging performance in aqueous self-charging hydrogen batteries.

[0050] Based on the above embodiments, the structure of an aqueous self-charging hydrogen battery includes coin cells, cylindrical cells, or flow batteries. Coin cells are characterized by their small size and ease of operation, and are commonly used in laboratory research; cylindrical cells have high energy density and are commonly used in portable power supplies such as laptops and digital cameras; flow batteries have large capacity and are commonly used in large-scale energy storage devices.

[0051] The present disclosure is further illustrated below by way of proportions, embodiments, accompanying drawings, and related test experiments and results. In the following detailed description, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Moreover, the details in the following embodiments can be arbitrarily combined to form other feasible embodiments without conflict.

[0052] It should be noted that the specific embodiments described below are merely illustrative examples, and the scope of protection of this disclosure is not limited thereto. The chemicals and raw materials used in the following embodiments are all commercially available or prepared in-house using recognized methods.

[0053] Example 1

[0054] Aquatic self-recharging hydrogen batteries using a chemical self-recharging method

[0055] Example 1 uses an I2-H2 battery based on an iodine (I2) cathode as an example to demonstrate a chemically self-charging hydrogen battery. The reduction peak potential of the I2 cathode relative to H... + Theoretically, the potential of H2 is 0.54V, but the oxygen reduction reaction has a relatively high potential (1.23V vs. H2). + / H2). For example Figure 2 As shown, I - During the battery's self-charging process, it can undergo an oxidation reaction with oxygen in the air, promoting the formation of solid I2 and OH- from the electrolyte on the positive electrode material composed of activated carbon. - OH - The H generated during the discharge process will be + Water is produced by combining in the electrolyte.

[0056] The mechanism of self-charging in aqueous chemically self-charging I2-H2 batteries is described by the following reaction:

[0057] 4I - +O2+4H + →2I2+2H2O (E=0.69V).

[0058] The mechanism of the discharge process is represented by the following reaction:

[0059] Positive electrode: I2 + 2e - →2I - (E = 0.54V);

[0060] Negative electrode: H2 → 2H + +2e - (E = 0V);

[0061] The overall reaction during the discharge process is: I₂ + H₂ → 2I₂ - +2H + (E = 0.54V).

[0062] Electrolyte preparation: Add 2M phosphoric acid to 0.5M KI solution and stir to dissolve to obtain the electrolyte.

[0063] Preparation of the positive electrode: Activated carbon, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 8:1:1, and an appropriate amount of N-methylpyrrolidone was added and stirred until homogeneous. After thorough grinding, the mixture was coated onto titanium foil and vacuum dried at 70°C for 12 hours.

[0064] According to the aqueous self-charging hydrogen battery in this embodiment, a self-purchased Swagelok device is used for assembly and testing. The Swagelok device has a stainless steel flange-connected ball valve as its outer shell, which serves to fill and seal hydrogen and oxygen. The internal assembly consists of a positive electrode, a negative electrode, and a separator material assembled in a cladding manner. The electrolyte is a solution of different pH values ​​prepared above, which fills the separator completely.

[0065] The electrochemical performance of the above-mentioned aqueous chemical self-charging I2-H2 battery was tested. The chemical self-charging hydrogen battery disclosed herein, after being charged with O2 in an acidic electrolyte for 5 minutes for self-charging oxidation, achieves an open-circuit voltage of 0.51V. - After the ions are further oxidized for 1.5-2 hours, the open-circuit voltage of the battery is very close to its initial open-circuit voltage (E≈0.7V).

