High-capacity battery

Abstract

The utility model provides a high-capacity battery, which mainly solves the problem of potential safety hazards caused by combustion during thermal runaway of the existing battery. The high-capacity battery comprises a shell and a plurality of single batteries arranged in the shell along the same direction, a shared chamber is arranged in the shell, and the inner cavity of the shared chamber is communicated with the inner cavities of all the single batteries; the system further comprises at least one flame-retardant device arranged in the sharing cavity, and the flame-retardant device comprises a flame-retardant shell and a flame-retardant fire extinguishing substance in the flame-retardant shell. The flame-retardant shell is provided with the first weak area, the first weak area is opened at the set temperature or the set pressure, and the flame-retardant fire extinguishing substance in the flame-retardant shell enters the shell through the first weak area, so that the combustion of the high-capacity battery is avoided, and the safety of the high-capacity battery in use is improved.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and in particular relates to a large-capacity battery. Background Art

[0002] Lithium-ion batteries have many advantages, such as high packaging reliability, high energy efficiency, simple structure, and relatively convenient expansion. Multiple lithium-ion batteries can be connected in parallel to form a large-capacity battery, and then the large-capacity batteries can be used in series and parallel in many fields such as energy storage and power batteries. However, after lithium-ion batteries are connected in parallel to form a large-capacity battery, it is necessary to ensure that they have stable electrical performance and high safety.

[0003] Due to the principles and structural characteristics of lithium-ion batteries, a lot of heat will be generated during the charging and discharging process, and the heat will gradually increase. Under the influence of factors such as overcharging, over-discharging, overheating, and mechanical collision, the battery diaphragm will collapse and internal short circuit will occur, leading to thermal runaway, which may eventually cause fire and combustion inside the battery, posing a safety hazard. Summary of the invention

[0004] The utility model provides a large-capacity battery, which mainly solves the problem of combustion and potential safety hazards caused by thermal runaway of existing batteries.

[0005] In order to solve the above problems, the technical solution provided by the utility model is:

[0006] A large-capacity battery comprises an outer shell and a plurality of single cells arranged in the outer shell in the same direction; a shared chamber is arranged in the outer shell, and the inner cavity of the shared chamber is connected to the inner cavities of all the single cells; the battery is special in that it also comprises at least one flame retardant device arranged in the shared chamber, the flame retardant device comprises a flame retardant shell and a flame retardant fire extinguishing substance in the flame retardant shell; a first weak area is arranged on the flame retardant shell, and the first weak area is opened at a set temperature or a set pressure, and the flame retardant fire extinguishing substance in the flame retardant shell enters the outer shell through the first weak area.

[0007] Furthermore, the shared chamber comprises a gas shared chamber, and the flame retardant and fire extinguishing material of the flame retardant device in the gas shared chamber is a flame retardant and fire extinguishing gas.

[0008] Furthermore, the shared chamber comprises an electrolyte shared chamber, the flame retardant and fire extinguishing substance of the flame retardant device in the electrolyte shared chamber is a liquid flame retardant and fire extinguishing agent, and the first weak zone of the flame retardant shell opens at a set temperature.

[0009] Furthermore, the shared chamber includes a gas shared chamber and an electrolyte shared chamber, and both the gas shared chamber and the electrolyte shared chamber are provided with flame retardant devices, the flame retardant and fire extinguishing material of the flame retardant device in the gas shared chamber is a flame retardant and fire extinguishing gas, and the flame retardant and fire extinguishing material of the flame retardant device in the electrolyte shared chamber is a liquid flame retardant and fire extinguishing agent.

[0010] Furthermore, the flame-retardant shell in the gas sharing chamber includes an inner tube and an outer tube, the outer tube is provided with a first weak area, the inner tube is located inside the outer tube, and the inner tube has a second weak area, the temperature or pressure at which the second weak area is opened is lower than the temperature or pressure at which the first weak area is opened; the inner tube has a first reaction medium, the outer tube has a second reaction medium, the second weak area is opened, the first reaction medium and the second reaction medium contact and react to generate a flame-retardant fire-extinguishing gas, and the flame-retardant fire-extinguishing gas enters the outer shell through the first weak area.

[0011] Furthermore, the flame retardant fire extinguishing gas is carbon dioxide, the first reaction medium is water, the second reaction medium is sodium bicarbonate and aluminum sulfate solid, the second weak zone of the inner tube is located at the end of the inner tube, and the first weak zone of the outer tube is located at the top of the outer tube.

[0012] Furthermore, the flame retardant and fire extinguishing substance in the electrolyte sharing chamber is a fluorinated liquid, and the first weak area is located at the bottom of the flame retardant shell.

[0013] Furthermore, avoidance holes are provided on the top plate of the shell corresponding to the polarity terminals of each single cell; each single cell polarity terminal extends out of the avoidance hole, and the top plate area of ​​the shell corresponding to the avoidance hole is fixedly sealed with the single cell shell, and a clamping portion is provided at the position where each single cell polarity terminal extends out of the avoidance hole, and a heat transfer tube is fixed on the clamping portion of each single cell polarity terminal, and the heat transfer tube is insulated from each single cell polarity terminal, and the clamping portion is a through groove or through hole provided on each single cell polarity terminal, and the heat transfer tube is a metal tube, and the metal tube has at least one of an insulating layer and an insulating sleeve.

