Manufacturing method for large-capacity battery, and large-capacity battery

Abstract

Disclosed in the present invention are a manufacturing method for a large-capacity battery, and a large-capacity battery. The manufacturing method for a large-capacity battery comprises the following steps: performing a formation treatment on a plurality of electrode assemblies, and testing the electrode assemblies, which have been subjected to the formation treatment, so as to select electrode assemblies having an acceptable performance; and placing in a case the plurality of electrode assemblies having an acceptable performance, injecting an electrolyte into the case, and ensuring that the container is sealed after the electrolyte is injected, wherein positive electrodes of the plurality of electrode assemblies having an acceptable performance are connected as a main positive electrode of a large-capacity battery, and negative electrodes of the plurality of electrode assemblies having an acceptable performance are connected as a main negative electrode of the large-capacity battery, so as to complete the manufacturing of the large-capacity battery. In the present invention, a formation operation is directly performed on electrode assemblies, and a plurality of acceptable electrode assemblies are then directly placed into a case to form a large-capacity battery, thereby greatly improving the manufacturing efficiency of large-capacity batteries and reducing the manufacturing costs thereof.

Description

A large capacity battery manufacturing method and a large capacity battery TECHNICAL FIELD

[0001] The present application belongs to the technical field of batteries, and particularly relates to a large capacity battery manufacturing method and a large capacity battery. BACKGROUND

[0002] At present, a plurality of single batteries are connected in parallel or in series to form a large capacity battery (which can also be referred to as a battery module or a battery pack) on the market.

[0003] A large capacity battery is known in the art, which is composed of a plurality of single batteries and a box. Since the single batteries are in a shared electrolyte system, the consistency of the single batteries is ensured, and the cycle life of the large capacity battery is improved. The manufacturing process of the large capacity battery is roughly as follows:

[0004] Manufacturing a finished single battery

[0005] The electrode assembly is assembled in the form of winding or lamination, and then the electrode assembly is placed in the shell. Then, the electrolyte is injected into the shell for the first time. Then, the single battery is subjected to opening, formation, sealing, aging, and capacity distribution and selection operations to complete the manufacturing of the finished single battery.

[0006] Manufacturing a large capacity battery

[0007] The single batteries in the same group are connected in parallel and loaded into the box. Then, the second liquid injection and formation are performed to complete the manufacturing of the large capacity battery.

[0008] According to the above method, it can be seen that, in the manufacturing of the existing large capacity battery, there are the liquid injection steps in the manufacturing of the single battery, and there are the steps of opening, formation, sealing, aging, and capacity distribution and selection of the single battery. In addition, in the manufacturing of the large capacity battery, there are the steps of opening the single battery twice and injecting the liquid twice to realize the shared electrolyte.

[0009] Therefore, in the actual production process, it is found that the above method for manufacturing the large capacity battery is complicated and has high cost. SUMMARY

[0010] In order to solve the problem of complicated manufacturing process and high cost of the existing large capacity battery, the present application provides a large capacity battery manufacturing method in the first aspect.

[0011] The large capacity battery manufacturing method comprises the following steps:

[0012] The plurality of electrode assemblies are subjected to formation treatment, and the electrode assemblies subjected to the formation treatment are detected to screen out electrode assemblies with qualified performance;

[0013] The plurality of qualified electrode assemblies are placed into a box, electrolyte is injected into the box, and the box is sealed after the electrolyte is injected; the positive electrodes of the plurality of qualified electrode assemblies are connected to serve as the total positive electrode of the large-capacity battery, and the negative electrodes of the plurality of qualified electrode assemblies are connected to serve as the total negative electrode of the large-capacity battery, thereby completing the production of the large-capacity battery.

[0014] The present application directly performs formation operation on the electrode assembly, directly places the plurality of qualified electrode assemblies into the box to form the large-capacity battery, omits the assembly process of the electrode assembly to form the single battery and part of the components of the single battery, and cancels the secondary unpacking process of the single battery to form the large-capacity battery, thereby greatly improving the production efficiency and cost of the large-capacity battery.

[0015] Further, the above method further comprises an aging step performed on the qualified electrode assembly after the formation step.

[0016] Further, in order to make the plurality of electrode assemblies to form the large-capacity battery more consistent, the above method further comprises a capacity grading and sorting step performed on the qualified electrode assembly after the aging step.

[0017] The second aspect of the present application provides a large-capacity battery produced by the above-mentioned first aspect, which comprises a barrel, N cover plate assemblies, N electrode assemblies, a heat transfer pipe and electrolyte, and N≥2.

