High-capacity battery and manufacturing method therefor

Abstract

A high-capacity battery and a manufacturing method therefor. The high-capacity battery comprises a case (100), N battery units (200), and an electrolyte, where N≥2. The N battery units (200) are disposed in the case (100), and the top of the case (100) is provided with a total positive electrode terminal (8) and a total negative electrode terminal (9). The electrolyte is contained in the case (100), and the N battery units (200) are in an electrolyte system. The plurality of battery units (200) are mounted in the case (100) having the electrolyte, so that the battery units (200) are in a unified electrolyte system, ensuring the uniformity of the battery units (200), and further improving the cycle life of the large-capacity battery.

Description

Large-capacity battery and manufacturing method thereof Technical Field

[0001] The present invention belongs to the field of batteries, and in particular relates to a large-capacity battery and a manufacturing method thereof. Background Art

[0002] In recent years, the application of lithium-ion batteries has become more and more extensive. They are mainly used in energy storage systems such as hydropower, thermal power generation, wind power generation and solar power generation, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, special equipment, special aerospace, etc.

[0003] To meet high-capacity usage scenarios, existing high-capacity batteries are constructed by connecting multiple pre-assembled single cells in parallel, series, or a combination of series and parallel to form a battery module. Series-connected battery modules can increase the total voltage, while parallel-connected battery modules can increase the total capacity.

[0004] However, regardless of the above method, there are differences between the individual cells in the existing battery module, which results in differences in the consumption of electrolyte and lithium ions in each individual cell after the battery module has been running for a period of time. The uniformity of each individual cell is poor, which will directly lead to a limited cycle life of the battery module. Therefore, how to improve the uniformity of each individual cell in the battery module while ensuring large capacity has become the focus and difficulty of research in this field. Summary of the Invention

[0005] In order to solve the problem of poor uniformity of individual cells in existing battery modules, the present invention provides a large-capacity battery.

[0006] The large-capacity battery includes a box, N battery cells and an electrolyte, N≥2; the N battery cells are arranged in the box, and the top of the box has a total positive terminal and a total negative terminal; the box is filled with electrolyte, and the N battery cells are in an electrolyte system.

[0007] The present invention installs multiple battery cells in a box with electrolyte, so that each battery cell is in a unified electrolyte system, ensuring the uniformity of each battery cell and further improving the cycle life of the large-capacity battery.

[0008] Furthermore, the structures of large-capacity batteries mainly include the following:

[0009] In the first large-capacity battery, the housing includes a cylindrical body, and the battery cell includes a cover assembly and an electrode assembly;

[0010] The upper end of the cylinder is open;

[0011] The cover plate assemblies in the N battery cells are evenly fixed to the open end of the cylinder along the first direction of the cylinder, thereby forming a closed box; each cover plate assembly includes a plate body and a positive electrode column and a negative electrode column insulated and fixed to the plate body;

[0012] The electrode assemblies in the N battery cells are evenly arranged inside the sealed box along the first direction of the cylinder, each electrode assembly corresponds to a cover 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 on the cover assembly respectively;

[0013] The positive poles on each cover plate assembly are electrically connected to form a total positive terminal, and the negative poles on each cover plate assembly are electrically connected to form a total negative terminal; the total positive terminal and the total negative terminal exchange heat with an external temperature control device through at least one heat transfer tube.

[0014] In the second large-capacity battery, the box includes a cylindrical body with an open top and an upper cover fixed to the open end of the cylindrical body; the upper cover is provided with 2N first through holes;

[0015] The battery cell includes a cover plate assembly and an electrode assembly connected to the cover plate assembly; the cover plate assembly includes a plate body, a positive electrode column and a negative electrode column insulated and fixed on the plate body;

[0016] N battery cells are evenly arranged along the length of the cylinder after their corresponding cover plate assemblies are matched with the cylinder, and the positive electrode column and the negative electrode column of each cover plate assembly extend out of the upper cover through the corresponding first through-hole; each first through-hole and the corresponding positive electrode column and negative electrode column must be sealed;

[0017] The positive poles are electrically connected to form a total positive terminal, and the negative poles are electrically connected to form a total negative terminal; the total positive terminal and the total negative terminal exchange heat with an external temperature control device through at least one heat transfer tube.

[0018] The first and second types of large-capacity batteries place N battery cells into a cylinder with an open upper end, and use N cover assemblies or upper covers of the battery cells to seal the open end of the cylinder. All electrode assemblies are in an electrolyte system. Therefore, the large-capacity battery avoids the problem of different electrolyte and lithium ion consumption of each single cell in the existing battery module, ensuring the service life of the large-capacity battery. In addition, each electrode assembly is in the same air pressure system. Compared with the existing battery module, it also solves the problem that the internal pressure of each single cell will be different after running for a period of time, which affects the performance of the battery module. At the same time, it also solves the probability of thermal runaway problems in the existing battery module due to excessive air pressure in a single cell, thereby improving the safety of large-capacity batteries.

[0019] In addition, the temperature of each electrode assembly can be directly transferred to an external temperature control device through the heat transfer tubes installed at the total positive terminal and the total negative terminal, reducing the problem of overheating of the electrode assembly affecting the performance of large-capacity batteries. More importantly, the probability of thermal runaway is reduced by directly controlling the temperature of each electrode assembly. At the same time, the heat transfer tubes can directly heat each electrode assembly to control the water content in the electrode assembly during the production of large-capacity batteries. Compared with the traditional vacuum baking method, there is no need for a special vacuum baking oven, which reduces the production cost of large-capacity batteries and improves the production efficiency of large-capacity batteries.

[0020] The first and second large-capacity batteries have the following optimized designs in terms of structure:

[0021] 1. In the first and second large-capacity batteries, in order to ensure that the battery cells can be reliably positioned in the casing and to avoid the risk of short circuits caused by the contact between the electrode assemblies after swelling during operation, the casing is provided with N-1 first partitions at intervals along its length, dividing the casing into N placement areas for the electrode assemblies, and the N placement areas are interconnected.

[0022] 2. In the first large-capacity battery structure, in order to compensate for the problem of uneven upper surface of the plate body after the cover plate assembly is placed due to the open ends of each plate body and / or each placement area during processing, a circle of flexible gaskets is provided on the plate body of the cover plate assembly near the four edges, and the end surface of the open end of the placement area is a stepped surface, the first plane of the stepped surface is welded to the plate body, and the second plane of the stepped surface is matched with the flexible gasket; the first plane is located above the second plane.

[0023] In the second large-capacity battery structure, in order to facilitate the sealing of the upper cover to the cylinder, and at the same time utilize the positioning and installation of the battery unit, and at the same time to compensate for the problem of unevenness of the upper surface of the plate body when the cover plate assembly is spot-welded and positioned due to the open ends of each plate body and / or each placement area during processing, a circle of flexible gaskets is provided on the plate body of the above-mentioned cover plate assembly near the four edges, and the open end of the placement area is a stepped surface structure, including a first plane, a second plane lower than the first plane, and a third plane lower than the second plane; the upper cover is welded to the first plane, the plate body of the cover plate assembly is spot-welded and fixed to the second plane, and the flexible gasket cooperates with the third plane.

[0024] 3. In the second large-capacity battery structure, the peripheral areas of each of the first through holes and the corresponding plate bodies of the cover plate assembly are fixed and sealed by laser welding.

[0025] 4. In the first and second large-capacity batteries, both the positive and negative electrode posts are provided with grooves or through holes for clamping the heat transfer tubes.

[0026] 5. In the first and second large-capacity batteries, in order to simultaneously take into account the heat conduction efficiency of the heat transfer tube and ensure installation reliability, the above-mentioned heat transfer tube is an aluminum water-cooling tube. In order to ensure safety, insulation must be maintained between the aluminum water-cooling tube and the groove, or between the aluminum water-cooling tube and the through hole.

[0027] 6. In the first and second types of large-capacity batteries, the housing is provided with an explosion vent. This vent allows for the timely release of thermal runaway fumes when the large-capacity battery experiences thermal runaway, thus preventing more serious accidents. Furthermore, the housing is provided with a fluid injection / exchange interface, which not only facilitates initial fluid injection but also allows for increased or maintained capacity by replenishing the large-capacity battery with electrolyte, lithium additives, or replacing the entire electrolyte when the battery capacity decays to a certain extent, thereby ensuring the cycle life of the large-capacity battery.

[0028] 7. In the first type of large-capacity battery, in order to improve the cycle life of the large-capacity battery, the large-capacity battery also includes at least one second partition and an upper cover. The second partition is vertically installed in the cylinder, and a chamber with an upper end opening is formed between the second partition and the side wall of the cylinder. The chamber is connected to the placement area, and the upper open end of the chamber is sealed by the upper cover, and the electrolyte is contained in it.

[0029] In the second type of large-capacity battery, in order to improve the cycle life of the large-capacity battery, the large-capacity battery also includes at least one second separator, and an electrolyte storage chamber is formed between the second separator, the side wall of the cylinder, and the upper cover, and the electrolyte storage chamber is connected to the placement area.

[0030] 8. In both the first and second large-capacity batteries, the four sidewalls of the cylindrical body are provided with hollow reinforcing ribs. The addition of these ribs enhances the strength of the cylindrical body. Furthermore, the hollow reinforced cavity also serves as an air and liquid cooling channel, enhancing the temperature control capability of the large-capacity battery.

[0031] A first method for manufacturing a large-capacity battery includes the following steps:

[0032] Preparation of battery cells

[0033] The cover plate assembly and the electrode assembly are connected to form a battery unit by welding;

[0034] Install battery cells and form a sealed box

[0035] Place N battery cells into the cylinder from the open end, and then seal and fix the cover plate assembly in each battery cell to the open end of the cylinder by welding. The cylinder and the N cover plate assemblies form a sealed box;

[0036] Installing heat transfer tubes

[0037] Fitting at least one heat transfer tube with the device;

[0038] Water removal

[0039] Using heat transfer tubes to heat each electrode assembly to reduce the water content in the electrode assembly;

[0040] Assembly of the total positive terminal and the total negative terminal

[0041] All positive poles are electrically connected to form a total positive terminal, and all negative poles are electrically connected to form a total negative terminal;

[0042] Injection, formation, aging.

[0043] The second method for manufacturing a large-capacity battery includes the following steps:

[0044] Preparation of battery cells

[0045] The cover plate assembly and the electrode assembly are connected to form a battery unit by welding;

[0046] Install the top cover and battery unit

[0047] Place N battery cells into the cylinder from the open end thereof, arrange the N battery cells in sequence along a first direction of the cylinder, and secure the battery cells by cooperating with the cover assembly of the battery cells and the cylinder;

[0048] The upper cover is placed on N battery cells, and the positive and negative electrodes of each battery cell extend out of the upper cover through the corresponding first through-holes. The upper cover and the open end of the cylinder are then fixed and sealed. Finally, the gaps between the first through-holes and the corresponding positive and negative electrodes are sealed.

[0049] Installing heat transfer tubes

[0050] Match at least one heat transfer tube with the total positive terminal and the total negative terminal;

[0051] Water removal

[0052] Using heat transfer tubes to heat each electrode assembly to reduce the water content in the electrode assembly;

[0053] Assembly of the total positive terminal and the total negative terminal

[0054] All positive poles are electrically connected to form a total positive terminal, and all negative poles are electrically connected to form a total negative terminal;

[0055] Injection, formation, aging.

[0056] Compared with the existing battery module manufacturing method, the first and second large-capacity battery manufacturing methods require the capacity separation and sorting of each single cell in order to maintain the consistency of each single cell in the initial state of the battery module. In the present invention, multiple electrode assemblies are directly installed in a sealed box and are in a unified electrolyte system. There is no need for capacity separation and sorting, which improves the capacity of large-capacity batteries and also improves the battery manufacturing efficiency.

[0057] In addition, the second method for manufacturing a large-capacity battery has the following characteristics: the cover assembly of the battery cell is fixed to the open end of the cylinder by spot welding. This spot welding positioning method is relatively easy to operate and has relatively reliable positioning.

[0058] In the second method for manufacturing a large-capacity battery, the upper cover is fixed and sealed to the open end of the cylinder by welding.

[0059] In the second method for manufacturing a large-capacity battery, the specific method for keeping the gap between the first through hole and the positive electrode column and the negative electrode column sealed is: the peripheral area of ​​the first through hole and the corresponding plate body of the cover plate assembly are fixed and sealed by laser welding.

[0060] The third large-capacity battery structure includes a box body, a cylinder body and an upper cover; the top of the cylinder body is open, and the opening of the cylinder body is provided with a step surface; the step surface includes a first plane and a second plane lower than the first plane; an interface is provided on the cylinder body; 2N first through holes are provided on the upper cover; the upper cover is matched with the first plane by screw connection and welding, and a flexible gasket is provided between the upper cover and the second plane; the battery unit is a single cell, N single cells are placed side by side in the box body, each extending out of the corresponding first through hole and the gap between the first through hole and the polarity terminal of the single cell is filled with sealant; the N polarity terminals on one side of each single cell are electrically connected to form the total positive terminal of the large-capacity battery, and the N polarity terminals on the other side of each single cell are electrically connected to form the total negative terminal of the large-capacity battery; a second through hole is provided at the bottom of the outer shell of the N single cells to ensure that the electrolyte areas of each single cell are connected to each other.

