Flow battery bonding and sealing structure, first sealant, second sealant and preparation method of first sealant and second sealant

Abstract

The invention provides a flow battery bonding and sealing structure, a first sealant, a second sealant and a preparation method, in the flow battery bonding and sealing structure, a main body plate frame, a bipolar plate and a compression ring are sequentially bonded to form an integrated plate frame component, the main body of the main body plate frame is a rectangular annular plate, and the first sealant and the second sealant are bonded to form the integrated plate frame component. A liquid inlet flow channel is formed in the edge of the first surface of the rectangular annular plate and is used as a sealing groove; an outer sealing groove is also formed in the first surface of the rectangular annular plate outside the liquid inlet flow channel; sealing structures are arranged at the positions, corresponding to the liquid inlet flow channel and the outer sealing groove, of the second surface of the rectangular plate. According to the bonding and sealing structure of the flow battery, the problems of stress concentration and deformation caused by inconsistent expansion coefficients of different materials are solved, the problem of material compatibility does not exist, and the fusion welding effect can be achieved; according to the invention, the sealing leakage problem is thoroughly eliminated, and the reliability and long service life requirements of the flow battery are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid flow batteries, and in particular relates to a liquid flow battery bonding and sealing structure, first and second sealants, and a preparation method. Background Art

[0002] Theoretically, the service life of liquid flow batteries can be up to 25 years, but the reliability and life of their sealing structure are prominent shortcomings of liquid flow batteries. Currently, the sealing methods used in liquid flow batteries include: (a) rubber O-ring / gasket sealing; (b) laser welding; (c) hot melt adhesive, etc., but these sealing methods all have problems:

[0003] In sealing method (a), rubber O-rings / gaskets have natural aging problems. Usually, rubber O-rings / gaskets will age and fail after 12 to 15 years.

[0004] In sealing method (b), the weld of laser welding is narrow, the weld width does not exceed 3mm, the welding strength is poor, and it is easy to open under stress;

[0005] In sealing method (c), since the hot melt adhesive and the plate frame are not made of the same material, there are differences in the compatibility and expansion coefficient of the adhesive sealing materials, which makes the adhesive surface easy to peel and crack. At the same time, the hot melt adhesive will accelerate aging in the strong oxidizing environment of the flow battery.

[0006] In summary, there is an urgent need for a liquid flow battery bonding and sealing method that is better than the prior art. Summary of the invention

[0007] In view of the above problems, the present invention provides a liquid flow battery bonding and sealing structure, a first sealant, a second sealant and a preparation method.

[0008] The liquid flow battery bonding and sealing structure provided by the present invention comprises: a main plate frame, a bipolar plate and a pressure ring, wherein the main plate frame, the bipolar plate and the pressure ring are sequentially bonded to form an integrated plate frame component, and a plurality of the integrated plate frame components are sequentially bonded to form a multi-battery battery stack structure.

[0009] in,

[0010] The main body of the main plate frame is a rectangular annular plate, and a liquid inlet channel is provided at the edge of the first surface of the rectangular annular plate, and the liquid inlet channel is used as a sealing groove;

[0011] An outer sealing groove is also provided on the first surface of the rectangular annular plate outside the liquid inlet channel;

[0012] A sealing structure is provided at a position corresponding to the second surface of the rectangular plate and the liquid inlet channel and the outer sealing groove;

[0013] An annular bonding surface is provided on the first surface of the rectangular annular plate, inwardly from the liquid inlet channel, for bonding the rectangular bipolar plate;

[0014] The pressure ring is provided with a pressure ring bonding surface for pressing and bonding the bipolar plate.

[0015] further,

[0016] The direction perpendicular to the bipolar plate is taken as the plate accumulation direction of the battery stack structure. The battery stack structure is provided with sealing plates at both ends thereof in the plate accumulation direction. The edge of the sealing plate is the same as the edge of the main plate frame, and is provided with the liquid inlet channel, the external sealing groove and the sealing structure.

