Rechargeable lithium ion battery pack

Abstract

The utility model relates to a rechargeable lithium ion battery pack. The rechargeable lithium ion battery pack comprises a battery pack body, an electrolyte storage device, a temperature adjusting device and a flame retardant storage device. Electrolyte is stored in the electrolyte storage device, and the electrolyte storage device is connected with the battery pack through a pipeline to form a circulation loop. And the temperature adjusting device is used for heating or cooling the electrolyte in the electrolyte storage device. A flame retardant is stored in the flame retardant storage device, the flame retardant storage device is connected with the battery pack through a pipeline to form a circulation loop, and the battery pack is selectively communicated with the electrolyte storage device or the flame retardant storage device. When the battery pack is communicated with the electrolyte storage device, the interior of the battery can work at the optimal temperature all the time. And when the battery pack is communicated with the flame retardant storage, the flame retardant can quickly flow into the battery to cut off combustion, so that the safety of the battery is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a rechargeable lithium-ion battery pack. Background Art

[0002] Rechargeable lithium batteries play an important role in modern society. They are not only widely used as power sources for 3C electronic products, but also become the core power of new energy vehicles. They have also shown a rapid development trend in the field of electrochemical large-scale energy storage. However, the performance of most rechargeable lithium batteries is greatly affected by the ambient temperature. When the temperature is below 0 ℃ or above 40 ℃, the battery performance will decay rapidly, and even safety accidents will occur, which seriously limits the application of lithium batteries in high-cold / high-temperature areas. Therefore, it is necessary to solve the impact of temperature on the components of lithium batteries.

[0003] In the related technology, the improvement exploration of battery materials is generally aimed at, such as the development of solid electrolytes, but solid electrolyte batteries have the following disadvantages: the contact area between the solid electrolyte and the electrode material is small, so the wettability is poor and the ion conduction speed is slow; the internal resistance is large, which hinders fast charging; the cost is high, which hinders further commercialization.

[0004] Therefore, another solution needs to be proposed to address the problem that battery performance is greatly affected by temperature. Utility Model Content

[0005] Based on this, it is necessary to provide a rechargeable lithium-ion battery pack to address the problem that battery performance is greatly affected by temperature.

[0006] A rechargeable lithium-ion battery pack, comprising:

[0007] Battery pack;

[0008] An electrolyte storage device stores electrolyte, and the electrolyte storage device is connected to the battery pack through a pipeline to form a circulation loop;

[0009] a temperature regulating device, used for heating or cooling the electrolyte in the electrolyte storage;

[0010] A flame retardant storage device stores flame retardant therein, wherein the flame retardant storage device is connected to the battery pack via a pipeline to form a circulation loop, and the battery pack can be selectively connected to the electrolyte storage device or the flame retardant storage device.

[0011] In one embodiment, the battery pack has a first liquid outlet, the electrolyte storage has a second liquid inlet, the flame retardant storage has a third liquid inlet, and the first liquid outlet is connected to the second liquid inlet and the third liquid inlet through a three-way valve.

[0012] In one embodiment, the rechargeable lithium-ion battery pack includes a pump body having two inlets and one outlet;

[0013] The battery pack has a first liquid inlet, the electrolyte storage has a second liquid outlet, and the flame retardant storage has a third liquid outlet. The second liquid outlet and the third liquid outlet are respectively connected to the two inlets of the pump body, and the outlet of the pump body is connected to the first liquid inlet.

[0014] In one embodiment, the second liquid inlet and the second liquid outlet are respectively provided with a one-way valve, the one-way valve of the second liquid inlet is used to allow the electrolyte to flow into the electrolyte storage, and the one-way valve of the second liquid outlet is used to allow the electrolyte to flow out of the electrolyte storage.

[0015] In one embodiment, the battery pack includes a plurality of batteries arranged in sequence, each battery is provided with a first liquid inlet at the bottom, each battery is provided with a first liquid outlet at the top, and of two adjacent batteries, the first liquid outlet of the preceding battery is connected to the first liquid inlet of the succeeding battery.