[0014] Furthermore, an insulating sealant layer is laid on the top plate of the shell, and the liquid inlet end and the liquid outlet end of the heat transfer tube extend out of the insulating sealant layer.

[0015] Furthermore, an insulating protective cover is provided on the top of the shell, and polarity terminals of each single battery are located inside the insulating protective cover.

[0016] Compared with the prior art, the beneficial effects of the technical solution of the utility model are:

[0017] 1. A flame retardant device is provided in the shared chamber of the large-capacity battery of the utility model. A first weak area is provided on the flame retardant shell of the flame retardant device. The first weak area is opened at a set temperature or a set pressure, and the flame retardant and fire extinguishing material in the flame retardant shell enters the outer shell through the first weak area, thereby preventing the large-capacity battery from burning and improving the safety of the large-capacity battery when in use.

[0018] 2. In the large-capacity battery of the utility model, the shared chamber includes a gas shared chamber, and the flame retardant and fire extinguishing material in the flame retardant device is a flame retardant and fire extinguishing gas, which can not only reduce the concentration of combustible gas in the large-capacity battery casing and avoid combustion in the casing, but also reduce the concentration of combustibles in the thermal runaway smoke discharged outside the casing after the flame retardant and fire extinguishing gas are mixed and discharged, thereby avoiding combustion or explosion of thermal runaway smoke outside the casing, and further improving the safety of large-capacity batteries when in use.

[0019] 3. In the large-capacity battery of the utility model, the shared chamber includes an electrolyte shared chamber, and the flame retardant and fire extinguishing material of the flame retardant device in the electrolyte shared chamber is a liquid flame retardant and fire extinguishing agent, which is mixed with the electrolyte to avoid combustion of the electrolyte as much as possible.

[0020] 4. In the large-capacity battery of the utility model, the shared chamber includes a gas sharing chamber and an electrolyte sharing chamber. The flame retardant and fire extinguishing material flowing out of the flame retardant device in the gas sharing chamber is a flame retardant and fire extinguishing gas, which is convenient for fully mixing with the combustible gas in the large-capacity battery to avoid combustion of the combustible gas. At the same time, the flame retardant and fire extinguishing material in the flame retardant device in the electrolyte sharing chamber is a liquid flame retardant and fire extinguishing agent, which is mixed with the electrolyte to avoid combustion of the electrolyte as much as possible.

[0021] 5. In the utility model large-capacity battery, the first reaction medium is a liquid medium, and the second reaction medium is a solid medium. This arrangement not only enables the first reaction medium and the second reaction medium to react quickly after contact to produce a flame retardant and fire extinguishing gas, but also facilitates the filling and storage of the first reaction medium and the second reaction medium. At the same time, the flame retardant and fire extinguishing gas uses carbon dioxide, which is easy to make and has a good flame retardant effect. The carbon dioxide is obtained by reacting water, sodium bicarbonate and aluminum sulfate solids that are easy to fill.

[0022] 6. In the large-capacity battery of the utility model, the first weak area is arranged at the top of the outer tube so that the flame retardant and fire extinguishing gas can be discharged in time and smoothly. At the same time, the second weak area is installed at the end of the inner tube so that the first reaction medium can flow out in time, contact with the second reaction medium, and react quickly to produce the flame retardant and fire extinguishing gas.

[0023] 7. In the large-capacity battery of the utility model, a clamping part is provided at the polarity terminal of each single cell, and the heat transfer tube is fixed by the clamping part so that the heat transfer tube is in direct contact with the polarity terminal of the single cell, and the heat of the polarity terminal where the heat is most concentrated is transferred to the outside for processing. This heat dissipation method realizes balanced heat dissipation of the top of the large-capacity battery, especially the polarity terminal, and avoids performance problems and safety problems caused by excessively high or low temperature of the large-capacity battery. The clamping part is a through groove or through hole opened on the polarity terminal of each single cell, and the heat transfer tube is arranged in the through groove or through hole, and is in direct contact with the polarity terminal of each single cell, so that the heat transfer tube and the polarity terminal have a larger contact area, further improving the heat exchange efficiency.

[0024] 8. In the large-capacity battery of the utility model, an insulating layer and an insulating sleeve are provided on the heat transfer tube, so that when the heat transfer tube exchanges heat with each single battery, reliable insulation performance can be maintained, thereby improving the safety of the heat transfer tube and the large-capacity battery during use.

[0025] 9. In the large-capacity battery of the utility model, an insulating sealant layer is laid on the top plate of the shell. When condensation occurs on the surface of the heat transfer tube on the polarity terminal, the condensation cannot penetrate into the gap between the polarity terminal and the avoidance hole due to the blocking of the insulating sealant layer, thereby preventing the battery from short-circuiting.

[0026] 10. In the large-capacity battery of the utility model, an insulating protective cover is used to provide insulation protection for the polarity terminals, thereby avoiding the potential safety hazards of the polarity terminals being exposed during the operation of the large-capacity battery, and also avoiding the problem of some foreign objects in the external environment falling into the polarity terminal position causing a short circuit in the large-capacity battery, thereby improving the safety of the large-capacity battery.

