Battery pack and power-using device

Abstract

The present application provides a battery pack and an electrical device, wherein the battery pack includes a plurality of battery cells, the plurality of battery cells are stacked, an elastic insulating film is provided between two adjacent battery cells, a receiving cavity is formed inside the elastic insulating film, and the receiving cavity contains an insulating agent. When the battery cell is pierced by a nail, the elastic insulating film undergoes elastic deformation, and the elastic insulating film wraps around the piercing object, and can still isolate the two adjacent battery cells, thereby reducing the possibility of electrical connection between the two adjacent battery cells due to the piercing of the piercing object, and can effectively reduce the probability of short circuit between the battery cells due to the piercing nail, thereby improving the safety of the battery pack.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack and an electrical device. Background Art

[0002] Rechargeable cells are batteries that can be recharged to activate the active material after the cells are discharged and continue to be used. Rechargeable cells are widely used in electronic devices, such as mobile phones, laptops, etc.

[0003] A battery pack usually includes multiple cells to meet the voltage requirements of electronic devices. In the development of battery technology, how to improve the safety of battery packs has always been a research direction in the industry. Summary of the invention

[0004] In view of the above problems, the present application provides a battery pack, which can enhance the protection of internal battery cells and help improve the safety of the battery pack.

[0005] In order to achieve the above purpose, this application adopts the following technical solutions:

[0006] In the first aspect, the present application provides a battery pack, comprising a plurality of stacked battery cells and an elastic insulating film. The elastic insulating film is at least arranged between two adjacent battery cells, and a receiving cavity is formed inside the elastic insulating film, and the receiving cavity contains an insulating agent. When an external puncturing object punctures the receiving cavity surrounded by the elastic insulating film, the insulating agent will be coated on the surface of the external puncturing object, forming an insulating layer on the surface of the external puncturing object, so that the puncturing object has insulating properties.

[0007] Through the above scheme, when the battery cell is pierced by a nail, the elastic insulating film undergoes elastic deformation, and the elastic insulating film wraps around the piercing object, and can still isolate the two adjacent battery cells, thereby reducing the possibility of electrical connection between the two adjacent battery cells due to the piercing of the piercing object, and can effectively reduce the probability of short circuit between the battery cells due to the piercing nail, thereby improving the safety of the battery pack.

[0008] In some embodiments of the present application, the insulating agent includes insulating paint or insulating glue. The insulating paint or insulating glue has good insulation and certain adhesion, and can be coated on the surface of the external puncture object to form an insulating layer.

[0009] In some embodiments of the present application, the battery pack further includes a buffer, which is disposed between two adjacent battery cells and is connected to the elastic insulating film. The buffer is sandwiched between two adjacent battery cells, which can not only buffer the expansion force generated by the battery cells during use, but also protect the battery cells, which is beneficial to improving the safety of the battery pack. The buffer is connected to the elastic insulating film, and the operator can also take the elastic insulating film by holding the buffer, which is convenient for loading the elastic insulating film.

[0010] In some embodiments of the present application, the buffer is placed in the accommodating cavity and connected to the wall of the accommodating cavity, or the buffer is arranged between the battery cell and the elastic insulating film, so that the buffer can be connected to the elastic insulating film from inside or outside the accommodating cavity.

[0011] In some embodiments of the present application, the buffer is made of foam, so that the buffer has a series of characteristics such as elasticity, light weight, easy use, ultra-thin volume, and reliable performance.

[0012] In some embodiments of the present application, the elastic insulating film includes at least one of polypropylene, polyethylene, and nylon, so that the elastic insulating film not only has good insulation properties, but also has good corrosion resistance, can meet the requirements of insulation and corrosion resistance, and also enables the elastic insulating film to meet the requirements of elongation and tensile strength.

[0013] In some embodiments of the present application, the elongation of the elastic insulating film is greater than 50%, which enables the elastic insulating film to have sufficient elongation so that when an external puncturing object pierces the elastic insulating film, the elastic insulating film can deform and wrap around the surface of the external puncturing object to isolate two adjacent battery cells.

[0014] In some embodiments of the present application, the tensile strength of the elastic insulating film is greater than 100 gf, so that the elastic insulating film can undergo uniform plastic deformation in a larger range, and the elastic insulating film has a larger load-bearing capacity.

