A large capacity battery and an energy storage device

Abstract

The utility model discloses a kind of large capacity battery and energy storage device.The large capacity battery includes multiple single batteries placed side by side and heat exchange device;Heat exchange device includes two first hollow components, the large capacity battery of the utility model realizes the parallel connection of multiple single batteries by two first hollow components, and the flow-through passage of first hollow component as heat exchange medium, the heat concentrated on first hollow component can be taken out by heat exchange medium.In addition, since the first hollow component is directly connected with the positive pole column and negative pole column of single battery by welding mode, therefore, the heat concentrated on each single battery positive pole column and negative pole column can also be taken out by heat exchange medium.It can be seen from this that the heat exchange device of the utility model has electrical connection effect and heat exchange effect simultaneously, solves the technical problem that the temperature of single battery pole column and electrical connector in large capacity battery is increased, thereby affecting the cycle life of large capacity battery.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a high-capacity battery and an energy storage device. Background Technology

[0002] Currently, existing energy storage devices are constructed by connecting multiple high-capacity batteries (also known as battery packs, battery modules, or battery modules) in series using a busbar. The high-capacity battery is composed of multiple individual cells connected in parallel through electrical connectors.

[0003] Temperature control of energy storage devices has always been a hot topic of concern in this field. Since the terminals of individual cells in a large-capacity battery are the most concentrated part of heat, when the local heat of the terminals is too high, it will also cause the temperature of the electrical connectors connected to them to rise, affecting the cycle life of the large-capacity battery.

[0004] When the temperature of the electrical connection of a large-capacity battery in an energy storage device is too high, it will cause the temperature of the connected busbar to rise, affecting another large-capacity battery, and thus affecting the normal operation of the energy storage device. Utility Model Content

[0005] The first aspect of this utility model provides a high-capacity battery that solves the technical problem of temperature rise in electrical connectors in existing high-capacity batteries, which affects the cycle life of the high-capacity battery.

[0006] The high-capacity battery includes multiple individual cells placed side by side and a heat exchange device. The heat exchange device includes two first hollow components. One first hollow component is welded to the top surface of the positive electrode post of multiple individual cells to form the total positive electrode of the high-capacity battery. The other first hollow component is welded to the top surface of the negative electrode post of multiple individual cells to form the total negative electrode of the high-capacity battery, thereby realizing the parallel connection of multiple individual cells. The two first hollow components serve as flow channels for the heat exchange medium.

[0007] This invention relates to a high-capacity battery that achieves parallel connection of multiple individual cells through two first hollow components. The first hollow components serve as channels for the heat exchange medium, allowing heat concentrated on them to be carried away. Furthermore, because the first hollow components are directly welded to the positive and negative terminals of each individual cell, the heat concentrated on these terminals can also be carried away through the heat exchange medium. Therefore, this invention's heat exchange device simultaneously provides electrical connection and heat exchange, solving the technical problem of temperature rise in the individual cell terminals and electrical connectors, which affects the cycle life of high-capacity batteries.

[0008] Similarly, when the ambient temperature is too low, the temperature of each individual battery cell can be raised through the first hollow component and the heat exchange medium, so that the large-capacity battery can better adapt to working in low-temperature environments.

[0009] In addition, compared with the separate electrical connectors and heat exchange devices of existing large-capacity batteries, the structure of the large-capacity battery of this utility model is simpler and more compact; it is easier to assemble and has a lower cost.

[0010] Furthermore, the heat exchange device also includes a second hollow component, which is connected to one end of the two first hollow components located on the same side, and the second hollow component is insulated from the two first hollow components. The ends of the two first hollow components away from the second hollow component serve as the heat exchange medium inlet and heat exchange medium outlet, respectively.

[0011] This invention simplifies the connection between the heat exchange device and external equipment by connecting the two first hollow components through the second hollow component, making assembly easier and reducing costs to some extent.

[0012] Since the first hollow component and each individual battery terminal are connected by welding, this utility model provides the following two specific forms of the first hollow component:

[0013] Form 1: The first hollow component is long and has a split structure, including a cover plate and a slender tube with an open top; the bottom of the slender tube is used to weld to the top surface of multiple individual battery terminals, and the cover plate is fixedly sealed to the open top end of the slender tube.