[0016] In one embodiment, along the flow direction of the electrolyte, the first liquid outlet of the last battery is connected to the electrolyte storage via a first pipeline, and a vent is provided on the first pipeline.

[0017] In one embodiment, a drain port is provided at the bottom of each battery.

[0018] In one embodiment, a liquid replenishing port is provided on the electrolyte storage.

[0019] In one embodiment, the rechargeable lithium-ion battery pack includes a housing, and the battery pack, electrolyte storage and flame retardant storage are sealed in the housing.

[0020] In one embodiment, the temperature regulating device includes a heat exchanger, the electrolyte storage is arranged in the form of a serpentine pipeline in the heat exchanger, and a heat exchange fluid is arranged in the heat exchanger.

[0021] For the above-mentioned rechargeable lithium-ion battery pack, when the temperature of the electrolyte in the battery pack is too high, the battery pack is connected to the electrolyte storage, so that the high-temperature electrolyte can flow into the electrolyte storage for cooling, and the electrolyte after cooling is returned to the battery pack through a circulation loop; when the temperature of the electrolyte in the battery pack is too low, the battery pack is connected to the electrolyte storage, so that the low-temperature electrolyte can flow into the electrolyte storage for heating, and the electrolyte after heating is returned to the battery pack through a circulation loop. That is, the interior of the battery pack can always operate at the optimal temperature to prevent the rapid attenuation of electrical performance due to too low or too high temperature. At the same time, when there is an irreversible risk of loss of control such as thermal runaway, short circuit fire, etc. inside the battery pack, the battery pack forms a loop with the flame retardant storage, and the flame retardant can quickly flow into the battery pack to cut off combustion, so as to ensure the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. 1 is a schematic diagram of system connections of a rechargeable lithium-ion battery pack in one embodiment.

[0023] Figure 2 FIG. 4 is a schematic diagram of the structure of a battery pack in one embodiment.

[0024] Figure 3 Schematic diagram of the structure of the electrolyte storage and heat exchanger in one embodiment.

[0025] Reference numerals: 100, battery pack; 110, first liquid outlet; 120, first liquid inlet; 132, exhaust port; 140, battery;

[0026] 200, electrolyte storage; 210, second liquid outlet; 220, second liquid inlet; 230, liquid replenishing port;

[0027] 300, temperature regulating device; 310, heat exchanger; 311, heat exchange fluid inlet; 312, heat exchange fluid outlet;

[0028] 400, flame retardant storage; 410, third liquid outlet; 420, third liquid inlet;

[0029] 500. Pump body. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply 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 application.

[0032] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0034] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0036] See also Figure 1 , a rechargeable lithium-ion battery pack 100 provided in one embodiment of the present application, the rechargeable lithium-ion battery pack 100 includes a battery pack 100, an electrolyte storage 200, a temperature regulating device 300 and a flame retardant storage 400. The electrolyte storage 200 stores electrolyte, and the electrolyte storage 200 is connected to the battery pack 100 through a pipeline to form a circulation loop. The temperature regulating device 300 is used to heat or cool the electrolyte in the electrolyte storage 200. The flame retardant storage 400 stores flame retardant, and the flame retardant storage 400 is connected to the battery pack 100 through a pipeline to form a circulation loop, and the battery pack 100 can selectively communicate with the electrolyte storage 200 or the flame retardant storage 400.

[0037] In this embodiment, when the temperature of the electrolyte in the battery pack 100 is too high, the battery pack 100 is connected to the electrolyte storage 200, so that the high-temperature electrolyte can flow into the electrolyte storage 200 for cooling, and the electrolyte after cooling is returned to the battery pack 100 through the circulation loop; when the temperature of the electrolyte in the battery pack 100 is too low, the battery pack 100 is connected to the electrolyte storage 200, so that the low-temperature electrolyte can flow into the electrolyte storage 200 for heating, and the electrolyte after heating is returned to the battery pack 100 through the circulation loop. That is, the inside of the battery pack 100 can always work at the optimal temperature to prevent the rapid attenuation of electrical performance due to too low or too high temperature. At the same time, when there is an irreversible risk of thermal runaway, short circuit fire, etc. inside the battery pack 100, the battery pack 100 forms a loop with the flame retardant storage 400, and the flame retardant can quickly flow to the inside of the battery pack 100 to cut off the combustion, so as to ensure the safety of the battery pack 100.

