A solid-state secondary hydrogen battery

Abstract

A hydrogen solid-state secondary battery relates to the technical field of battery energy storage. Its structure is as follows: The battery includes a LiVPO4F positive electrode, an H2 negative electrode, a solid electrolyte composed of an acidic electrolyte and clay, and a negative electrode catalyst Pt / C. The acidic electrolyte is H3PO4 or H2SO4; the clay is one or two of Mg2H2(SiO3)3·3.0H2O, H2Al2O6Si·1.19H2O, and H4Al2O9Si2·0.32H2O. The beneficial effects of the present invention are as follows: It can be applied to the field of large-scale battery energy storage; the LiVPO4F positive electrode of this battery is applied to a new hydrogen solid-state secondary battery system, and the solid electrolyte composed of an acidic electrolyte and clay [Mg2H2(SiO3)3·3.0H2O, H2Al2O6Si·1.19H2O, H4Al2O9Si2·0.32H2O] is applied to a new hydrogen solid-state secondary battery system for the first time. The new hydrogen solid-state secondary battery has excellent cycle stability, high-rate performance, and low-temperature performance. In addition, it is simple to prepare, consumes less energy, has a low cost, is not restricted by resources, is green and environmentally friendly, and is easy to industrialize.

Description

Technical Field

[0001] The present invention relates to the technical field of battery energy storage, and particularly to a hydrogen solid-state secondary battery. Background Art

[0002] Due to advantages such as the smallest ionic radius, the lightest molar mass, high ionic conductivity, and sustainability, protons have become a current research hotspot as ion carriers in proton batteries. So far, although some cathode and anode materials have been proven to be able to stably store protons in acidic electrolytes. However, when assembling full cells using these electrode materials, the rate and cycle performance are often lower than those of other aqueous metal-ion battery systems. The main reason is that the acidic electrolyte easily damages the electrode structure and corrodes the current collector of the battery. Therefore, exploring solid-state proton full cells with excellent performance and giving full play to the advantages of proton electrodes is of extremely important significance for their practical applications.

[0003] A solid electrolyte is a solid ionic conductor electrolyte, which is divided into all-solid-state electrolytes and quasi-solid-state electrolytes. All-solid-state electrolytes are divided into solid electrolytes, solid polymer electrolytes, and composite polymer electrolytes; among them, solid polymer electrolytes conduct ions by interacting with substituents of polymer chains, while quasi-solid-state electrolytes mainly conduct ions in solvents or plasticizers and will not damage the electrode structure and corrode the current collector of the battery. Therefore, exploring solid-state proton full cells with excellent performance and giving full play to the advantages of proton electrodes is of extremely important significance for their practical applications.

[0004] Hydrogen is considered a very promising anode because the hydrogen oxidation and reduction reactions occurring under the action of a catalyst exhibit low overpotential and long cycle stability. In addition, the hydrogen electrode is extremely stable in acid solutions, and only protons participate in the electrochemical reaction, showing fast reaction kinetics, making it a natural proton battery. In summary, developing inexpensive solid electrolytes to construct hydrogen solid-state secondary batteries is of great significance and value. In existing research, acidic electrolytes added with clay (Mg2H2(SiO3)3·3.0H2O, H2Al2O6Si·1.19H2O, H4Al2O9Si2·0.32H2O) have been proven to be effective as solid electrolytes for proton batteries, but there is no literature or patent report on using acidic electrolytes added with clay (Mg2H2(SiO3)3·3.0H2O, H2Al2O6Si·1.19H2O, H4Al2O9Si2·0.32H2O) for new hydrogen solid-state secondary batteries. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a hydrogen solid-state secondary battery to solve the above-mentioned existing technical problems.

[0006] The present invention provides a hydrogen solid-state secondary battery, whose structure includes a LiVPO4F positive electrode, a H2 negative electrode, a solid electrolyte composed of an acidic electrolyte and clay, and a negative electrode catalyst Pt / C.

[0007] Further, the acidic electrolyte is H3PO4 or H2SO4.