[0018] The upper end of the barrel is open;

[0019] The N cover plate assemblies are uniformly fixed and sealed to the open end of the barrel along the first direction of the barrel, thereby forming a box; each cover plate assembly comprises a cover plate body and a positive electrode column and a negative electrode column fixedly arranged on the cover plate body;

[0020] The N electrode assemblies are uniformly arranged inside the box along the first direction of the barrel, and each electrode assembly corresponds to a cover plate assembly above the electrode assembly, and the positive electrode sheet and the negative electrode sheet of the electrode assembly are electrically connected to the positive electrode column and the negative electrode column of the cover plate assembly, respectively;

[0021] The positive electrode columns of the cover plate assemblies are electrically connected to form the total positive electrode of the large-capacity battery, and the negative electrode columns of the cover plate assemblies are electrically connected to form the total negative electrode of the large-capacity battery; the total positive electrode and the total negative electrode of the large-capacity battery exchange heat with the external temperature control device through at least one heat transfer pipe; the box is provided with a liquid injection interface, and the box contains electrolyte. Further, in order to avoid contact between the electrode assemblies during operation, which may cause short circuit, the barrel is provided with N-1 separators along the first direction, thereby dividing the barrel into N placement areas of the electrode assemblies, and the N placement areas are in communication with each other.

[0022] Further, the box is provided with an explosion venting part.

[0023] The third aspect of the present application provides another method for manufacturing a large capacity battery, comprising the following steps:

[0024] The electrode assemblies are subjected to formation treatment, and the electrode assemblies after formation treatment are detected to screen out qualified electrode assemblies;

[0025] A semi-finished single battery is manufactured by using the qualified electrode assemblies, and the semi-finished single battery is provided with a through hole at the bottom or side of the shell;

[0026] The plurality of semi-finished single batteries are placed in a box, electrolyte is injected into the box, and the box is sealed after injection; the positive electrodes of the plurality of semi-finished single batteries are connected to serve as the total positive electrode of the large capacity battery, and the negative electrodes of the plurality of semi-finished single batteries are connected to serve as the total negative electrode of the large capacity battery, thereby completing the manufacturing of the large capacity battery.

[0027] The present application directly performs formation operation on the electrode assemblies, and then uses the plurality of qualified electrode assemblies to manufacture semi-finished single batteries, and directly places the semi-finished single batteries in the box to form the large capacity battery, thereby omitting the processes of opening, formation and sealing of the single battery, and canceling the secondary unpacking process of the single battery when the single battery is used to form the large capacity battery, so that the manufacturing efficiency and cost of the large capacity battery are greatly improved.

[0028] Further, the method further comprises an aging step performed on the qualified electrode assemblies after the formation step.

[0029] Further, in order to make the plurality of electrode assemblies used to form the large capacity battery more consistent, the method further comprises a capacity grading and sorting step performed on the qualified electrode assemblies after the aging step.

[0030] The fourth aspect of the present application provides a large capacity battery manufactured by the method of the third aspect, and the large capacity battery comprises a box and N semi-finished single batteries, N≥2; the N semi-finished single batteries are arranged side by side in the box;

[0031] The box is provided with an injection and replacement liquid interface;

[0032] The box is provided with a second through hole for leading out the positive electrode column and the negative electrode column of each semi-finished single battery, and the top area of the box corresponding to each second through hole is fixedly sealed with the top shell of the semi-finished single battery corresponding to the second through hole; the positive electrode columns of the semi-finished single batteries are electrically connected to form the total positive electrode of the large capacity battery, and the negative electrode columns of the semi-finished single batteries are electrically connected to form the total negative electrode of the large capacity battery; the total positive electrode and the total negative electrode are heat exchanged with an external temperature control device through at least one heat transfer pipe;

[0033] The electrolyte in each semi-finished single battery communicates with the electrolyte in the box through the through hole, and then each semi-finished single battery is in a shared electrolyte system.

[0034] Further, the box is provided with a blast relief part. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 is a process flow diagram of the large-capacity battery in Example 1;

[0036] Fig. 2 is a structural diagram of the large-capacity battery in Example 1;

[0037] Fig. 3 is a structural diagram of the large-capacity battery in Example 1 after the hidden cylinder is hidden;

[0038] Fig. 4 is a structural diagram of the cylinder in Example 1;

[0039] Fig. 5 is a process flow diagram of the large-capacity battery in Example 2;

[0040] Fig. 6 is a structural diagram of the semi-finished single battery in Example 2;

[0041] Fig. 7 is a structural diagram of the large-capacity battery in Example 2;

[0042] Fig. 8 is a structural diagram of the large-capacity battery in Example 2;

[0043] Fig. 9 is a structural diagram of the cylinder in Example 2.

