CN116111201B

CN116111201B - High-capacity battery and manufacturing method thereof

Info

Publication number: CN116111201B
Application number: CN202310380248.4A
Authority: CN
Inventors: 雷政军; 刘毅; 翟腾飞
Original assignee: Shaanxi Olympus Power Energy Co Ltd
Current assignee: Shaanxi Olympus Power Energy Co Ltd
Priority date: 2023-04-11
Filing date: 2023-04-11
Publication date: 2023-09-08
Anticipated expiration: 2043-04-11
Also published as: CN116111201A

Abstract

The invention discloses a high-capacity battery and a manufacturing method thereof. The high-capacity battery comprises a battery string and hollow members welded on the battery string, wherein the inner cavities of all single batteries in the battery string are communicated through the hollow members, so that a sharing system is formed. The manufacturing method of the high-capacity battery comprises the following steps: step 1: preparing a fitting; step 2: manufacturing a battery string with a shared chamber; step 3: performing a cleaning process on the shared chamber; step 4: and injecting liquid into the shared cavity of the battery string to form the high-capacity battery. The high-capacity battery provided by the invention has reasonable structure, high yield in the manufacturing process and difficult leakage problem of the electrolyte sharing channel.

Description

High-capacity battery and manufacturing method thereof

Technical Field

The invention belongs to the field of batteries, and particularly relates to a high-capacity battery and a manufacturing method thereof.

Background

With the further development of lithium ion batteries in recent years, the application fields of lithium ion batteries are more and more extensive. In order to make a lithium ion battery have a larger capacity, a plurality of single batteries (single batteries are generally cylindrical batteries or prismatic batteries) are connected together in a serial, parallel or serial-parallel combination manner to form a large-capacity battery (also called a battery pack or a battery module).

However, due to the difference of the individual cells in the large-capacity battery, the uniformity of the individual cells in the large-capacity battery is poor, and the cycle life of the battery pack or the large-capacity battery is directly limited, so how to improve the uniformity of the individual cells in the large-capacity battery becomes a key point and a difficulty of research in the field.

Chinese patent, publication No. CN218525645U, discloses a "cell housing, a cell and a large-capacity battery", in which the large-capacity battery includes a cell group formed by connecting a plurality of cells in parallel, and an electrolyte sharing channel formed by splicing pipes on each cell housing. After the electrolyte sharing channel is formed by pipeline splicing, electrolyte injected through the electrolyte injection mechanism enters the cell shell, so that all cells in the cell group are in a unified electrolyte environment, and the uniformity of the cell group can be effectively improved.

However, when the electrolyte sharing channel is formed by the splicing method, there are the following problems:

in a first aspect, the part itself is subject to error; the cause of this error is: because the pipeline and the lower cover plate are integrated, certain deviation can exist in the position of the upper pipeline of each integrated part on the lower cover plate in the process of processing and integrated forming, and meanwhile, the size of each pipeline can slightly deviate;

in a second aspect, a welding error; because the lower cover plate with the pipeline is connected with the cylinder body in a welding mode, the position relationship between the pipeline on each battery cell and the cylinder body is difficult to be kept consistent;

in a third aspect, assembly errors; in the splicing process, two adjacent electric core upper pipelines are connected in an extrusion mode, and assembly errors can be caused due to improper use of a positioning tool and extrusion splicing equipment or influence of construction proficiency of constructors;

based on the errors of the three aspects, when an electrolyte sharing channel is formed in an extrusion splicing mode, the coaxiality of each pipeline is deviated; moreover, when grafting, the deviation between each pipeline can increase along with the increase of grafting quantity, leads to the more grafting quantity, and the axiality between each pipeline is difficult to guarantee more, leads to the high-capacity battery yields lower, even still has the concentricity and also is not ideal enough problem between each pipeline to the butt joint completion, and then makes the probability of high-capacity battery weeping after using a period higher after the preparation is accomplished.

Disclosure of Invention

In order to solve the problems that when an electrolyte sharing channel of the existing high-capacity battery is manufactured in a splicing mode, the yield is low and the probability of leakage of the electrolyte sharing channel is high, the invention provides a manufacturing method of the high-capacity battery.