[0008] Further, the clay is one or two of sepiolite Mg2H2(SiO3)3·3.0H2O, bentonite H2Al2O6Si·1.19H2O, and bentonite H4Al2O9Si2·0.32H2O.

[0009] Further, the specific preparation method of the LiVPO4F positive electrode is as follows: Mix a vanadium source, a phosphoric acid source, and LiF with a content of 99.9% in a ball mill according to the chemical molar ratio, and ball mill for 0.5 - 2 h. Subsequently, treat it in an argon atmosphere at 300 °C for 3 - 6 h, cool it naturally, grind it for 30 minutes, and finally calcine it in a tube furnace at 800 °C in an argon atmosphere for 8 - 10 h, and the obtained material is LiVPO4F.

[0010] Further, the vanadium source is one or two of V2O3, V2O5, VO2, V3O7, and V6O 13 in the list.

[0011] Further, the phosphoric acid source is one or two of NH4H2PO4H and (NH4)2HPO4.

[0012] Further, the concentration of the acidic electrolyte is 10% - 85%.

[0013] Further, the mass ratio of the acidic electrolyte to the clay is 1:5.

[0014] Further, in the negative electrode catalyst Pt / C, Pt accounts for 15% - 50% of the total mass fraction.

[0015] Further, the solid electrolyte is an acidic electrolyte plus clay.

[0016] The beneficial effects of the present invention are as follows: It can be applied to the field of large-scale battery energy storage; the LiVPO4F positive electrode of this battery is applied to a new hydrogen solid-state secondary battery system, and the solid electrolyte composed of an acidic electrolyte and clay [Mg2H2(SiO3)3·3.0H2O, H2Al2O6Si·1.19H2O, H4Al2O9Si2·0.32H2O] is applied to a new hydrogen solid-state secondary battery system for the first time. The new hydrogen solid-state secondary battery has excellent cycle stability, high rate performance, and low-temperature performance. In addition, its preparation is simple, energy consumption is low, cost is low, it is not restricted by resources, it is green and environmentally friendly, and it is easy to realize industrialization. Description of the Drawings

[0017] Figure 1 This is a schematic diagram of the principle of the charge and discharge process of the hydrogen solid secondary battery of the present invention;

[0018] Figure 2 This is a 1um scanning electron microscope image of the LiVPO4F cathode of the present invention;

[0019] Figure 3 This is a 2um scanning electron microscope image of the LiVPO4F cathode of the present invention;

[0020] Figure 4 This is a 10um scanning electron microscope image of the LiVPO4F cathode of the present invention;

[0021] Figure 5 This is a 30um scanning electron microscope image of the LiVPO4F cathode of the present invention;

[0022] Figure 6 This is an X-ray energy spectrum map of the elements of the LiVPO4F cathode of the present invention;

[0023] Figure 7 This is a 1um scanning electron microscope image of the sepiolite (Mg2H2(SiO3)3·3.0H2O) of the invention;

[0024] Figure 8 This is a 10um scanning electron microscope image of the sepiolite (Mg2H2(SiO3)3·3.0H2O) of the invention;

[0025] Figure 9 This is an X-ray diffraction pattern of the sepiolite (Mg2H2(SiO3)3·3.0H2O) solid electrolyte of the present invention;

[0026] Figure 10 This is a 1um scanning electron microscope image of the bentonite (H2Al2O6Si·1.19H2O) of the present invention;

[0027] Figure 11 This is a 10um scanning electron microscope image of the bentonite (H2Al2O6Si·1.19H2O) of the present invention;

[0028] Figure 12 This is an X-ray diffraction pattern of the bentonite (H2Al2O6Si·1.19H2O) solid electrolyte of the present invention;

[0029] Figure 13 This is a 1um scanning electron microscope image of the bentonite (H4Al2O9Si2·0.32H2O) of the present invention;

[0030] Figure 14 This is a 10um scanning electron microscope image of the bentonite (H4Al2O9Si2·0.32H2O) of the present invention;