[0014] Form 2: The first hollow component is long and strip-shaped, and is an integral structure, including a slender tube and folded edges; there are two folded edges, which are fixed to the bottom two sides of the slender tube respectively. The bottom of the slender tube is used to contact the top surface of multiple individual battery terminals, and the folded edges are used to weld to the top surface of multiple individual battery terminals.

[0015] Furthermore, since large-capacity batteries may experience thermal runaway, to prevent accidents that may occur if a single cell in a large-capacity battery explodes during thermal runaway; and to facilitate the connection between the heat exchange device and the terminals of each single cell, as well as the connection between the heat exchange device and the external heat exchange medium source, the large-capacity battery of this invention also includes a housing. The top of the housing is provided with a terminal clearance hole, and multiple single cells are located inside the housing. Each single cell terminal extends out of its corresponding terminal clearance hole, and the top area of ​​the housing corresponding to the terminal clearance hole is fixedly sealed to the top cover of the single cell.

[0016] Furthermore, each individual cell has a first through-hole at its bottom, and an insulating pad is provided on the inner wall of the bottom of the outer casing and at the bottom of each individual cell. The insulating pad has elongated holes, and the area of ​​these elongated holes projected onto the bottom of multiple individual cells covers the first through-hole at the bottom of each individual cell, thus ensuring that the electrolyte zones within each individual cell are connected through the elongated holes. Due to the presence of the first through-hole and the elongated holes at the bottom of each individual cell, the electrolyte zones of each individual cell are interconnected, placing each individual cell within a unified electrolyte system, thereby improving the consistency of the individual cells in a large-capacity battery.

[0017] Furthermore, the outer casing includes a cylindrical body with an open top and a top cover sealed and fixed to the open top; the top cover is provided with a gas balance channel covering the second through hole on the top of each individual battery cell.

[0018] The second aspect of this utility model provides an energy storage device, including a busbar and multiple high-capacity batteries as described in the first aspect; the multiple high-capacity batteries are placed side by side, and the positive and negative terminals of adjacent high-capacity batteries are connected in series through the busbar. Since the positive and negative terminals of the high-capacity batteries not only have the electrical connection function of connecting multiple individual batteries in parallel, but also have their own heat exchange function, the busbar will not experience a temperature rise problem, and the energy storage device will not be affected by the temperature rise of the busbar during operation.

[0019] The beneficial effects of this utility model are:

[0020] This invention uses a first hollow component with a heat exchange medium flow channel as an electrical connector for parallel connection of individual cells in a large-capacity battery. The heat concentrated on the terminals of each individual cell and the electrical connector can be carried away through the heat exchange medium, solving the technical problem that the temperature rise of the terminals of the individual cells and the electrical connector affects the cycle life of the large-capacity battery, and improving the performance of the large-capacity battery.

[0021] At the same time, this invention also reduces the probability of thermal runaway in large-capacity batteries due to excessively high temperatures to a certain extent, thus improving the safety of large-capacity batteries. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the large-capacity battery in Example 1;

[0023] Figure 2 This is a schematic diagram of the heat exchange device.

[0024] Figure 3 This is a sectional view of the first hollow component, type one;

[0025] Figure 4 This is a sectional view of the first hollow component, type one;

[0026] Figure 5 This is a schematic diagram of the structure of the large-capacity battery in Example 2;

[0027] Figure 6 This is a schematic diagram of the structure of the large-capacity battery in Example 3;

[0028] Figure 7 This is a cross-sectional view of the high-capacity battery in Example 3;

[0029] Figure 8 This is a schematic diagram of the insulating pad structure;

[0030] The attached figures are labeled as follows:

[0031] 1-Single cell, 11-First through hole, 12-Second through hole, 2-Heat exchange device, 21-First hollow component, 211-Cover plate, 212-Slender tube, 213-Folded edge, 22-Second hollow component, 3-Shell, 31-Electrode post clearance hole, 32-Top cover, 33-Cylinder, 4-Electrolyte sharing channel, 5-Gas balance channel, 6-Insulating pad, 61-Elongated hole. Detailed Implementation

[0032] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0033] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] In the description of this utility model, it should be noted that the terms "top," "bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] The basic design concept of this utility model is:

[0036] By designing the electrical connectors that connect the individual cells in a large-capacity battery as hollow structures, and using the interior of the hollow structure as a heat exchange medium flow channel, this invention not only solves the problem of self-heating by using the electrical connectors themselves as heat exchange devices, but also cools down the terminals of each individual cell in a timely manner, thus solving the problems existing in current large-capacity batteries.

