阅读说明：本技术 用于锌溴液流电池极板的导电粘结剂及其制备方法 (Conductive adhesive for zinc-bromine flow battery pole plate and preparation method thereof ) 是由 王学华 申楷赟 王强 王浩 卢苗苗 白志城 张宗永 于 2019-10-28 设计创作，主要内容包括：本发明提供一种用于锌溴液流电池极板的导电粘结剂及其制备方法,该导电粘结剂,按质量百分数计,由以下组分组成：溶剂：40-55％,胶料：19-25％,增韧剂：2-10％,导电剂：20-25％,余量为附着力促进剂。本发明的用于锌溴液流电池极板的导电粘结剂通过各组分的协同作用,具有良好的导电性,其在电化学反应过程中不失效、不分解,且其剥离强度大,韧性好,具有较好的抗热震能力,同时,其固化速度快,无需高温烘烤,使用方便,另外,本发明的胶体干燥后可再生,无不良溶剂,环保安全。(The invention provides a conductive adhesive for a zinc-bromine flow battery pole plate and a preparation method thereof, wherein the conductive adhesive comprises the following components in percentage by mass: solvent: 40-55%, sizing material: 19-25%, toughening agent: 2-10%, conductive agent: 20-25% and the balance adhesion promoter. The conductive adhesive for the zinc-bromine flow battery pole plate has good conductivity through the synergistic effect of the components, does not lose efficacy or decompose in the electrochemical reaction process, has high peel strength and good toughness, has good thermal shock resistance, and is high in curing speed, free of high-temperature baking and convenient to use.)

1. The conductive adhesive for the polar plate of the zinc-bromine flow battery is characterized by comprising the following components in percentage by mass: solvent: 40-55%, sizing material: 18-25%, toughening agent: 2-10%, conductive agent: 20-25% and the balance adhesion promoter.

2. The conductive adhesive for zinc-bromine flow battery plates of claim 1, wherein the solvent is one or more of N-methylpyrrolidone, N-dimethylformamide, dimethyl sulfoxide, methyl acetate, ethyl acetate, acetone, xylene.

3. The conductive adhesive for zinc-bromine flow battery plates of claim 1, wherein the sizing is composed of a fluorine-containing resin and an acrylic resin; the mass ratio of the fluorine-containing resin to the acrylic resin is (1-2) to (8-9).

4. The conductive adhesive for the plates of the zinc-bromine flow battery as claimed in claim 3, wherein the molecular weight of the fluorine-containing resin is greater than 400000, and the purity is greater than 99.5%; the molecular weight of the acrylic resin is 75000-120000, and the purity is more than 99 percent.

5. The conductive adhesive for the plates of the zinc-bromine flow battery as claimed in claim 1, wherein the toughening agent is one or more of styrene-butadiene rubber, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, and methyl methacrylate-ethyl acrylate copolymer.

6. The conductive adhesive for zinc-bromine flow battery plates of claim 1, wherein the adhesion promoter is a silicone-free n-butyl acetate solution of a modified polyester resin; the weight percentage of the modified polyester resin without silicone is 10-30%.

7. The conductive adhesive for zinc-bromine flow battery plates of claim 6, wherein the modified polyester resin without silicone is one of epoxy modified acrylic resin, polyurethane modified acrylic resin, and acrylic modified polyester resin.

8. The conductive adhesive for the plates of the zinc-bromine flow battery as claimed in claim 1, wherein the conductive agent is one or more of graphite powder, conductive carbon black, carbon nanotubes and graphene.

9. A method of preparing an electrically conductive binder for a zinc-bromine flow battery plate according to any one of claims 1 to 8, comprising the steps of:

1) dissolving the sizing material in the solvent to obtain a solution A;

2) mixing the solution A, the toughening agent and the adhesion promoter, and stirring to obtain a glue solution B;

3) and adding the conductive agent into the glue solution B, stirring, and performing vacuum degassing to obtain the conductive adhesive for the zinc-bromine flow battery plate.

10. The method for preparing the conductive adhesive for the zinc-bromine flow battery plate as claimed in claim 9, wherein the stirring speed in the step 2) is 200-300r/min, and the stirring time is 2-4 h.

Technical Field

The invention relates to the technical field of flow energy storage batteries, in particular to a conductive adhesive for a zinc-bromine flow battery pole plate and a preparation method thereof.

