阅读说明：本技术 一种高效能的全固态钠-氧-水电池 (High-efficiency all-solid-state sodium-oxygen-water battery ) 是由 姜成功 章辉 刘志 于 2021-08-17 设计创作，主要内容包括：本发明涉及一种高效能的全固态钠-氧-水电池。该电池包括纳米金属聚合物电极材料；该电极材料是将金属纳米颗粒、乙酸正丁酯、1-甲氧基-2-丙醇乙酸酯和丙烯酸树脂混合反应,静置获得。本发明利用金属纳米颗粒和聚合物合成了阴极材料,组装了一种可充电的高性能全固态钠–氧–水电池,在中等湿度的环境下工作,电池可循环使用100次以上,过电位低,循环效率高。(The invention relates to a high-efficiency all-solid-state sodium-oxygen-water battery. The battery comprises a nano metal polymer electrode material; the electrode material is obtained by mixing and reacting metal nanoparticles, n-butyl acetate, 1-methoxy-2-propanol acetate and acrylic resin and standing. The invention synthesizes cathode material by utilizing metal nano particles and polymer, assembles a rechargeable high-performance all-solid-state sodium-oxygen-water battery, works in the environment of medium humidity, can be recycled for more than 100 times, and has low overpotential and high cycle efficiency.)

1. a nano metal polymer electrode material is characterized in that metal nano particles, n-butyl acetate, 1-methoxy-2-propanol acetate and acrylic resin are mixed and reacted, and the nano metal polymer electrode material is obtained by standing.

2. The electrode material of claim 1, wherein the metal nanoparticles comprise one or both of nano-silver particles and nano-copper particles.

3. A preparation method of a nano metal polymer electrode material comprises the following steps:

mixing metal nanoparticles, n-butyl acetate, 1-methoxy-2-propanol acetate and acrylic resin for reaction, and standing to obtain the nano metal polymer electrode material, wherein the mass fraction of the metal nanoparticles is 35-65%, the mass fraction of the n-butyl acetate is 10-30%, the mass fraction of the 1-methoxy-2-propanol acetate is 10-30%, and the mass fraction of the acrylic resin is 5-10% based on the total mass of the metal nanoparticles, the n-butyl acetate, the 1-methoxy-2-propanol acetate and the acrylic resin.

4. The preparation method according to claim 3, wherein the mixing reaction time is 1.5 to 3 hours.

5. The preparation method according to claim 3, wherein the standing time is 11 to 13 hours.

6. An all-solid sodium-oxygen-water battery comprising the nanometal polymer electrode material according to claim 1.

7. The all-solid sodium-oxygen-water battery of claim 6, wherein the all-solid sodium-oxygen-water battery comprises an anode, a solid ion-transporting electrolyte, and a nanometal polymer electrode material.

8. The all-solid sodium-oxygen-water battery according to claim 7, wherein said anode is metallic sodium, sealed in a stainless steel container with solid ceramic electrolyte and epoxy glue.

9. The all-solid sodium-oxygen-water battery according to claim 7, wherein the solid ion-transporting electrolyte is Na- β "-Al₂O₃。

Technical Field

The invention belongs to the field of metal-air batteries, and particularly relates to a high-efficiency all-solid-state sodium-oxygen-water battery.

Background

Sodium-air batteries that can be charged and discharged have received much attention in the past few years due to their higher theoretical energy density, abundant sodium resources and lower cost. The normal structure of a sodium-air battery is a metallic sodium anode, a non-aqueous/aqueous sodium electrolyte and a porous conductive cathode. During the discharge process, O₂Is reduced and reacts with Na at the cathode⁺Combine to form a discharge product (usually Na) filling the porous electrode₂O₂、NaO₂And some other sodium compounds). The porous electrode is not an active material but an electrically conductive stable framework carrying the reaction products, a lighter electrode material providing higher specific energy. For the charging process, the previously formed discharge products must be completely removed to prevent the channels of the electrode from being clogged with the discharge products and unnecessary side reaction products.

Moisture (H) as a non-negligible component of air₂O) is another important factor that deserves careful consideration for sodium-air batteries. H in air₂The concentration of O is generally expressed in terms of Relative Humidity (RH), which is calculated from the ratio of the actual water vapor pressure to the saturated water vapor pressure at the same temperature. It is widely believed that water reacts very readily with liquid electrolytes, and is therefore destructive to sodium-air batteries.