The method comprises the following steps:

step 1: manufacturing a battery string with a shared chamber

Contacting the cylinder with a hollow tube; one end of the cylinder body is open, one end of the cylinder body is closed, and a first through hole is formed in the closed end of the cylinder body; a plurality of second through holes are formed in the hollow pipe fitting;

extending a welding head of welding equipment into the cylinder from one side of the open end of the cylinder, welding a welding area of the first through hole and a welding area of the second through hole, completing sealing and fixing of the cylinder and the hollow pipe fitting, ensuring that projection of the first through hole on the hollow pipe fitting can cover the second through hole at the moment, repeating the process, and welding a plurality of cylinders on the hollow pipe fitting;

the method comprises the steps of putting an electrode assembly into each barrel, sealing and welding a cover plate at the open end of the barrel, and then forming a battery pack string composed of a plurality of semi-finished single batteries, wherein the inner cavity of each semi-finished single battery and the interior of a hollow pipe fitting in the battery pack string form a communicated sharing cavity;

step 2: filling a shared chamber of a battery string with a liquid

And (3) injecting electrolyte into the shared chamber of the battery string, and then executing formation operation to finish the manufacture of the high-capacity battery.

According to the method, the hollow pipe fitting is used as the shared pipeline of the high-capacity battery, so that the problems of low yield and high liquid leakage probability of the high-capacity battery caused by difficulty in ensuring coaxiality among pipelines when the plurality of pipelines form an electrolyte shared channel in a squeezing and splicing mode are solved.

In addition, the invention realizes the sealing and fixing of each cylinder body and the hollow pipe fitting in a mode of welding one side in the cylinder body, the operation process is relatively simple, and the construction efficiency is higher.

Further, in order to avoid the problem that impurities such as air may exist in the shared chamber under the influence of external environment during the process of manufacturing the high-capacity battery, the impurities may damage the electrolyte, and the method further includes a step of performing a cleaning process on the shared chamber before injecting the electrolyte into the shared chamber. Through which air or other impurities within the shared chamber may be removed.

Further, the method further comprises the step of connecting the battery packs in series and parallel before the electrolyte is injected into the sharing chamber, or the step of connecting the battery packs in series and parallel after the electrolyte is injected into the sharing chamber.

A second aspect of the present invention provides a high-capacity battery including a battery string and a hollow pipe member;

the battery pack string comprises a plurality of single batteries which are arranged in parallel;

the single battery comprises a cylinder body, a cover plate and an electrode assembly; one end of the cylinder body is open, the other end of the cylinder body is closed, and a first through hole is formed in the closed end of the cylinder body; the cover plate is arranged at the open end of the cylinder body in a sealing way; the electrode assembly is arranged in the cylinder body and is connected with the positive and negative electrode posts arranged on the cover plate;

a plurality of second through holes are formed in the hollow pipe fitting, and the aperture of each second through hole is smaller than that of each first through hole;

the edges of the first through holes on each single battery are welded with the pipe wall of the hollow pipe corresponding to one of the second through holes on the hollow pipe respectively, and the first through holes are communicated with the corresponding second through holes, so that a shared cavity is formed between the inner cavity of each single battery and the interior of the hollow pipe.

According to the invention, the large-capacity battery is taken as the shared pipeline by using the hollow pipe fitting, so that the problems of low yield and high leakage probability of the large-capacity battery caused by difficulty in ensuring coaxiality among pipelines when the electrolyte shared channel is formed by a plurality of pipeline extrusion splicing modes are avoided.

In addition, the sealing and fixing of each cylinder and the hollow pipe fitting are realized by the welding mode of one side in the cylinder, the construction process is relatively simple, and the construction efficiency is higher.

And if the shared pipeline is arranged above the battery pack string, the gas areas in the inner cavities of the single batteries are communicated and can be used as a shared gas pipe, the gas pressure in the single batteries is in a balance system due to the existence of the shared gas pipe, and the single batteries are always under the same gas pressure, so that the difference among the single batteries caused by inconsistent gas pressures in the single batteries is reduced.

If the device is arranged below the battery string, the electrolyte areas in the inner cavities of the single batteries are communicated and can be used as a shared electrolyte pipe. The existence of the shared electrolyte pipe enables the electrolyte in each single battery to be in one balance system, and each single battery is always in the same electrolyte system, so that the difference among the single batteries caused by inconsistent electrolytes in the single batteries is reduced.

Further, the hollow pipe member described above has various forms:

first form: the hollow pipe fitting is a rectangular pipe, a plurality of second through holes are formed in the rectangular pipe, and the central connecting line of each second through hole is parallel to the edge of the side wall of the rectangular pipe.

Second form: the hollow pipe fitting comprises a horizontal plate and a round pipe, and the round pipe is arranged on the horizontal plate; the horizontal plate is provided with a plurality of second through holes penetrating through the round pipe, and the center connecting line of each second through hole is parallel to the side edge of the length direction of the horizontal plate.