[0015] In some embodiments of the present application, two side surfaces of the elastic insulating film are respectively bonded to the side surfaces of two adjacent battery cells by adhesive, so that the elastic insulating film is connected between the side surfaces of the two adjacent battery cells to cover the side surfaces of the two battery cells.

[0016] In a second aspect, the present application provides a battery pack, which includes the battery pack provided by any of the above technical solutions.

[0017] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects:

[0018] The present application provides a battery pack, which includes a plurality of battery cells, which are stacked, and an elastic insulating film is provided between two adjacent battery cells, and the elastic insulating film is configured to elastically deform when an external puncturing object pierces the elastic insulating film to cover the puncturing object. When the battery cell is pierced by a nail, the elastic insulating film is elastically deformed, and the elastic insulating film is wrapped around the puncturing object, and can still isolate the two adjacent battery cells, thereby reducing the possibility of electrical connection between the two adjacent battery cells due to the puncture of the puncturing object, and can effectively reduce the probability of short circuit between the battery cells due to the puncturing nail, thereby improving the safety of the battery pack.

[0019] The present application also provides an electrical device, which has high safety because it includes the battery pack provided by the aforementioned technical solution.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0022] Figure 1 A partial structural schematic diagram of a battery pack provided in some embodiments of the present application;

[0023] Figure 2 In some embodiments Figure 1 Sectional view at A in the middle;

[0024] Figure 3 In some further embodiments Figure 1 Sectional view at A in the middle;

[0025] Figure 4 for Figure 1 A schematic diagram of the structure of an electrical device provided in some embodiments of the present application.

[0026] In the figure: 1. battery cell; 2. elastic insulating film; 3. accommodating cavity; 4. circuit board; 5. tab; 7. buffer; 2000. battery pack; 3000. electrical device. DETAILED DESCRIPTION

[0027] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0028] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0029] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0030] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0031] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0032] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature 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, a first feature being "above", "above" or "above" a 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. A first feature being "below", "below" or "below" a 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.

[0033] At present, from the perspective of market development, the application of battery packs is becoming more and more extensive. Battery packs are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as communication equipment, military equipment and aerospace and other fields. With the continuous expansion of the application field of battery packs, its market demand is also constantly expanding.

[0034] The technical solution of a battery pack and an electrical device provided by the present application is further described below through specific implementation methods.

[0035] Please refer to Figure 1 , Figure 1 A partial structural schematic diagram of a battery pack provided in some embodiments of the present application, wherein the battery pack includes a battery cell and an elastic insulating film, wherein a plurality of battery cells are provided, and the plurality of battery cells are stacked, and the elastic insulating film is arranged at least between two adjacent battery cells, and the elastic insulating film is configured so that when an external puncturing object pierces the elastic insulating film, the elastic insulation will undergo elastic deformation to cover the external puncturing object, and the elastic insulating film can completely cover the contact surface between two adjacent battery cells, so that the external puncturing object passing through the battery cell can act on the elastic insulating film, thereby preventing omission due to too small a coverage area of ​​the elastic insulating film.

[0036] Through the above technical solution, when the battery cell is pierced by a nail, when the external piercing object pierces the elastic insulating film, the insulating film undergoes elastic deformation, and the elastic insulating film wraps around the external piercing object. The elastic insulating film can still isolate the two adjacent battery cells, thereby reducing the possibility of electrical connection between the two adjacent battery cells due to the piercing of the external piercing object, and can effectively reduce the probability of short circuit between the battery cells due to the piercing nail, thereby improving the safety of the battery pack.

[0037] In some embodiments of the present application, the two side surfaces of the elastic insulating film are bonded to the side surfaces of two adjacent battery cells by an adhesive, so that the elastic insulating film is connected between the side surfaces of the two adjacent battery cells, thereby covering the side surfaces of the two battery cells. There is no restriction on the type of adhesive, and it can be a material with an adhesive effect such as a double-sided tape. The two side surfaces of the elastic insulating film can be bonded to the side surfaces of two adjacent battery cells by an adhesive, thereby achieving connection and covering of the side surfaces of the two battery cells; the two side surfaces of the elastic insulating film can be bonded to the side surfaces of two adjacent battery cells by an adhesive, so that the elastic insulating film is bonded between the two adjacent battery cells, and the adhesive can be glue, thereby achieving connection between the elastic insulating film and the battery cells.