[0027] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of a large-capacity battery (polarity terminals are poles) in Example 1;

[0029] Figure 2 An exploded view of a large-capacity battery (polarity terminals are poles and pole adapters) in Example 1;

[0030] Figure 3 The structure of the flame retardant device in Example 1 is schematically shown;

[0031] Figure 4 is a cross-sectional view of the flame retardant device in Example 2;

[0032] Figure 5 This is a schematic diagram of the structure of a large-capacity battery in Example 4;

[0033] Figure 6 This is a schematic diagram of the structure of a large-capacity battery (with an insulating sealant layer) in Example 5;

[0034] Figure 7 Schematic diagram of the structure of a large-capacity battery (with an insulating protective cover) in Example 5.

[0035] Figure markings: 1-large capacity battery, 2-flame retardant device, 3-heat transfer tube, 11-housing, 12-single battery, 13-polarity terminal, 14-insulating sealant layer, 15-insulating protective cover, 16-explosion venting part, 17-first electrical connector, 18-second electrical connector, 111-gas sharing chamber, 112-electrolyte sharing chamber, 131-clamping part, 21-flame retardant shell, 22-first weak area, 23-second weak area, 211-inner tube, 212-outer tube, 31-first tube, 32-second tube, 33-connecting tube. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0037] The "other embodiments" that appear in different places in this specification do not all refer to the same embodiment, nor are they separate or selective embodiments that are mutually exclusive with other embodiments. In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of this utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited.

[0038] In the description of this specification, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0039] At the same time, in the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom, inside and outside" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] Research shows that when a lithium-ion battery experiences thermal runaway, a series of chemical reactions will occur inside, releasing a large amount of heat and gas, such as: SEI film decomposition reaction (90-120°C), cathode and electrolyte reaction (100-350°C), electrolyte decomposition reaction (110-300°C), diaphragm shrinkage and melting reaction (>130°C), cathode and electrolyte reaction (200-300°C), and binder decomposition reaction (200-300°C), etc. The above reactions do not occur in a fixed order, nor do they proceed independently.

[0041] When the battery temperature is around 90-120℃, first, the SEI film decomposes, releasing heat and producing gases such as C2H4, CO2 and O2. As the temperature continues to rise, when the battery temperature is around 120℃, the negative electrode surface has lost the protection of the SEI film, and the embedded lithium reacts with the electrolyte organic solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) to produce C x H y Gas. When the temperature is 110-300°C, the electrolyte and the electrolyte itself will also undergo a series of decomposition reactions to produce some fluorides. As the temperature continues to rise, the positive electrode material begins to decompose and produce O2. The O2 produced by the decomposition of the positive electrode material reacts with the solvent of the electrolyte: when the O2 concentration is high, the reaction produces CO2, and when the O2 concentration is low, the reaction produces CO. When the battery temperature exceeds 235°C, the binder polyvinylidene fluoride (PVDF) will react with lithium and self-decompose.

[0042] From the above process, it can be seen that when the battery thermal runaway occurs, the thermal runaway smoke mainly includes the following components: vaporized electrolyte, CO2, CO, H2, C x H y , C x H y O z , C x H y F, POF3 and HF, etc. Among the above gases, electrolyte, CO, H2, C x H y , C x H y O z , Cx H y F, POF3 and HF are all combustible substances, and the combustible gas accounts for a considerable proportion. The combustible substances are prone to combustion or explosion, causing safety hazards.

[0043] Example 1

[0044] like Figure 1 and Figure 2 As shown, the large-capacity battery 1 in this embodiment includes a shell 11 and a plurality of single cells 12 arranged in the same direction and placed in the shell 11. The single cells 12 in this embodiment are square shell batteries, and the number can be adjusted according to actual needs. The inner cavity of each single cell 12 includes an electrolyte area and a gas area. After the multiple single cells 12 are arranged in the same direction and placed in the shell 11, avoidance holes are opened on the top plate of the shell 11 corresponding to the polarity terminals 13 of each single cell 12, and the polarity terminals 13 of each single cell 12 extend out of the corresponding avoidance holes as the polarity terminals 13 of the large-capacity battery 1 (the polarity terminals 13 of all single cells 12 on one side serve as the positive polarity terminals of the large-capacity battery 1, and the polarity terminals 13 of all single cells 12 on the other side serve as the negative polarity terminals of the large-capacity battery 1), and the top plate area of ​​the shell 11 corresponding to the avoidance hole is fixedly sealed with the shell of the single cell 12.

[0045] It should be noted that the polarity terminal 13 of the single cell 12 here can be a pole of the single cell 12, such as Figure 1 In order to prevent the pole of the single battery 12 from being able to smoothly extend out of the avoidance hole as the polarity terminal 13, a pole adapter can be connected to the pole of the single battery 12, and the overall structure of the pole of the single battery 12 and the pole adapter can be used as the polarity terminal 13 of the single battery 12, as shown. Figure 2 shown.

[0046] The shared chamber in this embodiment is an electrolyte shared chamber 112, the inner cavity of the electrolyte shared chamber 112 is connected to the electrolyte area of ​​the inner cavity of all the single cells 12, and the electrolyte shared chamber 112 can make each single cell 12 in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single cell 12, and improving the performance and charge-discharge cycle life of the large-capacity battery 1. The electrolyte shared chamber 112 in this embodiment is a liquid channel arranged between the bottom plate of the shell 11 and the bottom of each single cell 12.