A third aspect of the present invention provides a method of manufacturing a large-capacity battery, the method differing from the above method in that a finished battery is used instead of an electrode assembly, the method comprising the steps of:

separating and sorting

Carrying out capacity grading and sorting on a plurality of finished batteries, and classifying the finished batteries into different grades according to grade standards;

manufacturing battery string

extending a welding head of welding equipment into the cylinder from one side of the open end of the cylinder, welding a welding area of the first through hole and a welding area of the second through hole, completing sealing and fixing of the cylinder and the hollow pipe fitting, ensuring that the first through hole can cover the second through hole on the projection of the hollow pipe fitting at the moment, repeating the process, and welding a plurality of cylinders on the hollow pipe fitting;

putting finished batteries with the same grade and provided with third through holes into each barrel, sealing and welding a cover plate at the open end of the barrel, and forming a battery pack string;

at least one part of the first through hole, the second through hole or the third through hole in the battery pack string is provided with a sealing mechanism;

forming a sharing system within a battery string

Opening the sealing mechanism by using external force, and communicating the inner cavity of each finished battery with the hollow pipe fitting to form a high-capacity battery with a sharing system;

or directly injecting electrolyte to dissolve the sealing mechanism, and communicating the inner cavity of each finished battery with the hollow pipe fitting to form a high-capacity battery with a sharing system.

Further, the method also includes performing a clean process step on the hollow tubing prior to opening or dissolving the sealing mechanism.

Further, the sharing system formed by connecting the hollow pipe and each finished battery may be difficult to inject the electrolyte due to the large internal pressure, and the method further comprises a step of vacuumizing the sharing system before injecting the electrolyte to ensure that the pressure in the sharing system can smoothly enter the electrolyte.

Further, after the plurality of single batteries form a unified electrolyte system, in order to form a more complete SEI film, the method further comprises a step of forming the high-capacity battery with a sharing system so as to enable the high-capacity battery to have more stable circulation capacity.

A fourth aspect of the present invention provides another form of a large-capacity battery, which is different from the above-described large-capacity battery in that a finished battery is employed in place of an electrode assembly, and specifically includes a battery string and a hollow pipe member;

the single battery comprises a cylinder body, a cover plate and a finished battery; one end of the cylinder body is open, the other end of the cylinder body is closed, and a first through hole is formed in the closed end of the cylinder body; the cover plate is arranged at the open end of the cylinder body in a sealing way; the finished battery is arranged in the cylinder body, and a third through hole communicated with the first through hole is formed in the finished battery;

the hollow pipe fitting is provided with a plurality of second through holes;

the edges of the first through holes on each single battery are welded with the pipe wall of the hollow pipe corresponding to one of the second through holes on the hollow pipe respectively, and the first through holes are communicated with the corresponding second through holes, so that a sharing system is formed between the inner cavity of the finished battery in each single battery and the interior of the hollow pipe.

Further, the hollow pipe may have various forms as well:

first form: the hollow pipe fitting is a rectangular pipe, a plurality of second through holes are formed in the rectangular pipe, and the central connecting line of each second through hole is parallel to the side wall of the rectangular pipe. Rectangular pipes belong to more common sectional materials, and the cost of batch purchase and processing is lower, so that the cost of the high-capacity battery can be reduced to a certain extent.

Drawings

FIG. 1 is a schematic perspective view of a large capacity battery as a gas sharing system;

FIG. 2 is a schematic perspective view of a large capacity battery as an electrolyte sharing system;

FIG. 3 is an exploded view of the cartridge and cover plate;

FIG. 4 is a diagram of the locations of the corresponding lands when the apertures of the first and second vias are the same;

FIG. 5 is a diagram of the location of the corresponding bond pad when the first via is larger than the second via;

FIG. 6 is a cross-sectional view of the hollow tube in form 2;

FIG. 7 is a cross-sectional view of the hollow tube in form 3;

FIG. 8 is a flow chart of example 1;

fig. 9 is a schematic structural view of a first type of finished battery and a second type of finished battery;

FIG. 10 is a schematic diagram of a finished battery constructed from a plurality of commercially available flexible packages connected in parallel;

fig. 11 is a flow chart of embodiment 2.

The reference numerals are as follows:

1-battery string, 2-hollow pipe fitting, 21-second through hole, 22-horizontal plate, 23-round pipe, 3-single battery, 31-barrel, 311-first through hole, 32-cover plate, 4-shell, 5-sealing mechanism.