[0017] further,

[0018] The main plate frame, bipolar plate and pressure ring are all made of chlorinated polyvinyl chloride;

[0019] The sealing structure is a convex strip;

[0020] In the battery stack structure, the sealing grooves and outer sealing grooves of all the main plate frames face the same direction, and the sealing grooves and outer sealing grooves of each main plate frame are sealed by inserting convex strips at corresponding positions of the main plate frame or sealing plate adjacent to one side thereof, and the convex strips of each main plate frame are inserted into the sealing grooves and outer sealing grooves of the main plate frame or sealing plate adjacent to the other side thereof for sealing, wherein the sealing groove, i.e., the liquid inlet flow channel, is sealed by introducing a first adhesive;

[0021] In a group of the integrated plate-frame components, the bipolar plate and the pressure ring, and the bipolar plate and the main plate frame are bonded and sealed by a second adhesive;

[0022] The first adhesive comprises 15-35wt% of chlorinated polyvinyl chloride, 4-8wt% of a main plasticizer dioctyl phthalate, 1.5-5wt% of a low-temperature plasticizer dioctyl sebacate, and the rest is a mixed solvent of tetrahydrofuran and cyclohexanone in a ratio of 1:1.5-5;

[0023] The second adhesive comprises 20-40wt% of chlorinated polyvinyl chloride, 20-40wt% of zirconium oxide powder, 3-15wt% of elastomer chlorosulfonated polyethylene, and the rest is a mixed solvent of tetrahydrofuran and dimethylformamide in a ratio of 1:1.5-5.

[0024] further,

[0025] The first adhesive comprises 25wt% of chlorinated polyvinyl chloride, 6wt% of dioctyl phthalate as a main plasticizer, 3wt% of dioctyl sebacate as a low-temperature plasticizer, and the rest is a mixed solvent of tetrahydrofuran and cyclohexanone in a ratio of 1:3;

[0026] The second adhesive comprises 30 wt % of chlorinated polyvinyl chloride, 30 wt % of zirconium oxide powder, 5-10 wt % of elastomer chlorosulfonated polyethylene, and the rest is a mixed solvent of tetrahydrofuran and dimethylformamide in a ratio of 1:3.

[0027] The present invention also provides a first sealant preparation method, comprising the steps of:

[0028] S11, weigh tetrahydrofuran and cyclohexanone in a ratio of 1:1.5-5 and put them into a stirring kettle;

[0029] S12, weighing 15-35wt% of chlorinated polyvinyl chloride according to the amount of solvent prepared in step S11, and adding the solvent to the stirring tank in batches to dissolve the solvent under stirring;

[0030] S13, after the chlorinated polyvinyl chloride is fully dissolved, 4-8 wt% of the main plasticizer dioctyl phthalate and 1.5-5 wt% of the low-temperature plasticizer dioctyl sebacate are added to the stirring kettle respectively, and the mixture is stirred evenly and set aside.

[0031] further,

[0032] In the step S11, the ratio of tetrahydrofuran to cyclohexanone is 1:3;

[0033] In the step S12, 25 wt% of chlorinated polyvinyl chloride is weighed;

[0034] In the step S13, 6 wt% of the main plasticizer dioctyl phthalate and 3 wt% of the low-temperature plasticizer dioctyl sebacate are added into the stirring kettle respectively.

[0035] The present invention also provides a second sealant preparation method, comprising the steps of:

[0036] S21, weighing a required amount of dimethylformamide and putting it into a stirring tank;

[0037] S22, weighing 3-15 wt% of chlorosulfonated polyethylene, adding it into the stirring kettle, stirring and dissolving;

[0038] S23, after the chlorosulfonated polyethylene is dissolved, tetrahydrofuran is added to the stirring tank, wherein the ratio of tetrahydrofuran to dimethylformamide is 1:1.5-5;

[0039] S24, adding 20-40 wt% of chlorinated polyvinyl chloride in batches, stirring while adding;

[0040] S25. After the chlorinated polyvinyl chloride is dissolved, 20-40 wt% of zirconium oxide powder is added in batches and stirred to form a suspension for standby use.

[0041] further,

[0042] In the step S22, 5 to 10 wt% of chlorosulfonated polyethylene is weighed;

[0043] In the step S23, the ratio of tetrahydrofuran to dimethylformamide is 1:3;

[0044] In the step S24, 30 wt% of chlorinated polyvinyl chloride is added in batches;

[0045] In the step S25, 30 wt% of zirconium oxide powder is added in batches.

[0046] The present invention also provides a first sealant, which is prepared by the above-mentioned method for preparing the first sealant.

[0047] The present invention also provides a second sealant, and the second sealant is prepared by the above-mentioned second sealant preparation method.

[0048] The liquid flow battery bonding and sealing structure provided by the present invention eliminates the stress concentration and deformation problems caused by inconsistent expansion coefficients of different materials, and there is no material compatibility problem, and the effect of fusion welding can be achieved; according to the different bonding requirements of various parts, by adjusting the adhesives with different elastic moduli and solid contents, the elastic moduli and filling amounts of different bonding parts are configured in stages, so as to achieve different bonding effects and potting effects, and completely eliminate the stress caused by thermal expansion and contraction of the liquid flow battery when working at different temperatures and the sealing leakage problem, thereby ensuring the reliability and long life requirements of the liquid flow battery.