[0044] The reference signs are as follows: 1-cylinder, 2-cover plate assembly, 3-electrode assembly, 4-heat transfer pipe, 5-cover plate body, 6-positive pole, 7-negative pole, 8-total positive, 9-total negative, 10-separator, 11- placement area, 12-blast relief part, 13-liquid injection and replacement interface, 14-box, 15-semi-finished single battery, 151-housing, 152-first through hole, 16-second through hole, 17-hollow member, 18-first cover plate, 19-second cover plate, 20-electrolyte communication channel, 21-third cover plate, 22-fourth cover plate. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of, not all of the embodiments. Based on the following embodiments, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0046] Meanwhile, it should be noted that the terms "top, bottom, inner and outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the technical solutions. In addition, the terms "first, second or third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0047] Unless otherwise explicitly specified and limited, the terms "mounting, connecting, connecting" in the present application should be understood broadly, for example: it can be fixed connection, detachable connection or integral connection; It can also be mechanical connection, electrical connection or direct connection, it can also be indirectly connected through intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] Embodiment 1

[0049] As shown in Figure 1, the present embodiment provides a method for manufacturing a large-capacity battery, and the steps of the method are as follows:

[0050] Step 1: perform formation treatment on a plurality of electrode assemblies, and detect the electrode assemblies after the formation treatment to screen out electrode assemblies with qualified performance;

[0051] Among them, the electrode assembly is made by winding or stacking the positive plate, the negative plate and the separator.

[0052] In step 1, the formation treatment of the electrode assembly can be understood as directly performing formation treatment on the electrode assembly, or as connecting the electrode assembly and the cover plate assembly into a whole before performing formation treatment.

[0053] The cover plate assembly described here includes a cover plate body and positive and negative poles fixedly insulated on the cover plate body.

[0054] Step 2: place a plurality of electrode assemblies with qualified performance in a box, seal the box, and inject electrolyte into the box; the positive poles of the plurality of electrode assemblies with qualified performance are connected to serve as the total positive pole of the large-capacity battery, and the negative poles of the plurality of electrode assemblies with qualified performance are connected to serve as the total negative pole of the large-capacity battery, thereby completing the manufacturing of the large-capacity battery.

[0055] In step 2, after injecting electrolyte into the box, the operation of connecting the positive poles of the plurality of electrode assemblies with qualified performance and connecting the negative poles of the plurality of electrode assemblies with qualified performance is performed;

[0056] Or, after performing the operations of connecting the positive electrodes of the plurality of performance-qualified electrode assemblies and connecting the negative electrodes of the plurality of performance-qualified electrode assemblies, the electrolyte is injected into the box.

[0057] The positive electrodes of the plurality of performance-qualified electrode assemblies are actually the positive electrode columns on the cover plate assemblies corresponding to the performance-qualified electrode assemblies, and the negative electrodes of the plurality of performance-qualified electrode assemblies are actually the negative electrode columns on the cover plate assemblies corresponding to the performance-qualified electrode assemblies.

[0058] The sealing of the box is specifically as follows: after the plurality of electrode assemblies are placed into the box with an open top, the cover plate assemblies connected with the electrode assemblies are used to seal the open end of the box.

[0059] The cover plate assemblies can connect the electrode assemblies and the cover plate assemblies into a whole before the electrode assemblies perform the formation treatment, or can connect the electrode assemblies and the cover plate assemblies into a whole after the electrode assemblies perform the formation treatment.

[0060] Compared with the prior art large-capacity battery manufacturing method, the method provided in the embodiment omits the process of assembling the electrode assemblies into single batteries (i.e., omits the process of mounting the electrode assemblies into the single battery housings and omits the process of injecting the electrolyte into the single batteries), cancels some parts of the single batteries (cancels the single battery housings and the sealing opening parts on the single battery housings), and cancels the secondary opening process of the single batteries when the single batteries are assembled into the large-capacity batteries (i.e., the process of making the sealing opening parts fall off from the single batteries), thereby greatly improving the manufacturing efficiency and cost of the large-capacity batteries.

[0061] In order to further improve the yield of the electrode assemblies, the method provided in the embodiment further includes an aging step of the performance-qualified electrode assemblies after the formation treatment. In the aging process, the electrode assemblies with unqualified self-discharge can be screened out from the plurality of performance-qualified electrode assemblies.

[0062] Further, in order to make the plurality of electrode assemblies assembled into the large-capacity battery more consistent and ensure the performance of the large-capacity battery, the method provided in the embodiment further includes a capacity grading and sorting step of the performance-qualified electrode assemblies after the aging step. Through the capacity grading and sorting step, the plurality of electrode assemblies with good consistency in internal resistance, voltage, self-discharge and the like can be grouped, and the plurality of electrode assemblies in the same group are assembled into the large-capacity battery.

[0063] Based on the method provided in the embodiment, the embodiment further provides a structure of the large-capacity battery. As shown in FIGS. 2 to 4, the large-capacity battery provided in the embodiment includes a barrel 1, N cover plate assemblies 2, N electrode assemblies 3 (the electrode assemblies 3 are the performance-qualified electrode assemblies described above), a heat transfer pipe 4 and an electrolyte, N≥2, and N=10 in the embodiment. Of course, the number of N can be increased according to actual conditions.

[0064] The upper end of the cylinder body 1 is open; the cylinder body 1 can be made by casting, stamping, extrusion or 3D printing;

[0065] N cover plate assemblies 2 are uniformly fixed to the open end of the cylinder body 1 along the first direction of the cylinder body 1, thereby forming a box 14;

[0066] Specifically, the sum of the widths of the N cover plate assemblies 2 should be adapted to the size of the open end of the cylinder body 1 in the first direction, and the length of the cover plate assembly 2 should be adapted to the size of the open end of the cylinder body 1 in the second direction, so as to ensure that the N cover plate assemblies 2 can seal the cylinder body 1. The fixing mode of the cover plate assembly 2 on the open end of the cylinder body 1 can be welding or sealing glue combined with screw fixing, but the welding sealing mode is simpler to operate and has higher sealing performance and reliability.