[0061] The large-capacity battery of the present invention is constructed by placing N single cells with second through holes on the bottom into a cylindrical body with an open top, using an upper cover to seal the open end of the cylindrical body by screw connection in combination with a flexible gasket, and then performing a secondary sealing by welding. All single cells are in the same electrolyte system. Therefore, the large-capacity battery avoids the problem of different electrolyte and lithium ion consumption of each single cell in the existing battery module, thereby ensuring the service life of the large-capacity battery.

[0062] In addition, the box of the present invention serves as a shared electrolyte chamber for each single cell. Compared with existing large-capacity batteries, there is no need to consider the coaxial plug-in problem, and the requirements for processing accuracy and assembly accuracy are lower. At the same time, no special tooling is required, and the assembly process is relatively simple, which greatly reduces the processing difficulty and processing cost of such large-capacity batteries with a shared system.

[0063] Furthermore, since an interface is provided on the cylinder, the interface can be used to add electrolyte to or replace electrolyte in the large-capacity battery, which can improve the life of the large-capacity battery to a certain extent. An explosion relief valve can also be provided on the interface to ensure the safety of the large-capacity battery.

[0064] The third large-capacity battery structure has the following optimized designs:

[0065] 1. To allow the single battery to smoothly extend out of the top plate, the polarity terminal of the single battery includes the single battery pole and an adapter pole welded to the top of the pole; the adapter pole has an annular blind groove along its axial direction. The provision of the adapter pole extends the length of the original single battery pole, allowing it to smoothly extend out of the top plate. In addition, the use of the adapter pole can directly use commercially available batteries to assemble large-capacity batteries, which has strong adaptability. The provision of the annular blind groove provides a transmission channel for the laser during laser welding, allowing the adapter pole to be better welded to the original pole.

[0066] 2. In order to ensure that the sealant has a good molding space when being poured between the first through hole and the corresponding polarity terminal, an annular protrusion is provided on the top plate at a position corresponding to each first through hole.

[0067] 3. The polarity terminal also includes an adapter block welded to the top of the adapter post. The adapter block is provided with a slot for clamping a heat exchange tube. The installation of the heat exchange tube directly transmits the temperature of each single cell to an external temperature control device, reducing the problem of single cell overheating affecting the performance of large-capacity batteries. More importantly, the present invention further reduces the probability of thermal runaway by directly dissipating heat from each single cell pole.

[0068] 4. In order to ensure that the single battery can be reliably positioned in the box, the cylinder is provided with N-1 partitions at intervals along its length, thereby dividing the cylinder into N single battery placement areas, and the N placement areas are interconnected.

[0069] 5. The inner surface of the bottom plate of the housing is provided with two backing plates extending in the direction of the arrangement of the individual cells. An electrolyte channel is formed between the two backing plates, with the first channel communicating with the electrolyte area of ​​each individual cell. The provision of the backing plates ensures the flatness of the bottom of the individual cells when in contact with the bottom of the housing. The electrolyte channel formed between the two backing plates also ensures better continuity of the electrolyte level between each individual cell.

[0070] 6. The above-mentioned first plane includes a first area and a second area; the first area is provided with a plurality of threaded holes, and the second area is used as the area for welding with the upper cover plate.

[0071] A third method for manufacturing a large-capacity battery includes the following steps:

[0072] Step 1: Sorting

[0073] Sorting a number of commercially available square aluminum lithium-ion batteries by capacity and classifying the commercially available square aluminum lithium-ion batteries into different grades according to grade standards;

[0074] Step 2: Unpacking the Battery

[0075] Selecting N commercially available square aluminum lithium-ion batteries of the same grade, and under specific circumstances, opening a second through hole in the bottom of the casing of the N commercially available square aluminum lithium-ion batteries;

[0076] Step 3: Assemble the High-Capacity Battery

[0077] Place N commercially available square aluminum lithium-ion batteries with second through holes formed therein into the cylinder;

[0078] A flexible gasket is placed on the second plane, and the top plate is fixed to the open end of the cylinder by screw connection. This process ensures that the polarity terminals of each square aluminum lithium-ion battery extend out of their corresponding first through holes;

[0079] Filling sealant at each first through hole and its corresponding polarity terminal;

[0080] The top plate and the second plane of the open end of the cylinder are fusion-welded by welding;

[0081] The N polarity terminals on one side of each single battery are electrically connected to form a first polarity pole of a large-capacity battery, and the N polarity terminals on the other side of each single battery are electrically connected to form a second polarity pole of a large-capacity battery.

[0082] Compared with existing large-capacity batteries, the manufacturing method of the present invention does not require secondary unpacking of single cells. Instead, a second through hole is directly opened on a commercially available square aluminum lithium-ion battery, which is then placed in a cylinder and sealed to complete a large-capacity battery with a shared electrolyte function. The operation is simple, and commercially available batteries can be directly used for manufacturing, thus having strong applicability.

[0083] In addition, the present invention realizes the primary sealing of the box body by threaded connection combined with a flexible gasket, and realizes the secondary sealing of the box body by fusion welding. Compared with the existing large-capacity batteries, the sealing of the box body is stronger, and after the primary sealing, it can be ensured that impurities during fusion welding will not affect the large-capacity battery, thereby ensuring the performance of the large-capacity battery.

[0084] The third method for manufacturing a large-capacity battery also includes the step of welding an adapter sleeve to the original pole of each commercially available square aluminum lithium-ion battery after capacity separation and sorting.

[0085] The third method for manufacturing a large-capacity battery also includes step 4: welding an adapter block on the adapter sleeve and installing a heat exchange tube.

[0086] The fourth large-capacity battery structure, the box body includes a shell with an open top, n partitions and m upper covers; wherein n and m are both integers greater than 1; the shell includes a cylinder and a lower cover, and the lower cover is provided with an electrolyte sharing chamber; the battery unit is a single cell; the n partitions are arranged in the same direction in the cylinder, dividing the inner cavity of the cylinder into n-1 single cell accommodating cavities; at least one single cell is arranged in each single cell accommodating cavity; the electrolyte area of ​​the inner cavity of each single cell is connected to the inner cavity of the electrolyte sharing chamber; m upper covers are fixed one by one to the top open end of each single cell accommodating cavity; a first through hole is opened on each upper cover corresponding to the polarity terminal of each single cell; each single cell polarity terminal extends out of the first through hole, and the upper cover area corresponding to the first through hole is fixedly sealed to the single cell shell.

[0087] The present invention places multiple single cells inside a shell with a shared electrolyte chamber, and uses the shared electrolyte chamber to communicate with the inner cavities of each single cell located in the shell, so that the electrolyte of each single cell is shared to ensure the consistency of each single cell. That is, the electrolyte of each single cell is connected so that the electrolyte of all single cells is in the same system, which reduces the differences between each single cell and improves the consistency between each single cell to a certain extent, thereby improving the cycle life of the large-capacity battery to a certain extent.

[0088] The shared cavity of the present invention does not need to be plugged in, and there is no need to consider the coaxial plug-in problem in the arrangement direction of the single battery cells, and the requirements for processing accuracy and assembly accuracy are relatively low. At the same time, no special tooling is required, and the assembly process is relatively simple, which greatly reduces the processing difficulty and processing cost of such large-capacity batteries with a shared system, and can realize mass production.

[0089] The present invention's upper covers correspond to the open ends of each battery cell housing. Each upper cover has a corresponding clearance hole for each battery cell terminal. Each battery cell terminal extends through the corresponding clearance hole, and the upper cover area corresponding to the clearance hole is securely sealed to the battery cell housing. Compared to solutions that use a single, large cover plate fixed to the open end of the housing, this system offers the following advantages:

[0090] 1. The upper cover is easier to process and the flatness is easier to ensure;

[0091] 2. The upper cover plate used in the present invention has relatively low requirements for the height consistency of each single cell. That is, when the height deviations of the single cells constituting a large-capacity battery are large, the position of each upper cover plate at the open end of the single cell accommodating cavity can be adjusted so that the polarity terminals of the single cells extend out of the corresponding avoidance holes. The edges of each upper cover plate are then welded to the inner wall of the open end of the corresponding single cell accommodating cavity, and the gaps between the polarity terminals and the avoidance holes are sealed. Furthermore, based on the deformation of each upper cover plate in the thickness direction, the height deviations of each single cell can be compensated, so that the polarity terminals of the single cells extend out of the corresponding avoidance holes. The upper cover plate is then sealed and fixed to the open end of the corresponding single cell accommodating cavity, and the gaps between the polarity terminals and the avoidance holes are sealed.

[0092] 3. Under the premise of having the same thickness, the upper cover has higher structural strength than the entire large cover. Therefore, under the premise of ensuring a certain structural strength, the thickness of the upper cover can be appropriately reduced to reduce the weight of the entire large-capacity battery and meet the lightweight usage requirements.

[0093] The fourth large-capacity battery structure has the following optimized designs:

[0094] 1. Each cell cavity contains a single cell. The sidewalls of each cell near the center are in contact with the separator. For the two cells near the outermost sides, one sidewall contacts the separator, and the other contacts the sidewall of the cylinder. Heat generated during the charge and discharge process of each cell can be transferred to the outside through the separator, reducing the risk of thermal runaway. Furthermore, compared to solutions with two or more cells in each cell cavity, the presence of more separators in the cylinder further improves its strength, assuming the same number of cells.

[0095] 2. Each separator has an opening that connects adjacent battery cells. Each battery cell housing has a second through-hole that connects to the gas zone within the cell cavity. The gas zones within each cell cavity are interconnected through the second through-hole and the opening. This gas connection achieves gas balance between the cells, improving the performance and charge-discharge cycle life of large-capacity batteries.

[0096] 3. In order to further optimize the gas communication effect, the second through hole is opened on the upper cover of the single cell; in the height direction of the single cell, there is a gap between each single cell upper cover and the corresponding upper cover plate, and the opening and the gap are directly connected.

[0097] 4. A step structure is provided on the inner wall of the open top end of each single cell accommodating cavity; each upper cover is fixed on the step surface.

[0098] 5. The cylinder and the lower cover are separate parts, and the cylinder is formed by aluminum extrusion process.

[0099] 6. The partition and the cylinder are integrated, which makes processing easy and gives the cylinder good structural strength.

[0100] 7. The shell is provided with a liquid replenishing and replacing component for replenishing electrolyte into the electrolyte shared chamber and the inner cavity of each single cell, or replacing the electrolyte in the electrolyte shared chamber and the inner cavity of each single cell.

[0101] 8. The liquid replenishing and exchanging component includes a liquid replenishing and exchanging component body, an electrolyte flow pipe section, and a blocking component;

[0102] The main body of the fluid replacement component is fixed to the housing, and is provided with a first channel and a second channel that are in communication with the inner cavity of the housing; the first channel and the second channel are isolated from each other, the first channel is used to communicate with the electrolyte area of ​​the inner cavity of the housing, and the second channel is used to communicate with the gas area of ​​the inner cavity of the housing;

[0103] One end of the electrolyte circulation pipe section is fixed to the main body of the replenishing and exchanging fluid component and is communicated with the first channel; the other end of the electrolyte circulation pipe section is communicated with the electrolyte sharing chamber in the inner cavity of the shell;

[0104] The blocking member is used to block the first channel and the second channel from the outside of the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] FIG1 is a schematic diagram of the structure of a large-capacity battery in Example 1;

[0106] Figure 2 is a schematic diagram of the structure of a large-capacity battery without the cylinder;

[0107] FIG3 is a second schematic diagram of the large-capacity battery structure of Example 1;

[0108] Figure 4 is a schematic structural diagram of the cylinder;

[0109] FIG5 is a schematic structural diagram of a cover plate assembly provided with a flexible gasket;

[0110] Figure 6 is a partial structural diagram of the cylinder.

[0111] FIG7 is a schematic diagram of the three-dimensional structure of a large-capacity battery in Example 3;

[0112] FIG8 is a front view of a large-capacity battery according to Example 3;

[0113] FIG9 is a cross-sectional view taken along line A of FIG8 ;

[0114] FIG10 is a second schematic diagram of the large-capacity battery structure of Example 3;

[0115] Figure 11 is an enlarged view of the local structure of the cylinder in Example 3;

[0116] FIG12 is a schematic diagram of the three-dimensional structure of a large-capacity battery in Example 4 (without the upper cover);

[0117] Figure 13 is a schematic diagram of the cylinder structure of Example 4;

[0118] FIG14 is a schematic structural diagram of a cover plate assembly provided with a flexible gasket;

[0119] Figure 15 is an enlarged view of the local structure of the cylinder in Example 4.

[0120] FIG16 is a schematic structural diagram of a large-capacity battery according to Example 5;

[0121] FIG17 is a schematic diagram of the partial structure of a large-capacity battery with the upper cover removed;

[0122] FIG18 is a cross-sectional view of a large-capacity battery according to Example 5;

[0123] Figure 19 is a schematic structural diagram of the top plate;

[0124] Figure 20 is a schematic structural diagram of the cylinder in the large-capacity battery of Example 5;

[0125] FIG21 is a schematic structural diagram of a large-capacity battery according to Example 6;

[0126] Figure 22 is a schematic structural diagram of the cylinder in the large-capacity battery of Example 6;

[0127] FIG23 is a cross-sectional view of a large-capacity battery according to Example 6;

[0128] Figure 24 is a schematic diagram of the structure of the bottom plate in a large-capacity battery.

