CN114141994A - A metal/alloy electrode containing polymer solid electrolyte and preparation method thereof - Google Patents

Abstract

The invention discloses a metal/alloy electrode containing polymer solid electrolyte, which is characterized in that polymer solid electrolyte is uniformly mixed or coated in the electrode, polymer monomer, solvent and metal/alloy material powder are mixed, and then free radical polymerization is initiated in modes of heating, electrochemistry, catalysis and the like to obtain metal/alloy powder electrode material uniformly coated with polymer, and finally the metal/alloy electrode containing solid electrolyte is prepared. The electrode of the invention has good electronic conductivity and ionic conductivity; the stability between the polymer solid electrolyte and the metal/alloy material improves the efficiency of the metal/alloy electrode; meanwhile, the solid electrolyte has high elastic modulus, can block the growth of metal dendrites and improve the cycle performance of the electrode.

Description

A metal/alloy electrode containing polymer solid electrolyte and preparation method thereof

technical field

The invention relates to the technical field of alkaline battery manufacturing, in particular to a metal/alloy electrode and a preparation process thereof.

Background technique

As a kind of clean and green energy, electric energy has been widely used in human life, and the development of electric energy storage containers, batteries, especially storage batteries, has always attracted people's attention. Starting from carbon-zinc batteries, zinc-manganese batteries, magnesium-manganese batteries, nickel-hydrogen batteries, lithium-ion batteries, lithium metal batteries and other batteries are being continuously researched and commercialized. Good cycle performance, safer use conditions and lower cost, battery electrode materials and processes are very important factors.

In the battery structure, metal/alloy electrodes have been focused on because of their extremely high energy density. However, due to the relatively active metal electrode materials, it is easy to react with the electrolyte during the cycle, which affects the overall efficiency of the battery. Because the volume of the metal/alloy electrode changes greatly during cycling, this instability results in a low cycle life of the metal electrode, which is generally less than 100 cycles. At the same time, since dendrites will appear during the charging and discharging process of the metal electrodes, if the dendrites penetrate the diaphragm and cause an internal short circuit, it will easily lead to safety problems. The above problems are all important reasons for restricting the commercialization of metal electrode batteries.

SUMMARY OF THE INVENTION

Aiming at the above problems of metal/alloy electrodes, the present invention proposes a metal/alloy electrode protected or mixed with a polymer solid electrolyte and a preparation method thereof. The material has high stability and good ionic conductivity and electronic conductivity, thereby Improve the cycling performance and efficiency of batteries using this material.

The technical scheme of the present invention is as follows:

A preparation method of a metal/alloy electrode containing a polymer solid electrolyte, comprising the steps of:

1) Add the binder into the solvent, dilute and stir to obtain a uniform solution;

2) Add the polymer solid electrolyte, metal/alloy material powder and additives into the above slurry, and stir well at high speed, so that the polymer solid electrolyte is coated on the surface of the metal/alloy material;

3) compound the above-mentioned slurry on the current collector by coating or drawing method;

4) drying the solvent of the above-mentioned electrode to obtain a coated metal/alloy electrode;

Wherein, the solid electrolyte material is an oxidized polymer electrolyte with a continuous conjugated structure in the main chain, and the polymer solid electrolyte is mixed in the metal/alloy electrode by a wet mixing method to obtain continuous ion channels.

The invention also discloses another preparation method of the metal/alloy electrode containing the polymer solid electrolyte, comprising the following steps:

1) Mix and fully stir the polymer monomer, solvent, and metal/alloy powder;

2) Use heating, electrolysis, irradiation or catalytic initiation to make the polymer monomer carry out free radical polymerization;

3) drying solvent to obtain metal/alloy powder coated by polymer;

4) Doping the polymer-coated metal/alloy powder in the presence of Lewis acid to convert the polymer into an electronic ion conductor, washing and drying to obtain a solid-state electrolyte-coated metal/alloy powder;

5) uniformly mix the binder, the metal/alloy powder coated by the solid electrolyte, the additive and the solvent;

6) compound the above-mentioned slurry onto the current collector by coating or pulling;

7) drying the solvent of the above-mentioned electrode to obtain a coated metal/alloy electrode;

Wherein, after the polymer monomer is polymerized, a continuous conjugated structure is formed on the main chain; Lewis acids include oxygen, sulfur trioxide, arsenic pentafluoride, quinone organic compounds, ferric chloride and dinitrogen tetroxide and other electron-deficient compounds compound.

Preferably, the solid electrolyte material is one or more of polyphenylene sulfide, polythiophene, polyaniline, polyphenylene ether, and polysulfone; the particle size D50 of the solid electrolyte material ranges from 0.001um to 10um.

Preferably, the polymer monomer is p-phenylene sulfide, thiophene, aniline, phenylene ether or phenylsulfone.

Preferably, the Lewis acid is oxygen, sulfur trioxide, arsenic pentafluoride, quinone organic compounds, ferric chloride or dinitrogen tetroxide.