[0047] like Figure 3As shown, at least one flame retardant device 2 is provided in the electrolyte sharing chamber 112, and the flame retardant device 2 includes a flame retardant shell 21 and a flame retardant fire extinguishing substance arranged in the flame retardant shell 21. The flame retardant shell 21 is specifically a slender tubular structure, which is generally made of high temperature resistant flame retardant material. At least one first weak area 22 is provided on the flame retardant shell 21, and the first weak area 22 is opened at a set temperature to allow the flame retardant fire extinguishing substance in the flame retardant shell 21 to enter the outer shell 11 through the first weak area 22, thereby avoiding combustion of the large-capacity battery 1 and improving the safety of the large-capacity battery 1 during use.

[0048] The first weak area 22 can be realized by various structures, as long as it can be opened at a set temperature or a set pressure. The first weak area 22 is a plastic film arranged on the opening of the flame retardant shell 21. The plastic film is made of a material that melts or melts at a set temperature. For example, when the temperature inside the shell reaches 150°C, the plastic film melts or melts. When specifically arranged, Figure 2 and Figure 3 As shown, an outward protrusion is provided on the flame-retardant housing 21 , and a sealing film or a plastic film is mounted on the protrusion.

[0049] like Figure 3 As shown, the flame retardant fire extinguishing material in the flame retardant shell 21 can be a liquid flame retardant fire extinguishing agent, such as a fluorinated liquid, etc. At this time, the flame retardant shell 21 is a closed elongated tube structure, and the liquid flame retardant fire extinguishing agent is filled inside the elongated tube structure. At the same time, the first weak area 22 on the flame retardant shell 21 is set at the bottom of the flame retardant shell 21. When the first weak area 22 is opened, the liquid flame retardant fire extinguishing agent flows out of the flame retardant shell 21 to prevent the large-capacity battery 1 from burning.

[0050] Example 2

[0051] The structure of the large-capacity battery 1 in this embodiment is similar to that in embodiment 1. The difference from embodiment 1 is that the shared chamber in this embodiment includes a gas shared chamber 111, such as Figure 2 As shown, the inner cavity of the gas sharing chamber 111 is connected to the gas area of ​​the inner cavity of all the single cells 12, and the gas balance of each single cell 12 is achieved through the gas sharing chamber 111, which can also improve the performance and charge-discharge cycle life of the large-capacity battery 1. In this embodiment, the gas sharing chamber 111 is a gas channel arranged on the top plate of the shell 11. At this time, the top plate of the shell 11 is provided with a protrusion extending along the arrangement direction of the single cells 12, and a gas channel is formed at the protrusion.

[0052] At least one flame retardant device 2 is provided in the gas sharing chamber 111. The flame retardant and fire extinguishing material in the flame retardant and fire extinguishing material is a flame retardant and fire extinguishing gas, such as an inert gas or a carbon dioxide gas. Compared with the liquid flame retardant and fire extinguishing agent, the flame retardant and fire extinguishing gas has the following advantages: the flame retardant and fire extinguishing gas can not only reduce the concentration of the combustible material in the outer shell 11, but also avoid combustion in the outer shell 11 of the large-capacity battery 1; at the same time, the flame retardant and fire extinguishing gas can also be mixed with the thermal runaway smoke and then discharged, so as to reduce the concentration of the combustible gas in the thermal runaway smoke. Since the concentration of the combustible gas in the mixed gas is relatively small, the thermal runaway smoke after being discharged will not burn or explode outside the shell of the large-capacity battery 1.

[0053] The flame retardant and fire extinguishing gas can be obtained by reaction, or inert gas can be filled in the flame retardant housing 21. The amount of gas in the method of filling inert gas is small. In contrast, the amount of gas obtained by reaction is relatively large, which can more fully perform flame retardancy and fire extinguishing. Based on this, the specific structure of the flame retardant device 2 in this embodiment is as follows:

[0054] like Figure 4 As shown, the flame-retardant shell 21 includes an inner tube 211 and an outer tube 212, both of which are sealed pipelines. The outer tube 212 is provided with a first weak area 22. The above-mentioned first weak area 22 can be realized by a variety of structures, as long as it can be opened at a set temperature or a set pressure. For example, the first weak area 22 is a sealing film arranged on the opening of the outer tube 212, and the sealing film is similar to an explosion-proof film. When the internal pressure of the shell exceeds a set value, the sealing film is opened. At this time, the opening pressure of the sealing film is required to be less than the opening pressure of the explosion-proof part 16 on the large-capacity battery 1, that is, when the explosion-proof part 16 is opened, the sealing film has been opened in advance; or, the first weak area 22 is a plastic film arranged on the opening of the outer tube 212, and the plastic film is made of a material that is melted or melted at a set temperature. For example, when the inside of the shell reaches 150°C, the plastic film melts or melts.

[0055] The inner tube 211 is arranged as a whole in the outer tube 212, and the inner tube 211 is provided with a second weak zone 23. The temperature or pressure at which the second weak zone 23 is opened is lower than the temperature or pressure at which the first weak zone 22 is opened. Specifically, the temperature at which the second weak zone 23 is opened is lower than 120°C. The inner tube 211 has a first reaction medium, and the outer tube 212 has a second reaction medium. The second weak zone 23 is opened. At this time, the inner cavity of the outer tube 212 is connected to the inner cavity of the inner tube 211, and the first reaction medium in the outer tube 212 and the second reaction medium in the inner tube 211 contact and react to generate flame retardant and fire extinguishing gas. The flame retardant and fire extinguishing gas enters the outer shell 11 through the first weak zone 22.