[0067] The above-mentioned first direction is the length direction of the cylinder body, i.e. the X direction in FIG. 1; the second direction is the width direction of the cylinder body, i.e. the Y direction in FIG. 1.

[0068] As shown in FIG. 3, each cover plate assembly 2 includes a cover plate body 5, and a positive pole 6 and a negative pole 7 fixed to the cover plate body; the cover plate assembly 2 is similar to the upper cover assembly of the commercially available finished square single lithium battery, and the difference between the two is that the cover plate assembly is not provided with a pressure relief film and a liquid injection part. Of course, the cover plate assembly without the pressure relief film and the liquid injection part can also be customized by the manufacturer of the upper cover assembly finished standard part for use as the cover plate assembly of the present application. When a large number of cover plate assemblies 2 are customized, the price may be lower than that of the existing upper cover assembly finished standard part.

[0069] N electrode assemblies 3 are uniformly arranged inside the box 14 along the first direction of the cylinder body, and each electrode assembly 3 corresponds to a cover plate assembly 2 above, and the positive pole and the negative pole of the electrode assembly 3 are respectively electrically connected to the positive pole and the negative pole of the cover plate assembly; the electrode assembly 3 is made by winding or laminating multiple layers of pole pieces, and each layer of pole pieces includes a positive pole, a separator and a negative pole.

[0070] The positive poles 6 of the cover plate assemblies 2 are electrically connected to form a total positive pole 8 of the large-capacity battery, and the negative poles 7 of the cover plate assemblies are electrically connected to form a total negative pole 9 of the large-capacity battery; the total positive pole and the total negative pole are in heat exchange with an external temperature control device through at least one heat transfer pipe 4; the box 14 is provided with a liquid injection port, and the box 14 is filled with electrolyte.

[0071] Among them, the total positive pole and the total negative pole can be formed in the following three ways;

[0072] 1、All positive pole 6 can be electrically connected by multiple first cables to form large capacity battery total positive 8, and all negative pole 7 can be electrically connected by multiple second cables to form large capacity battery total negative 9.

[0073] 2、All positive pole 6 can be electrically connected by multiple first electric connection plates to form large capacity battery total positive 8, and all negative pole 7 can be electrically connected by multiple second electric connection plates to form large capacity battery total negative 9.

[0074] 3、All positive pole 6 can be electrically connected by a first electric connection plate with a length corresponding to the length of the cylinder to form large capacity battery total positive 8, and all negative pole 7 can be electrically connected by a second electric connection plate with a length corresponding to the length of the cylinder to form large capacity battery total negative 9.

[0075] In order to balance the electrical conductivity and the installability, the first electric connection plate and the second electric connection plate are usually made of aluminum plate or copper plate with low price and good flexibility.

[0076] The heat transfer pipe can be specifically used in the following ways:

[0077] 1、A U-shaped aluminum pipe is used, two parallel pipe sections are used to cooperate with the large capacity battery total positive 8 and the large capacity battery total negative 9 respectively to realize heat exchange between the electrode assemblies and the external temperature control device, and the inlet and outlet of the aluminum pipe are located on the same side; the transmission medium in the aluminum pipe can be water, insulating oil or fluorinated liquid; or two aluminum pipes are used to cooperate with the large capacity battery total positive and the large capacity battery total negative respectively.

[0078] 2、Two core heat pipes are used to cooperate with the large capacity battery total positive 8 and the large capacity battery total negative 9 respectively to realize heat exchange between the electrode assemblies and the external temperature control device, the core heat pipe is a heat exchange device of evaporation-condensation type, and the heat transfer is realized by the state change of the working medium in the pipe.

[0079] Since the heat transfer effect of the core heat pipe is affected by the length of the core heat pipe, when the number of electrode assemblies in the large capacity battery is large (i.e. the length of the large capacity battery is long), the use of the core heat pipe will be limited, therefore, in this embodiment, the aluminum pipe is preferred as the heat transfer pipe, if the insulation between the heat transfer pipe and the pole can be effectively ensured, water can be preferred as the heat transfer medium flowing in the aluminum pipe from the aspects of heat transfer efficiency and cost.

[0080] Since the large capacity battery total positive 8 and the large capacity battery total negative 9 are charged, in order to ensure safety, the heat transfer pipe 4 and the large capacity battery total positive 8, and the heat transfer pipe 4 and the large capacity battery total negative 9 must be insulated, the insulation can be realized by oxidation treatment of the heat transfer pipe, or an insulation layer can be arranged at the contact area between the heat transfer pipe and the pole.