[0049] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 A schematic diagram of the exploded view of the bonding and sealing structure of a flow battery according to an embodiment of the present invention is shown;

[0052] Figure 2 It shows a front view of a main plate frame in a bonding and sealing structure of a flow battery provided with an embodiment of the present invention;

[0053] Figure 3 A rear view of a main plate frame in a liquid flow battery bonding and sealing structure according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", "third", etc. in the specification and claims of this application or the above-mentioned figures are used to distinguish different objects, not to describe a specific order or a primary and secondary relationship. "Multiple" appearing in this application refers to more than two (including two).

[0056] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0057] Figure 1 This is a schematic diagram of the exploded view of the bonding and sealing structure of the flow battery provided by the present invention. Figure 2 and Figure 3 The front view and rear view of the main plate frame in the liquid flow battery bonding and sealing structure are shown respectively. Figure 1 , Figure 2 and Figure 3 The liquid flow battery bonding and sealing structure provided by the present invention comprises a main plate frame A, a bipolar plate B and a pressure ring C. The main plate frame A, the bipolar plate B and the pressure ring C are sequentially bonded to form an integrated plate frame component, and a plurality (more than 1) of the integrated plate frame components are sequentially bonded to form a multi-battery battery stack structure.

[0058] in,

[0059] The main body of the main plate frame A is preferably a rectangular annular plate, and a liquid inlet channel E is provided at the edge of the first surface of the rectangular annular plate, and the liquid inlet channel E is used as a sealing groove. An outer sealing groove F is also provided on the first surface of the rectangular annular plate outside the liquid inlet channel E. A sealing structure such as a convex strip H is provided at the corresponding position of the second surface of the rectangular plate (opposite to the first surface of the rectangular plate) and the liquid inlet channel E and the outer sealing groove F. The position and arrangement shape of the liquid inlet channel E and the outer sealing groove F are determined by the technicians according to the working conditions.

[0060] An annular bonding surface G is provided on the first surface of the rectangular annular plate from the liquid inlet channel E inwardly, for bonding the rectangular bipolar plate B.

[0061] The pressure ring is provided with a pressure ring bonding surface D for pressing and bonding the bipolar plate B.

[0062] The direction perpendicular to the bipolar plate B is taken as the plate accumulation direction of the stack structure. The stack structure is provided with sealing plates at both ends along the plate accumulation direction. The edge of the sealing plate is the same as the edge of the main plate frame A, and is provided with the liquid inlet channel E, the external sealing groove F and the sealing structure.

[0063] The main plate frame A, bipolar plate B and pressure ring C are all made of chlorinated polyvinyl chloride (CPVC).

[0064] In the battery stack structure, the sealing grooves and outer sealing grooves of all the main plate frames A face the same direction, and the sealing grooves and outer sealing grooves of each main plate frame A are sealed by inserting the sealing structure at the corresponding position of the adjacent main plate frame A or sealing plate on one side, and the sealing structure of each main plate frame A is inserted into the sealing grooves and outer sealing grooves of the adjacent main plate frame A or sealing plate on the other side for sealing, wherein the first adhesive is introduced into the sealing groove, i.e., the liquid inlet channel E, for sealing.

[0065] In a set of integrated plate-frame components, the bipolar plate B and the pressure ring C, and the bipolar plate B and the main plate frame A are bonded and sealed using a second adhesive.

[0066] The first adhesive and the second adhesive are CPVC adhesives having different elastic moduli and solid contents respectively.

[0067] The first adhesive comprises 15-35wt% (weight percentage), preferably 25wt% CPVC, 4-8wt%, preferably 6wt% of the main plasticizer dioctyl phthalate (DOP), 1.5-5wt%, preferably 3wt% of the low-temperature plasticizer dioctyl sebacate (DOS), and the rest is a mixed solvent of tetrahydrofuran and cyclohexanone in a ratio of 1:1.5-5, preferably 1:3. Among them, the main plasticizer provides elasticity of the adhesive, the low-temperature plasticizer improves the low-temperature resistance of the bonding part, and dissolves and softens the bonding part through the adhesive to eliminate the stress generated by the installation and matching between the plate frame.