[0056] When the second weak zone 23 is specifically set, it can be set at any position of the inner tube 211, preferably at the end of the inner tube 211, so that the first reaction medium can flow out in time, contact with the second reaction medium, and react quickly to produce flame retardant and fire extinguishing gas. At the same time, the first weak zone 22 of the outer tube 212 is set at the top of the outer tube 212, and the first weak zone 22 is set at the top of the outer tube 212, so that the flame retardant and fire extinguishing gas can be discharged in time and smoothly.

[0057] After the second weak zone 23 is opened, the first reaction medium and the second reaction medium come into contact and react to produce a flame retardant fire extinguishing gas. The flame retardant fire extinguishing gas is specifically a non-flammable gas, preferably carbon dioxide gas, which can be obtained through a reaction under relatively simple conditions and has a certain fire extinguishing effect. At room temperature, carbon dioxide gas can be obtained by reacting different liquid substances or solid substances. There are different placement methods according to the reaction principle:

[0058] 1) The first reaction medium is water, and the second reaction medium is sodium bicarbonate and aluminum sulfate solid;

[0059] 2) The first reaction medium is an aluminum sulfate solution, and the second reaction medium is a sodium bicarbonate solution;

[0060] 3) The first reaction medium is a sodium bicarbonate solution, and the second reaction medium is an aluminum sulfate solid;

[0061] 4) The first reaction medium is solid sodium bicarbonate, and the second reaction medium is aluminum sulfate solution;

[0062] In the above method, the first reaction medium is water, and the second reaction medium is sodium bicarbonate and aluminum sulfate solid, which is the best choice. This method is convenient for filling separately and can continue to maintain its effect after being placed for a long time.

[0063] There is at least one flame retardant device 2 in this embodiment, and the number is set according to the number of single cells 12 in the large-capacity battery 1. Generally, it is best to set it to multiple. After multiple flame retardants are set, when the first weak area 22 of one of the flame retardant devices 2 fails and cannot be opened in time, the other flame retardant devices 2 can continue to achieve the corresponding functions.

[0064] In this embodiment, the flame retardant device 2 is arranged in the shell 11 of the large-capacity battery 1. The overall appearance of the large-capacity battery 1 does not change, and there is no need to increase the space for the volume change of the large-capacity battery 1. It will not affect the assembly relationship of the large-capacity battery 1, which facilitates the installation and use of the large-capacity battery 1.

[0065] Example 3

[0066] The structure of the large-capacity battery 1 in this embodiment is similar to that in Embodiment 1 or Embodiment 2. The difference from Embodiment 1 or Embodiment 2 is that the shared chamber in this embodiment includes a gas shared chamber 111 and an electrolyte shared chamber 112. Flame retardant devices 2 are respectively provided in the gas sharing chamber 111 and the electrolyte sharing chamber 112 of the large-capacity battery 1, and the best installation method is: the flame retardant and fire extinguishing material in the flame retardant device 2 in the gas sharing chamber 111 is a flame retardant and fire extinguishing gas, and the flame retardant and fire extinguishing material in the flame retardant device 2 in the electrolyte sharing chamber 112 is a liquid flame retardant and fire extinguishing agent, wherein the flame retardant and fire extinguishing material flowing out of the flame retardant device 2 in the gas sharing chamber 111 is a flame retardant and fire extinguishing gas, and the flame retardant and fire extinguishing gas is convenient to be fully mixed with the combustible gas in the large-capacity battery 1 to avoid combustion of the combustible gas, and at the same time, the flame retardant and fire extinguishing material in the flame retardant device 2 in the electrolyte sharing chamber 112 is a liquid flame retardant and fire extinguishing agent, and the liquid flame retardant and fire extinguishing agent is mixed with the electrolyte to avoid combustion of the electrolyte as much as possible.

[0067] Example 4

[0068] like Figure 5 As shown, in this embodiment, a heat transfer tube 3 is added to the large-capacity battery 1 of embodiment 1, so that the large-capacity battery 1 can work safely and reliably, avoiding performance problems and safety problems caused by excessively high or low temperature of the large-capacity battery 1.

[0069] The heat transfer tube 3 is installed on the polarity terminal 13 of the large-capacity battery 1, and is mainly used to control the temperature of the top of the large-capacity battery 1, especially the polarity terminal 13 of the large-capacity battery 1, to ensure that the large-capacity battery 1 operates within the optimal temperature range. Figure 1 and Figure 2 As shown, a clamping part 131 is provided on the polarity terminal 13 of the large-capacity battery 1, and the heat transfer tube 3 is fixed in the clamping part 131, so that the heat transfer tube 3 is directly connected to the polarity terminal 13 of the large-capacity battery 1, and the heat on the polarity terminal 13 where the heat is relatively concentrated is promptly discharged, thereby improving the heat dissipation effect on the top of the large-capacity battery 1. In addition, when the temperature of the large-capacity battery 1 is lower than the set threshold, a heat transfer medium with a higher temperature is introduced into the heat transfer tube 3 to increase the temperature of the large-capacity battery 1; by controlling the temperature of the heat transfer medium, it can be ensured that the large-capacity battery 1 always operates at a normal operating temperature.