[0081] Need to explain one more point: as shown in Figure 4, in this embodiment, N-1 partitions 10 are arranged in the first direction inside the cylinder 1, the height of the partition 10 is consistent with the height inside the cylinder 1, which divides the cylinder 1 into N electrode assembly placement areas 11, and the N placement areas 11 are interconnected, and each adjacent two partitions 10 have an electrode assembly therebetween.

[0082] The partition 10 is set for the following five purposes:

[0083] Purpose one: the partition 10 is set to facilitate the welding of the cover plate assembly 2 at the open end of the cylinder 1. Specifically, when welding, the periphery of each cover plate assembly 12 can be welded to the upper edges of the two side walls in the first direction of the cylinder 1 and the upper edges of the two adjacent partitions 10 to achieve fixation and sealing. In some other embodiments, the width direction edges of the cover plate assembly 2 can also be directly welded to the upper edges of the two side walls in the first direction of the cylinder 1, and then the length direction edges of the adjacent two cover plate assemblies 2 are directly welded and sealed, but compared with the welding and sealing of the partition in this embodiment, the sealing and reliability of the welding are higher.

[0084] Purpose two: the setting of the partition 10 can inhibit the swelling of the electrode assembly and improve the performance of the large-capacity battery;

[0085] Purpose three: the setting of the partition 10 can avoid the short circuit problem caused by the swelling of the two electrode assemblies, and the safety is higher;

[0086] Purpose four: the heat of the electrode assembly can be directly transmitted to the cylinder 1 through the partition 10, which improves the heat dissipation effect of the electrode assembly.

[0087] Purpose five: the setting of the partition 10 can improve the overall strength of the cylinder, so that the pressure bearing capacity of the cylinder is stronger.

[0088] The partition 10 can be set in the cylinder 1 by integral molding or fixed in the cylinder 1 by welding. From the perspective of convenient processing and cost control, the partition is set in the cylinder by integral molding in this embodiment.

[0089] The interconnection between the placement areas 11 can be a channel with a large diameter opened at the bottom of each partition 10 to ensure that each electrode assembly is in an electrolyte system, or a plurality of through holes can be opened on each partition 10 to ensure that each electrode assembly is in an electrolyte system.

[0090] In order to prevent the large-capacity battery from losing control in extreme cases and to timely discharge the heat loss smoke from the sealed box to avoid more serious accidents, the box of the large-capacity battery is also provided with a pressure relief part 12, which can be a commercially available pressure relief valve or a pressure relief membrane fixed on a pipe.

[0091] In this embodiment, the large capacity battery is connected with the external liquid injection device through the liquid injection interface 13, which not only facilitates the initial liquid injection of the battery, but also can ensure the cycle life of the large capacity battery by supplementing electrolyte or lithium additive or replacing electrolyte in whole when the capacity of the battery is attenuated to a certain extent.

[0092] Embodiment 2

[0093] As shown in FIG. 5, the present embodiment provides a manufacturing method of a large capacity battery, and the steps of the method are as follows:

[0094] Step 1: performing formation treatment on a plurality of electrode assemblies, and detecting the electrode assemblies after the formation treatment to screen out electrode assemblies with qualified performance;

[0095] The electrode assembly is made of a positive plate, a negative plate and a separator in a winding or stacking manner.

[0096] In step 1, the formation treatment of the electrode assembly can be understood as directly performing formation treatment on the electrode assembly, or connecting the electrode assembly with the cover plate assembly and then performing formation treatment.

[0097] The cover plate assembly 2 described herein includes a cover plate body, and a positive pole 6 and a negative pole 7 fixedly and insulatively on the cover plate body.

[0098] Step 2: using the electrode assemblies with qualified performance to manufacture a semi-finished single battery; in this embodiment, as shown in FIG. 6, the semi-finished single battery 15 includes a shell 151 with an open top, a cover plate assembly 2 and an electrode assembly 3; the electrode assembly 3 is arranged in sequence by a positive electrode, a separator and a negative electrode, and is assembled by stacking or winding process; the positive plate of the electrode assembly 3 is connected with the positive pole of the cover plate assembly, and the negative plate of the electrode assembly is connected with the negative pole at the top of the cover plate assembly; the inner cavity of the shell 151 is not injected with electrolyte; the sidewall or bottom of the shell 151 is provided with a first through hole 152;

[0099] In order to facilitate the connection of the heat transfer pipe with the total positive and total negative of the large capacity battery, recesses or through holes for clamping the heat transfer pipe can be formed on the positive pole 6 and the negative pole 7 of the semi-finished single battery 15.

[0100] The semi-finished single battery manufacturing process of this step 2 has the following two cases:

[0101] 1. If the electrode assembly is directly formed in step 1, the process of making the semi-finished single cell is as follows: connect the electrode assembly and the cover plate assembly into an integral structure, then place the integral structure into the shell with the top opening, and finally fix and seal the cover plate assembly to the open end of the shell to complete the production of the semi-finished single cell.