[0129] FIG25 is a schematic structural diagram of a large-capacity battery according to Example 7;

[0130] FIG26 is an exploded view of a large-capacity battery according to Example 7;

[0131] Figure 27 is a schematic diagram of the cylinder structure in Example 7;

[0132] FIG28 is a schematic diagram of a lower cover structure in Example 7;

[0133] FIG29 is a schematic diagram of another lower cover structure in Example 7;

[0134] Figure 30 is a schematic diagram of the cylinder structure in Example 8;

[0135] FIG31 is a cross-sectional view of a large-capacity battery according to Example 8;

[0136] FIG32 is a schematic diagram of the installation structure of the upper cover plate and the sealing connector in Example 8;

[0137] FIG33 is a schematic structural diagram of a large-capacity battery according to Example 9;

[0138] FIG34 is a schematic structural diagram of a fluid replenishing and exchanging component in Example 9;

[0139] FIG35 is a cross-sectional view of the cylinder with the fluid replacement component fixed thereto in Example 9;

[0140] Figure 36 is a schematic structural diagram of the cylinder in Example 9;

[0141] FIG37 is a schematic diagram of the structure of an existing large-capacity battery.

[0142] The accompanying drawings are marked as follows: 100-box, 200-battery unit; 1-cylinder, 2-cover assembly, 3-electrode assembly, 4-heat transfer tube, 5-plate body, 6-positive pole, 7-negative pole, 8-total positive terminal, 9-total negative terminal, 10-groove, 11-through hole, 12-first partition, 13-placement area, 14-explosion venting part, 15-liquid injection and replacement interface, 16-second partition, 17-upper cover, 18-chamber, 19-flexible gasket, 20-step surface, 21-first plane, 22-second plane; 23-upper cover, 24-first through hole, 25-hollow tube, 26-electrolyte storage chamber, 27-third plane; 28-adapter column, 29-annular blind groove, 30-annular protrusion, 31-second through hole, 32-adapter block, 3 3-card slot, 34-bottom plate, 35-pad, 36-electrolyte channel, A-gap; 37-upper cover assembly, 38-lower cover, 39-upper cover, 40-electrolyte shared chamber, 41-support ribs, 42-opening, 43-gap, 44-step structure, 45-sealing connector, 46-fluid replenishing component, 47-fluid replenishing component body, 48-electrolyte circulation pipe section, 49-blocking part, 50-mounting hole, 51-first channel, 52-second channel, 53-gas pipeline, 54-fluid replenishing component installation space; 01-sub-pipeline, 02-middle connecting pipe, 03-single cell lower cover. DETAILED DESCRIPTION

[0143] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments. Obviously, the embodiments described are only some embodiments, not all embodiments. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this invention.

[0144] At the same time, it should be noted that the terms "top, bottom, inner, and outer" used herein to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the technical solution. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0145] Unless otherwise specified or limited, the terms "mounted, connected, and connected" in this disclosure should be understood broadly. For example, they may refer to fixed, removable, or integral connections. They may also refer to mechanical, electrical, or direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure.

[0146] The basic design idea of ​​the present invention is:

[0147] N battery cells are arranged in a box to form a large-capacity battery. The N electrode assemblies of the large-capacity battery are in an electrolyte system, which not only ensures that the large-capacity battery has a large capacity, but also avoids the problem of reduced cycle life of the existing battery module due to the consistent consumption of electrolyte and lithium ions in each single battery cell.

[0148] Example 1

[0149] As shown in FIG1 , the large-capacity battery of this embodiment includes a housing 100 and N battery cells 200 , where N is ≥ 2. In this embodiment, N is 10, and the number N can be increased according to actual conditions.

[0150] The box body 100 includes a barrel 1, and the battery cell 200 includes a cover assembly 2 and an electrode assembly 3;

[0151] The upper end of the cylinder 1 is open; the cylinder 1 can be made by casting, stamping, extrusion or 3D printing;

[0152] N cover plate assemblies 2 are evenly fixed to the open end of the cylinder 1 along the first direction of the cylinder, thereby forming a closed box;

[0153] Specifically, the sum of the widths of the N cover plate assemblies 2 should fit the dimensions of the open end of the cylinder 1 in a first direction, and the length of the cover plate assemblies 2 should fit the dimensions of the open end of the cylinder 1 in a second direction, thereby ensuring that the N cover plate assemblies 2 can seal the cylinder 1. The cover plate assemblies 2 can be secured to the open end of the cylinder 1 by welding or by a combination of sealant and screws. However, welding is simpler to operate and provides greater sealing and reliability than the latter.

[0154] The first direction mentioned above is the length direction of the cylinder, that is, the X direction in FIG. 1 ; the second direction is the width direction of the cylinder, that is, the Y direction in FIG. 1 .

[0155] As shown in Figure 2, each cover plate assembly 2 includes a plate body 5 and a positive electrode column 6 and a negative electrode column 7 insulated and fixed on the plate body; the cover plate assembly is similar in structure to the upper cover assembly of the commercially available finished square single-cell lithium battery. The difference from the upper cover assembly of the commercially available finished square single-cell lithium battery is that the cover plate assembly is not provided with an explosion-proof membrane and a liquid injection part. Of course, you can also choose to customize the cover plate assembly without the explosion-proof membrane and the liquid injection part from the manufacturer of the finished standard parts of the upper cover assembly for use as the cover plate assembly of the present invention. When the cover plate assembly is customized in large quantities, the price may be lower than the price of the existing finished standard parts of the upper cover assembly.

[0156] N electrode assemblies 3 are evenly arranged inside the sealed box along the first direction of the cylinder, and there is a cover assembly 2 above each electrode assembly 3, and the positive electrode sheet and the negative electrode sheet of the electrode assembly 3 are electrically connected to the positive electrode column and the negative electrode column on the cover assembly respectively; the electrode assembly 3 is a multi-layer electrode sheet made by winding or stacking, and each layer of electrode sheet includes a positive electrode sheet, a diaphragm and a negative electrode sheet.

[0157] The positive poles 6 on each cover plate assembly 2 are electrically connected to form a total positive terminal 8, and the negative poles 7 on each cover plate assembly are electrically connected to form a total negative terminal 9; the total positive terminal 8 and the total negative terminal 9 exchange heat with an external temperature control device through at least one heat transfer tube 4; the sealed box contains electrolyte.

[0158] Among them, the total positive terminal and the total negative terminal can be formed in the following three ways;

[0159] 1. All positive poles 6 can be electrically connected through a plurality of first cables to form a total positive terminal 8, and all negative poles 7 can be electrically connected through a plurality of second cables to form a total negative terminal 9;

[0160] 2. All the positive poles 6 are electrically connected through a plurality of first electrical connection plates to form a total positive terminal 8, and all the negative poles 7 are electrically connected through a plurality of second electrical connection plates to form a total negative terminal 9;

[0161] 3. All positive poles 6 are electrically connected to form a total positive terminal 8 through a first electrical connection plate having a length equivalent to the length of the cylinder, and all negative poles 7 are electrically connected to form a total negative terminal 9 through a second electrical connection plate having a length equivalent to the length of the cylinder;

[0162] In order to take both electrical conductivity and installability into consideration, the first electrical connection plate is usually made of aluminum plate or copper plate, which is relatively inexpensive and has good flexibility.

[0163] The heat transfer tube can be made in the following ways:

[0164] 1. An aluminum tube is bent into a U-shaped structure, and two parallel tube sections are used to cooperate with the total positive terminal 8 and the total negative terminal 9 respectively, so as to realize heat exchange between each electrode assembly and the external temperature control device, and the liquid inlet and outlet of the aluminum tube are located on the same side; the transmission medium in the aluminum tube can be water, insulating oil or fluorinated liquid; or two aluminum tubes can be used to cooperate with the total positive terminal and the total negative terminal respectively.

[0165] 2. Two cored heat pipes are used to cooperate with the total positive terminal 8 and the total negative terminal 9 respectively, so as to realize heat exchange between each electrode assembly and the external temperature control device. The cored heat pipe is an evaporation-condensation type heat exchange device, which realizes heat transfer by the state change of the working fluid in the pipe.

[0166] Since the heat transfer effect of the cored heat pipe is affected by the length of the cored heat pipe, the use of the cored heat pipe will be limited when the number of electrode assemblies in a large-capacity battery is large (that is, when the length of the large-capacity battery is long). Therefore, in this embodiment, aluminum tubes are preferably selected as heat transfer tubes. If the insulation between the heat transfer tubes and the poles can be effectively ensured, water can be preferably used as the heat transfer medium flowing in the aluminum tubes from the perspectives of heat transfer efficiency and cost.

[0167] In this embodiment, the heat transfer tube 4 is matched with the main positive terminal and the main negative terminal in the following two ways:

[0168] As shown in FIG3 , each of the positive and negative electrode posts 6 and 7 has a groove 10 perpendicular to the axial direction of the posts. A heat transfer tube 4 is clamped in the groove 10 of either the positive or negative electrode post 6 or 7. The cross-section of the groove 10 is preferably C-shaped, and the open end of the C-shape is flexible enough to tightly clamp the heat transfer tube therein.

[0169] 3. As shown in FIG1 , a through hole 11 is formed on each of the positive electrode column 6 and the negative electrode column 7. The heat transfer tube 4 is inserted into the through holes 11 of all the positive electrode columns 6 or all the negative electrode columns 7 through a transition fit or interference fit.

[0170] Of the two methods mentioned above, the groove 10 is easier to install the heat transfer tube 4 than the through hole 11 method. The through hole 11 has a larger contact area between the heat transfer tube and the pole than the groove 10, and has a better heat transfer effect.

[0171] Since the main positive terminal 8 and the main negative terminal 9 are charged, to ensure safety, insulation must be maintained between the heat transfer tube 4 and the main positive terminal 8, and between the heat transfer tube 4 and the main negative terminal 9. This insulation can be maintained by oxidizing the heat transfer tube or providing an insulating layer in the area where the heat transfer tube contacts the pole.

[0172] One point that needs to be explained is: as shown in Figure 4, in this embodiment, N-1 first partitions 12 are arranged at intervals along the first direction in the cylinder 1, and the height of the first partition 12 is consistent with the height inside the cylinder 1, dividing the cylinder 1 into N placement areas 13 for electrode assemblies, and the N placement areas 13 are interconnected, and there is an electrode assembly between each two adjacent first partitions 12.

[0173] The first partition 12 is provided for the following four purposes:

[0174] Purpose 1: After the first partition 12 is set, it is convenient to weld the cover assembly 2 to the open end of the cylinder 1. During welding, the four sides of each cover 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 first partitions 12 to achieve a fixed seal; in some other embodiments, the width direction edges of the cover 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 two adjacent cover assembly 2 can be directly welded and sealed. However, compared with the setting of the first partition for welding and sealing in this embodiment, the sealing and reliability of the welding are higher.

[0175] Purpose 2: The provision of the first separator 12 can avoid the short circuit problem that may be caused by the swelling of the two electrode assemblies, thereby improving safety;

[0176] Purpose three: The heat of the electrode assembly can be directly transferred to the cylinder 1 through the first partition 12, thereby improving the heat dissipation effect of the electrode assembly.

[0177] Purpose 4: The provision of the first partition 12 can enhance the overall strength of the cylinder, thereby increasing the pressure-bearing capacity of the cylinder.

[0178] The first partition 12 can be set in the cylinder 1 by an integral molding method, or can be fixed in the cylinder 1 by welding. From the perspective of facilitating processing and controlling costs, this embodiment chooses to set the first partition in the cylinder by an integral molding method.

[0179] The placement areas 13 can be interconnected by opening a larger-diameter channel at the bottom of each first separator 12 to ensure that each electrode assembly is in the same electrolyte system, or by opening multiple through holes on each first separator 12 to ensure that each electrode assembly is in the same electrolyte system.

[0180] In order to prevent the large-capacity battery from thermal runaway in extreme cases, the thermal runaway smoke can be discharged from the sealed box in time to avoid the occurrence of more serious and dangerous accidents, the sealed box of the large-capacity battery is also provided with an explosion relief part 14, which can be a commercially available explosion relief valve or an explosion relief membrane fixedly sealed on a pipe.

[0181] In this embodiment, the sealed housing of the large-capacity battery is also provided with a fluid injection / exchange port 15. This port, in conjunction with external fluid injection / exchange equipment, not only facilitates initial battery injection, but also allows for increased or maintained capacity by replenishing the large-capacity battery with electrolyte, lithium additives, or replacing the entire electrolyte when the battery capacity decays to a certain extent, thereby ensuring the cycle life of the large-capacity battery. It is important to note that this port must remain sealed during battery operation to ensure the sealing of the large-capacity battery.

[0182] Based on the above introduction to the large-capacity battery structure, the manufacturing method of the large-capacity battery is now described in detail:

[0183] Step 1: Prepare the battery cell

[0184] The cover plate assembly 2 and the electrode assembly 3 are connected to form a battery unit by welding;

[0185] Step 2: Install the battery cells and form a sealed box

[0186] Place N battery cells into the cylinder 1 from the open end, then seal and fix the cover plate assembly 2 in each battery cell to the open end of the cylinder 1 by welding. The cylinder 1 and the N cover plate assemblies 2 form a sealed box.

[0187] Step 3: Install the heat transfer tube

[0188] Two parallel sections of a U-shaped heat transfer tube 4 are installed in the grooves 10 or through holes 11 of all positive poles 6 and all negative poles 7 respectively;

[0189] Step 4: Remove water

[0190] Heat is transferred to each electrode assembly through the heat transfer tube for heating, controlling the water content in the electrode assembly to a safe limit, thereby preventing hydrofluoric acid generated after water contacts the electrolyte from damaging the battery. Dynamic nitrogen negative pressure is required during the water removal process, which can immediately remove the vaporized water vapor. In addition, the dynamic nitrogen negative pressure link can also remove impurities in the sealed box during the assembly process, preventing the impurities from affecting the electrolyte environment in the box. At the same time, the negative pressure state facilitates the smooth entry of the electrolyte into the sealed box and makes it easier for the electrolyte to fully infiltrate each electrode assembly.