[0031] Figure 15 This is the X-ray diffraction pattern of the bentonite (H4Al2O9Si2·0.32H2O) solid electrolyte of the present invention;

[0032] Figure 16 This is the X-ray diffraction pattern of the sepiolite (Mg2H2(SiO3)3·3.0H2O)+H3PO4 solid electrolyte of the present invention;

[0033] Figure 17 This is the charge-discharge curve (voltage range 0.2 - 1.2V) of the LiVPO4F cathode and the bentonite (H2Al2O6Si·1.19H2O) solid electrolyte of the present invention at a current density of 1C;

[0034] Figure 18 This is the charge-discharge curve (voltage range 0.2 - 1.2V) of the LiVPO4F cathode and the sepiolite (Mg2H2(SiO3)3·3.0H2O) solid electrolyte of the present invention at a current density of 1C;

[0035] Figure 19 This is the line graph of the cycling performance and the corresponding Coulombic efficiency of the LiVPO4F cathode and the bentonite (H2Al2O6Si·1.19H2O) solid electrolyte of the present invention at a current density of 1C.

[0036] Figure 20 This is the line graph of the cycling performance and the corresponding Coulombic efficiency of the LiVPO4F cathode and the bentonite (H2Al2O6Si·1.19H2O) solid electrolyte of the present invention at a current density of 30C. Detailed implementation manners

[0037] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Embodiment 1

[0038] Refer to Figure 1 As shown, a hydrogen solid-state secondary battery includes a LiVPO4F cathode, an H2 anode, a solid electrolyte of acidic electrolyte plus clay, and a negative electrode catalyst Pt / C; during charging, lithium ions are released from the cathode and hydrogen is generated at the anode; during discharging, lithium ions and protons are embedded in the cathode material, and hydrogen at the anode is oxidized to protons. The chemical reactions are as follows:

[0039] Cathode: LiVPO4F = VPO4F + Li + + e -

[0040] Negative electrode: 2H2O + 2e - = H2 + 2OH -

[0041] Overall reaction: 2LiVPO4F + 2H2O = 2VPO4F + 2Li + + 2OH - + H2

[0042] The principle of its charge and discharge process is shown in the appendix Figure 1 . Example 2

[0043] A method for preparing the positive electrode LiVPO4F of a hydrogen solid-state secondary battery, in which V2O3 (99.9%), NH4H2PO4 and LiF are mixed in a ball mill for 0.5 - 2 h according to the chemical molar ratio, and then treated in an argon atmosphere at 300 °C for 3 - 6 h. After natural cooling, it is ground for 30 minutes, and finally calcined in a tube furnace at 800 °C in an argon atmosphere for 8 - 10 h, and the obtained material is LiVPO4F;

[0044] The LiVPO4F positive electrode shows a blocky morphology about 1.5 - 2.5 μm wide, and its scanning electron micrographs of 1 μm - 30 μm (see appendix Figures 2 - 5 ); The composition of this material was confirmed by the energy spectrum scanning map of the elements (see appendix Figure 6 ); The successful synthesis of the LiVPO4F positive electrode was further confirmed by the X-ray scanning diffraction pattern (see appendix Figure 6 ); After assembling the full battery, the cycle performance and the corresponding Coulomb efficiency were tested (see appendix Figure 19 ). At a rate of 1C, the capacity is 60 mAh / g, and there is no obvious attenuation after 500 cycles. It is expected that the cycle can reach more than 10,000 cycles; According to the charge-discharge curve, the charge-discharge voltage range is 0.3 - 1.2 V (see appendix Figures 17 - 18 ). Example 3

[0045] A hydrogen solid-state secondary battery, which includes a LiVPO4F positive electrode, an H2 negative electrode, a solid electrolyte composed of an acidic electrolyte and clay, and a negative electrode catalyst Pt / C;

[0046] The acidic electrolyte is H3PO4;

[0047] The clay is sepiolite Mg2H2(SiO3)3·3.0H2O;

