Manufacturing method of integrated sealed galvanic pile
Technical Field
The invention belongs to the technical field of manufacturing, and particularly relates to a manufacturing method of an integrated sealed galvanic pile.
Background
The fuel cell is an energy conversion device, directly converts chemical energy stored in fuel and oxidant into electric energy according to the electrochemical principle, has the advantages of high power generation efficiency and less environmental pollution, and has wide application prospect. Because the output power of the single cell of the fuel cell is limited, in practical application, a plurality of single cells need to be stacked like building blocks to form a fuel cell stack, and the corresponding power, voltage and current requirements are met. The fuel of the fuel cell is generally hydrogen, methanol, methane, air or oxygen, etc. as the oxidant, wherein the fuel and the oxidant cannot be in direct contact and need to be separated by a sealing device, otherwise the safety of the cell is greatly reduced and even there is a danger of explosion. The sealing performance is critical to the fuel cell.
The traditional galvanic pile sealing mode is that a sealing ring is placed on a bipolar plate or sealant is coated between the bipolar plate and a membrane electrode, and the sealing ring is slightly deformed under certain pressure, so that the sealing effect is achieved. However, such a seal presents several problems: 1) generally, the sealing process adopts an ex-situ method to form the sealing gasket, namely, the sealing gasket is manufactured by other dies, and then the formed sealing gasket is bonded in the sealing groove by a dispensing method or other methods to form sealing. It can be seen that the process is relatively complex on the one hand; on the other hand, the sealing gasket is adhered into the sealing groove of the bipolar plate by glue dispensing or other methods, so that the depth of the sealing groove is changed, the assembly process parameters are seriously influenced, the pressure born by a sealing line during packaging is increased, mechanical damage to the bipolar plate due to overlarge stress can be possibly caused, and the performance of a galvanic pile can be influenced; in addition, the sealing gasket is adhered in the sealing groove by adopting a glue dispensing process or other processes, so that the requirement on the glue dispensing process or other bonding processes is high. 2) By adopting the sealing process, the sealing and final assembly effects of the galvanic pile are dynamic, namely, the galvanic pile can be sealed in a certain deformation range of the sealing gasket, but the final galvanic pile can be different, so that the sealing mode has the influence on the final assembly effect on the aspects of very high requirements on assembly parameters, the size of assembly force, the flow of a press-fitting process, the press-fitting position and the like; on the other hand, because bipolar plate, sealed pad, go up the lower end plate clamp plate thickness and all have certain tolerance, the back of assembling like this, the phenomenon that membrane electrode deformation is not of uniform size in the pile can appear, and this can directly influence the performance and the running life of pile.
Disclosure of Invention
The invention aims to provide a manufacturing method of an integrated sealed electric pile, which is characterized by comprising the following steps:
1) finishing the processing of the bipolar plate and the processing of the membrane electrode according to the data of a galvanic pile design drawing; the depth range of the sealing grooves on the two sides of the bipolar plate is between 0.25 and 0.8mm, two opposite side faces of the bipolar plate are respectively provided with a glue injection hole, the glue injection holes are communicated with the sealing grooves on the two sides of the bipolar plate, the thickness of the membrane electrode protective edge is between 0.25 and 0.45mm, the membrane electrode protective edge is made of PET, PEN or PI and has high hardness and extremely small deformation rate;
2) if an in-situ online dispensing process is adopted, dispensing operation is respectively carried out on two sides of the bipolar plate, the dispensing sectional area is smaller than that of the sealing groove, the dispensing height protrudes out of the bipolar plate by 0.05-0.2mm, then the dispensed bipolar plate and the membrane electrode are overlapped one by one according to the galvanic pile assembly process, a certain pressure or torsion is applied to the galvanic pile on an assembly table of the galvanic pile, the thickness of the galvanic pile is not changed, the edge protector is perfectly attached to the bipolar plate, equidistant stable sealing is realized, and finally, the galvanic pile assembly and sealing are finished after the glue is naturally cured or the whole galvanic pile is placed in a certain temperature environment for heating and curing;
3) if an in-situ online glue filling process is adopted, firstly, the bipolar plate and the membrane electrode are overlapped one by one according to a galvanic pile assembly process, and a certain pressure or torsion is applied to the galvanic pile on a galvanic pile assembly platform on the basis of no change of the thickness of the galvanic pile; the edge protector is perfectly attached to the bipolar plate, so that equidistant sealing is realized; then the galvanic pile is placed according to a certain direction, two glue injection holes on the bipolar plate of the galvanic pile are ensured to be arranged one above the other and glue is injected into the bipolar plate from the glue injection hole below, the glue can gradually fill the sealing grooves at the two sides of the whole bipolar plate and flow out from the glue injection hole above, when the glue flows out, the glue injection is indicated to be sufficient, and the glue injection can be stopped; and then plugging the two glue injection holes, curing the galvanic pile in a natural environment or an environment with a certain temperature, and after the curing is finished, realizing the assembly and sealing of the galvanic pile.