[0191] Step 5: Assembly of the total positive terminal and the total negative terminal

[0192] All positive poles 6 are electrically connected to form a total positive terminal 8, and all negative poles 7 are electrically connected to form a total negative terminal 9; the total positive terminal 8 is actually the positive pole of the large-capacity battery, and the total negative terminal 9 is actually the negative pole of the large-capacity battery;

[0193] Step 6: Filling

[0194] Connect the liquid injection and replacement equipment to the liquid injection and replacement interface, and inject electrolyte into the sealed box. The amount of electrolyte injected should be sufficient to fully soak the electrode of each electrode assembly;

[0195] Step 7: Formation

[0196] After charging to 3.4V at 0.1C constant current, switch to 3.4V constant voltage charging to a cut-off current of 0.01C and let it rest for 30 minutes;

[0197] Then discharge at 0.1C constant current to 2.5V and let it stand for 30 minutes;

[0198] After charging to 3.4V at a constant current of 0.2C, switch to a constant voltage charge of 3.4V to a cut-off current of 0.01C, and then let it rest for 30 minutes. The formation process allows a complete SEI film to form on each electrode component in the large-capacity battery, giving the large-capacity battery a more stable cycle capacity;

[0199] Step 8: Aging

[0200] The large-capacity battery is placed in an environment with a temperature of 40 to 50° C. for 24 to 72 hours, thereby completing the aging treatment of the large-capacity battery and completing the production of the large-capacity battery.

[0201] Compared with the existing battery module manufacturing process, the large-capacity battery manufacturing process of the present invention requires the capacity separation and sorting of each single cell in order to maintain the consistency of each single cell in the initial state of the battery module. In the present invention, multiple electrode assemblies are directly installed in a sealed box, and each electrode assembly is placed in a unified electrolyte system, without the need for capacity separation and sorting, thereby improving the capacity of large-capacity batteries and the battery manufacturing efficiency.

[0202] Example 2

[0203] The large-capacity battery structure in this embodiment differs from that in embodiment 1 in the following aspects:

[0204] 1. As shown in FIG4 , at least one second partition 16 and an upper cover 17 are further provided in the cylinder 1. A chamber 18 with an open upper end can be formed between the second partition 16 and the side wall of the cylinder 1. The upper cover 17 is fixed to the top of the chamber 18 by welding. The chamber can provide a more sufficient electrolyte in the large-capacity battery, and the chamber needs to be connected to each placement area. Such a design is helpful in improving the cycle life of the large-capacity battery.

[0205] It should be noted that in this embodiment, the upper cover 17 can be integrally formed with the plate body 5, thereby sealing the open end of the cylinder and the top of the chamber at one time, reducing the welding process.

[0206] 2. As shown in Figures 5 and 6, in order to compensate for the problem of uneven upper surface of the plate body after the cover plate assembly is placed due to the open end of each plate body and / or each placement area during processing, a circle of flexible gaskets 19 are provided on the plate body 5 of the cover plate assembly 2 near the four edges, and the open end surface of the placement area 13 is a stepped surface 20. The first plane 21 of the stepped surface 20 is welded to the plate body 5, and the second plane 22 of the stepped surface 20 is matched with the flexible gasket 19; the first plane 21 is located above the second plane 22.

[0207] 3. In this embodiment, the fluid injection and exchange interface can be designed as a multifunctional interface so that it can be connected to both the fluid injection and exchange equipment and the equipment that provides dynamic nitrogen negative pressure.

[0208] 4. Since a large amount of electrolyte is stored in a large capacity battery, in order to reduce the probability of large-scale combustion of the electrolyte in the box when thermal runaway occurs, in this embodiment, it is preferred to set the explosion vent near the bottom of the cylinder. Once thermal runaway occurs, the electrolyte in the sealed box will first be discharged out of the sealed box, and then the thermal runaway smoke will be discharged to the outside, thereby improving the safety of the large capacity battery.

[0209] 5. Hollow reinforcement ribs are provided on both the first and second side walls of the cylinder 1. The addition of these ribs enhances the strength of the cylinder. The hollow reinforcement cavity also serves as an air and liquid cooling channel, further enhancing the temperature control capabilities of large-capacity batteries.

[0210] Example 3

[0211] As shown in FIG7 and FIG8 , the large-capacity battery of this embodiment includes a housing 100 and N battery cells 200 , where N is greater than or equal to 2. In this embodiment, N is equal to 10, and the number N can be increased according to actual conditions.

[0212] The box body 100 includes a cylinder 1 with an open top and an upper cover 23 fixed to the open end of the cylinder 1; the cylinder 1 can be made by casting, stamping, extrusion or 3D printing; the upper cover 23 is provided with 2N first through holes 24;

[0213] As shown in FIG9 , the battery cell 200 includes a cover plate assembly 2 and an electrode assembly 3 connected to the cover plate assembly 2 ; the cover plate assembly 2 includes a plate body 5 , a positive electrode column 6 insulated and fixed on the plate body 5 , and a negative electrode column 7 .

[0214] The structure of the cover plate assembly 2 is similar to that of the upper cover assembly of the commercially available finished square single-cell lithium battery. The difference from the upper cover assembly of the commercially available finished square single-cell lithium battery is that the cover plate assembly 2 is not provided with an explosion-proof membrane and a liquid injection part. Of course, you can also choose to customize the cover plate assembly without the explosion-proof membrane and the liquid injection part from the manufacturer of the finished standard parts of the upper cover assembly and use it as the cover plate assembly of the present invention. When the cover plate assembly is customized in large quantities, the price may be lower than the price of the existing finished standard parts of the upper cover assembly.

[0215] The electrode assembly 3 is made of multiple layers of electrode sheets by winding or laminating, and each layer of electrode sheets includes a positive electrode sheet, a separator and a negative electrode sheet.

[0216] N battery cells 200 battery cells are evenly arranged along the length direction of the cylinder 1 after their corresponding cover plate assemblies 2 and the cylinder 1 are matched;

[0217] Specifically, the fixing and sealing methods of the upper cover 23 and the open end of the barrel 1, as well as the fixing methods of the cover assembly 2 and the barrel 1 in the battery unit 200 are as follows:

[0218] 1. The upper cover 23 has downward flanges on all sides. The battery unit is fixed to the cylinder 1 by screwing or welding the plate body 5 in the cover assembly 2 to the open end of the cylinder 1. Then, the upper cover 23 is snapped together with the open end of the cylinder 1, and the flanges around the upper cover 23 are welded to the upper edges of the side walls of the cylinder 1. Then, the upper cover 23 and the open end of the cylinder 1 are fixedly sealed, and the battery unit 200 is fixedly installed.

[0219] 2. As shown in Figure 10, the open end of the above-mentioned cylinder 1 has a stepped surface structure, including a first plane 21 and a second plane 22 lower than the first plane; the upper cover 23 is welded to the first plane 21, and the plate body 5 of the cover plate assembly 2 is fixed to the second plane 22, thereby achieving fixed sealing between the upper cover 23 and the open end of the cylinder 1, and fixed installation of the battery unit 200.

[0220] In the above two methods, the cover assembly 2 and the open end of the cylinder 1 are fixed, and the cover assembly 2 and the second plane 22 can be fixed by welding, bonding, or screwing. In order to ensure good reliability and simple operation, spot welding is preferably used for fixing.

[0221] The positive electrode column 6 and the negative electrode column 7 of each cover plate assembly 2 extend out of the upper cover through the corresponding first through hole 24; each first through hole 24 and the corresponding positive electrode column 6 and negative electrode column 7 must be sealed;

[0222] Here, there are two ways to seal the first through hole 24 and the corresponding positive electrode column 6 and negative electrode column 7:

[0223] One is: as shown in FIG7 , the area around each first through hole 24 on the upper cover 23 is directly sealed and fixed to the plate body 5 of the cover plate assembly 2 corresponding to the first through hole 24 by welding.

[0224] Second, as shown in FIG11 , a hollow tube 25 is sleeved on the positive pole 6 and the negative pole 7 of the cover assembly 2. The bottom of the hollow tube 25 is welded to the plate body 5 of the cover assembly 2. The top of the hollow tube 25 is flanged and welded to the area corresponding to the first through hole 24 on the upper cover 23 to ensure the sealing of the box. Then, insulating glue is filled into the gap between the hollow tube 25 and the pole or an insulating sleeve is set to achieve insulation between the hollow tube and the pole.

[0225] The positive poles 6 on each cover plate assembly 2 are electrically connected to form a total positive terminal 8, and the negative poles 7 on each cover plate assembly are electrically connected to form a total negative terminal 9; the total positive terminal 8 and the total negative terminal 9 exchange heat with an external temperature control device through at least one heat transfer tube 4; the box body 1 contains electrolyte.

[0226] The shapes of the total positive terminal, total negative terminal, and heat transfer tube, as well as the connection method between the heat transfer tube and the total positive terminal and total negative terminal are the same as those in Example 1 and will not be described in detail here.

[0227] One point that needs to be explained is: as shown in Figure 13, in this embodiment, N-1 first partitions 12 are arranged in the length direction of the box body, and the height of the first partition 12 is consistent with the height inside the cylinder 1, dividing the box body 1 into N placement areas 13, and the N placement areas 13 are interconnected, and there is an electrode assembly 3 between each two adjacent first partitions 12.

[0228] The first partition 12 is provided for the following four purposes:

[0229] Purpose 1: After the first partition 12 is provided, it is convenient to weld the cover plate assembly 2 to the open end of the cylinder 1. Specifically, during welding, the four sides of each cover plate assembly 2 can be spot welded to the upper edges of the two side walls in the longitudinal direction of the cylinder 1 and the upper edges of two adjacent first partitions 12 to achieve fixation;

[0230] Purpose 2: The provision of the first separator 12 can avoid the short circuit problem that may be caused by the swelling of the two electrode assemblies, thereby improving safety;

[0231] Purpose three: The heat of the electrode assembly can be directly transferred to the box body 1 through the first separator 12, thereby improving the heat dissipation effect of the electrode assembly;

[0232] Purpose 4: The provision of the first partition 12 can enhance the overall strength of the cylinder 1, thereby increasing the pressure-bearing capacity of the cylinder.

[0233] The first partition 12 can be set in the cylinder 1 by an integral molding method, or can be fixed in the cylinder 1 by welding. From the perspective of facilitating processing and controlling costs, this embodiment chooses to set the first partition 12 in the cylinder 1 by an integral molding method.

[0234] The placement areas 13 can be interconnected by providing a larger-diameter channel at the bottom of each first separator 12 to ensure that each electrode assembly is in the same electrolyte system, or by providing multiple through holes on each first separator 12 to ensure that each electrode assembly is in the same electrolyte system.

[0235] As shown in Figures 7 and 11, in order to prevent the large-capacity battery from thermal runaway in extreme cases, the thermal runaway smoke can be discharged from the sealed box in time to avoid the occurrence of more serious and dangerous accidents. The large-capacity battery box of this embodiment is also provided with an explosion relief part 14. The explosion relief part 14 can be a commercially available explosion relief valve or an explosion relief membrane fixedly sealed on a pipe.

[0236] As shown in Figures 7 and 11, in this embodiment, a fluid injection / exchange interface 15 is further provided on the casing of the large-capacity battery. The provision of this fluid injection / exchange interface 15 in conjunction with an external fluid injection / exchange device not only facilitates the initial injection of the battery, but also allows the interface to be used to increase or maintain capacity by replenishing electrolyte or lithium additives or replacing the electrolyte as a whole when the battery capacity decays to a certain extent, thereby ensuring the cycle life of the large-capacity battery. It should be noted that this interface must remain sealed during battery operation to ensure the sealing of the large-capacity battery.

[0237] Based on the above introduction of the large-capacity battery structure, the manufacturing method of the large-capacity battery is now described in detail:

[0238] Step 1: Prepare the battery cell

[0239] The cap plate assembly 2 and the electrode assembly 3 are connected to form a battery unit 200 by welding;

[0240] Step 2: Install the upper cover and battery unit

[0241] Place N battery cells 200 into the cylinder 1 from the open end thereof. Arrange the N battery cells 200 in sequence along the length of the cylinder 1. Secure the battery cells 200 by using the cover assembly 2 of the battery cells 200 and the cylinder 1.

[0242] The upper cover 23 is placed on N battery cells 200, and the positive electrode column 6 and the negative electrode column 7 of each battery cell 200 extend out of the upper cover 23 through the corresponding first through hole 24. Then, the upper cover 23 and the open end of the cylinder 1 are fixed and sealed. Finally, the gap between the first through hole 24 and the corresponding positive electrode column 6 and negative electrode column 7 is sealed.

[0243] Step 3: Install the heat transfer tube

[0244] Two parallel sections of a U-shaped heat transfer tube 4 are installed in the grooves 10 or through holes 11 of all positive poles 6 and all negative poles 7 respectively;

[0245] Step 4: Remove water

[0246] Heat is transferred to each electrode assembly through the heat transfer tube for heating, controlling the water content in the electrode assembly to a safe limit, thereby preventing hydrofluoric acid generated after water contacts the electrolyte from damaging the battery. Dynamic nitrogen negative pressure is required during the water removal process, which can immediately remove the vaporized water vapor. In addition, the dynamic nitrogen negative pressure link can also remove impurities in the sealed box during the assembly process, preventing the impurities from affecting the electrolyte environment in the box. At the same time, the negative pressure state facilitates the smooth entry of the electrolyte into the sealed box and makes it easier for the electrolyte to fully infiltrate each electrode assembly.

