A battery pack and an electric vehicle

Abstract

The application relates to a battery pack and an electric vehicle, and belongs to the technical field of new energy automobile power batteries. The battery pack comprises a battery box and a single battery, the battery box comprises a box cover and a lower box body, a waterproof, breathable and explosion-proof valve is arranged on the lower box body, the single battery is directly bonded to the lower box body through heat-conducting structural glue, the single battery comprises a battery body, a battery pole and a battery explosion-proof valve, the battery body is in a flat square structure, and the battery pole and the battery explosion-proof valve are arranged on different side walls of the battery body. Compared with the prior art, the application has the advantages of high heat transfer efficiency and high safety.

Description

[0001] This application is a divisional application of the parent application with application number "202110188956.9", application date "2021.02.19", and title "A Battery Pack and an Electric Vehicle". Technical Field

[0002] This invention relates to the field of power battery technology for new energy vehicles, and in particular to a battery pack and an electric vehicle. Background Technology

[0003] In recent years, with the rapid development of lithium-ion battery technology, the pace at which lithium-ion batteries are replacing traditional lead-acid batteries in various power supply fields, such as electric vehicles, is gradually accelerating. Compared with traditional lead-acid batteries, lithium-ion batteries have advantages such as high energy density, small size, light weight, long service life, and wide operating temperature range. Currently, the technology of lithium-ion batteries is becoming increasingly mature, and the cost is gradually becoming more reasonable, making them a mainstream high-end starting power solution.

[0004] Existing technologies primarily use prismatic aluminum-cased batteries. Prismatic aluminum-cased individual batteries (i.e., cells) generally need to be assembled into battery modules first, and multiple battery modules, along with some accessories, are then assembled into a battery pack, such as... Figure 1 As shown, the battery pack comprises a battery box and battery modules 103 and BMS 107 housed within the battery box. The battery box includes a lower housing 104 and a cover 101. A BDU (Battery Distribution Unit) is installed on the inner wall of the lower housing 104, and connectors 105 are correspondingly provided on the outer wall. A waterproof, breathable, and explosion-proof valve 106 is also provided on the outer wall of the lower housing 104. Existing battery packs still suffer from shortcomings such as low heat transfer efficiency, low assembly efficiency, and low safety performance. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a battery pack and electric vehicle with high heat transfer efficiency and high safety.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a battery pack, including a battery box and individual batteries. The battery box includes a box cover and a lower box body. A waterproof, breathable, and explosion-proof valve is provided on the lower box body. The individual batteries are directly bonded to the lower box body by thermally conductive structural adhesive. The individual batteries include a battery body, battery terminals, and a battery explosion-proof valve. The battery body has a flat square structure. The battery terminals and the battery explosion-proof valve are disposed on different side walls of the battery body.

[0007] In an optional embodiment, a flow guide shroud communicating with the waterproof, breathable, and explosion-proof valve is provided on the inner side wall of the lower housing.

[0008] In an optional embodiment, the flow deflector and the battery explosion-proof valve are located on the same side.

[0009] In an optional embodiment, each of the individual batteries is provided with two battery explosion-proof valves, and the two inner sidewalls of the lower housing are provided with the flow guides.

[0010] In an optional embodiment, a plurality of the individual cells are arranged in the lower housing with the side having the largest area as the contact surface.

[0011] In an optional embodiment, the battery body includes a battery casing, which is an ultra-thin stainless steel foil casing.

[0012] In an optional embodiment, the thickness of the battery body is 8 to 30 mm.

[0013] In an optional implementation, the battery explosion-proof valve may be provided in one or two manner.

[0014] In an optional embodiment, the two battery explosion-proof valves are distributed on two symmetrical sidewalls of the battery body.

[0015] Secondly, the present invention provides an electric vehicle including the battery pack described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The single battery cell of the present invention is directly bonded to the lower housing by thermally conductive structural adhesive, which greatly improves the rigidity and structural strength of the lower housing shell. At the same time, a good thermal interface is formed between the battery and the lower housing, which improves the heat transfer efficiency of the battery and the lower housing.