[0102] 2. If step 1 involves connecting the electrode assembly and the cover plate assembly before formation processing, then the process of manufacturing the semi-finished single cell is as follows: the entire structure connecting the electrode assembly and the cover plate assembly is placed into the shell with the top opening, and finally the cover plate assembly is fixed and sealed to the open end of the shell to complete the manufacturing of the semi-finished single cell.

[0103] Step 3: Place multiple semi-finished individual cells into a box, inject electrolyte into the box, and ensure that the box is sealed after the electrolyte is injected. Connect the positive terminals of the multiple semi-finished individual cells to form the total positive terminal of the large-capacity battery, and connect the negative terminals of the multiple semi-finished individual cells to form the total negative terminal of the large-capacity battery, thus completing the production of the large-capacity battery.

[0104] In step 3, after injecting electrolyte into the box, the positive electrode connection of multiple semi-finished single cells and the negative electrode connection of multiple semi-finished single cells are then performed.

[0105] Alternatively, after performing the positive electrode connection and negative electrode connection of multiple semi-finished individual cells, electrolyte is injected into the box.

[0106] The method provided in this embodiment, compared with the existing large-capacity battery manufacturing method, omits the processes of opening, formation, and sealing of individual cells, and eliminates some parts of the individual cells (the sealing and unpacking parts on the individual cell casing are eliminated). It also eliminates the secondary unpacking process of individual cells when assembling large-capacity batteries (that is, the process of removing the sealing and unpacking parts from the individual cells), thereby significantly improving the manufacturing efficiency and cost of large-capacity batteries.

[0107] To further improve the yield of electrode components, this embodiment also includes an aging step for qualified electrode components after formation. During the aging process, electrode components that fail to meet self-discharge standards can be screened out from multiple electrode components.

[0108] To improve the consistency of multiple electrode components that make up a large-capacity battery and ensure the performance of the large-capacity battery, the method in this embodiment also includes a capacity sorting and grading step for the electrode components after the aging step. Through the capacity sorting and grading step, multiple electrode components with good consistency in parameters such as internal resistance, voltage, and self-discharge can be grouped together, and then the electrode components in the same group can be made into multiple semi-finished single cells to form a large-capacity battery.

[0109] Based on the method of the embodiment, the embodiment further provides a structure of the large-capacity battery, as shown in FIGS. 7 to 9, which comprises a box 14 and N semi-finished single batteries 15 arranged side by side in the box 14.

[0110] The box 14 is provided with a liquid injection interface 13.

[0111] The box 14 is provided with a second through hole 16 for leading out the positive pole and the negative pole of each semi-finished single battery 15, and the top region of the box 14 corresponding to each second through hole 16 is fixedly sealed with the top of the shell of the semi-finished single battery 15 corresponding to the second through hole 16.

[0112] The positive poles of each semi-finished single battery 15 are electrically connected to form a total positive pole 8 of the large-capacity battery, and the negative poles of each semi-finished single battery 15 are electrically connected to form a total negative pole 9 of the large-capacity battery; the total positive pole 8 and the total negative pole 9 are in heat exchange with an external temperature control device through at least one heat transfer pipe 4 (i.e., the large-capacity battery can be heated or cooled).

[0113] The electrolyte in each semi-finished single battery 15 is in communication with the electrolyte in the box 14 through the first through hole 152, so that each semi-finished single battery 15 is in a shared electrolyte system.

[0114] In the embodiment, the box 14 is made of aluminum material.

[0115] The top region of the box corresponding to each second through hole 16 and the top of the shell of the semi-finished single battery corresponding to the second through hole 16 are fixedly sealed in two ways as follows.

[0116] I. A sealing connecting piece is additionally arranged between the top region of the box 14 corresponding to the second through hole 16 and the top of the shell of the semi-finished single battery 15 corresponding to the second through hole to realize sealing. The sealing connecting piece comprises a hollow member 17, the bottom of the hollow member 17 is used for sealing connection with a first region of the semi-finished single battery 15, and the top of the hollow member 17 is sealingly connected with a second region of the box 14; the first region is a region around any pole at the top of the shell of any semi-finished single battery 15; the second region is a region at the top of the box 14 corresponding to any one of the second through holes 16. The region corresponding to the second through hole 16 is a peripheral region of the second through hole 16 on the outer surface of the box 14; or the region corresponding to the second through hole 16 is the hole wall of the second through hole 16. The region around the pole is a region around the insulating sealing gasket on the pole.

[0117] Second, the second hole 16 corresponding to the perimeter of the box 14 region and the shell of the monomer battery pole perimeter of the semi-finished product can be directly fixed and sealed by laser welding. This method is generally applicable to the case where the height of the semi-finished product monomer battery is consistent.

[0118] In this embodiment, the box 14 structure has the following several kinds:

[0119] One, see Figure 7, the box 14 includes a cylinder 1, a first cover plate 18, a second cover plate 19; the top and bottom of the cylinder 1 are open, the first cover plate 18 is sealed and fixed (welded) on the top of the cylinder 1, and the second cover plate 19 is sealed and fixed (welded) on the bottom of the cylinder 1; 2N second through holes 16 are provided on the first cover plate 18.