[0070] The heat transfer tube 3 is a pipe with a heat exchange function. There is no requirement for the cross-sectional shape of the heat transfer tube 3 as long as it can contact the polarity terminal 13 of the single battery 12 for heat exchange. For example, a square tube, an elliptical tube, a round tube, etc. can be used. In this embodiment, the heat transfer tube 3 is preferably a round tube, which is easy to install and can be made of existing metal tubes, with relatively low cost.

[0071] The heat transfer tube 3 in this embodiment specifically adopts a metal tube with good thermal conductivity, such as an aluminum tube, a copper tube, etc. Preferably, the heat transfer tube 3 adopts an aluminum tube with good thermal conductivity and relatively low cost. In order to ensure the thermal conductivity, the thinner the wall thickness of the aluminum tube, the better. However, if the wall thickness of the aluminum tube is too thin, the aluminum tube is relatively soft and is easy to bend and break during installation. Therefore, in this embodiment, the wall thickness of the aluminum tube is preferably 0.5mm to 1.5mm. The aluminum tube with this wall thickness can maintain its installation reliability while having good thermal conductivity, avoiding the risk of easy bending and damage when the wall thickness of the aluminum tube is thin. In specific use, the diameter of the aluminum tube is generally about 10mm to 20mm.

[0072] The above heat transfer tube 3 can be manufactured by adopting the following structure:

[0073] First, the heat transfer tube 3 can be made of a whole tube, and the whole aluminum tube is bent into a U-shaped tube, and the two straight tubes of the U-shaped tube are respectively fixed to the positive terminal and the negative terminal of each single battery 12 in the large-capacity battery 1;

[0074] Second, in order to facilitate installation, such as Figure 5 As shown, the heat transfer pipe 3 is a spliced ​​pipe, mainly including a first pipe 31, a second pipe 32 and a connecting pipe 33; the first pipe 31 is fixed on the clamping part 131 of the positive terminal of each single battery 12 in the large-capacity battery 1; the second pipe 32 is fixed on the clamping part 131 of the negative terminal of each single battery 12 in the large-capacity battery 1, and the two ends of the connecting pipe 33 are respectively connected to the ports of the first pipe 31 and the second pipe 32 located on the same side.

[0075] When the heat transfer tube 3 is matched with the polarity terminal 13 of the large-capacity battery 1, in order to ensure safety, the heat transfer tube 3 and the large-capacity battery 1 need to be insulated. Specifically, the insulation treatment can be achieved in the following ways: the heat transfer tube 3 is an insulating pipe made of insulating material, such as a plastic pipe or a ceramic pipe, etc. However, compared with a metal pipe, the thermal conductivity of the plastic pipe or the ceramic pipe is poor. Therefore, in this embodiment, an insulating layer or an insulating sleeve is provided on the metal pipe to ensure the insulation between the metal pipe and the large-capacity battery 1 when in use.

[0076] Preferably, an insulating layer and an insulating sleeve are provided on the heat transfer tube 3 to form a double insulation structure; this double insulation arrangement enables the heat transfer tube 3 to maintain reliable insulation performance with the large-capacity battery 1 when heat is exchanged with the large-capacity battery 1, even if one of the insulating layer or the insulating sleeve is damaged, thereby improving the safety of the large-capacity battery 1 during use. The specific structure of the heat transfer tube 3 with an insulating layer and an insulating sleeve is described in detail below, taking the metal tube as an aluminum tube as an example.

[0077] When an insulating layer is provided on an aluminum tube, the insulating layer is formed on the tube wall of the aluminum tube and is an integral structure with the aluminum tube. The insulating layer can be implemented in the following ways:

[0078] First, a ceramic coating, i.e., a high-temperature electrical insulation coating, is formed on the wall of the aluminum tube to form an insulating layer. The ceramic coating may be boron nitride, aluminum oxide, or copper fluoride coating. However, the insulating layer formed in this way is easy to fall off and the processing cost is high.

[0079] Second, a layer of insulating material (such as insulating paint, etc.) is coated on the wall surface of the aluminum tube to form an insulating layer; this method is easy to process and implement, and the processing cost is low;

[0080] Third, the aluminum tube is oxidized to form an insulating layer. Oxidation is to use the chemical reaction between the metal surface and oxygen to form an oxide film to improve the insulation performance of the metal surface. For example, electrochemical oxidation method, etc. Specifically, the aluminum tube is oxidized to form a hard oxide layer. The insulating layer formed by this method is not easy to fall off, and the insulation performance is relatively good.

[0081] It should be noted that the tube wall can be the outer tube wall of the aluminum tube or the inner tube wall, preferably the outer tube wall. The thicker the hard oxide layer formed by oxidation treatment, the better the insulation, but its thermal conductivity will be reduced. In this embodiment, the thickness of the hard oxide layer is preferably 20um to 50um. The hard oxide layer of this thickness ensures the insulation performance while also making the side wall of the aluminum tube have better thermal conductivity.