[0038] In some embodiments, the elongation of the elastic insulating film is greater than 50%, or the tensile strength of the elastic insulating film is greater than 100 gf.

[0039] The elongation δ is the percentage of the total deformation ΔL of the gauge section after the specimen is stretched and ruptured to the original gauge length L: δ = ΔL / L × 100%. The elongation of the elastic insulating film is greater than 50%, which can make the elastic insulating film have sufficient elongation, so that when an external puncture object pierces the elastic insulating film, the elastic insulating film can deform and cover the surface of the external puncture object to isolate two adjacent battery cells. The elongation of the elastic insulating film can be set to 60%, 70% or 80%. The specific value of the elongation of the elastic insulating film can be selected by those skilled in the art according to actual conditions, as long as the elastic insulating film can be deformed and covered on the surface of the external puncture object without being easily broken.

[0040] In some embodiments of the present application, the elongation of the elastic insulating film is greater than that of the buffer, so that when the battery pack is pierced by a nail, after the buffer is ruptured by the puncture of the external puncture object, the elastic insulating film will not rupture but will deform and wrap around the surface of the external puncture object.

[0041] The essence of tensile strength is the resistance of the material to maximum uniform plastic deformation, which is the maximum load-bearing capacity under static tensile conditions. The tensile strength of the elastic insulating film is greater than 100gf, so that the elastic insulating film can undergo uniform plastic deformation in a larger range, so that the elastic insulating film has a larger load-bearing capacity, and also enables the elastic insulating film to deform and wrap around the surface of the external puncture object when an external puncture object pierces the elastic insulating film, so as to isolate two adjacent battery cells. The tensile strength of the elastic insulating film can be set to 110gf, 120gf or 130gf. The specific value of the tensile strength of the elastic insulating film can be selected by those skilled in the art according to actual conditions, as long as the elastic insulating film can be deformed and wrapped around the surface of the external puncture object without being easily broken.

[0042] In some embodiments, the elastic insulating film is configured not to rupture when an external puncturing object penetrates 2 mm, so that the elastic insulating film can wrap around the external puncturing object to isolate two adjacent battery cells, thereby reducing the possibility of electrical connection between the two adjacent battery cells due to puncture by the external puncturing object, and can effectively reduce the probability of short circuit between battery cells due to piercing nails.

[0043] Preferably, the elastic insulating film is made of one of polypropylene, polyethylene and nylon. Polypropylene, polyethylene and nylon not only have good insulation properties, but also have good corrosion resistance, which can meet the requirements of insulation and corrosion resistance, and also enable the elastic insulating film to meet the requirements of elongation and tensile strength.

[0044] like Figure 2 and Figure 3 As shown, in some embodiments of the present application, a receiving cavity is formed inside the elastic insulating film, and the receiving cavity contains an insulating agent. The receiving cavity is a cavity body, which is used to contain the insulating agent, and the receiving cavity is surrounded by the elastic insulating film.

[0045] In some embodiments, the accommodating cavity can be formed together with the processing of the elastic insulating film when the elastic insulating film is processed and formed. Specifically, when processing the elastic insulating film, two layers of elastic insulating film are processed to form an accommodating cavity for accommodating the insulating agent between the two layers of elastic insulating film; or when forming the elastic insulating film, a cavity is formed in a single layer of elastic insulating film, and the cavity is used as the accommodating cavity for accommodating the insulating agent. In some embodiments, the accommodating cavity can be formed by connecting another layer of elastic insulating film to the formed elastic insulating film, so that the accommodating cavity is formed between the two layers of elastic insulating film. The method for forming the accommodating cavity can be selected by those skilled in the art according to actual conditions.

[0046] The insulating agent is a reagent with good insulating properties. It has a certain adhesion ability and can adhere to the surface of an object to form an insulating layer on the surface of the object, thereby making the object insulating. When an external puncturing object punctures the accommodating cavity surrounded by the elastic insulating film, the insulating agent will be coated on the surface of the external puncturing object to form an insulating layer on the surface of the external puncturing object, making the puncturing object insulating. Regardless of whether the puncturing object itself has insulating properties, it has insulating properties after being coated with the insulating agent in the accommodating cavity. Therefore, even if the external puncturing object passes through two adjacent battery cells, it still cannot electrically connect the adjacent battery cells, reducing the possibility of short circuits between adjacent battery cells.