[0120] In some embodiments, the cylinder 1 and the second cover plate 19 can also be integrally formed;

[0121] In some embodiments, in order to enable the electrolyte to smoothly enter the box 14 and the inner cavity of each semi-finished monomer battery 15 during the liquid injection process, electrolyte communication channels 20 extending along the arrangement direction of the semi-finished monomer battery 15 and corresponding to the first through hole 152 on the shell of each semi-finished monomer battery 15 can be provided on the length direction side wall of the cylinder 1 or the bottom according to the position of the first through hole on the shell of each semi-finished monomer battery 15; when the electrolyte communication channel 20 is provided, the liquid injection port 13 is arranged in the box 14 region corresponding to any one end of the electrolyte communication channel 20.

[0122] Two, see Figure 7, the box 14 includes a cylinder 1, a third cover plate 21, a fourth cover plate 22; the front and rear of the cylinder 1 are open, the third cover plate 21 is sealed and fixed (welded) on the front of the cylinder 1, and the fourth cover plate 22 is sealed and fixed (welded) on the rear of the cylinder 1; 2N second through holes 16 are provided on the top of the cylinder 1.

[0123] In some embodiments, in order to enable the electrolyte to smoothly enter the box 14 and the inner cavity of each semi-finished monomer battery 15 during the liquid injection process, electrolyte communication channels 20 extending along the arrangement direction of the semi-finished monomer battery 15 and corresponding to the first through hole 152 on the shell of each semi-finished monomer battery 15 can be provided on the length direction side wall of the cylinder 1 or the bottom according to the position of the first through hole on the shell of each semi-finished monomer battery 15; when the electrolyte communication channel 20 is provided, the liquid injection port 13 is arranged in the box 14 region corresponding to any one end of the electrolyte communication channel 20.

[0124] Among them, the total positive 8 and the total negative 9 can adopt the following three ways;

[0125] 1、All positive pole 6 can be electrically connected by multiple first cables to form large capacity battery total positive 8, and all negative pole 7 can be electrically connected by multiple second cables to form large capacity battery total negative 9.

[0126] 2、All positive pole 6 can be electrically connected by multiple first electric connection plates to form large capacity battery total positive 8, and all negative pole 7 can be electrically connected by multiple second electric connection plates to form large capacity battery total negative 9.

[0127] 3、All positive pole 6 can be electrically connected by a first electric connection plate with a length equivalent to the length of the cylinder to form large capacity battery total positive 8, and all negative pole 7 can be electrically connected by a second electric connection plate with a length equivalent to the length of the cylinder to form large capacity battery total negative 9.

[0128] In order to balance the electrical conductivity and the installability, the first electric connection plate and the second electric connection plate are usually made of aluminum plate or copper plate with low price and good flexibility.

[0129] The heat transfer pipe 4 can be specifically implemented in the following ways:

[0130] 1、A U-shaped aluminum pipe is adopted, two parallel pipe sections are used to cooperate with the large capacity battery total positive 8 and the large capacity battery total negative 9 respectively to realize the heat exchange between the electrode assemblies and the external temperature control device, and the liquid inlet and the liquid outlet of the aluminum pipe are located on the same side; the transmission medium in the aluminum pipe can be water, insulating oil or fluorinated liquid; or two aluminum pipes are used to cooperate with the large capacity battery total positive and the large capacity battery total negative respectively.

[0131] 2、Two core heat pipes are adopted to cooperate with the large capacity battery total positive 8 and the large capacity battery total negative 9 respectively to realize the heat exchange between the electrode assemblies and the external temperature control device, the core heat pipe is a heat exchange device of evaporation-condensation type, and the heat transfer is realized by the state change of the working medium in the pipe.

[0132] Since the heat transfer effect of the core heat pipe is affected by the length of the core heat pipe, when the number of electrode assemblies in the large capacity battery is large (i.e. the length of the large capacity battery is long), the use of the core heat pipe will be limited, therefore, in the embodiment, the aluminum pipe is preferentially selected as the heat transfer pipe, if the insulation between the heat transfer pipe and the pole can be effectively ensured, water can be preferentially selected as the heat transfer medium flowing in the aluminum pipe from the aspects of heat transfer efficiency and cost.

[0133] Since the large capacity battery total positive 8 and the large capacity battery total negative 9 are electrified, in order to ensure safety, the heat transfer pipe 4 and the large capacity battery total positive 8, and the heat transfer pipe 4 and the large capacity battery total negative 9 must be insulated, the insulation can be realized by oxidizing the heat transfer pipe or by setting an insulation layer in the area where the heat transfer pipe contacts the pole.

[0134] In order to timely discharge the thermal runaway smoke out of the sealed box in case of thermal runaway of the large capacity battery in extreme cases, and to avoid more serious accidents, the box of the large capacity battery is further provided with a venting part 12, which can be a commercially available venting valve or a venting membrane fixed on a pipe.