Detailed Description

The technical solutions of the embodiments will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden, are within the scope of the present invention based on the following examples.

Meanwhile, it should be noted that the positional or positional relationship indicated by the terms such as "upper, lower, inner and outer" and the like herein are based on the positional or positional relationship shown in the drawings, and are merely for convenience of description, and are not intended to indicate or imply that the apparatus or element to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the technical scheme. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The terms "mounted, connected, and coupled" should be construed broadly in this disclosure unless otherwise specifically indicated and defined, such as: can be fixedly connected, detachably connected or integrally connected: it may also be a mechanical connection, an electrical connection, or a direct connection, or may be indirectly connected through an intermediate medium, or may be a communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

The method aims at solving the problems that the manufacturing difficulty of a spliced electrolyte sharing channel in the existing large-capacity battery is high, the yield is low, and the leakage probability of the electrolyte sharing channel is high. The invention redesigns the manufacturing method of the large-capacity battery, and overcomes the problems.

Example 1

As shown in fig. 1 and 2, the large-capacity battery of the present embodiment includes a battery string 1 and a hollow pipe member 2; the battery string 1 includes a plurality of unit cells 3 arranged in parallel;

as shown in fig. 3 to 5, the unit cell 3 includes a can 31, a cap plate 32, and an electrode assembly; one end of the cylinder 31 is open, the other end is closed, and the closed end of the cylinder 31 is provided with a first through hole 311; the cover plate 32 is mounted on the open end of the cylinder in a sealing manner; the electrode assembly is mounted in the can 31; the hollow pipe fitting 2 is provided with a plurality of second through holes 21; the welding area of the first through hole 311 on each single battery is welded with the welding area of one of the second through holes 21 on the hollow pipe fitting 2, and the first through hole 311 and the corresponding second through hole 21 are communicated with each other, so that the inner cavity of each single battery 3 and the interior of the hollow pipe fitting 2 form a sharing cavity, and after electrolyte is injected into each single battery 3, a high-capacity battery with a sharing system is formed. The positive and negative electrode posts in the single battery are arranged on the cover plate or the closed end, and the positive and negative electrode posts are connected with the electrode assembly in the cylinder body.

The hollow pipe fitting in the embodiment has the advantages that coaxial problems are required to be ensured when the plugging is not needed, and requirements on machining precision and assembly precision are low, so that the yield of the high-capacity battery is improved; meanwhile, a special tool is not needed, and the assembly process is simpler; when welding, welding equipment's soldered connection stretches into from the open side of barrel, does not have any shielding, and sealed effectual to when cavity pipe fitting used as electrolyte sharing passageway, weeping probability also greatly reduced.

There are several points to explain for the structure of the large-capacity battery of the present embodiment:

1. the closed end of the cylinder 31 is a flat plate and is fixed on the cylinder by welding, or the cylinder 31 is an integral structure with one end open and one end closed, which is formed by stamping or casting. In view of convenience in processing, sealability and the like, the embodiment adopts an integrally formed processing mode to manufacture a cylinder structure with one closed end and one open end.

2. The specific way of welding the welding area of the first through hole 311 on each single battery 3 and the welding area of one second through hole 21 on the hollow pipe 2 is to extend the welding head of the welding device into the cylinder 31 from the open end side of the cylinder, and fixedly weld the cylinder 31 on the hollow pipe 2.

As shown in fig. 4, when the aperture of the first through hole 311 is equal to the aperture of the second through hole 21, the hole wall of the first through hole 311 and the hole wall of the second through hole 21 are welded and fixed by a welding head of the welding device, and at this time, the welding area of the first through hole 311 is the hole wall of the first through hole, and the welding area of the second through hole 21 is the hole wall of the second through hole;

as shown in fig. 5, when the aperture of the first through hole 311 is larger than that of the second through hole 21, the welding head of the welding device welds and fixes the first through hole edge 311 and the hollow pipe wall corresponding to the second through hole 21, and at this time, the welding area of the first through hole is the first through hole edge, and the welding area of the second through hole is the hollow pipe wall around the second through hole. The present embodiment uses a welding method in which the first through hole aperture is larger than the second through hole aperture, which is affected by the size of the welding head of most welding apparatuses.

3. The electrode assembly is formed by sequentially arranging an anode, a diaphragm and a cathode and adopting lamination or winding technology.