[0066] Figure 5 The schematic diagram illustrates the charge-discharge test results curves of the chemical self-charging iodine-hydrogen battery of Example 1 at different self-charging times; Figure 6 The rate test results curves of the chemically self-charging I2-H2 battery in Example 1 at different current densities are illustrated schematically. Figure 7 The diagram schematically illustrates the self-charge-discharge cycle performance test curves of the chemically self-charging I2-H2 battery of Example 1. The discharge capacity gradually increases with increasing oxidation time, as shown... Figure 5 As shown, it reaches 0.361 mAh / cm³ after 2 hours of self-charging. 2It reached 97.8% of its charging capacity (of which the total charging capacity was 0.369 mA / cm²). 2 ).like Figure 6 As shown, the chemically self-charging I2-H2 battery exhibits excellent rate performance at 6 mA / cm². 2 At a current density of 1 mA / cm 2 It can maintain 86.6% of its discharge capacity. For example... Figure 7 As shown, the battery can operate at 1 mA / cm. 2 After 10 stable cycles with an oxidation time of 1.5 hours, it still provides a high capacity retention of 90% and a stable open-circuit voltage of 0.583V.

[0067] Example 2

[0068] Aquatic self-charging hydrogen batteries using short-circuit induced self-charging method

[0069] This embodiment 2 uses a PBA-H2 battery based on Prussian blue (PBA) cathode material as an example to demonstrate a short-circuit induced self-charging hydrogen battery. In this embodiment, nickel hexacyanoferrite is used as the cathode material for the short-circuit induced self-charging battery. After the battery discharges, O2 is introduced, and the introduced O2 replaces the original H2 electrode on the Pt / C electrode, becoming the O2 electrode. Figure 3 As shown, by using an external short-circuit induced operation, the discharge products of the PBA are electrochemically oxidized and further restored to their charged state by connecting the O2 electrode and the fully discharged PBA electrode.

[0070] The mechanism of the self-charging process of the aqueous short-circuit inductive self-charging PBA-H2 battery is described by the following reaction:

[0071] O2 electrode (positive electrode): O2 + 4H+ + +4e - →2H₂O (E=1.23V);

[0072] PBA electrode (negative electrode): PBA-xNa → PBA+xNa + +xe - (E = 0.93V);

[0073] The overall reaction during self-charging is: 4PBA - Na + O2 + 4H+ + →4PBA+4Na + +2H2O(x=1)(E=0.3V).

[0074] The mechanism of the discharge process is represented by the following reaction:

[0075] Positive electrode: PBA + xNa + +xe -→PBA-xNa (E=0.93V);

[0076] Negative electrode: H2 → 2H + +2e - (E 0 =0V);

[0077] Overall reaction: 2PBA + 2Na + +H2→2PBA-Na+2H + (x=1)(E=0.93V).

[0078] Electrolyte preparation: Add 1M phosphoric acid to a 1M sodium dihydrogen phosphate buffer solution and stir to dissolve, thus obtaining the electrolyte.

[0079] Preparation of the positive electrode: Prussian blue nickel hexacyanoferrate, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 8:1:1, and an appropriate amount of N-methylpyrrolidone was added and stirred until homogeneous. After thorough grinding, the mixture was coated onto titanium foil and vacuum dried at 70°C for 12 hours.

[0080] Using the Swagelok device mentioned in Example 1 to assemble a short-circuit induced self-charging PBA-H2 battery, after the battery was discharged, it was short-circuited and self-charged. After 15 minutes, the open-circuit voltage of the discharged battery could be quickly restored to 0.829V, and the battery capacity was restored to 76%.

[0081] Figure 8 The schematic diagram illustrates the charge-discharge test results curves of the short-circuit induced self-charging PBA-H2 battery in this embodiment 2 at different self-charging times; Figure 9 The diagram illustrates the rate test results curves of the short-circuit induced self-charging PBA-H2 battery in this embodiment 2 at different current densities. Figure 10 The diagram schematically illustrates the self-charge-discharge cycle performance test results curve of the short-circuit induced self-charging PBA-H2 battery in Example 2. Figure 8 As shown, the open-circuit voltage and discharge capacity increase with increasing self-charging time, and after 24 hours of self-charging, they are basically close to the open-circuit voltage of 1V (E≈1V) and capacity (48.4mAh / g) achievable after conventional charging. Figure 9 As shown, the short-circuit induced self-charging PBA-H2 battery exhibits excellent rate performance, maintaining 70.6% of its discharge capacity at a current density of 5 A / g compared to 0.5 A / g. Figure 10 As shown, the battery can be stably cycled 10 times at 0.5 A / g, and after 24 hours of short-circuit induced operation, the battery can still provide a high capacity retention of 97%.