[0068] The second adhesive includes 20-40wt%, preferably 30wt% CPVC, 20-40wt%, preferably 30wt% zirconium oxide powder, 3-15wt%, preferably 5-10wt% elastomer chlorosulfonated polyethylene, and the rest is a mixed solvent of tetrahydrofuran and dimethylformamide (DMF) in a ratio of 1:1.5-5, preferably 1:3. Among them, the elastomer is used to eliminate stress, especially the acid-resistant, alkali-resistant and oxidation-resistant elastomer chlorosulfonated polyethylene has good compatibility with CPVC, can be blended in any proportion, and provides excellent elastic deformation for the adhesive; the acid-resistant, alkali-resistant, oxidation-resistant and insulating inorganic filler zirconium oxide increases the solid content, which not only plays a bonding role, but also plays a potting role, completely eliminating the problem of cross-liquid of the positive and negative electrolytes on both sides of the bipolar plate.

[0069] The present invention also provides a first and a second adhesive configuration method, that is, a preparation method. The first adhesive configuration method comprises the steps of:

[0070] S11, weighing a certain amount of tetrahydrofuran and cyclohexanone and putting them into a stirring kettle, the ratio of tetrahydrofuran to cyclohexanone is 1:1.5-5, preferably 1:3;

[0071] S12, according to the amount of solvent prepared in step S11, weigh and configure 15-35wt% CPVC, preferably 25wt% CPVC, and add it to the stirring tank in batches under stirring to fully dissolve. After one batch is completely dissolved, add the next batch. The number of additions is determined according to the actual dissolution conditions, because the molecular weight of CPVC is inconsistent in each configuration, and the solubility performance is different;

[0072] S13, after the CPVC is fully dissolved, add 4-8wt%, preferably 6wt% of the main plasticizer DOP and 1.5-5wt%, preferably 3wt% of the low-temperature plasticizer DOS into a stirring kettle, stir evenly and set aside.

[0073] The configuration method of the second adhesive, i.e., the preparation method, comprises the following steps:

[0074] S21, weigh a certain amount of DMF and put it into a stirring tank;

[0075] S22, weighing 3 to 15 wt%, preferably 5 to 10 wt% of chlorosulfonated polyethylene, adding it to a stirring kettle, stirring and dissolving thoroughly;

[0076] S23, after the chlorosulfonated polyethylene is fully dissolved, tetrahydrofuran is added into a stirred tank, wherein the ratio of tetrahydrofuran to DMF is 1:1.5-5, preferably 1:3;

[0077] S24, adding 20-40wt%, preferably 30wt% of CPVC in batches, stirring while adding, and after one batch is completely dissolved, adding the next batch, the number of times of adding is determined according to the actual dissolution condition;

[0078] S25. After the CPVC is completely dissolved, add 20-40wt%, preferably 30wt% of zirconium oxide powder in multiple times (more than 1), stir well to form a suspension, and set aside. The number of additions depends on the specific working conditions.

[0079] The liquid flow battery bonding and sealing method provided by the present invention eliminates the stress concentration and deformation problems caused by the inconsistency of expansion coefficients of different materials, does not have material compatibility problems, and can achieve the effect of fusion welding; according to the different bonding requirements of various parts, by adjusting the adhesives with different elastic moduli and solid contents, the elastic moduli and filling amounts of different bonding parts are configured in stages, so as to achieve different bonding effects and potting effects, completely eliminating the stress caused by thermal expansion and contraction of the liquid flow battery working at different temperatures and the sealing leakage problem, thereby ensuring the reliability and long life requirements of the liquid flow battery.

[0080] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A liquid flow battery bonding and sealing structure, characterized in that: include: The main plate frame, bipolar plate and pressure ring are sequentially bonded to form an integrated plate frame component, and multiple integrated plate frame components are sequentially bonded to form a multi-battery battery stack structure. in, The main body of the main plate frame is a rectangular annular plate, and a liquid inlet channel is provided at the edge of the first surface of the rectangular annular plate, and the liquid inlet channel is used as a sealing groove; An outer sealing groove is also provided on the first surface of the rectangular annular plate outside the liquid inlet channel; A sealing structure is provided at a position corresponding to the second surface of the rectangular plate and the liquid inlet channel and the outer sealing groove; An annular bonding surface is provided on the first surface of the rectangular annular plate, inwardly from the liquid inlet channel, for bonding the rectangular bipolar plate; The pressure ring is provided with a pressure ring bonding surface for pressing and bonding the bipolar plate.

2. The liquid flow battery bonding and sealing structure according to claim 1, characterized in that: The direction perpendicular to the bipolar plate is taken as the plate accumulation direction of the battery stack structure. The battery stack structure is provided with sealing plates at both ends thereof in the plate accumulation direction. The edge of the sealing plate is the same as the edge of the main plate frame, and is provided with the liquid inlet channel, the external sealing groove and the sealing structure.