The certain pressure or torsion, namely the assembly force of the galvanic pile is applied to the galvanic pile according to the size or the structure of the galvanic pile, the sizes are different, and the pressure applied to the membrane electrode ranges from 0.1 MPa to 2 MPa;
the glue for dispensing is silicone glue, ethylene propylene diene monomer glue or polyolefin glue.
The glue for injecting glue is silicone glue or perfluorinated silica gel.
The bipolar plate in-situ packaging process route has the beneficial effects that the process route of the bipolar plate in equal-interval sealing, glue pouring or dispensing in-situ packaging fundamentally solves the technical defects of the conventional galvanic pile assembly process; by adopting an in-situ dispensing or glue injection process and an equidistant stable sealing process, the assembly process is simplified, the influence of factors such as labor force and dimensional tolerance on the assembly of the galvanic pile is reduced, and the consistency, safety, durability and production efficiency of the galvanic pile are improved. The first characteristic of the invention is that the thickness of the membrane electrode guard edge is used to determine the final thickness of the membrane electrode after assembly, because the deformation rate of the guard edge is very small, in the process of the galvanic pile assembly, as long as the guard edge is completely attached to the bipolar plate, the deformation of the membrane electrode remains unchanged no matter how much the assembly force of the galvanic pile is adjusted; the prior dynamic sealing process is changed into an equidistant steady-state sealing process, so that the problems of stack failure or poor stack consistency caused by dimensional tolerance or slight change of stack assembly parameters are thoroughly solved. The second characteristic is in-situ packaging, which simplifies the packaging process, reduces uncertain factors and improves the assembly power and efficiency.
Detailed Description
The invention provides a manufacturing method of an integrated sealed galvanic pile, which comprises the following steps: 1) finishing the processing of the bipolar plate and the processing of the membrane electrode according to the data of a galvanic pile design drawing; 2) adopting an in-situ online glue dispensing process, namely respectively performing glue dispensing operation on two sides of the bipolar plate; 3) the in-situ on-line glue filling process is adopted, the bipolar plate and the membrane electrode are firstly overlapped one by one according to the galvanic pile assembly process, and certain pressure or torsion is applied to the galvanic pile on a galvanic pile assembly platform on the basis of no change of the thickness of the galvanic pile. The present invention will be described with reference to examples.
Example 1 fabrication of a 20kw Stack Module
1) According to the design of a drawing, a 20kw galvanic pile is produced, the width of a sealing groove of a cathode and an anode of a bipolar plate of the galvanic pile is 4mm, the groove depth is 0.5mm and 0.3mm respectively, the effective area of a membrane electrode is 230cm2, the edge protection material of the membrane electrode is a PET material with the thickness of 0.125mm, and the thickness of the edge protection of the encapsulated membrane electrode is 0.25 mm.
2) The precise online glue dispenser is utilized to respectively perform glue dispensing operation on the cathode and anode sealing grooves of the bipolar plate, the adopted glue is polyolefin glue, the width and the height of cathode glue dispensing are 3mm and 0.6mm, and the width and the height of anode glue dispensing are 3mm and 0.4 mm.
3) The 20kw stack requires 136 cells, 136 bipolar plates and membrane electrodes are stacked in a sandwich configuration and a pressure of about 1500kg is applied, at which time the stack thickness does not change.
4) And (3) fastening the galvanic pile by using a screw or a binding steel belt to finish the assembly of the galvanic pile, then baking the galvanic pile for 6 hours in an environment of 50 ℃, and finally finishing the sealing of the galvanic pile.
Example 2 fabrication of a 36kw Stack Module
1) According to the design of a drawing, a 36kw galvanic pile module is produced, the width of a sealing groove of a cathode and an anode of a bipolar plate of the galvanic pile is 3.5mm, the depth of the groove is 0.4mm, the effective area of a membrane electrode is 330cm2, the edge protection material of the membrane electrode is a PEN material with the thickness of 0.15mm, and the thickness of the edge protection of the membrane electrode after encapsulation is 0.3 mm. The bipolar plate has a size of 340 x 150mm, and a pore channel with the size of 0.8mm is respectively processed in the middle of the short sides of the two sides of the bipolar plate and is respectively communicated with the seal grooves of the cathode and the anode.
2) 170 single cells are required for assembling the 36kw stack, and 170 bipolar plates and membrane electrodes are stacked in a sandwich configuration in an intersecting manner, and a pressure of about 2100kg is applied, at which time the stack thickness does not change.
3) The galvanic pile is fastened by a screw or a binding steel belt, and then the galvanic pile is laterally placed to ensure that the glue injection holes are respectively arranged at the upper end and the lower end. Then, by using a precise glue injection device, the two-component perfluorinated silica gel is gradually injected into the cathode and anode sealing grooves through a pore channel with the diameter of 0.8mm, and can be injected piece by piece, or by using a connecting pipeline, the two-component perfluorinated silica gel is arranged and injected in series, and when the glue flows out of the glue injection pore channel positioned on the upper side, the glue injection is finished, and then two holes on each bipolar plate are plugged by using a patch.
3) And (5) curing the galvanic pile for 24 hours in a natural environment, namely finishing the assembly and sealing of the galvanic pile.