[0047] In some embodiments, the insulating agent includes insulating paint or insulating glue. Insulating paint is a coating with excellent electrical insulation. It has good electrochemical properties, thermal properties, mechanical properties and chemical properties, and is a special paint in the paint category. Insulating paint is an important insulating material based on high molecular polymers that can be cured into an insulating film or an insulating whole under certain conditions. Insulating paint is usually composed of a base material, a flame retardant, a curing agent, a pigment, a filler and a solvent.

[0048] Insulation glue is a composite glue with good electrical insulation properties. It can be used to cast device joints, impregnate the surface of devices, and be used as sealing insulation for transformers, capacitors or radio devices, as well as surface sheaths for electrical and electronic components.

[0049] like Figure 2 and Figure 3 As shown, in some embodiments, the battery pack further includes a buffer, which is disposed between two adjacent battery cells and is connected to the elastic insulating film. The buffer is sandwiched between two adjacent battery cells, which can not only buffer the expansion force generated by the battery cells during use, but also protect the battery cells, which is beneficial to improving the safety of the battery pack; the operator can also take the elastic insulating film by holding the buffer, which is convenient for loading the elastic insulating film.

[0050] In some embodiments of the present application, the buffer is made of foam, the foam is configured in layers, and the layered foam is sandwiched between two adjacent battery cells to facilitate the stacking of multiple battery cells. The buffer is made of foam and is used to buffer the force between the battery cells, so that the buffer has a series of characteristics such as elasticity, light weight, easy use, ultra-thin volume, and reliable performance.

[0051] like Figure 2 As shown, in some embodiments, the buffer is placed in the accommodating cavity and connected to the inner wall surface of the accommodating cavity, so that the buffer is connected to the wall surface in the accommodating cavity, and the buffer can support the accommodating cavity, so that the elastic insulating film with the accommodating cavity can be installed between two adjacent battery cells by using the buffer, so that the installation of the elastic insulating film is convenient. Figure 3 As shown, in some embodiments, a buffer component can also be arranged between the battery cell and the elastic insulating film. The buffer component is located outside the accommodating cavity and is connected to the outer wall surface of the elastic insulating film that forms the accommodating cavity, so that the buffer component can support the elastic insulating film, and it is convenient to use the buffer component to install the elastic insulating membrane with the accommodating cavity between two adjacent battery cells, so that the installation of the elastic insulating film is convenient.

[0052] In some embodiments, Figure 1 As shown, the battery pack also includes a circuit board, which is electrically connected to the tabs of the battery cell. The circuit board can intelligently manage and maintain each battery cell.

[0053] The present application also provides a method for assembling a battery pack. The technical solution for the method for assembling a battery pack provided in the present application is further described below through specific implementation methods.

[0054] Exemplarily, the assembly method of a battery pack in which the buffer is disposed between the battery cell and the elastic insulating film includes the following steps:

[0055] S1. Test the battery cells.

[0056] That is, the obtained finished battery cells are tested.

[0057] S2. Connect the support members to the sides of the battery cell.

[0058] That is, a support member is attached to the side of the battery cell that is connected to other battery cells.

[0059] S3. Connect the elastic insulating film.

[0060] That is, the elastic insulating film is connected to the support member by double-sided adhesive to achieve the arrangement of the elastic insulating film between two adjacent battery cells.

[0061] S4. Multiple battery cells are stacked to form a battery cell module.

[0062] That is, a plurality of battery cells are stacked to form a battery cell module.

[0063] S5. The battery cell modules are assembled to form a battery pack.

[0064] That is, the cell module is processed and assembled to form a battery module. The specific steps are: foam is set on both end surfaces of the cell module, and then the cell module is placed on the laser welding fixture, the cell tabs are bent and rolled flat, and then connected to the copper sheet through the first laser welding, and the solder joints are cleaned and the internal resistance is tested, the total positive and negative tabs are rolled flat, and then connected to the circuit board through the second laser welding, and the solder joints are cleaned and the internal resistance is tested, and the cell module connected to the circuit board is tested, and the cell module is locked and pressurized and then installed in the shell, and the battery pack is formed after the wire harness is arranged, the shell is assembled, and it is placed at high temperature.