[0017] 2. The individual cells of the present invention are arranged in the lower box, eliminating the traditional module structure. Multiple individual cells are directly assembled into a battery pack, reducing the number of battery pack components, simplifying the product structure, and increasing production efficiency.

[0018] 3. In this invention, the battery explosion-proof valve and the battery terminal are not set on the same side, but on both sides. When the battery experiences thermal runaway, the battery explosion-proof valve ruptures, and the electrolyte, gas and flame generated inside the battery are sprayed out to both sides of the cell. This can reduce the impact on the top and prevent the discharged material from splashing onto the aluminum bar and causing a short circuit or high-voltage spark, and prevent the box cover from deforming and breaking.

[0019] 4. This invention features a guide shroud connected to a waterproof, breathable, and explosion-proof valve, forming an exhaust channel on the side of the battery pack. When a single cell experiences thermal runaway, the explosion-proof valve on the battery sidewall ruptures, and electrolytes, gases, and other substances inside the battery are discharged into the exhaust channel on the side. They then travel along the exhaust channel to the waterproof, breathable, and explosion-proof valve and are quickly discharged outside the battery pack. This exhaust channel effectively prevents the high-temperature substances discharged from the battery from damaging the battery pack cover and also prevents the discharged substances from splashing onto the aluminum foil, causing short circuits or high-voltage sparks, thus improving the safety performance of the battery pack.

[0020] 5. The battery pack constructed using the batteries of this invention has a simpler structure, higher production efficiency, and is safer. Experimental results show that the battery pack's mass energy density is increased by 3%, assembly efficiency by 3%, volume utilization by 5%, and cost is reduced by 5%. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an existing battery pack; Figure 2 This is a schematic diagram of the battery pack structure of the present invention; Figure 3 This is a schematic diagram illustrating the configuration of the air deflector of the present invention; Figure 4 This is a schematic diagram showing the positional relationship between the flow guide cover and the battery explosion-proof valve of the present invention; Figure 5 This is a schematic diagram of the structure of a single cell battery of the present invention; In the diagram: 101, cover; 102, BDU; 103, battery module; 104, lower casing; 105, connector; 106, waterproof, breathable, and explosion-proof valve; 107, BMS; 108, single battery cell; 109, air deflector; 201, battery explosion-proof valve; 202, battery positive terminal; 203, battery casing; 204, battery negative terminal. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0028] refer to Figure 2 As shown, this embodiment provides a battery pack, including a battery box and individual batteries 108. The battery box includes a cover 101 and a lower box body 104. A waterproof, breathable, and explosion-proof valve 106 is provided on the lower box body 104. The individual batteries 108 are directly bonded to the lower box body 104 using thermally conductive structural adhesive, which significantly improves the rigidity and structural strength of the lower box body. At the same time, a good thermal interface is formed between the battery cell and the lower box body, improving the heat transfer efficiency between the battery and the lower box body. This battery pack eliminates the traditional module structure, directly assembling multiple individual batteries into a battery pack, reducing the number of components, simplifying the product structure, and increasing production efficiency.

[0029] refer to Figure 5As shown, a single battery cell 108 includes a battery body, battery terminals, and a battery explosion-proof valve 201. The battery body has a flat, square structure with a thickness T of 8–30 mm. The battery terminals are located on a first side of the battery body and include a positive electrode 202 and a negative electrode 204. The battery explosion-proof valve 201 is located on a second side perpendicular to the first side. Both the first and second sides are surfaces with smaller areas than the battery body. In this embodiment, the first side is a surface composed of the width and thickness directions, and the second side is a surface composed of the thickness and height directions. When the batteries are assembled into a battery pack, the first side faces upwards. Multiple batteries are arranged to form a battery pack using the surface with the largest area (i.e., the surface composed of the width and height directions) as the contact surface, resulting in high packing efficiency.

[0030] In an optional implementation, the battery explosion-proof valve may be provided or provided in one or two ways. When provided in one way, it may be located on the left or right side. When provided in two ways, one may be located on each side.