[0048] Sepiolite Mg2H2(SiO3)3·3.0H2O shows a fine strip-like layered morphology under the electron micrograph, and its scanning electron micrographs of 1 μm and 10 μm (see appendix Figures 7 - 8), the composition of sepiolite Mg2H2(SiO3)3·3.0H2O was confirmed by X-ray diffraction pattern (see the appendix for details Figure 9 ), the composition of sepiolite (Mg2H2(SiO3)3·3.0H2O) + H3PO4 was confirmed by X-ray diffraction pattern (see the appendix for details Figure 16 ). Example 4

[0049] A hydrogen solid-state secondary battery, which includes a LiVPO4F positive electrode, an H2 negative electrode, a solid electrolyte composed of an acidic electrolyte and clay, and a negative electrode catalyst Pt / C;

[0050] The acidic electrolyte is H3PO4;

[0051] The clay is bentonite (H2Al2O6Si·1.19H2O);

[0052] Bentonite (H2Al2O6Si·1.19H2O) presents a lamellar morphology under the electron microscope. Its scanning electron microscope images at 1μm and 10μm are shown in the appendix (see the appendix for details Figures 10 - 11 ), the composition of bentonite (H2Al2O6Si·1.19H2O) was confirmed by X-ray diffraction pattern (see the appendix for details Figure 12 ). After assembling the full battery, cycle performance and corresponding Coulomb efficiency tests were carried out (see the appendix for details Figure 20 ). At a rate of 30C, the capacity is 47mAh / g, the Coulomb efficiency is about 90%, and there is no obvious attenuation after 550 cycles (see the appendix for details Figure 20 ). Example 5

[0053] A hydrogen solid-state secondary battery, which includes a LiVPO4F positive electrode, an H2 negative electrode, a solid electrolyte composed of an acidic electrolyte and clay, and a negative electrode catalyst Pt / C;

[0054] The acidic electrolyte is H3PO4;

[0055] The clay is bentonite (H4Al2O9Si2·0.32H2O);

[0056] Bentonite (H4Al2O9Si2·0.32H2O) presents a small crystal lamellar morphology under the electron microscope. Its scanning electron microscope images at 1μm and 10μm are shown in the appendix (see the appendix for details Figures 13 - 14 ), the composition of bentonite (H4Al2O9Si2·0.32H2O) was confirmed by X-ray diffraction pattern (see the appendix for details Figure 15 ).

Claims

1. A solid-state secondary hydrogen battery, characterized in that: The battery includes a LiVPO4F positive electrode, an H2 negative electrode, a solid electrolyte composed of an acidic electrolyte and clay, and a negative electrode catalyst Pt / C; The clay is one or two of Mg2H2(SiO3)3·3.0H2O, H2Al2O6Si·1.19H2O, and H4Al2O9Si2·0.32H2O; The mass ratio of the acidic electrolyte to the clay is 1:5; In the negative electrode catalyst Pt / C, Pt accounts for 15% - 50% of the total mass fraction.

2. The hydrogen solid-state secondary battery according to claim 1, wherein: The acidic electrolyte is H3PO4 or H2SO4.

3. The hydrogen solid-state secondary battery according to claim 1, characterized in that: The specific preparation method of the LiVPO4F positive electrode is as follows: Mix a vanadium source, a phosphoric acid source, and LiF with a content of 99.9% according to the chemical molar ratio, ball mill in a ball mill for 0.5 - 2 h, then treat in an argon atmosphere at 300 °C for 3 - 6 h, cool naturally, grind for 30 minutes, and finally calcine in a tubular furnace at 800 °C in an argon atmosphere for 8 - 10 h. The obtained material is LiVPO4F.

4. The solid-state secondary hydrogen battery according to claim 3, wherein: The vanadium source is one or two of V2O3, V2O5, VO2, V3O7 and V6O 13 ; the phosphoric acid source is one or two of NH4H2PO4H and (NH4)2HPO4.

5. The hydrogen solid secondary battery according to claim 1, characterized in that: The concentration of the acidic electrolyte is 10% - 85%.

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