[0247] Step 5: Assembly of the total positive terminal and the total negative terminal

[0248] All positive poles 6 are electrically connected to form a total positive terminal 8, and all negative poles 7 are electrically connected to form a total negative terminal 9; the total positive terminal 8 is actually the positive pole of the large-capacity battery, and the total negative terminal 9 is actually the negative pole of the large-capacity battery;

[0249] Step 6: Filling

[0250] Connect the liquid injection and replacement equipment to the liquid injection and replacement interface, and inject electrolyte into the sealed box. The amount of electrolyte injected should be sufficient to fully soak the electrode of each electrode assembly;

[0251] Step 7: Formation

[0252] After charging to 3.4V at 0.1C constant current, switch to 3.4V constant voltage charging to a cut-off current of 0.01C and let it rest for 30 minutes;

[0253] Then discharge at 0.1C constant current to 2.5V and let it stand for 30 minutes;

[0254] After charging to 3.4V at a constant current of 0.2C, switch to a constant voltage charge of 3.4V to a cut-off current of 0.01C, and then let it rest for 30 minutes. The formation process allows a complete SEI film to form on each electrode component in the large-capacity battery, giving the large-capacity battery a more stable cycle capacity;

[0255] Step 8: Aging

[0256] The large-capacity battery is placed in an environment with a temperature of 40 to 50° C. for 24 to 72 hours, thereby completing the aging treatment of the large-capacity battery and completing the production of the large-capacity battery.

[0257] Compared with the existing battery module manufacturing process, in order to maintain the consistency of each single battery in the initial state of the battery module, the large-capacity battery manufacturing process of the present invention requires the capacity separation and sorting of each single battery. In the present invention, multiple electrode assemblies are directly installed in a box, and each electrolytic assembly is placed in a unified electrolyte system, without the need for capacity separation and sorting, thereby improving the capacity of large-capacity batteries and the battery manufacturing efficiency.

[0258] Example 4

[0259] The structure of the large-capacity battery in this embodiment is shown in FIG12 , which differs from that in embodiment 3 in the following aspects:

[0260] 1. As shown in FIG13 , at least one second partition 16 is further provided in the box body. An electrolyte storage chamber 26 can be formed between the second partition 16, the side wall of the cylinder 1, and the upper cover 23. The electrolyte storage chamber 26 can provide more sufficient electrolyte in the large-capacity battery, and the electrolyte storage chamber 26 needs to be connected to each placement area 13. Such a design is helpful to improve the cycle life of the large-capacity battery.

[0261] 2. As shown in Figures 14 and 15, in order to compensate for the problem of uneven upper surface of the plate body 5 after the cover plate assembly 2 is placed due to the open end of each plate body and / or each placement area during processing, a circle of flexible gaskets 19 are provided on the plate body 5 of the above-mentioned cover plate assembly 2 near the four edges, and the open end of the placement area is in a stepped surface structure, including a first plane 21, a second plane 22 lower than the first plane 21, and a third plane 27 lower than the second plane 22; the upper cover 23 is welded to the first plane 21, the plate body 5 of the cover plate assembly is spot-welded to the second plane 22, and the flexible gasket 19 cooperates with the third plane 27.

[0262] 3. In this embodiment, the injection and replacement fluid interface 15 can be designed as a multifunctional interface so that it can be connected to both the injection and replacement fluid equipment and the equipment providing dynamic nitrogen negative pressure.

[0263] 4. Since the amount of electrolyte stored in large-capacity batteries is large, in order to reduce the probability of large-scale combustion of the electrolyte in the box when thermal runaway occurs, in this embodiment, it is preferred to set the explosion venting part near the bottom of the cylinder. Once thermal runaway occurs, the electrolyte in the sealed box will first be discharged out of the sealed box, and then the thermal runaway smoke will be discharged to the outside, thereby improving the safety of large-capacity batteries.

[0264] 5. Hollow reinforcement ribs are provided on all four side walls of the cylinder 1. The addition of these ribs increases the strength of the cylinder. The hollow reinforcement cavity can also be used as an air cooling channel and a liquid cooling channel, further improving the temperature control capability of the large-capacity battery.

[0265] Example 5

[0266] As shown in FIG16 to FIG20 , the large-capacity battery of this embodiment includes a housing 100 and N battery cells 200 ; N ≥ 2; in this embodiment, N = 10, and of course, the number N can be increased according to actual conditions;

[0267] In this embodiment, the box body 100 includes a cylinder 1 and an upper cover 23; the top of the cylinder 1 is open, and the opening of the cylinder 1 is provided with a stepped surface; the stepped surface includes a first plane 21 and a second plane 22 lower than the first plane 21; the cylinder 1 can be manufactured by casting, stamping, extrusion or 3D printing;

[0268] The battery unit is a single battery;

[0269] The upper cover 23 is secured to the first flat surface 21 via screws and welding, with a flexible gasket 19 positioned between the upper cover 23 and the second flat surface 22. Specifically, the first flat surface 21 comprises a first region and a second region; the first region is provided with multiple threaded holes, while the second region serves as the area for welding to the upper cover. When the upper cover 23 is fastened to the open end of the cylinder 1, it is secured there with screws. The screws apply pressure to the flexible gasket 19, causing it to deform, thereby achieving a primary seal between the cylinder 1 and the upper cover 23.

[0270] Afterwards, the upper cover 23 and the second area are welded together by welding, thereby completing the secondary sealing of the cylinder body 1 and the upper cover 23 .

[0271] As shown in Figures 18 and 19, 2N first through holes 24 are provided on the upper cover 23; N single cells are placed side by side in the box body 1, each extending out of the corresponding first through hole 24, and the gap A between the first through hole 24 and the polarity terminal of the single cell is filled with sealant; the purpose of requiring the polarity terminal of the single cell to extend out of the top plate is mainly to achieve electrical connection between the polarity terminals of each single cell. Since the polarity terminal of the single cell needs to extend from the first through hole 24, there is a gap between the first through hole 24 and the polarity terminal of the single cell. In this embodiment, sealant is poured into this gap to achieve sealing. It should be emphasized that in order to make the sealant solidify quickly to achieve sealing at this location and avoid reaction between the sealant and the electrolyte, epoxy glue is used in this embodiment.

[0272] In this embodiment, as shown in Figure 18, the polarity terminal of a single cell includes a pole of the single cell and an adapter post 28 welded to the top of the pole. The adapter post 28 has an annular blind groove 29 formed along its axial direction. The provision of the adapter post 28 extends the length of the original pole of the single cell, allowing it to smoothly extend out of the upper cover 23. In addition, the use of the adapter post 28 allows the direct use of commercially available batteries to assemble large-capacity batteries, which is highly adaptable. The provision of the annular blind groove 29 provides a transmission channel for the laser during laser welding, allowing the adapter post 28 to be better welded to the original pole.

[0273] In order to ensure the thickness of the sealant layer for better sealing, an annular protrusion 30 is provided on the upper cover 23 at a position corresponding to each first through hole 24 in this embodiment. It should also be noted here that the annular protrusion 30 needs to extend from the top surface of the adapter column 28.

[0274] The N polarity terminals on one side of each single battery are electrically connected to form the total positive terminal of the large-capacity battery, and the N polarity terminals on the other side of each single battery are electrically connected to form the negative positive terminal of the large-capacity battery;

[0275] Among them, the total positive terminal and the total negative terminal can be formed in the following three ways;

[0276] 1. The positive terminals of all single cells can be electrically connected through a plurality of first cables to form a total positive terminal, and the negative terminals of all single cells can be electrically connected through a plurality of second cables to form a total negative terminal;

[0277] 2. Electrically connect the positive terminals of all the single cells through a plurality of first electrical connection plates to form a total positive terminal, and electrically connect the negative terminals of all the single cells through a plurality of second electrical connection plates to form a total negative terminal;

[0278] 3. The positive terminals of all the single cells are electrically connected to form a total positive terminal through a first electrical connection plate having a length equivalent to the length of the cylinder, and the negative terminals of all the single cells are electrically connected to form a total negative terminal through a second electrical connection plate having a length equivalent to the length of the cylinder;

[0279] In order to take into account both electrical conductivity and installability, the first electrical connection plate and the second electrical connection plate are usually made of aluminum plates or copper plates which are relatively inexpensive and have good flexibility.

[0280] The bottom of the N battery cells is provided with a second through-hole 31, ensuring interconnected electrolyte zones within each cell. In this embodiment, the inner cavity of the housing serves as a shared chamber connecting the electrolyte zones of each cell. Compared to existing large-capacity batteries that use a spliced, shared electrolyte channel, this makes sealing easier and allows for a larger volume of shared electrolyte, further extending the cycle life of the large-capacity battery.

[0281] In this embodiment, the single cell can directly adopt commercially available square aluminum lithium-ion batteries. When using, only the following two improvements need to be made to the commercially available square aluminum lithium-ion batteries:

[0282] 1. Welding the adapter post 28 onto the original pole of a commercially available square aluminum lithium-ion battery;

[0283] 2. Use a cutter to cut a second through hole 31 at the bottom of a commercially available square aluminum lithium-ion battery.

[0284] Since commercially available batteries can be directly used for simple modification, the large-capacity battery provided by this embodiment has greater applicability and lower cost compared to existing large-capacity batteries.

[0285] In addition, in this embodiment, a liquid injection / exchange interface 15 is provided on the cylinder body. The liquid injection / exchange interface 15 can be arranged near the bottom of the cylinder body 1, and the liquid injection / exchange interface 15 has the following multiple functions:

[0286] 1. The liquid filling and replacement interface 15 is used to connect with the liquid filling and replacement equipment to perform the operation of replenishing and replacing the electrolyte for the large-capacity battery. The liquid filling and replacement function can improve the cycle life of the large-capacity battery.

[0287] 2. An explosion relief valve is provided on the fluid injection and replacement interface 15. Once thermal runaway occurs, the explosion relief valve opens and the electrolyte is ejected first, followed by the thermal runaway smoke. Since the electrolyte is ejected first, further expansion and spread of thermal runaway can be avoided, thereby improving the safety of large-capacity batteries.

[0288] 3. A plug for sealing can also be provided on the liquid injection / exchange interface 15. However, compared with the above 1 and 2, although the sealing performance can be ensured, it does not help to improve the cycle life and safety.

[0289] The specific manufacturing method of the large-capacity battery of this embodiment is as follows:

[0290] Step 1: Sorting

[0291] Several commercially available square aluminum lithium-ion batteries are sorted by capacity, and the commercially available square aluminum lithium-ion batteries are classified into different grades according to grade standards; the capacity sorting indicators include internal resistance, capacity, thickness, voltage, etc., and in specific operations, any one of these indicators or a combination of multiple indicators can be used for screening;

[0292] Step 2: Install the adapter post

[0293] 10 commercially available square aluminum lithium-ion batteries of the same grade were selected, and adapter posts were welded to the original poles of the 10 commercially available square aluminum lithium-ion batteries (the original pole + adapter post structure here serves as the polarity terminal);

[0294] Step 3: Unpacking the Battery

[0295] Under a specific environment, a second through hole was opened in the bottom of 10 commercially available square aluminum lithium-ion battery casings. The specific environment is the clean environment required for battery manufacturing, preferably an environment with a dew point of -25 to 40°C, humidity ≤1%, temperature 23°C ± 2°C, and cleanliness level 100,000.

[0296] Step 4: Assemble the High-Capacity Battery

[0297] Step 4.1: Place 10 commercially available square aluminum lithium-ion batteries with second through holes formed therein into the cylinder;

[0298] Step 4.2: Place a flexible gasket on the second flat surface and secure the top plate to the open end of the cylinder using screws. This process ensures that the polarity terminals of each square aluminum lithium-ion battery extend through their corresponding first through-holes.

[0299] Step 4.3: Pour sealant into each first through hole and its corresponding polarity terminal; let it stand for the sealant to solidify, thereby completing the primary sealing of the large-capacity battery;

[0300] Step 4.4: The top plate and the second flat surface of the open end of the cylinder are welded together to complete the secondary sealing of the large-capacity battery;

[0301] Step 4.5: Electrically connect the 10 polarity terminals on one side of each single battery to form a total positive terminal of the large-capacity battery, and electrically connect the 10 polarity terminals on the other side of each single battery to form a total negative terminal of the large-capacity battery;

[0302] Step 5: Injection

[0303] Connect the liquid injection and replacement device to the interface and inject electrolyte into the box;

[0304] In order to ensure the reliability of the later operation of the large-capacity battery, this embodiment can also perform formation and aging steps on the large-capacity battery after liquid injection.

[0305] Specifically, the formation process is: after charging to 3.4V at a constant current of 0.1C, switch to a constant voltage of 3.4V and charge to a cut-off current of 0.01C, and let it stand for 30 minutes;

[0306] Then discharge at 0.1C constant current to 2.5V and let it stand for 30 minutes;

[0307] After charging at a constant current of 0.2C to 3.4V, the battery is switched to a constant voltage charge at 3.4V to a cutoff current of 0.01C and then left to rest for 30 minutes. This formation process allows a complete SEI film to form on each electrode component in the high-capacity battery, giving it more stable cycling performance.