4. The sharing chamber is electrolyte sharing, and may be gas sharing.

As shown in fig. 1, in some embodiments, when the hollow pipe 2 is sealed and fixed under the battery string 1, the electrolyte in each unit cell can be communicated through the hollow pipe, so that an electrolyte sharing system can be formed. Since there is no structure under the battery string, the pipe diameter of the hollow pipe may not be limited by space. At this time, the hollow pipe fitting can be provided with a liquid injection port, when liquid injection is needed, the liquid injection can be carried out by opening the plug arranged on the liquid injection port, and when in other states, the sealing isolation between the interior of the hollow pipe fitting and the external environment is needed.

In other embodiments, as shown in fig. 2, when the hollow pipe 2 is sealed and fixed above the battery string 1, the gas areas in the individual cells can be communicated with each other through the hollow pipe, and thus a gas sharing system can be formed. Because the positive electrode and the negative electrode exist above the battery pack string, the pipe diameter of the hollow pipe fitting and the installation position ensure that the hollow pipe fitting does not interfere with the positive electrode and the negative electrode. At this time, the hollow pipe fitting can be provided with an exhaust valve to exhaust the gas in the large-capacity battery at regular time, so that the occurrence of thermal runaway phenomenon is avoided. Or the explosion venting valve or the explosion venting membrane is arranged on the hollow pipe fitting, and when thermal runaway occurs, explosion venting can be realized.

5. There are also various structural forms of hollow pipe fittings:

form 1: in some embodiments, the pipe wall area of the hollow pipe fitting 2 provided with the second through hole 21 is a spherical surface or an arc surface protruding towards the direction of the first through hole, so that the first through hole and the second through hole can be sealed and welded easily, but the hollow pipe fitting is a special-shaped piece, which is inconvenient to process and manufacture.

Form 2: in some embodiments, as shown in fig. 6, the hollow tube 2 includes a horizontal plate 22 and a circular tube 23, and the circular tube 23 is disposed on the horizontal plate 22; the horizontal plate 22 is provided with a plurality of second through holes 21 penetrating through the circular tube 23, and the central connecting line of each second through hole 21 is parallel to the side edge of the horizontal plate 22 in the length direction. The hollow pipe fitting in the form can be integrally formed in an extrusion forming or casting mode, and the horizontal plate and the round pipe can be fixed in a welding mode.

Form 3: in some embodiments, as shown in fig. 7, the hollow tube 2 is a rectangular tube, and a plurality of second through holes 21 are formed in the rectangular tube, and the central connecting line of each second through hole is parallel to the side wall of the rectangular tube. Compared with the form 1, the horizontal plate, the rectangular pipe and the round pipe are all common sectional materials in the market, so that the cost for batch purchase and processing is low, and the cost of the high-capacity battery can be reduced to a certain extent. The present embodiment may therefore prefer the hollow tube provided in forms 2, 3.

Based on the above description of the structure of the large-capacity battery, a method for manufacturing the large-capacity battery will be described in detail, as shown in fig. 8:

step 1: preparing the fitting

Preparing a plurality of cylinders 31, one hollow tube 2, and a plurality of electrode assemblies in advance;

step 2: manufacturing a battery string with a shared chamber

Step 2.1: contacting a cylinder 31 with the hollow pipe 2, ensuring that the first through hole 311 is aligned with one of the second through holes 21 on the hollow pipe 2, extending a welding head of welding equipment into the cylinder from one side of the open end of the cylinder, welding a welding area of the first through hole 311 and a welding area of the second through hole 21, and completing sealing and fixing of the cylinder and the hollow pipe, so as to ensure that the projection of the first through hole 311 on the hollow pipe can cover the second through hole 21 (and the first through hole and the second through hole are communicated);

step 2.2: repeating the step 2.1, and welding the other cylinders 31 on the hollow pipe fitting 2;

step 2.3: the electrode assemblies are put into the cylinder bodies 31, the cover plates 32 are sealed and welded at the open ends of the cylinder bodies 31, then a battery pack string composed of a plurality of semi-finished single batteries is formed, and the inner cavities of the semi-finished single batteries and the inner parts of the hollow pipe fittings in the battery pack string form a communicated shared cavity; the semi-finished single battery refers to a single battery without electrolyte injection;

step 3: performing a cleaning process on a shared chamber

The step needs to remove air or other impurities in the shared cavity, so that the influence of the air or other impurities on electrolyte injected into the shared cavity is avoided;

step 4: filling a shared chamber of a battery string with a liquid

And (3) injecting electrolyte into the shared chamber of the battery string, and then executing formation operation to finish the manufacture of the high-capacity battery. In the step, the liquid can be injected through the liquid injection port on the hollow pipe fitting, and the liquid can be injected through the liquid injection port on any single battery. The process is preferably carried out in an environment with a dew point standard of-25 to 40 ℃, a humidity of less than or equal to 1%, a temperature of 23 ℃ +/-2 ℃ and a cleanliness of 10 ten thousand. In addition, the battery strings are required to be connected in parallel before or after the injection is performed.