Preferably, the metal/alloy material powder is pure metal powder, alloy powder or metal oxide powder of Zn, Al, Mg, Cu, Sn, Pb, In or Li metal electrode material.

Preferably, the binder is a water-based binder, and further preferably, one or more selected from CMC/SBR, polyacrylonitrile, polyacrylic acid PAA and its derivatives, and polyvinyl alcohol PVA

Preferably, the binder is an oil-based binder, more preferably, one or more selected from PVDF and PTFE.

Preferably, the pulping solvent is deionized water, ethanol, or an oil-based solvent, such as NMP, DMF, acetone, acetonitrile, xylene or benzene.

Preferably, the current collector is metal foil, metal mesh, carbon fiber paper or a polymer film covered with a conductive layer.

The present invention also provides the metal/alloy electrode containing the polymer solid electrolyte prepared by the above method.

Compared with the prior art, the present invention has the following beneficial effects:

The metal/alloy electrode containing the polymer solid electrolyte prepared by the invention utilizes the high modulus and stability of the polymer solid electrolyte, reduces the contact between the metal/alloy electrode and the electrolyte, and reduces the side reactions and dendrites of the metal/alloy The probability of generation, thus improving the charge-discharge efficiency and cycle performance of the electrode material. Because the solid electrolyte is used, the usage amount of the electrolyte can be reduced. For the battery using the combustible organic electrolyte, the invention improves the safety performance of the battery, and the process is simple, which can be realized by using the existing electrode manufacturing equipment.

Description of drawings

Fig. 1 is the SEM test chart of the zinc negative electrode surface containing polymer solid electrolyte in Example 1;

2 is a cycle efficiency diagram of a zinc-manganese battery containing a polymer solid electrolyte in Example 4;

FIG. 3 is a cycle performance diagram of the zinc-manganese battery containing the polymer solid electrolyte in Example 4. FIG.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments, but the implementation of the present invention is not limited thereto.

Example 1

A zinc negative electrode containing a polymer solid electrolyte, the preparation process comprising the following steps:

The polymer solid electrolyte is crushed using an air-flow mill to obtain polymer solid electrolyte powder with a fineness of D50=2um.

Dissolve 10 g of sodium polyacrylate, 10 g of CMC, and 30 g of PTFE emulsion with 1 kg of deionized water, and stir in a mixer at room temperature for 4-12 hours to obtain a uniformly dissolved binder solution.

Mix 1kg D50=20um metal zinc powder and zinc oxide powder, 6g indium oxide, 20g bismuth oxide and 10g pulverized polymer solid electrolyte into the binder solution, and uniformly distribute the polymer solid electrolyte material in the slurry by stirring. material.

The above-mentioned mixture is compounded on a tin-plated copper mesh by a slurry method, and the deionized water is removed by baking at 60 degrees under a vacuum ventilation condition to obtain a metal zinc negative electrode containing a polymer solid electrolyte.

Referring to Fig. 1, using the scanning electron microscope SEM to measure the surface of the metal zinc electrode obtained above, it can be observed that the polymer solid electrolyte is uniformly distributed in the middle of the electrode, forming an ion pathway.

Example 2

A kind of aluminum electrode production containing solid electrolyte, the production process comprises the following steps:

Dissolve 40 g of sodium polyacrylate, 40 g of CMC, and 60 g of PTFE emulsion with 2 kg of deionized water, and stir in a mixer at room temperature for 4-12 hours to obtain a uniformly dissolved binder solution.

Mix 2kg D50=1um aluminum metal particles with alumina protective layer, 20g tin powder and 800g pulverized polymer solid electrolyte into the binder solution, and uniformly distribute the polymer solid electrolyte material in the slurry by stirring .

The above mixture was coated on copper foil, and the deionized water was removed by baking under vacuum ventilation at 60 degrees to obtain a metal-aluminum negative electrode containing a polymer solid electrolyte.

Example 3

A preparation process of a tin negative electrode containing a solid electrolyte, the process comprises the steps:

Dissolve 20 g of sodium polyacrylate, 20 g of CMC, and 25 g of PTFE emulsion with 1 kg of deionized water, and stir in a mixer at room temperature for 4-12 hours to obtain a uniformly dissolved binder solution.

2kg of cleaned tin metal particles with D50=0.1um and 160g of pulverized polymer solid electrolyte were mixed into the binder solution, and the polymer solid electrolyte material was uniformly distributed in the slurry by stirring.

The above mixture was coated on copper foil, and the deionized water was removed by baking under vacuum ventilation at 80 degrees to obtain a metal tin negative electrode containing a polymer solid electrolyte.

Table 1: Ratios of solid electrolytes and materials in Examples 1-3

Example 4

A preparation process of a zinc negative electrode containing a solid electrolyte, the process comprises the following steps:

Take 8.4 g of thiophene and add 1 L of [Bmim][BF4] solvent to prepare a 0.1 mol/L thiophene-[Bmim][BF4] solution.

The above thiophene solution was put into an electrolytic cell container and 1 kg of metallic zinc powder was added to the solution.

