阅读说明：本技术 一体化集流板、其制备方法与应用 (Integrated collector plate, and preparation method and application thereof ) 是由 李铎 黄绵延 于 2018-08-21 设计创作，主要内容包括：本发明提供了一种一体化集流板,由集流体基体与聚合物复合材料板组成,所述集流体基体设置于所述聚合物复合材料板内部,所述聚合物复合材料板由热塑性聚合物树脂与导电碳制备得到。本申请还提供了所述一体化集流板的制备方法。本申请还提供了一种钒液流电池。本申请以一体化集流板代替端双极板与集流板用于钒液流电池,可有效防止电解液的泄露与腐蚀,提高了机械强度,且可降低接触内阻,提高钒液流电池的电性能。(The invention provides an integrated current collecting plate which comprises a current collecting matrix and a polymer composite plate, wherein the current collecting matrix is arranged in the polymer composite plate, and the polymer composite plate is prepared from thermoplastic polymer resin and conductive carbon. The application also provides a preparation method of the integrated collector plate. The application also provides a vanadium redox flow battery. The integrated current collecting plate replaces the end bipolar plate and the current collecting plate to be used for the vanadium redox flow battery, so that leakage and corrosion of electrolyte can be effectively prevented, mechanical strength is improved, contact internal resistance can be reduced, and electrical property of the vanadium redox flow battery is improved.)

1. An integrated current collector plate comprises a current collector substrate and a polymer composite material plate, wherein the current collector substrate is arranged inside the polymer composite material plate, and the polymer composite material plate is prepared from thermoplastic polymer resin and conductive carbon.

2. The integrated current collector plate according to claim 1, wherein said current collector body is equidistant from both large cross-sections of said polymer composite plate in a direction perpendicular to said large cross-sections of said integrated current collector plate.

3. The integrated current collecting plate according to claim 1, wherein the current collector substrate is a copper mesh, the thickness of the copper mesh is 1-2 mm, and the pore diameter is 1-15 mm.

4. The integrated current collecting plate according to claim 1, wherein the thickness of the integrated current collecting plate is 2 to 5 mm.

5. The integrated current collector plate of claim 1, wherein said thermoplastic polymer resin is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polybutylene, polymethyl methacrylate, and polystyrene, and said conductive carbon is selected from one or both of carbon black and graphite powder; the mass ratio of the thermoplastic polymer resin to the conductive carbon is 3: (2-7).

6. A preparation method of an integrated current collecting plate comprises the following steps:

mixing thermoplastic polymer resin with conductive carbon powder, extruding and granulating to obtain conductive mixed granules;

and carrying out hot pressing on the current collector matrix and the conductive mixed granules to obtain the integrated current collector.

7. The preparation method according to claim 6, wherein the thermoplastic polymer resin is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polybutylene, polymethyl methacrylate and polystyrene, and the conductive carbon powder is selected from one or two of carbon black and graphite powder; the mass ratio of the thermoplastic polymer resin to the conductive carbon powder is 3: (2-7).

8. The method according to claim 6, wherein the hot pressing is carried out at a temperature of 150 to 300 ℃ under a pressure of 30 to 50MPa for 15 to 50 min.

9. The method according to claim 6, wherein the process for obtaining the conductive mixed pellet is specifically:

mixing thermoplastic polymer resin powder and conductive carbon powder in a mixer, and putting the obtained conductive mixture into a double-screw extruder for extrusion and granulation to obtain conductive mixed granules.

10. The vanadium flow battery is characterized in that only integrated current collecting plates are arranged at two ends of a pile of the vanadium flow battery, and the integrated current collecting plates are the integrated current collecting plates according to any one of claims 1 to 5 or the integrated current collecting plates prepared by the preparation method according to any one of claims 6 to 9.

Technical Field

The invention relates to the technical field of vanadium flow batteries, in particular to an integrated collector plate, and a preparation method and application thereof.

Background

The two metal electrode plates arranged at two ends of the vanadium flow battery pile are generally called current collecting plates or electricity taking plates. The current collecting plate is important in function, and has the functions of conducting internal and external circuits of the pile and conducting current.

The collector plate as an electrode material can be used for the vanadium redox flow battery only by having the following two characteristics; 1) the current collector plate generally adopts metal electrodes, such as copper plates; 2) the metal collector plate is corrosion-resistant, the electrolyte is very strong in corrosion to metal, and in order to avoid direct contact between the metal collector plate and the electrolyte, a layer of bipolar plate is often arranged in the middle of the metal collector plate, and the bipolar plate blocks the electrolyte and conducts current to the collector plate.