Currently, in the field of metal-oxygen batteries, the problems that the overpotential of the batteries is high and the charging and discharging times are few are always solved. The effect of water vapor on the liquid electrolyte during the transition from a metal-oxygen cell to a metal-air cell is again not negligible. Therefore, the development of a metal-oxygen battery with high performance and long service life is of great significance.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-efficiency all-solid-state sodium-oxygen-water battery to overcome the defects of high overpotential, few charging and discharging times and the like of a metal-oxygen battery in the prior art.

The invention provides a nano metal polymer electrode material, which is obtained by mixing and reacting metal nano particles, n-butyl acetate, 1-methoxy-2-propanol acetate and acrylic resin and standing.

Preferably, in the above electrode material, the metal nanoparticles include one or both of nano silver particles and nano copper particles.

The invention also provides a preparation method of the nano metal polymer electrode material, which comprises the following steps:

mixing metal nanoparticles, n-butyl acetate, 1-methoxy-2-propanol acetate and acrylic resin for reaction, and standing to obtain the nano metal polymer electrode material, wherein the mass fraction of the metal nanoparticles is 35-65%, the mass fraction of the n-butyl acetate is 10-30%, the mass fraction of the 1-methoxy-2-propanol acetate is 10-30%, and the mass fraction of the acrylic resin is 5-10% based on the total mass of the metal nanoparticles, the n-butyl acetate, the 1-methoxy-2-propanol acetate and the acrylic resin.

Preferably, in the preparation method, the mixing reaction time is 1.5-3 h.

Preferably, in the preparation method, the standing time is 11-13 h.

The invention also provides an all-solid-state sodium-oxygen-water battery which comprises the nano metal polymer electrode material.

Preferably, in the above all-solid sodium-oxygen-water battery, the all-solid sodium-oxygen-water battery includes an anode, a solid ion transport electrolyte and a nano metal polymer electrode material, and the nano metal polymer electrode material is a cathode.

More preferably, in the above all-solid sodium-oxygen-water battery, the anode is metallic sodium, and is sealed in a stainless steel container with a solid ceramic electrolyte and an epoxy resin gel (Locite).

More preferably, in the above all-solid sodium-oxygen-water battery, the solid ion-transporting electrolyte is Na- β ″ -Al₂O₃。

The invention adopts the metal nano polymer anode material for the first time, successfully assembles the all-solid-state sodium-oxygen-water battery which can directly work under certain humidity, and systematically researches the influence of relative humidity on the electrochemical behavior and reaction mechanism of the all-solid-state sodium-oxygen-water battery. All-solid-state sodium-oxygen batteries were tested in a dry and wet environment. The electrochemical and chemical mechanisms of the reaction are studied systematically by electrochemical cycling in combination with various in situ and ex situ characterization techniques. Revealing the critical role of the humidity effect in performance.

The invention carries out systematic research on the current cycle and the characterization of corresponding discharge products, and clearly shows that NaOH is a main discharge product. Understanding the reaction mechanism and reaction path of the sodium-oxygen-water battery under the condition of medium humidity has important significance for the development from the sodium-oxygen battery to the sodium-air battery with high performance and long service life.

The invention utilizes the solid electrolyte as the ion conductor, and well solves the problem that water has destructiveness on the sodium-air battery.

Advantageous effects

The invention synthesizes cathode material by utilizing metal nano particles and polymer, and assembles a rechargeable high-performance all-solid-state sodium-oxygen-water battery. When the battery works in the environment with medium humidity, the battery can be recycled for more than 100 times, the overpotential of the battery is low (the overpotential of the battery is between 50mV and 75 mV), and the cycle efficiency is high. At O₂The introduction of water, even in minute amounts, can even reduce the overpotential of charging by triggering the solution mechanism. At moderate relative humidity, NaOH is the main product, and the influence of water on sodium-oxygen-water batteries and complex reaction mechanisms are systematically studied.

Drawings

Fig. 1 is a schematic structural diagram of an all-solid-state sodium-oxygen battery of the present invention.

FIG. 2 is a schematic diagram of the preparation of the metal nanoparticle polymer electrode material of the present invention.

Fig. 3 is a schematic structural view of a solid sodium-oxygen-water battery in example 2 of the present invention.

FIG. 4 is a schematic view of a current cycling test apparatus according to the present invention.

Fig. 5 is a summary graph comparing the cycling efficiency and cycling times of the nanosilver particle polymer electrode of the present invention with other sodium air/oxygen cells using different electrode materials.