[0082] The above-mentioned insulating sleeve can be specifically made of insulating materials with good thermal conductivity, so that it has excellent thermal conductivity and good insulation performance. In this embodiment, the insulating sleeve adopts a thermally conductive plastic sleeve or a thermally conductive rubber sleeve with good insulation and thermal conductivity, such as a thermally conductive silicone sleeve, etc. At the same time, the thickness of the insulating sleeve is preferably 0.1mm~1.5mm, which can ensure good thermal conductivity while ensuring excellent insulation performance. The cross-sectional shape of the insulating sleeve can be circular, U-shaped, or C-shaped, as long as it can be sleeved on the aluminum tube with an insulating layer to achieve insulation at the contact point between the aluminum tube and the polarity terminal 13 of the single battery 12. At the same time, the cross-sectional shape of the above-mentioned insulating sleeve is preferably the same as the cross-sectional shape of the aluminum tube, so that the insulating sleeve can be tightly nested on the aluminum tube to improve the thermal conductivity of the aluminum tube.

[0083] like Figure 2As shown, when the heat transfer tube 3 is installed, a through groove or through hole is provided at the position where the polarity terminal 13 of the single battery 12 extends out of the avoidance hole, as a clamping portion 131; compared with the through hole, the through groove is more convenient for on-site installation, and the installation requirements are relatively low. The through groove is arranged in a C-shaped cross section, and the opening width of the C-shaped through groove is smaller than the widest part of the through groove. Such a design is conducive to the interference fit of the heat transfer tube 3 in the through groove. The arc formed at both ends of the C-shaped through groove has natural tension, which is conducive to the heat transfer tube 3 being tightly clamped in the through groove.

[0084] In this embodiment, the polarity terminal 13 of the single battery 12 is a cylinder. In this case, the through groove can be set on the side wall or end face of the cylinder. The through groove or through hole is provided on the side wall. Compared with the through groove provided on the end face, the contact area between the heat transfer tube 3 in the through groove or through hole and the inner wall of the through groove or through hole is larger, and the heat exchange efficiency is higher. In addition, when the through groove or through hole is located on the side wall, the entire area of ​​the end face can be used as an electrical connection area. In addition, two through grooves or through holes can be provided on the side wall of the pole at the same time to increase the number of heat transfer tubes 3 placed and further improve the heat exchange efficiency. The above-mentioned heat transfer tube 3 is fixed in the through groove or through hole of the polarity terminal 13 of the large-capacity battery 1 to process the heat on the top of the large-capacity battery 1.

[0085] After the heat transfer tube 3 exchanges heat with the large-capacity battery 1, the heat transfer medium absorbs heat in the heat transfer tube 3 and is then transferred to an external heat treatment device through the liquid inlet manifold and the liquid return manifold for treatment. The heat treatment device is a device with heating and / or cooling functions, which is used to increase or decrease the temperature of the heat transfer medium (specifically, water, ethylene glycol / water, propylene glycol / water, methanol / water, ethanol / water, calcium formate / water, etc.). For example, the heat transfer unit is specifically a heater, a cold and warm machine, or a refrigerator with a compressor, a chiller, etc.

[0086] Example 5

[0087] During long-term use of the large-capacity battery 1, condensation will be generated on the surface due to the temperature difference between the inside and outside of the heat transfer tube 3. When the condensation accumulates to a certain amount, it will penetrate into the gap between the polarity terminal 13 of the single battery 12 and the avoidance hole, causing the polarity terminal 13 of the single battery 12 to be electrically conductive with the shell 11, which may cause a short circuit.

[0088] like Figure 6 and Figure 7As shown, this embodiment overcomes the above problems by optimizing the top structure of the large-capacity battery 1 and laying an insulating sealant layer 14 on the top plate of the shell 11. The end face of the polarity terminal 13 of each single battery 12 extends out of the insulating sealant layer 14, which is used to connect with the first electrical connector 17 or the second electrical connector 18; the liquid inlet end and the liquid outlet end of the heat transfer tube 3 extend out of the insulating sealant layer 14, which is used to connect with the liquid inlet manifold and the liquid return manifold. The first electrical connector 17 is a connecting device for connecting each single battery 12 in parallel, and the second electrical connector 18 is a connecting device for connecting two large-capacity batteries 1 in series, and can also be a connecting device for connecting the large-capacity battery 1 with an external load.

[0089] like Figure 6 and Figure 7 As shown, in this embodiment, an insulating sealant layer 14 is laid on the top plate of the shell 11, and a part of the polarity terminal 13 of each single battery 12 is covered by the insulating sealant layer 14, and the end surface of the polarity terminal 13 of each single battery 12 extends out of the insulating sealant layer 14 and is connected to the first electrical connector 17 and / or the second electrical connector 18; the main parts of the heat transfer tubes 3 are all covered by the insulating sealant layer 14, and the liquid inlet and liquid outlet ends of the heat transfer tubes 3 extend out of the insulating sealant layer 14 to be connected to the liquid inlet manifold and the liquid return manifold.

[0090] In some other embodiments, the thickness of the insulating sealant layer 14 can be smaller, lower than the main body of the heat transfer tube 3, or cover part of the main body of the heat transfer tube 3, as long as condensation cannot enter the gap between the polarity terminal 13 of the single battery 12 and the avoidance hole.