Turn on the electrochemical workstation, preheat, and place the working electrode, reference electrode, and counter electrode into the electrolytic cell.

The electrochemical workstation applies a voltage and continuously stirs the above solution, so that the zinc metal particles continuously collide with the working electrode in motion, and the thiophene polymerizes on the surface of the zinc metal at a low potential. The reaction was continued for 8h, so that the thiophene was fully polymerized.

The above-mentioned metal zinc powder coated with polythiophene is washed several times with ethanol and deionized water, and finally the product is dried in a drying oven to obtain a polymer solid electrolyte coated zinc powder material.

1kg of the above solid electrolyte-coated zinc powder material was mixed with 5g of CMC, 40g of PAA binder, 6g of indium oxide, 15g of bismuth oxide, 800g of deionized water, and 60g of conductive graphite to obtain a zinc paste slurry.

The zinc paste slurry is coated on the tin-plated copper mesh by pulling the slurry, and after being compacted, dried with deionized water to obtain a metal zinc negative electrode.

The above-mentioned metal zinc negative electrode and manganese dioxide positive electrode, separator, and KOH electrolyte were used to form a zinc-manganese alkaline battery, and the AC impedance and cycle performance were tested, as shown in Figures 2 and 3. After 500 cycles at 1C, the capacity of the zinc-manganese battery reaches 80% of the initial capacity, which is much higher than that of the commercial secondary zinc-manganese battery (the capacity drops to 80% after 100 cycles).

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. A method for preparing a metal/alloy electrode containing a polymer solid electrolyte, comprising the steps of:

1) Adding the binder into the solvent, diluting and stirring uniformly to obtain a uniform solution;

2) Adding a polymer solid electrolyte, metal/alloy material powder and an additive into the slurry, and sufficiently stirring uniformly at a high speed to ensure that the polymer solid electrolyte is coated on the surface of the metal/alloy material;

3) Compounding the slurry on a current collector in a coating or slurry drawing mode;

4) Drying the solvent of the electrode to obtain a coated metal/alloy electrode;

the solid electrolyte material is an oxidized polymer electrolyte with a main chain having a continuous conjugated structure, and the polymer solid electrolyte is mixed in the metal/alloy electrode by a wet mixing method to obtain a continuous ion channel.

2. A method for preparing a metal/alloy electrode containing a polymer solid electrolyte, comprising the steps of:

1) Mixing and fully stirring a polymer monomer, a solvent and metal/alloy powder;

2) Carrying out free radical polymerization on a polymer monomer by adopting a heating, electrolyzing, irradiating or catalyzing initiation mode;

3) Drying the solvent to obtain metal/alloy powder coated by the polymer;

4) Doping the metal/alloy powder coated with the polymer in the atmosphere with Lewis acid to convert the polymer into an electronic ion conductor, washing and drying to obtain the metal/alloy powder coated with the solid electrolyte;

5) Uniformly mixing a binder, metal/alloy powder coated by a solid electrolyte, an additive and a solvent;

6) Compounding the slurry on a current collector in a coating or slurry drawing mode;

7) Drying the solvent of the electrode to obtain a coated metal/alloy electrode;

wherein, a continuous conjugated structure is formed on the main chain after the polymer monomer is polymerized; lewis acids include oxygen, sulfur trioxide, arsenic pentafluoride, quinone organic compounds, ferric trichloride, dinitrogen tetroxide and other electron deficient compounds.

3. The preparation method according to claim 1, wherein the solid electrolyte material is one or more of polyphenylene sulfide, polythiophene, polyaniline, polyphenylene oxide and polysulfone; the particle fineness D50 of the solid electrolyte material is in the range of 0.001-10 um.

4. The method of claim 2, wherein the polymer monomer is p-phenylene sulfide, thiophene, aniline, phenylene ether or phenylsulfone.

5. The production method according to claim 1 or 2, wherein the lewis acid is oxygen, sulfur trioxide, arsenic pentafluoride, a quinone-based organic compound, ferric trichloride, or dinitrogen tetroxide.

6. The production method according to claim 1 or 2, characterized In that the metal/alloy material powder is a pure metal powder, an alloy powder or a metal oxide powder of a Zn, al, mg, cu, sn, pb, in or Li metal electrode material.

7. The method according to claim 1 or 2, wherein the binder is a water-based binder, and more preferably, the binder is one or more selected from the group consisting of CMC/SBR, polyacrylonitrile, polyacrylic acid PAA and its derivatives, and polyvinyl alcohol PVA.

8. The method according to claim 1 or 2, wherein the binder is an oil-based binder, and more preferably, is one or more selected from PVDF and PTFE. The pulping solvent is deionized water, ethanol, or an oil based solvent such as NMP, DMF, acetone, acetonitrile, xylene, or benzene.

9. The production method according to claim 1 or 2, wherein the current collector is a metal foil, a metal mesh, a carbon fiber paper, or a polymer film coated with a conductive layer.

10. A metal/alloy electrode containing a polymer solid electrolyte prepared by the production method according to any one of claims 1 to 9.

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