Fig. 6 is a schematic diagram of electrochemical characteristics of a battery assembled by the nano silver particle polymer electrode (including the number of charge-discharge cycles and charge-discharge plateau).

Fig. 7 is a graph showing the electrochemical curves of a battery assembled by the nano silver particle polymer electrode (a) and the nano copper particle polymer electrode (b) according to the present invention.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

And (3) carrying out electrochemical performance test on the battery by using an EC-Lab electrochemical workstation, charging and discharging the battery at the current of 20mA/g, discharging for 5 hours, and charging for 5 hours, wherein the result is recorded as a discharging period. The overpotential is calculated as the difference between the charge and discharge plateaus. The cycle efficiency is calculated as the ratio of the discharge plateau to the charge plateau.

Example 1

Preparing a nano metal polymer electrode material:

metallic nanoparticle polymer cathode material consisted of metallic nanoparticles (silver nanoparticles) (Alfa-Aesar, 20-40nm, 99.9%), n-butyl acetate (Alfa-Aesar, 99.5%), 1-methoxy-2-propanol acetate (Alfa-Aesar, 99%) and LR white acrylic resin (Sigma-Aldrich) (silver nanoparticles at 1mg, the latter two esters at 0.6mg, the last resin at 0.25 mg). The materials were synthesized by magnetic stirring (2 hours) to allow complete mixing of all ingredients. After the completion of the mixing, it was allowed to stand for 12 hours to remove air bubbles from the mixture. The composite material was applied to the solid electrolyte Al by spin coating (rotation speed 6000 rpm)₂O₃(commercial Na-. beta. -Al)₂O₃(Ionotec, diameter 10.5mm, thickness 0.7mm)) to obtain a homogeneous metal nanoparticle polymer obtained as a cathode material for batteries.

The metal nanoparticle polymer was prepared by replacing the nano silver particles with nano copper particles, and the rest was the same as above.

Example 2

Assembling an all-solid-state sodium-oxygen-water battery:

all-solid-state sodium-oxygen-water batteryThe three main parts are as follows: an anode, a solid ion-transporting electrolyte, and a metal nanoparticle polymer cathode. Sodium metal (Alfa-Aesar, 99.9%) was used as the anode and sealed in a self-made stainless steel container with solid ceramic electrolyte and epoxy glue (Locite). Commercial Na-beta "-Al₂O₃(Ionotec, diameter 10.5mm, thickness 0.7mm) was used as both separator and electrolyte in this sodium-oxygen-water cell system. To avoid oxidation of the sodium electrode (or reaction with atmospheric moisture), the cell was assembled in a pure argon glove box. The specific assembling process comprises the following steps: in the glove box, a 5g metal sodium block was pressed against the solid electrolyte side, compressed, and then the solid electrolyte was covered onto the stainless steel cell, with the metal sodium block now pressed between the solid electrolyte and the stainless steel cell. And then, uniformly coating epoxy resin glue between the solid electrolyte and the stainless steel tank, standing for 12 hours, and fixing the resin glue. The cell was taken out from the glove box, 1mg of the metal nanoparticle polymer electrode (the amount of the electrode applied to the cell surface was 1mg) in example 1 was dropped on the surface of the solid electrolyte, and the electrode was uniformly applied to the surface of the electrolyte by a spin coater at a speed of 6000 rpm, and then the cell was put into the glove box and left to stand for 12 hours, whereby the cell was obtained.

FIG. 5 shows that: compared with other sodium air/oxygen batteries using different electrode materials, the battery provided by the invention has the advantages that the cycle efficiency and the cycle times are compared and summarized, and the cycle efficiency and the cycle times of the battery are greatly improved compared with the battery of the same type (the position of SPC in the diagram).

FIG. 6 shows that: the electrochemical characteristic diagram (comprising the charge-discharge cycle times and the charge-discharge platform) of the invention has the advantages that the cycle times can reach 100 circles, and the overpotential between the charge-discharge platforms is very small and ranges from 50mV to 75 mV.

FIG. 7 shows that: compared with the battery assembled by taking the nano-silver particles as the electrode material, the battery assembled by taking the nano-copper particles as the electrode material has the advantages that the charging platform is obviously reduced, and the charging overpotential is obviously reduced.

The present invention is compared to the prior art as shown in the following table:

TABLE 1 summary of the overpotentials, cycling efficiencies, and cycling performance of the various air electrodes used in the present invention versus non-aqueous sodium-oxygen cells and hybrid sodium-air cells

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