The specific process of the formation step in this embodiment is as follows:

charging to 3.4V with constant current of 0.1C, charging to current of 0.01C at constant voltage of 3.4V, and standing for 30min;

discharging to 2.5V at constant current of 0.1C, and standing for 30min;

then charging to 3.4V with 0.2C constant current, charging to 0.01C current with 3.4V constant voltage, and standing for 30min. The formation process can enable the high-capacity battery to form a more complete SEI film, so that the high-capacity battery has more stable circulation capacity.

In some embodiments, the high-capacity battery can be aged at 50 ℃ for 48 hours after formation, and the high-capacity battery can be selectively exhausted after aging, so that the exhaust gas after formation is exhausted, and the probability of swelling of each single battery of the high-capacity battery is reduced.

The welding head of the welding apparatus in this embodiment means: if arc welding or argon arc welding is used, the welding head here refers to the end of the electrode, and if laser welding is used, the welding head here refers to the laser beam.

Example 2

The large-capacity battery structure of this embodiment is basically identical to that of embodiment 1, except that the electrode assembly is replaced by a finished battery. The positive and negative poles of the finished battery extend out of the cylinder body to be directly used as the positive and negative poles of the single battery, or terminals are respectively arranged on the positive and negative poles of the finished battery to be used as the positive and negative poles of the single battery.

The finished battery is divided into the following forms:

as shown in fig. 9, the first finished battery is a self-made aluminum square-shell battery, and comprises a shell 4 (the shell comprises a shell body, a top plate and a bottom plate), an electrode assembly and electrolyte are arranged in the shell 4, and a sealing mechanism 5 is arranged at a third through hole of the shell 4 (the sealing mechanism is arranged on the top plate or the bottom plate and is installed when the finished battery leaves a factory); the sealing mechanism 5 can seal the inner cavity of the finished battery (the inner cavity is divided into a gas area above the inner cavity and an electrolyte area below the inner cavity) from the external environment when the finished battery is used alone, and can be opened or dissolved by external force when a plurality of finished batteries are required to form a large-capacity battery with a shared system.

Referring to fig. 9, the second type of finished battery is a commercial prismatic battery, and the modification process is specifically as follows: a third through hole is formed on the purchased commercial square battery shell 4, and a sealing mechanism 5 is arranged at the third through hole, wherein the process is preferably carried out under the environment that the dew point standard is between-25 and 40 ℃, the humidity is less than or equal to 1 percent, the temperature is 23+/-2 ℃, and the cleanliness is 10 ten thousand grades. The sealing mechanism 5 can be opened by an external force or dissolved by an electrolyte when a large-capacity battery having a shared system is formed.

Referring to fig. 9 and 10, the third type of finished battery is directly connected in parallel by using a commercially available square battery or a plurality of commercially available soft package batteries, and the sealing mechanism is arranged on the second through hole of the hollow pipe or the first through hole of the cylinder.

The sealing mechanism in this embodiment is a structure in which electrolyte is soluble, and may be a sealing assembly disclosed in chinese patent CN218525645U, CN 218525614U.

Because the finished battery has electrolyte, the sealing problem needs to be considered, and when the sharing system shares the electrolyte, the sealing mechanism needs to be opened or dissolved to meet the requirement of electrolyte sharing, so the method for manufacturing the large-capacity battery by adopting the finished battery in the embodiment has a great difference from embodiment 1.

Specifically, the above first to second finished batteries constitute a large-capacity battery having a gas sharing system by the following procedure, as shown in fig. 11:

step 1: separating and sorting

Carrying out capacity grading and sorting on a plurality of finished batteries, and classifying the finished batteries into different grades according to grade standards; the indexes of capacity separation comprise internal resistance, capacity, thickness, voltage and the like, and the specific operation can be selected by any one index or a combination of a plurality of indexes;

step 2: manufacturing battery string

Step 2.1: a cylinder body is contacted with the hollow pipe fitting, so that the first through hole is aligned with one of the second through holes on the hollow pipe fitting, a welding head of welding equipment extends into the cylinder body from one side of the open end of the cylinder body, a welding area of the first through hole and a welding area of the second through hole are welded, sealing and fixing of the cylinder body and the hollow pipe fitting are completed, and the fact that the first through hole is projected on the hollow pipe fitting can cover the second through hole (the two through holes are kept through) is ensured;