[0038] In some embodiments, the battery pack 100 has a first liquid outlet 110, the electrolyte storage 200 has a second liquid inlet 220, the flame retardant storage 400 has a third liquid inlet 420, and the first liquid outlet 110 is connected to the second liquid inlet 220 and the third liquid inlet 420 through a three-way valve.

[0039] In this embodiment, the first liquid outlet 110 is connected to the second liquid inlet 220 and the third liquid inlet 420 through a three-way valve, so that the battery pack 100 can only be connected to the electrolyte storage 200 or the flame retardant storage 400, that is, when the battery pack 100 is connected to the electrolyte storage 200, the battery pack 100 is not connected to the flame retardant storage 400, which can ensure the normal operation of the battery 140. When the battery pack 100 is connected to the flame retardant storage 400, the battery pack 100 is not connected to the electrolyte storage 200, which can prevent the electrolyte in the electrolyte storage 200 from entering the battery 140 when the battery 140 is thermally runaway or short-circuited and ignited, further increasing the combustion risk of the battery 140.

[0040] In some embodiments, the rechargeable lithium-ion battery pack 100 includes a pump body 500, and the pump body 500 has two inlets and one outlet. The battery pack 100 has a first liquid inlet 120, the electrolyte storage 200 has a second liquid outlet 210, and the flame retardant storage 400 has a third liquid outlet 410. The second liquid outlet 210 and the third liquid outlet 410 are respectively connected to the two inlets of the pump body 500, and the outlet of the pump body 500 is connected to the first liquid inlet 120.

[0041] In this embodiment, through the setting of the pump body 500, when the battery pack 100 is connected to the electrolyte storage 200, the pump body 500 is used to allow the electrolyte in the electrolyte storage 200 to enter the battery pack 100 from the second liquid outlet 210 through the pipeline from the first liquid inlet 120, and then flow from the first liquid outlet 110 through the pipeline to the second liquid inlet 220 of the electrolyte storage 200, that is, the electrolyte with suitable temperature in the electrolyte storage 200 enters the battery pack 100, which can maintain the normal operation of the battery pack 100. When the battery pack 100 is connected to the flame retardant storage 400, the pump body 500 is used to allow the flame retardant in the flame retardant storage 400 to enter the battery pack 100 from the first liquid inlet 120, and then flow from the first liquid outlet 110 through the pipeline to the third liquid inlet 420 of the flame retardant storage 400, and then return to the battery pack 100 from the third liquid outlet 410 through the pump body 500. That is, when the battery 140 has internal thermal runaway or short circuit and catches fire, the pump body 500 can allow the flame retardant in the flame retardant storage 400 to enter the battery 140 to prevent combustion.

[0042] Furthermore, the second liquid inlet 220 and the second liquid outlet 210 are respectively provided with a one-way valve, the one-way valve of the second liquid inlet 220 is used to allow the electrolyte to flow into the electrolyte storage 200, and the one-way valve of the second liquid outlet 210 is used to allow the electrolyte to flow out of the electrolyte storage 200.

[0043] The one-way valve provided on the basis of the pump body 500 allows the electrolyte to flow in only one direction, that is, the electrolyte can only flow from the battery pack 100 through the pipeline to the second liquid inlet 220, and then return to the battery pack 100 from the second liquid outlet 210 through the pipeline, so as to form a loop between the battery pack 100 and the electrolyte storage 200.