[0037] In this invention, the so-called single battery can be a square lithium battery (i.e., the positive and negative terminals are located on the top cover of the battery) or a cylindrical lithium battery (i.e., the positive terminal is located on the top cover of the battery and the negative terminal is located on the bottom cover of the battery).

[0038] Hollow structures need to have good electrical and thermal conductivity, and also need to be more securely connected to the individual battery terminals. Therefore, hollow structures are made of metal materials, such as aluminum or copper. However, considering both cost and thermal and electrical conductivity, aluminum is generally chosen as the material for this type of hollow structure.

[0039] In this invention, the heat exchange medium is an insulating medium, such as fluorinated liquid, ethylene glycol aqueous solution, and insulating transformer oil, etc.

[0040] Example 1

[0041] like Figure 1 As shown, this embodiment provides a high-capacity battery, including six individual cells 1 and a heat exchange device 2;

[0042] Six individual cells 1 are arranged along the x-direction; wherein, the positive terminals of the six individual cells 1 are located in a straight line, and the negative terminals of the six individual cells 1 are located in a straight line;

[0043] The heat exchange device 2 includes two first hollow components 21. One first hollow component 21 is welded to the top surface of the positive electrode post of multiple individual cells 1 to form the total positive electrode of the large-capacity battery. The other first hollow component 21 is welded to the top surface of the negative electrode post of multiple individual cells 1 to form the total negative electrode of the large-capacity battery, thereby realizing the parallel connection of multiple individual cells. The two first hollow components 21 also serve as the flow channel for the heat exchange medium.

[0044] In this embodiment, the two first hollow components 21 are connected by a second hollow component 22. Specifically, the second hollow component 22 is connected to one end of the two first hollow components 21 on the same side, and the second hollow component 22 is insulated from the two first hollow components 21. The ends of the two first hollow components 21 away from the second hollow component 22 serve as the heat exchange medium inlet and heat exchange medium outlet, respectively. In use, an external heat exchange medium source is used, which is connected to the heat exchange medium and heat exchange medium outlet on the same side, forming a closed heat exchange medium circulation system, thereby achieving cooling or heating of the electrical connectors and individual battery terminals in the large-capacity battery.

[0045] It should be noted here that the insulation between the second hollow component 22 and the two first hollow components 21 can be achieved in the following two ways:

[0046] 1. The second hollow component 22 is made of insulating material and is connected by means of bonding or threaded connection;

[0047] 2. The second hollow component 22 and the first hollow component 21 are connected by an insulated and sealed joint.

[0048] In some other embodiments, the second hollow component 22 is not required, and the two first hollow components 21 operate independently. That is, the two ends of each first hollow component 21 serve as the heat exchange medium inlet and the heat exchange medium outlet, respectively.

[0049] The heat exchange medium inlet and outlet are typically insulated quick-connect fittings for quick connection to external pipelines or external heat exchange medium sources.

[0050] The first hollow component 21 and each individual battery 1 are connected by welding. Therefore, this utility model provides the following two specific forms of the first hollow component 21:

[0051] Form 1: The first hollow component 21 is elongated and has a split structure, including a cover plate 211 and a slender tube 212 with an open top. The bottom of the slender tube 212 is used for welding to the top surfaces of multiple individual battery terminals 1, and the cover plate 211 is fixedly sealed to the open top end of the slender tube 212. During installation, the bottom of the slender tube 212 is first brought into contact with the top surface of each individual battery terminal 1, and then the slender tube 212 is connected to each individual battery terminal 1 by fusion welding. Finally, the cover plate 211 is fixed to the open end of the slender tube 212 by welding. To ensure that the first hollow tube 21 has good thermal and electrical conductivity, it is necessary to ensure that the width of the slender tube is equal to or slightly larger than the diameter of the terminal.