step 2.2: repeating the step 2.1, and welding the other cylinders on the hollow pipe fitting;

step 2.3: putting finished batteries with the same grade into each barrel (the positions of the finished batteries with the sealing mechanisms are aligned with the first through holes, so that the inner cavities of the finished batteries can be mutually communicated through hollow pipe fittings after the sealing mechanisms are opened), and sealing and welding cover plates at the open ends of the barrels to form a battery pack string; after the step is finished, the hollow pipe fitting is integrally positioned above the battery string, and the purpose of the hollow pipe fitting is to be communicated with electrolyte areas in all finished batteries;

step 3: performing a cleaning process on the hollow pipe

step 4: forming a sharing system within a battery string

Firstly, opening all upper sealing mechanisms of the finished battery by using external force, wherein a gas area of the finished battery is communicated with the hollow pipe fitting to form a high-capacity battery with a gas sharing system;

or directly injecting the electrolyte to dissolve the sealing mechanism, and communicating the gas area of the finished battery with the hollow pipe fitting to form a high-capacity battery with a gas sharing system; the process is preferably carried out in an environment with a dew point standard of-25 to 40 ℃, a humidity of less than or equal to 1%, a temperature of 23 ℃ +/-2 ℃ and a cleanliness of 10 ten thousand. In addition, the battery strings are required to be connected in parallel before or after the injection is performed.

It should be noted that: because the third finished battery is formed by connecting a plurality of commercial square batteries or a plurality of commercial soft package batteries in parallel, the manufacturing mode is also different from that of the first and second finished batteries, and the difference is that: before step 2.3 is executed, a third through hole is required to be formed on a commercially available square battery or each commercially available soft package battery under the environment that the dew point standard is between-25 and 40 ℃ and the humidity is less than or equal to 1 percent, the temperature is 23+/-2 ℃ and the cleanliness is 10 ten thousand grades, so that when a sealing mechanism arranged on the first through hole or the second through hole is opened or dissolved, the gas area of the finished battery can be communicated with the hollow pipe fitting.

Specifically, the above first to second finished batteries constitute a large-capacity battery having an electrolyte sharing system as follows:

step 1: separating and sorting

step 2: manufacturing battery string

Step 2.1: a cylinder 31 is contacted with the hollow pipe fitting 2, so that the first through hole 311 is aligned with one of the second through holes 21 on the hollow pipe fitting 2, a welding head of welding equipment extends into the cylinder from one side of the open end of the cylinder, a welding area of the first through hole 311 and a welding area of the second through hole 21 are welded, sealing and fixing of the cylinder and the hollow pipe fitting are completed, and the projection of the first through hole 311 on the hollow pipe fitting can cover the second through hole 21 (the two are kept through);

step 2.3: putting finished batteries with the same grade into each barrel 31 (the positions of the finished batteries with the sealing mechanisms are aligned with the first through holes, so that the inner cavities of the finished batteries can be mutually communicated through hollow pipe fittings after the sealing mechanisms are opened), and sealing and welding cover plates at the open ends of the barrels to form a battery pack string; after the step is finished, the hollow pipe fitting is integrally positioned below the battery string, and the purpose of the hollow pipe fitting is to be communicated with electrolyte areas in all finished batteries;

step 3: performing a cleaning process on the hollow pipe

step 4: forming a sharing system within a battery string

Firstly, opening all upper sealing mechanisms of the finished batteries by using external force, communicating an electrolyte area of the finished batteries with the hollow pipe fitting, and flowing electrolyte in each finished battery into the hollow pipe fitting under the gravity to form a large-capacity battery with an electrolyte sharing system; of course, in order to ensure a sufficient amount of electrolyte, a new electrolyte may be injected into the electrolyte-sharing system after this step is completed. In some cases, the pressure in the electrolyte sharing system in the large-capacity battery manufactured by adopting the finished battery is high, and the problem that new electrolyte cannot be smoothly injected may exist, so that the gas in the sharing system needs to be exhausted in a vacuumizing mode, so that the internal pressure of the sharing system meets the condition that the new electrolyte can be injected.

Or directly injecting the electrolyte into the electrolyte dissolution sealing mechanism, and communicating the electrolyte area of the finished battery with the hollow pipe fitting to form a high-capacity battery with an electrolyte sharing system.