[0082] Example 3

[0083] Aquatic self-charging hydrogen batteries using energy input-induced self-charging method

[0084] This embodiment 3 uses a PbO2-H2 battery with a PbO2 positive electrode as an example to demonstrate an energy input-induced self-charging battery. In this embodiment, PbO2, with its higher potential, is used as the positive electrode material to increase the battery's discharge voltage, and H2 is used as the negative electrode to construct an energy input-induced self-charging PbO2-H2 battery. After the battery is fully discharged, O2 is added to the battery to replace the original H2 electrode, serving as the O2 reaction electrode. Since the reduction reaction potential of O2 is lower than the oxidation reaction potential of PbO2 / PbSO4, this means that additional energy input is required to drive the battery reaction. Figure 4 As shown, during the energy input-induced self-charging process, as the H+ on the Pt / C catalyst increases... + As ions are consumed, O2 is reduced to H2O, and the discharge product PbSO4 is converted into PbO2 at the positive electrode.

[0085] The mechanism of the self-charging process of the aqueous energy input-induced self-charging PbO2-H2 battery is described by the following reaction:

[0086] O2 electrode (negative electrode): O2 + 4H + +4e - →2H₂O (E=1.23V);

[0087] PbO2 electrode (positive electrode): PbSO4 + 2H2O → PbO2 + SO4 2- +4H + +2e - (E = 1.69V);

[0088] Overall reaction: 2PbSO4 + O2 + 2H2O → 2PbO2 + 2SO4 2- +4H + (E = -0.46V).

[0089] During the subsequent discharge process, the PbO2 positive electrode can be well coupled with the H2 negative electrode, theoretically achieving an output voltage of 1.69V. The mechanism of the self-charging PbO2-H2 discharge process is represented by the following reaction:

[0090] Positive electrode: PbO2 + SO4 2- +4H + +2e - →PbSO4 + 2H2O (E = 1.69V);

[0091] Negative electrode: H2 → 2H + +2e - (E = 0V);

[0092] Overall reaction: PbO2 + H2 + SO4 2- +2H + →PbSO4 + 2H2O (E = 1.69V).

[0093] Preparation of electrolyte: Take concentrated sulfuric acid and dilute it to a 4.5M sulfuric acid solution to obtain the electrolyte.

[0094] Electrode preparation: 6cm lead foil 2 The electrode was immersed in a 4.5M H2SO4 solution and subjected to constant current charge / discharge cycles in a three-electrode system, with a platinum sheet and a silver / silver chloride electrode serving as the counter and reference electrodes, respectively. The current, charging time, discharge cutoff voltage, and cycle time were fixed at 60mA, 200s, 1.3V, and 24h, respectively, which oxidized the surface Pb to PbO2.

[0095] In this embodiment 3, the Swagelok device from embodiment 1 is used to assemble an energy input-induced PbO2-H2 battery. Figure 11 The schematic diagram illustrates the charge-discharge test results curves of the energy input-induced self-charging PbO2-H2 battery in Example 3 under different self-charging current densities. Figure 12 The diagram schematically illustrates the self-charge-discharge cycle performance test curves of the energy input-induced self-charging PbO2-H2 battery in Example 3 of this embodiment. For example... Figure 11 The charge-discharge curves shown are for a fully discharged PbO2-H2 battery at different current densities of 10-60 mA / cm². 2 Energy input-induced charging was performed at a current density of 60 mA / cm². As the self-charging current density increased to 60 mA / cm², [further details needed]. 2 The discharge capacity can still reach 0.41 mAh / cm³. 2 At 20mA / cm 2 30mA / cm 2 40mA / cm 2 50mA / cm 2 and 60mA / cm 2 They provide energy efficiencies of 123.3%, 114.1%, 109.1%, 110.3%, and 102.9% at current densities, respectively. For example... Figure 12 As shown, the performance of the self-charging PbO2-H2 battery with energy input was continuously monitored for 10 cycles. The results showed that the charge-discharge curve remained basically stable, and the average energy efficiency reached 123.3%.