[0031] like Figure 5 As shown in this embodiment, there are two battery explosion-proof valves, one on each of the two second sides. When the battery experiences thermal runaway, the battery explosion-proof valve ruptures, and the electrolyte, gas, and generated flames inside the battery are ejected to both sides of the cell, which can reduce the impact on the top of the battery pack.

[0032] In the novel battery provided in this embodiment, the battery body only uses a battery casing 50 to encapsulate the internal materials, and the battery casing 50 is an ultra-thin stainless steel foil casing. In an optional embodiment, the thickness of the battery casing is 0.05–0.6 mm.

[0033] In this embodiment, the thickness of the battery casing is 0.1 mm, and the casing strength is similar to that of a square aluminum casing battery cell. Since the density of aluminum is about 1 / 3 that of steel, the weight of the battery casing is reduced.

[0034] In this embodiment, the width W of the battery body is 300-2000mm, which facilitates the rapid formation of the battery pack.

[0035] For reference Figure 3 and Figure 4 As shown, a ventilator 109, which communicates with a waterproof, breathable, and explosion-proof valve 106, is also provided on the inner wall of the lower casing 104 of the battery pack, forming an exhaust channel. In a preferred embodiment, the ventilator 109 and the battery explosion-proof valve 201 are located on the same side. When a single battery cell experiences thermal runaway, the explosion-proof valve on the battery sidewall ruptures, releasing electrolyte, gas, etc., from the battery.

[0036] The waste is discharged into the exhaust channel, and then along the exhaust channel to the waterproof, breathable, and explosion-proof valve of the battery pack, where it is quickly discharged outside the battery pack.

[0037] In an optional embodiment, each individual battery cell 108 is provided with two battery explosion-proof valves 201, and the two inner sidewalls of the lower housing 104 are provided with corresponding flow guides 109.

[0038] In other embodiments, an electric vehicle is provided, including the battery pack described above. In this embodiment, the vehicle may be a new energy vehicle, etc.

[0039] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A battery pack, characterized in that, It includes a battery box and individual batteries (108), the battery box including a box cover (101) and a lower box body (104); The single battery (108) includes a battery body, a battery terminal and at least one battery explosion-proof valve (201). The battery body has a flat square structure. The battery terminal is disposed on a first side of the battery body. The battery explosion-proof valve (201) is disposed on a second side perpendicular to the first side. The first side and the second side are both smaller surfaces of the battery body. Multiple individual cells (108) are arranged in a group with the side with the largest area as the contact surface; The individual battery cell (108) is bonded to the lower housing (104) with thermally conductive structural adhesive to form the battery pack, and the first side is the upward-facing side; A waterproof, breathable, and explosion-proof valve (106) is provided on the side wall of the lower housing (104).

2. The battery pack according to claim 1, characterized in that, The first side is a surface composed of the width direction and the thickness direction, and the second side is a surface composed of the thickness direction and the height direction.

3. The battery pack according to claim 1, characterized in that, It also includes a battery casing (203) for encapsulating the battery body, and the battery casing (203) is an ultra-thin stainless steel foil casing.

4. The battery pack according to claim 3, characterized in that, The thickness of the battery casing (203) is 0.05 to 0.6 mm.

5. The battery pack according to claim 1, characterized in that, The battery body has a thickness of 8-30 mm and a width of 300-2000 mm.

6. The battery pack according to claim 1, characterized in that, The at least one battery explosion-proof valve (201) is two, and the two battery explosion-proof valves (201) are respectively disposed on two symmetrical second sides of the battery body.

7. The battery pack according to claim 1, characterized in that, The inner wall of the lower housing (104) is provided with a guide hood (109) that communicates with the waterproof, breathable and explosion-proof valve (106) to form an exhaust channel.

8. The battery pack according to claim 7, characterized in that, The flow guide (109) and the battery explosion-proof valve (201) are located on the same side.

9. The battery pack according to claim 7, characterized in that, When the single cell (108) experiences thermal runaway, the discharge from the single cell (108) is discharged outside the battery pack through the waterproof, breathable, and explosion-proof valve (106) along the exhaust channel.

10. An electric vehicle, characterized in that, Includes the battery pack as described in any one of claims 1-9.

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