Before step 4 is executed, the battery string can be inverted (the hollow pipe is positioned above the battery string in the state), so that the electrolyte is prevented from flowing out under the action of gravity, and after step 4 is executed, the high-capacity battery needs to be inverted to realize electrolyte sharing (the hollow pipe is positioned below the battery string in the state).

Step 4 is preferably carried out in an environment with a dew point standard of-25 to 40 ℃ and a humidity of 1% or less, a temperature of 23 ℃ + -2 ℃ and a cleanliness of 10 ten thousand levels. In addition, the battery strings are required to be connected in parallel before or after the injection is performed.

It should be noted that: because the third finished battery is formed by connecting a plurality of commercial square batteries or a plurality of commercial soft package batteries in parallel, the manufacturing mode is also different from that of the first and second finished batteries, and the difference is that: before step 2.3 is executed, a third through hole is formed on a commercial square battery or each commercial soft package battery under the environment that the dew point standard is-25 to 40 ℃ and the humidity is less than or equal to 1 percent, the temperature is 23+/-2 ℃ and the cleanliness is 10 ten thousand grades, so that when a sealing mechanism arranged on the first through hole or the second through hole is opened or dissolved, the electrolyte of the finished battery can be communicated with the hollow pipe fitting.

In this embodiment, the formation process is performed once before the finished battery is manufactured into the large-capacity battery, so that the large-capacity battery is not required to be formed when the gas sharing system is formed. However, in order to form a more complete SEI film when the electrolyte sharing system is formed, the high-capacity battery is preferably formed by performing the formation process (two times of formation process are actually performed with respect to each finished battery) on the high-capacity battery after the step 4 is completed.

The formation process is substantially the same as that of embodiment 1, and will not be described here again.

Claims

1. A method for manufacturing a high-capacity battery, comprising the steps of:

manufacturing a battery string with a shared chamber

filling a shared chamber of a battery string with a liquid

2. The method of claim 1, further comprising performing a clean process step on the shared chamber prior to injecting the electrolyte into the shared chamber.

3. The method according to claim 1 or 2, further comprising the step of connecting the battery packs in series and parallel before the electrolyte is injected into the shared chamber, or the step of connecting the battery packs in series and parallel after the electrolyte is injected into the shared chamber.

4. A high capacity battery fabricated by the method of claim 1, comprising a battery string and a hollow tube;

the single battery comprises a cylinder body, a cover plate and an electrode assembly; one end of the cylinder body is open, the other end of the cylinder body is closed, and a first through hole is formed in the closed end of the cylinder body; the cover plate is arranged at the open end of the cylinder body in a sealing way; the electrode assembly is arranged in the cylinder body;

5. The large-capacity battery according to claim 4, wherein,

the hollow pipe fitting is a rectangular pipe, a plurality of second through holes are formed in the rectangular pipe, and the center connecting line of each second through hole is parallel to the edge of the side wall of the rectangular pipe.

6. The large-capacity battery according to claim 4, wherein,

the hollow pipe fitting comprises a horizontal plate and a round pipe, and the round pipe is arranged on the horizontal plate; the horizontal plate is provided with a plurality of second through holes penetrating through the round pipe, and the center connecting line of each second through hole is parallel to the side edge of the length direction of the horizontal plate.

7. A method for manufacturing a high-capacity battery, comprising the steps of:

separating and sorting

manufacturing battery string

forming a sharing system within a battery string

8. The method of manufacturing a high-capacity battery according to claim 7, further comprising performing a cleaning process step on the hollow pipe member before opening or dissolving the sealing mechanism.

9. The method of manufacturing a high-capacity battery according to claim 8, further comprising a step of evacuating before the injection of the electrolyte.

10. The method of manufacturing a large-capacity battery according to any one of claims 7 to 9, further comprising the step of forming the large-capacity battery having the shared system.

11. The method of manufacturing a high-capacity battery according to claim 8, further comprising the step of connecting the battery packs in series and parallel before the electrolyte is injected into the shared chamber, or the step of connecting the battery packs in series and parallel after the electrolyte is injected into the shared chamber.

12. A high capacity battery made by the method of claim 7, comprising a battery string and a hollow tube;

the hollow pipe fitting is provided with a plurality of second through holes;

13. The high-capacity battery as claimed in claim 12, wherein,

the hollow pipe fitting is a rectangular pipe, a plurality of second through holes are formed in the rectangular pipe, and the central connecting line of each second through hole is parallel to the side wall of the rectangular pipe.

14. The large-capacity battery according to claim 13, wherein,