Background

The flow battery is a new type of high capacity electrochemical energy storage device, it is different from the battery using solid material electrode or gas electrode, its active material is flowing electrolyte solution, the most obvious characteristic is large-scale electric storage, it has the characteristics of high capacity, wide application field and long cycle service life. For a long time, a zinc energy storage system with high energy density and low cost has good feasibility and operability in application, so that a zinc bromine redox flow battery is concerned and valued by people. Compared with a lead-acid battery, the zinc-bromine flow battery has higher energy density and power density, and is more efficient and clean; and has a price advantage compared with other flow batteries. The key materials of the zinc-bromine flow battery comprise an electrode, a diaphragm, an electrolyte and the like. Research shows that the cost of the electrode material accounts for about 50% of the cost of the battery, the electrode material is also a key material influencing the service life of the battery, the reliability of the electrode material is improved, the cost of the battery can be effectively reduced, and the electrode material has important significance for improving the performance and the service life of the battery.

The aqueous solution of bromine and bromine salt in the zinc-bromine flow battery has corrosivity to electrode materials, and long-time operation can cause electrode aging deformation, thereby greatly influencing the performance and the service life of the battery. Therefore, the electrode material needs to have good corrosion resistance, and common electrode materials include graphite, carbon felt, glassy carbon, metal plates, carbon-plastic composite materials and the like. The carbon-plastic composite material can greatly reduce the corrosion of bromine water and improve the electrode strength, but has high resistivity and higher overpotential, thereby causing poor battery performance.

Disclosure of Invention

In view of the above, the invention aims to provide a conductive adhesive for a zinc-bromine flow battery electrode plate, so as to solve the problems of poor mechanical properties of the existing graphite plate electrode, poor corrosion resistance of a metal plate, poor battery performance of a composite plate and high cost.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a conductive adhesive for a zinc-bromine flow battery pole plate comprises the following components in percentage by mass: solvent: 40-55%, sizing material: 19-25%, toughening agent: 2-10%, conductive agent: 20-25% and the balance adhesion promoter.

Optionally, the solvent is one or more of N-methylpyrrolidone, N-dimethylformamide, dimethyl sulfoxide, methyl acetate, ethyl acetate, acetone, xylene.

Optionally, the sizing is composed of a fluorine-containing resin and an acrylic resin; the mass ratio of the fluorine-containing resin to the acrylic resin is (1-2) to (8-9). Optionally, the molecular weight of the fluorine-containing resin is larger than 400000, and the purity is larger than 99.5%; the molecular weight of the acrylic resin is 75000-120000, and the purity is more than 99 percent.

Optionally, the toughening agent is one or more of styrene butadiene rubber, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer and methyl methacrylate-ethyl acrylate copolymer.

Optionally, the adhesion promoter is an n-butyl acetate solution of a modified polyester resin that is silicone-free; the weight percentage of the modified polyester resin without silicone is 10-30%.

Optionally, the modified polyester resin without silicone is one of epoxy modified acrylic resin, polyurethane modified acrylic resin, and acrylic modified polyester resin.

Optionally, the conductive agent is one or more of graphite powder, conductive carbon black, carbon nanotubes and graphene.

The second purpose of the invention is to provide a method for preparing the conductive adhesive for the polar plate of the zinc-bromine flow battery, which comprises the following steps:

1) dissolving the sizing material in the solvent to obtain a solution A;

2) mixing the solution A, the toughening agent and the adhesion promoter, and stirring to obtain a glue solution B;

3) and adding the conductive agent into the glue solution B, stirring, and performing vacuum degassing to obtain the conductive adhesive for the zinc-bromine flow battery plate.

Optionally, the stirring speed in the step 2) is 200-300r/min, and the stirring time is 2-4 h.

Compared with the prior art, the conductive adhesive for the zinc-bromine flow battery plate has the following advantages:

1. the conductive adhesive for the zinc-bromine flow battery pole plate has good conductivity through the synergistic effect of the components, does not lose efficacy or decompose in the electrochemical reaction process, has high peel strength and good toughness, has good thermal shock resistance, and is high in curing speed, free of high-temperature baking and convenient to use.

2. The conductive adhesive for the zinc-bromine flow battery pole plate can bond the porous graphite felt with good conductivity with the metal plate with good mechanical strength and corrosion resistance to form the battery pole plate with stable performance, meanwhile, the conductive adhesive has good bromine, bromine hydrogen acid and bromine salt aqueous solution corrosion resistance, the electrode is not aged in the process of multiple charging and discharging cycles, the stable charging and discharging process is maintained, and when the conductive adhesive is used for preparing the zinc-bromine flow battery, the price of the battery pole plate is reduced, and the charging and discharging cycle life of the battery is greatly prolonged.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of a battery bipolar plate prepared by using the conductive adhesive for the zinc-bromine flow battery plate.

Reference numerals:

1-metal plate, 2-conductive adhesive and 3-graphite felt.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail with reference to examples.