[0044] Among them, the third liquid outlet 410, the first liquid inlet 120 and the first liquid outlet 110 are all provided with valves. When the temperature of the electrolyte in the battery pack 100 is appropriate, the first liquid inlet 120 and the first liquid outlet 110 are both closed, and the battery pack 100 works normally. When the temperature of the electrolyte in the battery pack 100 is too high or too low, the third liquid outlet 410 is closed, the first liquid inlet 120, the first liquid outlet 110, the second liquid inlet 220 and the second liquid outlet 210 are all opened, and the battery pack 100 is connected to the electrolyte storage 200. When the battery pack 100 is thermally runaway or short-circuited and ignited, the second liquid inlet 220 and the second liquid outlet 210 are closed, the third liquid outlet 410 is opened, the first liquid inlet 120 and the first liquid outlet 110 are opened, and the battery pack 100 is connected to the flame retardant storage 400.

[0045] Combination Figure 2 In some embodiments, the battery pack 100 includes a plurality of batteries 140 arranged in sequence, each battery 140 is provided with a first liquid inlet 120 at the bottom, each battery 140 is provided with a first liquid outlet 110 at the top, and in two adjacent batteries 140, the first liquid outlet 110 of the preceding battery 140 is connected to the first liquid inlet 120 of the succeeding battery 140.

[0046] In this embodiment, the first liquid inlet 120 is located at the bottom of the battery pack 100, and the first liquid outlet 110 is located at the top of the battery pack 100. The electrolyte enters the battery pack 100 from the bottom, so that the electrolyte in the battery pack 100 overcomes the gravity and is quickly replaced from the top of the battery pack 100.

[0047] Furthermore, along the flow direction of the electrolyte, the first liquid outlet 110 of the last battery 140 is connected to the second liquid inlet 220 of the electrolyte storage 200 through the first pipeline, and the first pipeline is provided with an exhaust port 132.

[0048] In this embodiment, the battery cell will produce a large amount of gas during the formation stage, such as carbon monoxide, ethylene, and methane. At this time, multiple batteries 140 are connected in series, and the electrolyte enters from the bottom of the battery pack 100 under the action of the pump body 500, filling the batteries 140 arranged in sequence one by one, so that the gas generated in the battery cell can be discharged from the last battery 140. At this time, opening the exhaust port 132 can allow the gas to be discharged, and at the same time, some harmful byproducts can also be discharged.

[0049] In some other embodiments, the exhaust port 132 may also be directly opened at the top of the last battery 140 .

[0050] Combination Figure 1 In some embodiments, a liquid replenishing port 230 is provided on the electrolyte storage 200 .

[0051] In this embodiment, the electrolyte is inevitably decomposed and oxidized during the circulation process, resulting in the loss of some active lithium. In the later stage of conventional battery cycle, the electrolyte is generally dried up. By opening a replenishing port 230 on the electrolyte storage 200, the electrolyte can be properly replenished to achieve the purpose of replenishing active lithium and improving the dynamics of the battery 140.

[0052] In some embodiments, a drain port is provided at the bottom of each battery 140. When the electrolyte in the battery pack 100 becomes ineffective, the ineffective electrolyte can be drained through the drain port, and then the electrolyte can be refilled from the electrolyte storage 200.

[0053] In some embodiments, the rechargeable lithium-ion battery pack 100 includes a housing, and the battery pack 100, the electrolyte storage 200, and the flame retardant storage 400 are sealed in the housing.

[0054] In this embodiment, a shell is provided outside each battery 140, and the battery pack 100, the electrolyte storage 200 and the flame retardant storage 400 are sealed in the outer shell, that is, a two-layer shell is provided, which enables the battery 140 to be strictly protected in the shell. At the same time, the flame retardant can be directly charged into the battery 140 to directly block the fire source, which can further improve the safety performance of the entire rechargeable lithium-ion battery pack 100.

[0055] Combination Figure 3 In some embodiments, the temperature regulating device 300 includes a heat exchanger 310, the electrolyte storage 200 is arranged in a serpentine pipeline in the heat exchanger 310, a heat exchange fluid is arranged in the heat exchanger 310, and the second liquid inlet 220 and the second liquid outlet 210 are respectively located on the heat exchanger 310.