[0065] S6. Test the battery cell;

[0066] That is, the battery cell is subjected to a nail penetration test. The specific method of the nail penetration test can be:

[0067] 1. Charge the battery pack at a constant current of 3.9A to 54.2V, and then charge at a constant voltage of 54.2V until the current reaches 0.26A.

[0068] That is to say, the battery pack is charged before the test so that the cells in the battery pack are in a preset state. The battery pack is first charged at a constant current of 3.9A until the voltage of the battery pack reaches 54.2V, and then the battery pack is charged at a constant voltage of 54.2V until the charging current reaches 0.26A and is cut off.

[0069] 2. Arrange a temperature sensing wire on the outer shell of the battery pack and record the temperature of the temperature sensing wire during the measurement process.

[0070] That is, a temperature sensing wire is arranged on the surface of the battery pack casing, and the temperature measured by the temperature sensing wire during the measurement process is recorded.

[0071] 3. Use a 5mm diameter steel needle to puncture the battery cell at a speed of 25mm / s, so that the penetration depth of the steel needle is 36mm.

[0072] That is, a puncture device is used to pierce a steel needle with a diameter of 5 mm from the side of the battery cell at a speed of 25 mm / s. The penetration depth of the steel needle is 36 mm, so that the steel needle pierces at least two battery cells to ensure that the steel needle pierces the elastic insulating film.

[0073] 4. Observe for 2 hours.

[0074] That is, the battery cell is kept at rest for 2 hours, and the state of the battery cell is observed and recorded to determine whether thermal failure occurs in the battery cell.

[0075] Through the above technical solution, when the battery cell is pierced by a nail, when the external piercing object pierces the elastic insulating film between the two battery cells, the insulating film is elastically deformed, and even if the external piercing object continues to pierce the battery cell, the elastic insulating film is still wrapped by the external piercing object. The elastic insulating film can still isolate the two adjacent battery cells, thereby reducing the possibility of electrical connection between the two adjacent battery cells due to the piercing of the external piercing object, and can effectively reduce the probability of short circuit between the battery cells due to the piercing nail, thereby improving the safety of the battery pack.

[0076] Some embodiments of the present application further provide an electrical device, which includes a battery pack provided by the above technical solution, and the battery pack is used to provide electrical energy to the electrical device.

[0077] like Figure 4 As shown, the embodiment of the present application also provides an electric device 3000 using the battery pack 2000 as a power source, and the electric device 3000 can be a mobile phone, a portable device, a laptop computer, an electric toy, an electric tool, etc. The electric tool includes a metal cutting electric tool, a cleaning tool, etc., for example, an electric drill, an electric wrench, a vacuum cleaner, a sweeping robot, etc. The embodiment of the present application does not impose any special restrictions on the above-mentioned electric device 3000.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery pack, characterized in that: include: A plurality of battery cells arranged in a stacked manner; An elastic insulating film is provided at least between two adjacent battery cells, a receiving cavity is formed inside the elastic insulating film, and the receiving cavity contains an insulating agent; the insulating agent can wrap the external puncturing object when the external puncturing object punctures the receiving cavity; the elongation of the elastic insulating film is greater than 50%, or the tensile strength of the elastic insulating film is greater than 100gf; A buffer component is disposed between two adjacent battery cells, the buffer component is connected to the elastic insulating film, and the buffer component is placed in the accommodating cavity and connected to the wall surface of the accommodating cavity.

2. The battery pack according to claim 1, characterized in that: The insulating agent includes insulating varnish or insulating glue.

3. The battery pack according to claim 1, characterized in that: The buffer is made of foam.

4. The battery pack according to claim 1, characterized in that: The elastic insulating film includes at least one of polypropylene, polyethylene and nylon.

5. The battery pack according to claim 1, characterized in that: The two side surfaces of the elastic insulating film are respectively bonded to the side surfaces of two adjacent battery cells by adhesive.

6. An electrical device, characterized in that: A battery pack comprising the battery pack according to any one of claims 1 to 5.

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