Disclosure of Invention

The invention solves the technical problem of providing an integrated current collecting plate, which can reduce the leakage and corrosion of electrolyte, reduce the resistance, improve the mechanical property and be beneficial to the improvement of the performance of a vanadium flow battery.

In view of the above, the present application provides an integrated current collecting plate, which is composed of a current collector substrate and a polymer composite material plate, wherein the current collector substrate is disposed inside the polymer composite material plate, and the polymer composite material plate is prepared from a thermoplastic polymer resin and conductive carbon.

Preferably, in the vertical direction of the large cross section of the integrated current collecting plate, the distances between the current collector matrix and the two large cross sections of the polymer composite plate are the same.

Preferably, the current collector substrate is a copper mesh, the thickness of the copper mesh is 1-2 mm, and the aperture is 1-15 mm.

Preferably, the thickness of the integrated collecting plate is 2-5 mm.

Preferably, the thermoplastic polymer resin is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polybutylene, polymethyl methacrylate and polystyrene, and the conductive carbon is selected from one or two of carbon black and graphite powder; the mass ratio of the thermoplastic polymer resin to the conductive carbon powder is 3: (2-7).

The application also provides a preparation method of the integrated collector plate, which comprises the following steps:

mixing thermoplastic polymer resin with conductive carbon powder, extruding and granulating to obtain conductive mixed granules;

and carrying out hot pressing on the current collector matrix and the conductive mixed granules to obtain the integrated current collector.

Preferably, the thermoplastic polymer resin is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polybutylene, polymethyl methacrylate and polystyrene, and the conductive carbon powder is selected from one or two of carbon black and graphite powder; the mass ratio of the thermoplastic polymer resin to the conductive carbon powder is 3: (2-7).

Preferably, the hot pressing temperature is 150-300 ℃, the pressure is 30-50 Mpa, and the time is 15-50 min.

Preferably, the process for obtaining the conductive mixed granules comprises the following steps:

mixing thermoplastic polymer resin powder and conductive carbon powder in a mixer, and putting the obtained conductive mixture into a double-screw extruder for extrusion and granulation to obtain conductive mixed granules.

The application also provides a vanadium redox flow battery, wherein the two ends of the vanadium redox flow battery pile are only provided with integrated current collecting plates, and the integrated current collecting plates are the integrated current collecting plates prepared by the integrated current collecting plates or the preparation method of the scheme.

The application provides an integration current collector, it comprises mass flow body and polymer composite board, the mass flow body set up in inside the polymer composite board, polymer composite board is prepared with conductive carbon by thermoplastic polymer resin. The current collector substrate is wrapped by the polymer composite material plate, so that the sealing effect of the polymer composite material plate is excellent, and meanwhile, the polymer composite material plate has strong corrosion resistance and can block the corrosion of electrolyte to the current collector substrate, so that the integrated current collector plate can protect the current collector substrate more tightly, and the risk of electrolyte leakage and corrosion is greatly reduced; correspondingly, the current collector substrate is made of metal materials, has strong mechanical property, and can keep high strength after being formed into an integrated current collector plate with a polymer composite material, so that the integrated current collector plate is not easy to damage in the assembly and use of a galvanic pile, and the service life is prolonged; furthermore, the current collector substrate is arranged inside the polymer composite material plate, current is directly conducted from the inside, the contact area is increased, more current paths are provided, the resistance is reduced, and the performance of the vanadium flow battery is improved.

Drawings

Fig. 1 is a schematic structural view of an integrated current collecting plate according to the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

Aiming at the problems that a bipolar plate and a current collecting plate are arranged at two ends of a vanadium flow battery in the prior art in a shared mode, the invention provides an integrated current collecting plate. The embodiment of the invention discloses an integrated current collecting plate for a vanadium flow battery, which consists of a current collector substrate and a polymer composite material plate, wherein the current collector substrate is arranged inside the polymer composite material plate, and the polymer composite material plate is prepared from thermoplastic polymer resin and conductive carbon.

As shown in fig. 1, fig. 1 is a schematic structural diagram of the integrated current collecting plate of the present application, and it can be known from the figure that the current collector substrate is disposed inside the polymer composite material plate, in order to ensure the consistency of the performance of the integrated current collecting plate, the current collector substrate is disposed in the middle of the polymer composite material plate, i.e., in the vertical direction of the large cross section of the integrated current collecting plate (in the direction of the arrow shown in the figure), the current collector substrate is away from the two large cross sections of the polymer composite material plate, and the distances between the two large.