[0308] The specific aging process is: aging temperature 50 ° C, aging time 48 hours. After aging, the large-capacity battery can be vented to discharge the waste gas after formation and reduce the probability of swelling of each single cell of the large-capacity battery.

[0309] Example 6

[0310] As shown in FIG. 21 to FIG. 24 , the structure of this embodiment is similar to that of embodiment 5, except for the following points:

[0311] First, because the most concentrated heat in a single cell occurs at the cell terminal, this embodiment welds an adapter block 32 to the top of the adapter post 28 to effectively control its temperature. This adapter block 32 is equipped with a slot 33 for mounting a heat transfer tube. This heat transfer tube allows the temperature of each cell to be directly transferred to an external temperature control device, mitigating the problem of overheating affecting the performance of larger-capacity batteries. More importantly, this invention further reduces the probability of thermal runaway by dissipating heat directly from each cell terminal, as shown in Figures 21 and 23.

[0312] The heat transfer tube can be made in the following ways:

[0313] 1. An aluminum tube is bent into a U-shaped structure, and two parallel tube sections are used to match the total positive terminal and the total negative terminal respectively, so as to realize heat exchange between each single battery and the external temperature control device, and the liquid inlet and outlet of the aluminum tube are located on the same side; the transmission medium in the aluminum tube can be water, insulating oil or fluorinated liquid; or two aluminum tubes can be used to match the total positive terminal and the total negative terminal respectively.

[0314] 2. Two cored heat pipes are used to cooperate with the total positive terminal and the total negative terminal respectively, so as to realize the heat exchange between each single battery and the external temperature control device. The cored heat pipe is an evaporation-condensation type heat exchange device, which realizes heat transfer by the state change of the working fluid in the pipe.

[0315] Since the heat transfer effect of the core heat pipe is affected by the length of the core heat pipe, the use of the core heat pipe will be limited when the number of single cells in a large-capacity battery is large (that is, the length of the large-capacity battery is long). Therefore, in this embodiment, aluminum pipes are preferably selected as heat transfer pipes. If the insulation between the heat transfer pipe and the pole can be effectively ensured, water can be preferably used as the heat transfer medium flowing in the aluminum pipe from the aspects of heat transfer efficiency and cost.

[0316] Since the total positive terminal and the total negative terminal are charged, to ensure safety, insulation must be maintained between the heat transfer tube and the total positive terminal, and between the heat transfer tube and the total negative terminal. The insulation can be maintained by oxidizing the heat transfer tube or providing an insulating layer in the area where the heat transfer tube contacts the pole.

[0317] 2. As shown in Figures 22, 23, and 24, the housing 1 includes an upper cover 23, a cylindrical body 1, and a bottom plate 34. The top and bottom of the cylindrical body 1 are both open. The connection method between the upper cover 23 and the open top end of the cylindrical body 1 is consistent with that of Example 5. The bottom plate 34 is connected to the cylindrical body 1 by welding. In this embodiment, two pads 35 are provided on the inner surface of the bottom plate 34, extending along the arrangement direction of the single cells. An electrolyte channel 36 is formed between the two pads 35. The electrolyte channel 36 communicates with the electrolyte area of ​​each single cell. The design of the pad 35 has two advantages:

[0318] 1. When the pad 35 contacts the bottom surface of the single cell, it is easier to ensure flatness than when the bottom plate surface directly contacts the bottom surface of the single cell. That is, the height of the polarity terminals of the single cell when they extend out of the top plate can remain basically consistent.

[0319] 2. The electrolyte channel 36 formed between the two pads 35 can improve the continuity of the electrolyte level between each single battery (avoiding the occurrence of electrolyte interruption).

[0320] Of course, the structure of the bottom plate being provided with two pads is also applicable to the cylinder with only the top open given in Example 1, that is, two pads are provided on the bottom inner surface of the cylinder.

[0321] 3. As shown in FIG22 , in this embodiment, N-1 first partitions 12 are provided in the box body 1 along the length direction. The height of the first partition 12 is consistent with the height of the cylinder body, dividing the cylinder body 1 into N placement areas 13. The N placement areas 13 are interconnected, and there is a single battery between each two adjacent first partitions 12.

[0322] The setting of the partition has the following four purposes:

[0323] Purpose 1: The provision of the first separator 12 can suppress the swelling of the single battery;

[0324] Purpose 2: The heat of the single battery can be directly transferred to the box body 1 through the first partition 12, thereby improving the heat dissipation effect of the single battery.

[0325] Purpose three: The provision of the first partition 12 can enhance the overall strength of the cylinder 1 , thereby increasing the pressure-bearing capacity of the cylinder 1 .

[0326] The first partition 12 can be set in the cylinder 1 by an integral molding method, or can be fixed in the cylinder 1 by welding, or can be fixed in the cylinder 1 by plugging. From the perspective of facilitating processing and controlling costs, this embodiment chooses to set the first partition 12 in the cylinder 1 by an integral molding method.

[0327] The placement areas 13 can be interconnected by providing a larger-diameter channel at the bottom of each first separator 12 to ensure that each electrode assembly is in the same electrolyte system, or by providing multiple through holes on each separator to ensure that each electrode assembly is in the same electrolyte system.

[0328] Example 7

[0329] As shown in FIG25 and FIG26 , the large-capacity battery of this embodiment includes a housing 100 and 10 battery cells arranged in parallel in the housing 100; the battery cell 200 is a single battery;

[0330] The single cells in this embodiment are commercially available square-shell batteries, and the number is 10. In other embodiments, the number can be adjusted according to actual needs. The inner cavity of each single cell includes an electrolyte area and a gas area.

[0331] The box body 100 in this embodiment is a rectangular shell. For the convenience of description, the length direction of the box body 100 is defined as the x direction, the width direction is defined as the y direction, and the height direction is defined as the z direction.

[0332] As shown in Figure 26, the box body 100 includes a cylinder 1 with open ends at both ends (that is, the port parallel to the xy plane is the open end) and a lower cover plate 38 and an upper cover plate assembly 37 respectively fixed on the two open ends of the cylinder 1 (that is, the lower cover plate 38 and the upper cover plate assembly 37 are both parallel to the yz plane).

[0333] As shown in FIG27 , nine first partitions 12 are arranged at equal intervals along the x-direction in the cylinder 1 to divide the inner cavity of the cylinder 1 into ten single-cell battery accommodating cavities of equal volume; each single-cell battery accommodating cavity is used to place one single cell;

[0334] In some other embodiments, two or more single cells may be placed in each single cell receiving cavity.

[0335] In this embodiment, the cylinder 1 and the first partition 12 are an integral piece and are processed by aluminum extrusion technology.

[0336] In some other embodiments, the cylinder 1, the first partition 12 and the lower cover 38 can be an integral part, which can usually be processed by a casting process. However, compared with this embodiment, the entire cylinder 1 has a certain draft angle, which needs to be corrected later.

[0337] In some other embodiments, the first partition 12 and the cylinder 1 may be separate parts. Compared with this embodiment, corresponding matching structures need to be processed on the cylinder 1 or the first partition 12.

[0338] The lower cover plate 38 is provided with an electrolyte channel extending in the x-direction, serving as an electrolyte shared chamber 40;

[0339] The electrolyte sharing chamber 40 mainly includes the following three structures:

[0340] 1) As shown in FIG28 , a groove extending along the length of the lower cover plate 38 is directly provided on the inner surface thereof to serve as an electrolyte channel, i.e., an electrolyte sharing chamber 40 ;

[0341] The two ends of the electrolyte channel parallel to the yz plane are closed ends, that is, in the x direction, the size of the electrolyte channel is smaller than the size of the lower cover plate 38; the corresponding electrolyte channel can be directly formed on the upper surface of the lower cover plate 38 by milling or casting.

[0342] 2) The lower cover plate 38 has a raised portion extending in the z-direction. An electrolyte channel extending in the x-direction is defined on the raised portion. The two ends of the electrolyte channel, parallel to the yz plane, are open. It should be noted that during operation, the two open ends of the electrolyte channel (the open ends parallel to the yz plane) must be sealed to prevent the external environment from affecting the electrolyte in the individual battery cells.

[0343] 3) As shown in Figure 29, at least two support ribs 41 extending along the x-direction are provided on the inner surface of the lower cover plate 38. The two support ribs 41 and the area of ​​the lower cover plate 38 located between the two support ribs 41 form an electrolyte channel extending along the x-direction. It should be noted that during operation, the open ends of the electrolyte channel (the open ends parallel to the yz plane) need to be sealed to prevent the external environment from affecting the electrolyte in the internal cavity of each single cell.

[0344] It should be noted that the electrolyte shared chamber 40 serves as an electrolyte containing chamber. After it is connected to the electrolyte area of ​​each single battery cell, it is necessary to ensure that the electrolyte in the entire large-capacity battery does not come into contact with the external environment.

[0345] As can be seen from Figures 25 and 26, the upper cover assembly 37 of this embodiment includes 10 upper cover plates 39, and the 10 upper cover plates 39 correspond one-to-one to the 10 single cell accommodating cavities, and are used to seal the top open ends of the corresponding single cell accommodating cavities; the shape of the upper cover plates 39 is adapted to the shape of the top open ends of the single cell accommodating cavities, and the area can be slightly larger than the area of ​​the top open ends of the single cell accommodating cavities, and they are fixed to the top open ends of the single cell accommodating cavities by fusion welding; the area can also be slightly smaller than the area of ​​the top open ends of the single cell accommodating cavities, and they are fixed to the top open ends of the single cell accommodating cavities by embedding welding.

[0346] In this embodiment, each upper cover plate 39 is provided with a first through hole 24 corresponding to the polarity terminal of the corresponding single cell; the polarity terminal of the single cell extends out of the first through hole 24, and the upper cover plate 39 area corresponding to the first through hole 24 is fixedly sealed with the single cell housing.

[0347] In this embodiment, an independent upper cover plate 39 is fixed to the open end of each single cell accommodating cavity. Each upper cover plate 39 can be directly pressed against the corresponding single cell upper cover, and the upper cover plate 39 area around the first through hole 24 is welded to the single cell upper cover to achieve sealing.

[0348] The above-mentioned large-capacity battery can be assembled through the following process:

[0349] Step 1: Process the housing 100, including the barrel 1, the lower cover 38, and each upper cover 39. In this embodiment, the barrel 1 is a shell with open top and bottom ends. It can be formed using an aluminum extrusion process, and the first partition 12 can be integrally formed. Each upper cover 39 can be formed using a casting process. Depending on the structure of the electrolyte shared chamber 40, the lower cover 38 can be processed using different processes. If the electrolyte shared chamber 40 of the first structure is used, the lower cover 38 can be formed using a casting process. If the electrolyte shared chamber 40 of the second structure is used, the lower cover 38 can be formed using an aluminum extrusion process.

[0350] Step 2: Sealingly weld the lower cover plate 38 with the electrolyte sharing chamber 40 to the open end of the bottom of the cylinder 1.

[0351] Step 3: sorting by capacity to select multiple single cells that meet the requirements; opening a second through hole at the bottom of the single cell housing and sealing it with a sealing assembly; arranging the single cells with the sealing assembly at the second through hole in each single cell accommodating cavity of the component in step 2; ensuring that the first through hole with the sealing assembly corresponds to the electrolyte channel to ensure that after the sealing assembly is opened by external force or the electrolyte itself, the electrolyte area in the cavity of each single cell and the electrolyte shared chamber 40 are connected;

[0352] The sealing assembly may adopt the sealing assembly disclosed in Chinese patents CN218525645U and CN218525614U.

[0353] Step 4: Seal-weld each upper cover plate 39 to the open end of the corresponding single cell accommodating cavity. After each single cell polarity terminal extends out of the first through hole 24, the upper cover plate 39 area corresponding to the first through hole 24 is fixedly sealed to the single cell housing. The sealing can be achieved by welding the edge of the first through hole 24 to the single cell housing in the area surrounding the single cell polarity terminal.

[0354] In other embodiments, the lower cover plate 38, the upper cover plate 39 and the cylinder body 1 may also be fixed by bonding or screw connection. However, compared with welding, the sealing performance or connection reliability is relatively weaker.

[0355] Step 5: Use external force or the electrolyte itself to open the sealing component, so that the inner cavity of the electrolyte sharing chamber 40 and the electrolyte area of ​​each single battery cavity are connected.

[0356] After the inner cavities of each single cell and the electrolyte shared chamber 40 are connected, the electrolytes in the inner cavities of each single cell are connected through the electrolyte shared chamber 40. In order to prevent the interruption of the electrolyte, electrolyte can be injected into the electrolyte shared chamber 40 after the inner cavities of each single cell and the electrolyte shared chamber 40 are connected to ensure the continuity of the electrolyte.

[0357] Then, all the single cells are connected in parallel. In other embodiments, the single cells may be connected in parallel between step 4 and step 5.

[0358] In order to form a more complete SEI film and make the large-capacity battery have a more stable cycle capacity, the electrolyte is injected into the inner cavity of each single battery through the electrolyte sharing chamber 40, and then the entire large-capacity battery is formed.

[0359] Example 8

[0360] Unlike Example 1, this embodiment provides openings 42 on each first separator 12 that penetrate adjacent battery cavities. Furthermore, each battery housing provides a third through-hole that penetrates the gas zone within the battery cavity. The gas zones within each battery cavity are interconnected via the third through-hole and openings 42. This gas connection achieves gas balance between the individual batteries, improving the performance and charge-discharge cycle life of high-capacity batteries.