3. The liquid flow battery bonding and sealing structure according to claim 2, characterized in that: The main plate frame, bipolar plate and pressure ring are all made of chlorinated polyvinyl chloride; The sealing structure is a convex strip; In the battery stack structure, the sealing grooves and outer sealing grooves of all the main plate frames face the same direction, and the sealing grooves and outer sealing grooves of each main plate frame are sealed by inserting convex strips at corresponding positions of the main plate frame or sealing plate adjacent to one side thereof, and the convex strips of each main plate frame are inserted into the sealing grooves and outer sealing grooves of the main plate frame or sealing plate adjacent to the other side thereof for sealing, wherein the sealing groove, i.e., the liquid inlet flow channel, is sealed by introducing a first adhesive; In a group of the integrated plate-frame components, the bipolar plate and the pressure ring, and the bipolar plate and the main plate frame are bonded and sealed by a second adhesive; The first adhesive comprises 15-35wt% of chlorinated polyvinyl chloride, 4-8wt% of a main plasticizer dioctyl phthalate, 1.5-5wt% of a low-temperature plasticizer dioctyl sebacate, and the rest is a mixed solvent of tetrahydrofuran and cyclohexanone in a ratio of 1:1.5-5; The second adhesive comprises 20-40wt% of chlorinated polyvinyl chloride, 20-40wt% of zirconium oxide powder, 3-15wt% of elastomer chlorosulfonated polyethylene, and the rest is a mixed solvent of tetrahydrofuran and dimethylformamide in a ratio of 1:1.5-5.

4. The liquid flow battery bonding and sealing structure according to claim 3, characterized in that: The first adhesive comprises 25wt% of chlorinated polyvinyl chloride, 6wt% of dioctyl phthalate as a main plasticizer, 3wt% of dioctyl sebacate as a low-temperature plasticizer, and the rest is a mixed solvent of tetrahydrofuran and cyclohexanone in a ratio of 1:3; The second adhesive comprises 30 wt % of chlorinated polyvinyl chloride, 30 wt % of zirconium oxide powder, 5-10 wt % of elastomer chlorosulfonated polyethylene, and the rest is a mixed solvent of tetrahydrofuran and dimethylformamide in a ratio of 1:

3.

5. The first sealant preparation method is characterized in that: Includes steps: S11, weigh tetrahydrofuran and cyclohexanone in a ratio of 1:1.5-5 and put them into a stirring kettle; S12, weighing 15-35wt% of chlorinated polyvinyl chloride according to the amount of solvent prepared in step S11, and adding the solvent to the stirring tank in batches to dissolve the solvent under stirring; S13, after the chlorinated polyvinyl chloride is fully dissolved, 4-8 wt% of the main plasticizer dioctyl phthalate and 1.5-5 wt% of the low-temperature plasticizer dioctyl sebacate are added to the stirring kettle respectively, and the mixture is stirred evenly and set aside.

6. The first sealant preparation method according to claim 5, characterized in that: In the step S11, the ratio of tetrahydrofuran to cyclohexanone is 1:3; In the step S12, 25 wt% of chlorinated polyvinyl chloride is weighed; In the step S13, 6 wt% of the main plasticizer dioctyl phthalate and 3 wt% of the low-temperature plasticizer dioctyl sebacate are added into the stirring kettle respectively.

7. The second sealant preparation method is characterized in that: Includes steps: S21, weighing a required amount of dimethylformamide and putting it into a stirring tank; S22, weighing 3-15 wt% of chlorosulfonated polyethylene, adding it into the stirring kettle, stirring and dissolving; S23, after the chlorosulfonated polyethylene is dissolved, tetrahydrofuran is added to the stirring tank, wherein the ratio of tetrahydrofuran to dimethylformamide is 1:1.5-5; S24, adding 20-40 wt% of chlorinated polyvinyl chloride in batches, stirring while adding; S25. After the chlorinated polyvinyl chloride is dissolved, 20-40 wt% of zirconium oxide powder is added in batches and stirred to form a suspension for standby use.

8. The second sealant preparation method according to claim 7, characterized in that: In the step S22, 5 to 10 wt% of chlorosulfonated polyethylene is weighed; In the step S23, the ratio of tetrahydrofuran to dimethylformamide is 1:3; In the step S24, 30 wt% of chlorinated polyvinyl chloride is added in batches; In the step S25, 30 wt% of zirconium oxide powder is added in batches.

9. The first sealant is characterized by: The sealant is prepared by the first sealant preparation method according to claim 5 or 6.

10. The second sealant is characterized by: The second sealant is prepared by the second sealant preparation method according to claim 7 or 8.

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