[0091] The insulating sealant used in this embodiment is generally a battery potting glue commonly used in batteries, such as a silicone thermal conductive potting glue, which has good sealing, insulation, vibration resistance, heat dissipation and waterproof functions. In order to prevent the insulating sealant from overflowing, during the injection process of this embodiment, a glue injection mold can be added around the top plate of the shell 11 to ensure that the insulating sealant can be smoothly injected. After the injection is completed, demoulding is performed.

[0092] like Figure 7 As shown, on the basis of the above structure, this embodiment further provides an insulating protective cover 15 on the top of the large-capacity battery 1, thereby providing insulating protection for the polarity terminal 13, avoiding the potential safety hazard of the polarity terminal 13 being exposed during the operation of the large-capacity battery 1, and also avoiding the problem of some foreign matter in the external environment falling into the position of the polarity terminal 13 and causing the large-capacity battery 1 to short-circuit, thereby improving the safety of the large-capacity battery 1.

[0093] It should be noted that if the insulating protective cover 15 completely covers the polarity terminal 13, it will make the electrical connection of such a large-capacity battery 1 difficult. Therefore, in this embodiment, a slit is provided on the side wall of the insulating protective cover 15, through which the second electrical connector 18 can be connected to the polarity terminal 13 of the single battery 12, thereby achieving electrical connection. It should also be noted that a channel for the liquid inlet and liquid outlet of the heat transfer tube 3 to extend out needs to be provided on the side wall of the insulating protective cover 15.

Claims

1. A large-capacity battery, comprising a housing and a plurality of single cells arranged in the housing in the same direction; a shared chamber is provided in the housing, and the inner cavity of the shared chamber is connected to the inner cavities of all the single cells; It is characterized in that Also included is at least one flame retardant device disposed in the shared chamber, the flame retardant device comprising a flame retardant housing and a flame retardant fire extinguishing substance in the flame retardant housing; The flame retardant shell is provided with a first weak area, which opens at a set temperature or a set pressure, and the flame retardant fire extinguishing material in the flame retardant shell enters the outer shell through the first weak area.

2. The large-capacity battery according to claim 1, characterized in that: The shared chamber comprises a gas shared chamber, and the flame retardant and fire extinguishing material of the flame retardant device in the gas shared chamber is a flame retardant and fire extinguishing gas.

3. The large-capacity battery according to claim 1, characterized in that: The shared chamber comprises an electrolyte shared chamber, the flame retardant and fire extinguishing material of the flame retardant device in the electrolyte shared chamber is a liquid flame retardant and fire extinguishing agent, and the first weak area of ​​the flame retardant shell opens at a set temperature.

4. The large-capacity battery according to claim 1, characterized in that: The shared chamber includes a gas shared chamber and an electrolyte shared chamber, and both the gas shared chamber and the electrolyte shared chamber are provided with flame retardant devices. The flame retardant and fire extinguishing material of the flame retardant device in the gas shared chamber is a flame retardant and fire extinguishing gas, and the flame retardant and fire extinguishing material of the flame retardant device in the electrolyte shared chamber is a liquid flame retardant and fire extinguishing agent.

5. The large-capacity battery according to claim 2 or 4, characterized in that: The flame-retardant shell in the gas-sharing chamber comprises an inner tube and an outer tube, the outer tube is provided with a first weak zone, the inner tube is located inside the outer tube, and the inner tube has a second weak zone, the temperature or pressure at which the second weak zone is opened is lower than the temperature or pressure at which the first weak zone is opened; the inner tube has a first reaction medium, the outer tube has a second reaction medium, the second weak zone is opened, the first reaction medium and the second reaction medium come into contact and react to generate a flame-retardant fire-extinguishing gas, and the flame-retardant fire-extinguishing gas enters the outer shell through the first weak zone.

6. The large-capacity battery according to claim 5, characterized in that: The flame retardant fire extinguishing gas is carbon dioxide, the first reaction medium is water, the second reaction medium is sodium bicarbonate and aluminum sulfate solid, the second weak area of ​​the inner tube is located at the end of the inner tube, and the first weak area of ​​the outer tube is located at the top of the outer tube.

7. The large-capacity battery according to claim 3 or 4, characterized in that: The flame retardant and fire extinguishing substance in the electrolyte sharing chamber is fluorinated liquid, and the first weak area is located at the bottom of the flame retardant shell.

8. The large-capacity battery according to any one of claims 1 to 4, characterized in that: The top plate of the shell is provided with avoidance holes corresponding to the polarity terminals of each single cell; the polarity terminals of each single cell extend out of the avoidance holes, and the top plate area of ​​the shell corresponding to the avoidance holes is fixedly sealed with the shell of the single cell; the part where the polarity terminals of each single cell extend out of the avoidance holes is provided with a clamping part, and a heat transfer tube is fixed on the clamping part of the polarity terminals of each single cell, and the heat transfer tube is insulated from the polarity terminals of each single cell; the clamping part is a through groove or through hole provided on the polarity terminals of each single cell, and the heat transfer tube is a metal tube, and the metal tube has at least one of an insulating layer and an insulating sleeve.

9. The large-capacity battery according to claim 8, characterized in that: An insulating sealant layer is laid on the top plate of the shell, and the liquid inlet end and the liquid outlet end of the heat transfer tube extend out of the insulating sealant layer.

10. The large-capacity battery according to claim 9, characterized in that: An insulating protective cover is arranged on the top of the shell, and polarity terminals of each single battery are located inside the insulating protective cover.

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