[0361] In this embodiment, a third through hole is opened on each single cell upper cover, and the third through hole can be formed to open the explosion vent portion of the single cell; the corresponding openings 42 on each first partition 12 are opened near each upper cover 39, as shown in FIG7 .

[0362] In some other embodiments, the third through hole may be located at a position of each single cell barrel 1 close to the upper cover, as long as the third through hole is connected to the gas area of ​​the inner cavity of the single cell.

[0363] To ensure sufficient gas connectivity, as shown in FIG31 , in this embodiment, in the z direction, a gap 43 is provided between each single cell upper cover and the corresponding upper cover plate 39 , and the opening 42 and the gap 43 are directly connected.

[0364] As can be seen from Figures 30 and 31, in this embodiment, a step structure 44 is provided around the inner wall of the top open end of the single cell accommodating cavity. The step surface of the step structure 44 can be used as a positioning surface. The upper cover plate 39 can be positioned at the top open end of the single cell accommodating cavity by using the positioning surface, and then fixed by welding.

[0365] Due to the presence of the aforementioned gap 43, it is difficult to seal the area of ​​the upper cover plate 39 corresponding to the first through-hole 24 with the cell housing using direct welding as in Example 1. Therefore, in this embodiment, a sealing connector 45 is added between the first through-hole 24 and the polarity terminal, as shown in FIG32 (in FIG33 , to clearly illustrate the fixing method of the sealing connector 45 , the sealing connector 45 is installed at the upper right first through-hole 24, while the sealing connector 45 is not installed at the lower left first through-hole 24). The sealing connector 45 comprises a hollow member; the bottom of the hollow member is used to seal with the first area of ​​the cell, and the top of the hollow member is sealed with the second area of ​​the upper cover plate 39. The first area is the area surrounding any terminal in the upper cover plate 39 of any cell; the second area is the area corresponding to any first through-hole 24 on the upper cover plate 39. The area corresponding to the first through-hole 24 is the area on the outer surface of the upper cover plate 39 surrounding any first through-hole 24, or the area corresponding to the first through-hole 24 is the wall of the first through-hole 24. The area around the pole is the area around the insulating seal on the pole. The insulating seal is a component on the single battery used to insulate the pole from the upper cover.

[0366] The assembly method of the large-capacity battery in this embodiment is basically the same as that in the embodiment, except that in step 2, a third through hole needs to be opened on the upper cover of the single battery.

[0367] The single cell with the third through hole on the upper cover can be directly placed in the corresponding single cell accommodating cavity;

[0368] A sealing assembly disclosed in Chinese patents CN218525645U and CN218525614U may also be provided at the third through hole. In step five, the sealing assembly is opened by external force or the electrolyte itself, so that the gas areas in the inner cavities of the individual battery cells are connected. It should be noted that if an external force is used to open the sealing assembly, an operating port for an opening device needs to be provided at a corresponding portion of the cylinder 1. Specifically, when opening the package, the opening device is extended into the cylinder 1 through the operating port for the opening device, and passes through the opening 42 on the first partition 12 to open the sealing film sealed at the second through hole in the upper cover of each individual battery cell.

[0369] Example 9

[0370] As can be seen from Figure 33, unlike the above-mentioned embodiment, this embodiment provides a fluid replacement component 46 on the side wall of the cylinder 1 parallel to the yz plane; when such large-capacity batteries are assembled into energy storage equipment, multiple large-capacity batteries are arranged along the width direction of the large-capacity batteries, so that the end plate assemblies of each large-capacity battery are exposed. When the fluid replacement component 46 is provided on the end plate assembly, the fluid replacement operation can be conveniently performed.

[0371] In some other embodiments, the fluid replacement component 46 can be fixed at any position of the box body 100, for example, it can be set on the side wall of the cylinder body 1 parallel to the xz plane.

[0372] After a period of charge and discharge cycles of a large-capacity battery, the electrolyte decomposes and is consumed, resulting in a decrease in the performance of the large-capacity battery. The electrolyte can be replenished into the electrolyte shared chamber 40 and the inner cavity of each single cell through the liquid replenishing component 46 to improve the performance of the large-capacity battery. Alternatively, after a period of charge and discharge cycles of a large-capacity battery, the electrolyte in the electrolyte shared chamber 40 and the inner cavity of each single cell is affected by impurities in the electrolyte. The electrolyte can also be replaced by the liquid replenishing component 46 to improve the performance of the large-capacity battery. The replacement here can be a partial replacement or a complete replacement. In addition, after the electrolyte area of ​​each single cell inner cavity is connected to the electrolyte shared chamber 40, the electrolyte can be re-injected into the inner cavity of each single cell and the electrolyte shared chamber 40 through the liquid replenishing component 46 to ensure the continuity of the electrolyte.

[0373] As shown in FIG34 and FIG35 , the liquid replenishing and exchanging component 46 of this embodiment includes a liquid replenishing and exchanging component body 47 , an electrolyte flow pipe section 48 , and a blocking member 49 ;

[0374] The main body 47 of the fluid replacement component is fixed on the barrel 1. In this embodiment, the main body 47 of the fluid replacement component is a cylinder. In other embodiments, a rectangular column, a semi-cylinder, etc. can also be selected.

[0375] A fluid replacement component installation space 54 is provided in the cylinder 1, and a mounting hole 50 (see Figure 36) that passes through the fluid replacement component installation space 54 is opened on the side wall of the cylinder 1 parallel to the yz plane. The fluid replacement component body 47 is fixed in the installation hole 50, and the fluid replacement component body 47 is welded to the cylinder 1 area around the installation hole 50 to achieve fixation and seal the installation hole 50 at the same time.

[0376] A first channel 51 and a second channel 52, isolated from each other, are defined in the main body 47 of the replacement fluid member. After the main body 47 of the replacement fluid member is secured to the barrel 1, one end of each of the first channel 51 and the second channel 52 is located outside the barrel 1. The other end of the first channel 51 is located inside the barrel 1 for connection to the electrolyte flow tube section 48. The other end of the second channel 52 is located inside the barrel 1 for communication with the gas area within the housing 100. A gas pipe 53 can also be connected to the second channel 52 to communicate with the gas area within the housing 100.

[0377] One end of the electrolyte circulation pipe section 48 is fixed on the liquid replenishing component body 47 and communicates with the first channel 51 ; the other end is used to communicate with the electrolyte sharing chamber 40 in the inner cavity of the box body 100 .

[0378] It should be noted that the end of the electrolyte circulation pipe section 48 that is connected to the electrolyte sharing chamber 40 in the inner cavity of the box 100 can be directly extended into the bottom of the inner cavity of the box 100 and is always immersed in the electrolyte. When the liquid needs to be changed, as much electrolyte as possible in the inner cavity of the box 100 can be extracted, so that the liquid change is more thorough.

[0379] The electrolyte flow pipe section 48 and the liquid replenishing component body 47 can be an integral part or a separate part. When it is a separate part, it can be connected to the liquid replenishing component body 47 by welding or screwing. The material of the electrolyte flow pipe section 48 is generally selected from the same aluminum material as the liquid replenishing component body 47.

[0380] The blocking member 49 in this embodiment includes a cap (which can be a nut) buckled onto the main body 47 of the fluid replacement component and threadedly connected to the main body 47 of the fluid replacement component. A sealing ring can be provided at the threaded connection portion to improve the sealing performance of this portion.

[0381] In some other embodiments, the blocking member 49 may also be a rubber column inserted into the first channel 51 and the second channel 52 .

[0382] When fluid replacement is needed, follow these steps:

[0383] Remove the cap;

[0384] When there is gas in the inner cavity of the box body 100, the gas will overflow from the second channel 52, making it easy to inject liquid into the inner cavity of the box body 100. In order to make the injection smoother, in this step, an air extraction pipe can be inserted into the second channel 52, and an external air extraction device connected to the air extraction pipe can be started to extract gas, so that a certain negative pressure is formed in the inner cavity of the box body 100.

[0385] Afterwards, the electrolyte injection tube is extended into the first channel 51 and the electrolyte is injected. During the injection process, if there is a problem of injection difficulty, the external air extraction device can be activated to form a certain negative pressure in the inner cavity of the box body 100, and then the injection can be continued;

[0386] After the fluid replenishment is completed, the electrolyte injection tube and the air extraction tube are pulled out; and the cap is sealed and fixed on the fluid replenishment component body 47.

[0387] When the fluid needs to be changed, follow these steps:

[0388] Remove the cap;

[0389] Insert the electrolyte extraction tube into the first channel 51 and extract the electrolyte; when the electrolyte cannot be extracted, insert the gas injection tube into the second channel 52, inject protective gas into the inner cavity of the box 100 to extract the electrolyte; after the extraction is completed, remove the electrolyte extraction tube and the gas injection tube, extend the electrolyte injection tube into the first channel 51, and inject new electrolyte; after the injection is completed, remove the electrolyte injection tube; and seal the cap on the main body 47 of the liquid replacement component.

[0390] In addition to solving the problem of poor uniformity of individual cells in the existing battery module, the above-mentioned embodiments 7 to 9 also solve the problem of the large-capacity battery structure disclosed in Chinese patent CN219144456U.

[0391] Specifically, the large-capacity battery structure disclosed in Chinese patent CN219144456U is shown in Figure 37. It includes a battery pack body formed by several single cells connected in parallel, and a shared piping assembly located at the bottom of the battery pack body. The shared piping assembly is used to connect the internal cavities of the several single cells, so that all the single cells in the large-capacity battery are exposed to a single electrolyte system. The shared piping assembly can enhance the uniformity of the electrolyte in each single cell within the large-capacity battery, thereby improving cycle life. The shared piping assembly can also replenish the electrolyte in the large-capacity battery, extending the service life of the large-capacity battery and improving the safety of the large-capacity battery.

[0392] This type of shared pipeline assembly is formed by multiple sections of sub-pipes 01 and intermediate connecting pipes 02 that are directly sealed and plugged into each other through interference fit; at this time, the multiple sections of sub-pipes 01 are arranged one by one on the lower cover plate 03 of the single cell, and the sub-pipes extend along the arrangement direction of the single cell, and are extruded integrally with the lower cover plate 03 of the single cell, and are connected to the second through hole of the lower cover plate 03 of the single cell.

[0393] During assembly, the two ends of the sub-pipeline 01 are used as the connection ends to the middle connecting pipe 02. When two single cells are connected, one end of the sub-pipeline on the two single cells is squeezed into the two ends of the middle connecting pipe 02 respectively.

[0394] During the plugging process, the shared pipeline assembly requires that each sub-pipeline 01 and the intermediate connecting pipe 02 be coaxial to achieve effective connection. However, due to the following reasons, it is difficult to ensure the coaxiality of each sub-pipeline and the intermediate connecting pipe 02:

[0395] 1) The sub-pipeline and the lower cover are an integrated part. If the position of the sub-pipeline on the lower cover is slightly deviated, or the size of each sub-pipeline is slightly deviated, the coaxiality of each sub-pipeline will deviate when plugged in.

[0396] 2) When welding the above-mentioned integrated part to the cylinder, due to differences in the welding process, there may be inconsistencies in the positions of the sub-pipelines relative to the cylinder, which in turn leads to deviations in the coaxiality of the sub-pipelines when plugged in;

[0397] 3) This solution requires the use of special tooling during connection. Improper use of the tooling or operator errors can lead to deviations in the coaxiality of the sub-pipelines.

[0398] In addition, during plugging, the deviation between the sub-pipelines will increase as the number of plugging increases, resulting in the coaxiality between the sub-pipelines being more difficult to ensure as the number of plugging increases; resulting in the assembly process, the yield rate decreases as the number of plugging increases.

[0399] Because the sub-pipes of two adjacent single batteries are difficult to be coaxial, when plugging them in, the sub-pipes may be displaced relative to the lower cover, or the lower cover may be displaced relative to the cylinder, thereby causing battery damage.

Claims

1. A high-capacity battery, characterized in that: It includes a box body, N battery cells and electrolyte, where N≥2; the N battery cells are arranged in the box body, and the top of the box body has a total positive terminal and a total negative terminal; The box body is filled with electrolyte, and the N battery cells are under one electrolyte system.

2. The large-capacity battery according to claim 1, characterized in that: The box body includes a cylinder, and the battery cell includes a cover plate assembly and an electrode assembly; The upper end of the cylinder is open; The cover plate assemblies of the N battery cells are uniformly fixed to the open end of the cylinder along the first direction of the cylinder, thus forming a sealed box body; each cover plate assembly includes a plate body and a positive electrode column and a negative electrode column insulated and fixed on the plate body; The electrode assemblies of the N battery cells are uniformly arranged inside the sealed box body along the first direction of the cylinder. Above each electrode assembly, there is a corresponding cover plate assembly, and the positive electrode plate and the negative electrode plate of the electrode assembly are electrically connected to the positive electrode column and the negative electrode column on the cover plate assembly respectively; The positive electrode columns on each cover plate assembly are electrically connected to form a total positive terminal, and the negative electrode columns on each cover plate assembly are electrically connected to form a total negative terminal; the total positive terminal and the total negative terminal are in heat exchange with an external temperature control device through at least one heat transfer tube.

3. A large-capacity battery according to claim 1, characterized in that: The cylinder is provided with N - 1 first partition plates at intervals along the first direction, thus dividing the cylinder into N placement areas for the electrode assemblies, and the N placement areas communicate with each other.