[0056] Among them, a heat exchange fluid is arranged in the heat exchanger 310, and a heat exchange fluid inlet 311 and a heat exchange fluid outlet 312 are respectively opened on the heat exchanger 310. After being cooled or heated outside, the heat exchange fluid can enter the heat exchanger 310 from the heat exchange fluid inlet 311, thereby exchanging heat with the electrolyte in the electrolyte storage 200, and finally flowing out from the heat exchange fluid outlet 312. The serpentine pipeline arrangement of the electrolyte storage 200 is conducive to increasing the heat exchange effect, so that the electrolyte is quickly cooled or heated.

[0057] Of course, the temperature regulating device 300 also includes components in the prior art for directly heating or cooling the heat exchange fluid, which will not be elaborated herein.

[0058] In other embodiments, the electrolyte storage may be wrapped in a temperature regulating device to directly heat or cool the electrolyte in the electrolyte storage through the temperature regulating device. In this case, the electrolyte storage is made of a heat-conducting material.

[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A rechargeable lithium-ion battery pack, characterized in that: The rechargeable lithium-ion battery pack comprises: Battery pack; An electrolyte storage device stores electrolyte, and the electrolyte storage device is connected to the battery pack through a pipeline to form a circulation loop; a temperature regulating device, used for heating or cooling the electrolyte in the electrolyte storage; A flame retardant storage device stores flame retardant therein, wherein the flame retardant storage device is connected to the battery pack via a pipeline to form a circulation loop, and the battery pack can be selectively connected to the electrolyte storage device or the flame retardant storage device.

2. The rechargeable lithium-ion battery pack according to claim 1, characterized in that: The battery pack has a first liquid outlet, the electrolyte storage has a second liquid inlet, the flame retardant storage has a third liquid inlet, and the first liquid outlet is connected to the second liquid inlet and the third liquid inlet through a three-way valve.

3. The rechargeable lithium-ion battery pack according to claim 2, characterized in that: The rechargeable lithium-ion battery pack includes a pump body having two inlets and one outlet; The battery pack has a first liquid inlet, the electrolyte storage has a second liquid outlet, and the flame retardant storage has a third liquid outlet. The second liquid outlet and the third liquid outlet are respectively connected to the two inlets of the pump body, and the outlet of the pump body is connected to the first liquid inlet.

4. The rechargeable lithium-ion battery pack according to claim 3, characterized in that: The second liquid inlet and the second liquid outlet are respectively provided with a one-way valve, the one-way valve of the second liquid inlet is used to allow the electrolyte to flow into the electrolyte storage, and the one-way valve of the second liquid outlet is used to allow the electrolyte to flow out of the electrolyte storage.

5. The rechargeable lithium-ion battery pack according to claim 1, characterized in that: The battery pack includes a plurality of batteries arranged in sequence, each battery has a first liquid inlet at the bottom, each battery has a first liquid outlet at the top, and of two adjacent batteries, the first liquid outlet of the preceding battery is connected to the first liquid inlet of the succeeding battery.

6. The rechargeable lithium-ion battery pack according to claim 5, characterized in that: Along the flow direction of the electrolyte, the first liquid outlet of the last battery is connected to the electrolyte storage via a first pipeline, and an exhaust port is provided on the first pipeline.

7. The rechargeable lithium-ion battery pack according to claim 5, characterized in that: A liquid discharge port is respectively provided at the bottom of each battery.

8. The rechargeable lithium-ion battery pack according to claim 1, characterized in that: The electrolyte storage is provided with a liquid replenishing port.

9. The rechargeable lithium-ion battery pack according to claim 1, characterized in that: The rechargeable lithium-ion battery pack includes a housing in which the battery pack, an electrolyte reservoir, and a flame retardant reservoir are sealed.

10. The rechargeable lithium-ion battery pack according to claim 1, characterized in that: The temperature regulating device comprises a heat exchanger, the electrolyte storage is arranged in the form of a serpentine pipeline in the heat exchanger, and a heat exchange fluid is arranged in the heat exchanger.

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