[0135] In this embodiment, the large capacity battery is cooperated with the external liquid injection and replacement equipment through the set liquid injection and replacement interface 13, which not only facilitates the initial liquid injection of the battery, but also can be used to supplement the electrolyte or lithium additive or replace the electrolyte as a whole to improve or maintain the capacity when the capacity of the battery is attenuated to a certain extent, so as to ensure the cycle life of the large capacity battery. It should be noted that the interface needs to be kept blocked during the operation of the battery to ensure the sealing of the large capacity battery.

Claims

1. A method for manufacturing a high-capacity battery, characterized in that, Includes the following steps: Several electrode components were subjected to formation treatment, and the formed electrode components were tested to screen out those that met the performance requirements. Multiple qualified electrode assemblies are placed in a box, electrolyte is injected into the box, and the box is sealed after the electrolyte is injected. The positive terminals of the multiple qualified electrode assemblies are connected to form the total positive terminal of the large-capacity battery, and the negative terminals of the multiple qualified electrode assemblies are connected to form the total negative terminal of the large-capacity battery, thus completing the production of the large-capacity battery.

2. The method for manufacturing a high-capacity battery according to claim 1, characterized in that, It also includes an aging process performed on qualified electrode assemblies after the formation process.

3. The method for manufacturing a high-capacity battery according to claim 2, characterized in that, It also includes a capacity sorting step for qualified electrode assemblies after the aging process.

4. A high-capacity battery, characterized in that, The high-capacity battery is manufactured using the method described in any one of claims 1 to 3, and includes a cylindrical body, N cover plate assemblies, N electrode assemblies, a heat transfer tube, and an electrolyte, where N ≥ 2. The upper end of the cylinder is open; N cover plate assemblies are uniformly and sealed to the open end of the cylinder along the first direction of the cylinder, thus forming a box; each cover plate assembly includes a cover plate body and a positive terminal and a negative terminal that are insulated and fixed on the cover plate body. N electrode assemblies are evenly arranged inside the box along the first direction of the cylinder. Each electrode assembly is corresponding to a cover plate assembly above it, and the positive and negative electrode plates of the electrode assembly are electrically connected to the positive and negative electrode posts on the cover plate assembly, respectively. The positive terminals on each cover plate assembly are electrically connected to form the total positive terminal of the large-capacity battery, and the negative terminals on each cover plate assembly are electrically connected to form the total negative terminal of the large-capacity battery. The total positive and total negative terminals of the large-capacity battery exchange heat with an external temperature control device through at least one heat transfer tube. The housing is equipped with an electrolyte filling and replacement port, and the housing is filled with electrolyte.

5. A high-capacity battery according to claim 4, characterized in that: The cylinder is provided with N-1 partitions at intervals along the first direction, thereby dividing the cylinder into N electrode assembly placement areas, and the N placement areas are interconnected.

6. A high-capacity battery according to claim 5, characterized in that: The enclosure is equipped with an explosion vent.

7. A method for manufacturing a high-capacity battery, characterized in that, Includes the following steps: Several electrode components were subjected to formation treatment, and the formed electrode components were tested to screen out those that met the performance requirements. A semi-finished single cell is made using a qualified electrode assembly, and a first through hole is opened on the bottom or side of the casing of the semi-finished single cell. Multiple semi-finished individual cells are placed in a box, electrolyte is injected into the box, and the box is sealed after the electrolyte is injected. The positive terminals of the multiple semi-finished individual cells are connected to form the total positive terminal of the large-capacity battery, and the negative terminals of the multiple semi-finished individual cells are connected to form the total negative terminal of the large-capacity battery, thus completing the production of the large-capacity battery.

8. A method for manufacturing a high-capacity battery according to claim 7, characterized in that, It also includes an aging process performed on qualified electrode assemblies after the formation process.

9. A method for manufacturing a high-capacity battery according to claim 8, characterized in that, It also includes a capacity sorting step for qualified electrode assemblies after the aging process.

10. A high-capacity battery, manufactured using the method described in any one of claims 7 to 9, characterized in that, It includes a housing and N semi-finished individual batteries, where N ≥ 2; the N semi-finished individual batteries are arranged side by side inside the housing; The tank is equipped with a fluid filling / changing port; The top of the housing is provided with a second through hole for the positive and negative terminals of each semi-finished single cell to be led out, and the top area of ​​the housing corresponding to each second through hole is fixedly sealed to the top of the shell of the semi-finished single cell corresponding to the second through hole; the positive terminals on each semi-finished single cell are electrically connected to form the total positive of the large-capacity battery, and the negative terminals on each semi-finished single cell are electrically connected to form the total negative of the large-capacity battery; the total positive and total negative are heat-exchanged with an external temperature control device through at least one heat transfer pipe; The electrolyte in each semi-finished cell is connected to the electrolyte in the box through the first through hole, so that each semi-finished cell is in a shared electrolyte system.

11. A high-capacity battery according to claim 10, characterized in that: The enclosure is equipped with an explosion vent.

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