4. The large-capacity battery according to claim 2, wherein: A flexible gasket is arranged in a circle near the four peripheral edges on the plate body of the cover plate assembly. The open end face of the placement area is a stepped surface. The first plane of the stepped surface is welded to the plate body, and the second plane of the stepped surface is matched with the flexible gasket; the first plane is above the second plane.

5. A large-capacity battery according to claim 2, characterized in that: Both the positive electrode column and the negative electrode column are provided with grooves or through holes for clamping the heat transfer tube.

6. The large-capacity battery according to claim 5, wherein: The heat transfer tube is an aluminum water-cooled tube, and insulation needs to be maintained between the aluminum water-cooled tube and the groove or between the aluminum water-cooled tube and the through hole.

7. A large-capacity battery according to claim 6, characterized in that: A pressure relief part is arranged on the sealed box body.

8. A large-capacity battery according to claim 7, characterized in that: A liquid injection and replacement interface is arranged on the sealed box body.

9. A large-capacity battery according to any one of claims 3 to 8, characterized in that: It also includes at least one second partition plate and an upper cover. The second partition plate is vertically installed in the cylinder. A chamber with an open upper end is formed between the second partition plate and the side wall of the cylinder, and this chamber communicates with the placement area. The open upper end of the chamber is sealed by the upper cover, and its interior is filled with electrolyte.

10. A large-capacity battery according to claim 9, characterized in that: Reinforcing ribs with a hollow structure are arranged on the side wall of the cylinder in the first direction and on the side wall in the second direction.

11. A method for manufacturing a large-capacity battery according to claim 1, characterized in that: It includes the following steps: Prepare the battery cells Connect the cover plate assembly and the electrode assembly into a battery cell by welding; Install the battery cells and form a sealed box body Put the N battery cells into the cylinder from the open end of the cylinder, and then seal and fix the cover plate assembly in each battery cell to the open end of the cylinder by welding. The cylinder and the N cover plate assemblies form a sealed box body; Install the heat transfer tube Match at least one heat transfer tube with the total positive terminal and the total negative terminal; Water removal Heat each electrode assembly with the heat transfer tube to reduce the water content in the electrode assembly; Assembly of the total positive terminal and the total negative terminal Electrically connect all the positive electrode columns to form a total positive terminal, and electrically connect all the negative electrode columns to form a total negative terminal; Liquid injection, formation, and aging.

12. A large-capacity battery according to claim 1, characterized in that: The box body includes a cylinder with an open top and an upper cover fixed to the open end of the cylinder; The upper cover is provided with 2N first through holes; The battery unit includes a cover plate assembly and an electrode assembly connected to the cover plate assembly; the cover plate assembly includes a plate body, a positive electrode column and a negative electrode column insulated and fixed on the plate body; N battery units are evenly arranged along the length direction of the cylinder body after being matched with the corresponding cover plate assemblies and the cylinder body respectively, and the positive electrode columns and negative electrode columns of each cover plate assembly extend out of the upper cover through the corresponding first through holes respectively; a seal needs to be maintained between each first through hole and the corresponding positive electrode column and negative electrode column; All the positive electrode columns are electrically connected to form a total positive terminal, and all the negative electrode columns are electrically connected to form a total negative terminal; the total positive terminal and the total negative terminal are in heat exchange with an external temperature control device through at least one heat transfer pipe.

13. A large-capacity battery according to claim 12, characterized in that: N - 1 first partition plates are arranged at intervals along the length direction of the cylinder body, so as to divide the cylinder body into N placement areas for battery units, and the N placement areas are communicated with each other.

14. A large-capacity battery according to claim 13, characterized in that: A flexible gasket is arranged in a circle near the four peripheral edges on the plate body of the cover plate assembly, and the open end of the placement area has a stepped surface structure, including a first plane, a second plane lower than the first plane, and a third plane lower than the second plane; the upper cover is welded to the first plane, the plate body of the cover plate assembly is spot welded and fixed to the second plane, and the flexible gasket is matched with the third plane.

15. A large-capacity battery according to claim 14, characterized in that: The peripheral area of each first through hole and the plate body of the corresponding cover plate assembly are fixed and sealed by laser welding.

16. A large-capacity battery according to claim 15, characterized in that: Both the positive electrode column and the negative electrode column are provided with grooves or through holes for clamping the heat transfer pipe.

17. A large-capacity battery according to claim 16, characterized in that: The heat transfer pipe is an aluminum water-cooled pipe, and insulation needs to be maintained between the aluminum water-cooled pipe and the groove or between the aluminum water-cooled pipe and the through hole.

18. A large-capacity battery according to claim 17, characterized in that: It further includes an explosion venting part and a liquid injection / liquid replacement interface installed on the box body.

19. A large-capacity battery according to any one of claims 13-18, characterized in that: It further includes at least one second partition plate, and an electrolyte storage chamber is formed among the second partition plate, the side wall of the cylinder body, and the upper cover, and the electrolyte storage chamber communicates with the placement area.

20. A large-capacity battery according to claim 19, characterized in that: Hollow - structured reinforcing ribs are arranged on the four side walls of the cylinder body.

21. A method for manufacturing the large-capacity battery according to claim 12, characterized in that: It includes the following steps: Prepare battery units Connect the cover plate assembly and the electrode assembly into a battery unit by welding; Install the upper cover and battery units Put N battery units into the cylinder body from the open end of the cylinder body, the N battery units are arranged in sequence along the first direction of the cylinder body, and the battery units are fixed by using the cover plate assemblies of the battery units and the cylinder body for matching; Place the upper cover on the N battery units, the positive electrode columns and negative electrode columns of each battery unit extend out of the upper cover through the corresponding first through holes, then fix and seal the upper cover and the open end of the cylinder body, and finally seal the gap between the first through hole and the corresponding positive electrode column and negative electrode column; Install heat transfer pipes Match at least one heat transfer pipe with the total positive terminal and the total negative terminal; Dehydration Heat each electrode assembly by using the heat transfer pipe to reduce the water content in the electrode assembly; Assembly of the total positive terminal and the total negative terminal Electrically connect all the positive electrode columns to form a total positive terminal, and electrically connect all the negative electrode columns to form a total negative terminal; Inject liquid, formation, and aging.

22. The manufacturing method of a large-capacity battery according to claim 21, wherein: The fixing method of the cover plate assembly of the battery unit and the open end of the cylinder body is spot welding.

23. The manufacturing method of a high-capacity battery according to claim 21, characterized in that: The upper cover is fixedly sealed to the open end of the cylinder body by welding.

24. The manufacturing method of a high-capacity battery according to claim 21, characterized in that: The specific way to keep the gaps between the first through-holes, the positive electrode posts, and the negative electrode posts sealed is as follows: The peripheral area of the first through-holes and the plate body of the corresponding cover plate assembly are fixed and sealed by laser welding.

25. A large-capacity battery according to claim 1, characterized in that: The box body includes a cylinder and an upper cover; The top of the cylinder is open, and a stepped surface is provided at the open end of the cylinder; the stepped surface includes a first plane and a second plane lower than the first plane; an interface is provided on the cylinder; There are 2N first through-holes on the upper cover; the upper cover is fitted with the first plane by means of screw connection and welding, and a flexible gasket is provided between the upper cover and the second plane; The battery unit is a single battery, and N single batteries are placed side by side in the box body. Each extends out of the corresponding first through-hole, and the gap between the first through-hole and the polar terminal of the single battery is filled with sealant; The N polar terminals on one side of each single battery are electrically connected to form the total positive terminal of the large-capacity battery, and the N polar terminals on the other side of each single battery are electrically connected to form the total negative terminal of the large-capacity battery; There are second through-holes at the bottoms of the outer casings of the N single batteries to ensure that the electrolyte areas of the single batteries communicate with each other.

26. A large-capacity battery according to claim 25, characterized in that: The polar terminal of the single battery includes the electrode post of the single battery and a transfer post welded to the top of the electrode post; an annular blind groove is provided along the axial direction of the transfer post.

27. A large-capacity battery according to claim 26, characterized in that: An annular protrusion is provided on the upper cover corresponding to the position of each first through-hole.

28. A large-capacity battery according to claim 27, characterized in that: It also includes a transfer block welded to the top of the transfer post, and a card slot for clamping a heat exchange tube is provided on the transfer block.

29. A large-capacity battery according to any one of claims 25 to 28, characterized in that: N - 1 partitions are provided at intervals along the length direction of the cylinder, so as to divide the cylinder into N placement areas for single batteries, and the N placement areas communicate with each other.

30. A large-capacity battery according to claim 29, characterized in that: On the inner surface of the bottom plate of the box body, there are two pads extending along the arrangement direction of the single batteries, and an electrolyte channel is formed between the two pads, and the electrolyte channel communicates with the electrolyte area of each single battery.

31. A large-capacity battery according to claim 30, characterized in that: The first plane includes a first area and a second area; a plurality of threaded holes are provided in the first area, and the second area is used as the area welded to the upper cover plate.

32. A manufacturing method of a large-capacity battery, characterized in that: It includes the following steps: Step 1: Capacity grading and sorting Perform capacity grading and sorting on several commercially available square aluminum lithium-ion batteries, and classify the commercially available square aluminum lithium-ion batteries into different grades according to the grade standard; Step 2: Battery unpacking Select N from the commercially available square aluminum lithium-ion batteries of the same grade, and under specific conditions, open second through-holes at the bottoms of the outer casings of the N commercially available square aluminum lithium-ion batteries; Step 3: Assemble the large-capacity battery Put the N commercially available square aluminum lithium-ion batteries with second through-holes formed into the cylinder; Place a flexible gasket on the second plane, and then fix the top plate to the open end of the cylinder by means of screw connection. This process ensures that the polar terminals of each square aluminum lithium-ion battery extend out of their respective corresponding first through-holes; Pour sealant at each first through-hole and its corresponding polar terminal; Weld the upper cover and the second plane at the open end of the cylinder by welding; Electrically connect the N polar terminals on one side of each single battery to form the total positive terminal of the large-capacity battery, and electrically connect the N polar terminals on the other side of each single battery to form the negative terminal of the large-capacity battery.

33. The manufacturing method of a large-capacity battery according to claim 32, characterized in that: It also includes the step of welding an adapter sleeve on the original terminal posts of each commercially available square aluminum lithium-ion battery after formation and sorting.

34. The manufacturing method of a large-capacity battery according to claim 33, characterized in that: It also includes step 4: welding an adapter block on the adapter sleeve and installing a heat exchange tube.

35. A large-capacity battery according to claim 1, characterized in that: The box body includes a shell with an open top, n partitions and m upper covers; where n and m are both integers greater than 1; The shell includes a cylindrical body and a lower cover, and the lower cover is provided with an electrolyte sharing chamber; The battery unit is a single battery; The n partitions are arranged in the same direction in the cylindrical body, dividing the inner cavity of the cylindrical body into n - 1 single battery accommodation cavities; at least one single battery is arranged in each single battery accommodation cavity; the electrolyte areas in the inner cavities of the respective single batteries communicate with the inner cavity of the electrolyte sharing chamber. The m upper covers are fixedly arranged at the open top ends of the respective single battery accommodation cavities one by one; first through holes are opened in the respective upper covers corresponding to the polarity terminals of the respective single batteries; the polarity terminals of the respective single batteries extend out of the first through holes, and the area of the upper cover corresponding to the first through hole is fixedly sealed with the single battery shell.

36. A large-capacity battery according to claim 35, characterized in that: One single battery is arranged in each single battery accommodation cavity.

37. A large-capacity battery according to claim 36, characterized in that: Openings penetrating adjacent single battery accommodation cavities are opened in the respective partitions; second through holes penetrating the gas areas in the inner cavities of the single batteries are opened in the single battery shells, and the gas areas of the single batteries in each single battery accommodation cavity communicate with each other through the second through holes and the openings.

38. A large-capacity battery according to claim 37, characterized in that: The second through holes are opened in the upper covers of the single batteries; in the height direction of the single batteries, there is a gap between the upper covers of the respective single batteries and the corresponding upper covers, and the openings and the gaps are directly connected.

39. A large-capacity battery according to claim 35, characterized in that: Step structures are provided on the inner walls at the open top ends of the respective single battery accommodation cavities; the respective upper covers are fixed on the step surfaces.

40. A large-capacity battery according to claim 35, characterized in that: The cylindrical body and the lower cover are separate parts, and the cylindrical body is formed by an aluminum extrusion process.

41. A large-capacity battery according to claim 40, characterized in that: The partitions and the cylindrical body are integral parts.

42. A large-capacity battery according to claim 35, characterized in that: The shell is provided with a liquid replenishing and replacing member for replenishing electrolyte into the electrolyte sharing chamber and the inner cavities of the respective single batteries, or replacing the electrolyte in the electrolyte sharing chamber and the inner cavities of the respective single batteries.

43. A large-capacity battery according to claim 42, characterized in that: The liquid replenishing and replacing member includes a liquid replenishing and replacing member main body, an electrolyte flow pipe section and a plugging member; The liquid replenishing and replacing member main body is fixed on the shell, and a first channel and a second channel communicating with the inner cavity of the shell are opened on the liquid replenishing and replacing member main body; the first channel and the second channel are isolated from each other, the first channel is used for communicating with the electrolyte area in the inner cavity of the shell, and the second channel is used for communicating with the gas area in the inner cavity of the shell; One end of the electrolyte flow pipe section is fixed on the liquid replenishing and replacing member main body and communicates with the first channel; the other end of the electrolyte flow pipe section communicates with the electrolyte sharing chamber in the inner cavity of the shell; The plugging member is used for plugging the first channel and the second channel from the outside of the shell.

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