[0052] Form Two: The first hollow component 21 is elongated and integrally structured, comprising a slender tube 212 and flanges 213. Two flanges 213 are fixed to the bottom sides of the slender tube 212. The bottom of the slender tube 212 contacts the top surfaces of multiple individual battery terminals 1, and the flanges 213 are used for welding to the top surfaces of multiple individual battery terminals 1. During installation, the bottom of the slender tube 212 and the flanges 213 are first brought into contact with the top surface of each individual battery terminal 1, and then the flanges 213 on both sides are connected to each individual battery terminal 1 by fusion welding. To ensure that the first hollow tube 211 has good thermal and electrical conductivity, the width of the slender tube 212 plus the flanges 213 must be equal to or slightly larger than the diameter of the terminal.

[0053] In Form 1, the slender tube 212 of the first hollow component 21 is in full contact with the terminals of each individual battery 1 and can be fused together by welding, resulting in good thermal and electrical conductivity. However, the assembly process of the first hollow component 21 with multiple individual batteries 1 is relatively complex. If there are many individual batteries 1, the welding cost of the cover plate 211 and the open end of the slender tube 212 is high. In Form 2, the assembly process of the first hollow component 21 with multiple individual batteries 1 is relatively simple and the processing cost is low. However, the bottom of the slender tube 212 and the top surface of each individual battery terminal can only contact each other and cannot be fused together by welding, resulting in relatively poor thermal and electrical conductivity.

[0054] Example 2

[0055] like Figure 1 As shown, this embodiment provides a high-capacity battery. The difference from embodiment 1 is that a casing 3 is added in this embodiment.

[0056] Six individual battery cells 1 are arranged along the x-direction and located inside the outer casing 3. The top of the outer casing 3 is provided with a terminal clearance hole 31. Each terminal cell 1's terminal extends out of its corresponding terminal clearance hole 31, and the top area of ​​the outer casing 3 corresponding to the terminal clearance hole 31 is fixedly sealed to the top cover of the individual battery cell 1. Among them, the positive terminals of the six individual battery cells 1 extend out of their respective corresponding terminal clearance holes 31 and are arranged in a straight line. The top surface of each positive terminal cell 1 is welded to a first hollow component 21. The negative terminals of the six individual battery cells 1 extend out of their respective corresponding terminal clearance holes 31 and are arranged in a straight line. The top surface of each negative terminal cell 1 is welded to another first hollow component 21.

[0057] Compared with Example 1, this example adds a casing 3 to improve the safety of the large-capacity battery. Firstly, under the protection of the casing 3, the large-capacity battery can avoid being directly bumped and damaged during transportation, which could cause accidents such as leakage. Secondly, under the protection of the casing 3, even if a single cell 1 in the large-capacity battery experiences thermal runaway, the casing can act as a barrier to prevent the single cell casing from rupturing and causing a more serious thermal runaway accident.

[0058] In this embodiment, the outer casing 3 includes a top cover 32 and a cylindrical body 33 with an open top, which are constructed by welding; in some other embodiments, the outer casing 3 includes end caps and cylindrical bodies with open front and rear ends.

[0059] Example 3

[0060] This embodiment provides a high-capacity battery. The difference from embodiment 2 is that this embodiment adds an electrolyte sharing channel 4 and a gas balance channel 5 on the basis of embodiment 2.

[0061] The specific improvement in this embodiment is:

[0062] Each individual battery cell 1 has a first through hole 11 at its bottom. An insulating pad 6 (the area of ​​the insulating pad is equivalent to the size of the bottom of the outer casing) is provided on the inner wall of the bottom of the outer casing 3 and the bottom of each individual battery cell 1. An elongated hole 61 is provided on the insulating pad 6, and the area of ​​the elongated hole 61 projected onto the bottom of each individual battery cell 1 covers the first through hole 31 at the bottom of each individual battery cell. This ensures that the electrolyte areas in each individual battery cell 1 are connected through the elongated hole 61. The elongated hole 61 can serve as an electrolyte sharing channel 4. The electrolyte sharing channel 4 can ensure the consistency of each individual battery cell, that is, connect the electrolyte chambers of each individual battery cell, so that the electrolyte of all individual batteries cells is in the same system, reducing the difference between the electrolytes of each individual battery cell, and improving the cycle life of the large-capacity battery to a certain extent.