The current collector substrate is a current collector known to those skilled in the art, and is not particularly limited in this application, and in the specific examples of this application, a copper mesh is selected for the current collector substrate. The thickness of the current collector substrate is 1-2 mm, and the aperture is 1-15 mm; in a specific embodiment, the aperture of the current collector substrate is 5-10 mm. The current collector matrix is easy to deform and even break when being too thin; if the pore diameter is too large, the contact area between the current collector substrate and the wrapped polymer composite plate is reduced, and the current conduction capability is affected, and if the pore diameter is too small, difficulty is brought in the process of processing the integrated current collector plate, and particularly, when the polymer composite material is filled into the pores, the problems of air holes and the like are easy to occur. The thickness of the integrated current collector plate is 2-5 mm, according to the size of the current collector plate substrate, the thickness of the polymer composite material plate is 0.5-4 mm, if the thickness is too large, the resistance of the integrated current collector plate is increased, and if the thickness is too small, the wrapping performance is affected, so that the electrolyte corrodes the current collector substrate.

The application also provides a preparation method of the integrated current collecting plate, which comprises the following steps:

mixing thermoplastic polymer resin with conductive carbon powder, and then extruding and granulating to obtain conductive mixed granules;

and carrying out hot pressing on the current collector matrix and the conductive mixed granules to obtain the integrated current collector.

In the process of preparing the integrated collector plate, the application firstly prepares the conductive mixed granules, and specifically comprises the following steps: mixing thermoplastic polymer resin with conductive carbon powder, and extruding and granulating the obtained mixture to obtain conductive mixed granules; the mass ratio of the thermoplastic polymer resin to the conductive carbon powder is an important factor influencing the resistance value, and specifically, the mass ratio of the thermoplastic polymer resin to the conductive carbon powder is 3: (2-7), in some embodiments, the mass ratio of the thermoplastic polymer resin to the conductive carbon powder is 3: (4-6); more specifically, the mass ratio of the thermoplastic polymer resin to the conductive carbon powder may be 45:55, may be 55:45, and may also be 50: 50; if the content of the conductive carbon powder is less than the range, the conductive carbon material is insufficient, so that the overall resistance of the integrated collector plate is increased. The thermoplastic polymer resin is selected from one or more of polyethylene, polypropylene, polyvinyl chloride, polybutylene, polymethyl methacrylate, and polystyrene, and in specific embodiments, the thermoplastic polymer resin is selected from polyethylene, polypropylene, or polyvinyl chloride; the carbon powder is selected from one or two of carbon black and graphite powder.

After mixing the thermoplastic polymer resin with the conductive carbon powder, granulating and extruding the obtained mixture to obtain conductive mixed granules, wherein the extrusion is a technical mode well known to a person skilled in the art, and the specific implementation process of the conductive mixed granules is not particularly limited in the application; in the present application, the extrusion is preferably carried out in a twin-screw extruder. The granulation is a technique known to those skilled in the art, and the present application is not particularly limited thereto.

According to the invention, after the conductive mixed granules are obtained, the current collector matrix and the conductive mixed granules are subjected to hot pressing to obtain the integrated collector plate. In the process, in order to ensure the consistency of the thickness and the surface of both sides of the current collector substrate, the upper part and the lower part of the current collector substrate are conductive mixed granules with equal quality before hot pressing. The hot pressing temperature is 150-300 ℃, the hot pressing pressure is 30-50 Mpa, and the hot pressing time is 15-50 min; in a specific embodiment, the hot pressing temperature is 180-230 ℃, the hot pressing pressure is 35-45 Mpa, and the hot pressing time is 20-40 min; in the hot pressing process, the conductive mixed granules are required to be in a molten state firstly, so that the conductive mixed granules can be pressed into the pores of the current collector matrix in the hot pressing process.

The application also provides a vanadium redox flow battery, wherein the two ends of the galvanic pile are only provided with the integrated collector plates; namely, in the vanadium redox flow battery provided by the application, an integrated current collecting plate is used for replacing a system of an end bipolar plate and a metal current collecting plate at two ends of a stack.

The integrated current collecting plate is formed by wrapping a current collecting matrix by the polymer composite material plate, the sealing effect of the polymer composite material plate is excellent, and the leakage of electrolyte is effectively prevented; meanwhile, the polymer composite plate has strong corrosion resistance and can prevent the electrolyte from corroding the current collector matrix; the internal current collector matrix improves the mechanical strength of the integrated current collecting plate, and further prolongs the service life of the integrated current collecting plate; from the performance perspective, the current collector substrate is arranged in the polymer composite material plate, the current is directly conducted from the inside, the contact area is increased, compared with a bipolar plate system in direct contact with the current collector substrate in the prior art, the resistance is reduced, and the battery performance is improved.

For further understanding of the present invention, the integrated current collecting plate, the preparation method and the application thereof provided by the present invention will be described in detail with reference to the following examples, and the scope of the present invention is not limited by the following examples.