[0096] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. An aqueous self-charging hydrogen battery, comprising: The battery comprises a negative electrode, a positive electrode and an electrolyte, wherein The negative electrode carries a catalyst for the oxidation of H2 to H2O or H + at its interface with the electrolyte during discharge. The positive electrode comprises a positive electrode material with redox activity, for reducing reaction at the interface between the positive electrode material and the electrolyte during discharging; After discharging, the battery is filled with oxygen, and the reduction product of the positive electrode material is oxidized by self-charging in the presence of oxygen; the self-charging mode includes one of chemical self-charging, short-circuit induced self-charging and energy input induced self-charging; When the self-charging mode of the battery is chemical self-charging, the reduction product of the positive electrode material can be spontaneously oxidized by oxygen; When the self-charging mode of the battery is short-circuit induced self-charging, the negative electrode is used as an oxygen electrode for reduction reaction under positive and negative electrode short circuit, and the positive electrode is used to oxidize the reduction product of the positive electrode material under positive and negative electrode short circuit; When the self-charging mode of the battery is energy input induced self-charging, the negative electrode is used as an oxygen electrode for reduction reaction under the action of external voltage, and the positive electrode is used to oxidize the reduction product of the positive electrode material under the action of external voltage; When the oxidation potential of the positive electrode material is lower than the reduction reaction potential of oxygen, the self-charging mode of the battery is chemical self-charging or short-circuit induced self-charging; When the oxidation potential of the positive electrode material is higher than the reduction reaction potential of oxygen, the self-charging mode of the battery is energy input induced self-charging.

2. The battery of claim 1, wherein, The filling pressure of oxygen is 1-100 atm.

3. The battery of claim 1, wherein, The electrolyte is one of acidic, neutral or alkaline.

4. The battery of claim 1, wherein The positive electrode material is selected from inorganic material or organic material, The inorganic material includes halogen element, Prussian blue analogue, manganese oxide, vanadium oxide, cobalt oxide, polyanion compound; The organic material includes conductive polymer, carbonyl compound, imine compound, organic sulfide; The conductive polymer includes but is not limited to polyaniline, polypyrrole, polythiophene, polyacetylene.

5. The battery of claim 1, wherein, The negative electrode is a current collector, and the current collector is a carrier carrying the catalyst.

6. The battery of claim 1, wherein, The catalyst includes one or more of first metal catalyst, second metal catalyst, third metal catalyst and carbon material.

7. The battery of claim 6, wherein The first metal catalyst includes one or more of Pt, Pd, Ir, Ru, PtNi, PtCo, PtMo, PtW, PtNiCo, PtNiMo, PdNi, PdCo, PdMo, PdW, PdNiCo, PdNiMo, IrNi, IrCo, IrMo, IrW, IrNiCo, IrNiMo, RuNi, RuCo, RuMo, RuW, RuNiCo, RuNiMo; The second metal catalyst includes one or more of PtO2, PtOH, PtC, IrO2, IrC, IrN, IrS, IrP, RuO2, RuC, RuN, RuS, RuP; The third metal catalyst includes one or more of Ni, NiMo, NiCoMo, MoC, MoC2, MoO2, MoS2, MoP, WC, WC2, WO2, WS2, WP, NiN, NiS, NiP, NiPS; The carbon material includes one or more of microspheres, nanospheres, microparticles, nanoparticles, microsheets, nanosheets, microwires, nanowires, micropipes, nanotubes.

8. The battery of claim 1, wherein, The battery further includes a separator, which is arranged between the positive electrode and the negative electrode.

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