[0063] In some other embodiments, there can be multiple insulating pads 6, with each pair of insulating pads 6 located between the bottom of a single cell and the bottom of the casing 3 and distributed on both sides of the first through hole 11. There is a gap between the two insulating pads, and the multiple gaps form a shared electrolyte channel.

[0064] In this embodiment, a second through hole 12 is also provided on the top of each individual battery cell. A protrusion covering all the second through holes 12 is provided on the top cover of the outer casing 3 as a gas balance channel 5 to ensure that the gas pressure inside each individual battery cell 1 is always in a basically the same state, thus avoiding the expansion caused by excessive internal pressure of individual individual battery cells 1, which affects the performance of the large-capacity battery.

[0065] Example 4

[0066] This embodiment provides an energy storage device, including at least two high-capacity batteries as described in embodiments 1 to 3 above, and a busbar. Multiple high-capacity batteries are placed side-by-side, and the positive and negative terminals of adjacent high-capacity batteries are connected in series via a busbar. Since the positive and negative terminals of the high-capacity batteries not only provide electrical connection for connecting multiple individual batteries in parallel but also have their own heat exchange function, the busbar will not experience a temperature rise issue, and the energy storage device will not be affected by the busbar's temperature increase during operation.

Claims

1. A high-capacity battery, characterized in that, It includes multiple single-cell batteries placed side by side and a heat exchange device; the heat exchange device includes two first hollow components, one of which is welded to the top surface of the positive electrode post of multiple single-cell batteries to form the total positive of the large-capacity battery, and the other of which is welded to the top surface of the negative electrode post of multiple single-cell batteries to form the total negative of the large-capacity battery, thereby realizing the parallel connection of multiple single-cell batteries, and the two first hollow components serve as the flow channel for the heat exchange medium.

2. A high-capacity battery according to claim 1, characterized in that, The heat exchange device also includes a second hollow component, which is connected to one end of the two first hollow components located on the same side, and the second hollow component is insulated from the two first hollow components. The ends of the two first hollow components away from the second hollow component serve as the heat exchange medium inlet and heat exchange medium outlet, respectively.

3. A high-capacity battery according to claim 1 or 2, characterized in that, The first hollow component is long and has a split structure, including a cover plate and a slender tube with an open top; the bottom of the slender tube is used to weld to the top surface of multiple individual battery terminals, and the cover plate is fixedly sealed to the open top end of the slender tube.

4. A high-capacity battery according to claim 1 or 2, characterized in that, The first hollow component is long and has an integral structure, including a slender tube and folded edges; there are two folded edges, which are fixed to the bottom sides of the slender tube respectively. The bottom of the slender tube is used to contact the top surface of multiple individual battery terminals, and the folded edges are used to weld to the top surface of multiple individual battery terminals.

5. A high-capacity battery according to claim 1, characterized in that, It also includes a housing, the top of which is provided with a terminal clearance hole. Multiple individual cells are located inside the housing, with each individual cell's terminal extending out of its corresponding terminal clearance hole, and the top area of ​​the housing corresponding to the terminal clearance hole is fixedly sealed to the top cover of the individual cell.

6. A high-capacity battery according to claim 5, characterized in that, Each individual cell has a first through hole at its bottom. An insulating pad is provided on the inner wall of the bottom of the outer casing and at the bottom of each individual cell. An elongated hole is provided on the insulating pad, and the area of ​​the elongated hole projected onto the bottom of multiple individual cells covers the second first through hole at the bottom of each individual cell, thereby ensuring that the electrolyte areas in each individual cell are connected through the elongated hole.

7. A high-capacity battery according to claim 6, characterized in that, The outer casing includes a cylindrical body with an open top and a top cover that is sealed and fixed to the open top; the top cover is provided with a gas balance channel covering the second through hole on the top of each individual battery cell.

8. An energy storage device, comprising a busbar and a plurality of high-capacity batteries as described in any one of claims 1 to 7; the plurality of high-capacity batteries are arranged side by side, and the total positive and total negative of adjacent high-capacity batteries are connected in series through the busbar.

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