The present application relates to the technical field of batteries, and in particular to a battery, an electrical apparatus, and a method and an apparatus for making a battery.
Energy saving and emission reduction is the key to the sustainable development of automobile industry. In such cases, electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages of energy saving and environmental friendliness. For electric vehicles, battery technology is an important factor related to their development.
In the development of battery technology, in addition to improving battery performances, safety issues are also non-negligible. A battery cannot be used if battery safety cannot be guaranteed. Therefore, how to enhance the safety of a battery is an urgent technical issue in battery technology.
The present application provides a battery, an electrical apparatus, and a method and an apparatus for making a battery, which can enhance the safety of the battery.
In a first aspect, there is provided a battery comprising: a battery cell; a first component, wherein a first surface of the first component is connected to at least one of the battery cells through an adhesion member, the adhesion member comprises a first adhesion structure and a second adhesion structure, the first adhesion structure is located at the periphery of the second adhesion structure, and the first adhesion structure has an elongation at break greater than that of the second adhesion structure.
Therefore, in the battery according to the embodiments of the present application, the adhesion member comprising two adhesion structures is provided between the battery cell and the first component to fix the battery cell, wherein the first component may comprise a box body of the battery or an upper cover within the box body, so that the first adhesion structure with a higher elongation at break is located at the periphery of the second adhesion structure with a lower elongation at break, so that after the expansion and deformation of the battery cell, the edge position is the first adhesion structure with high elongation at break, which is able to maintain the connection between the battery cell and the upper cover or between the battery cell and the box body fixed, thus improving the stability of the battery cell within the battery, and in turn improving the safety of the battery.
In some embodiments, the elongation at break A1 of the first adhesion structure satisfies: 100%≤A1≤500%; and/or the elongation at break B1 of the second adhesion structure satisfies: 10%≤B1≤150%.
In some embodiments, the elongation at break A1 of the first adhesion structure satisfies: 150%≤B1≤400%; and/or the elongation at break B1 of the second adhesion structure satisfies: 60%≤B1≤120%.
By reasonably setting the elongation at break of the first adhesion structure and the elongation at break of the second adhesion structure, after the expansion and deformation of the battery cell, the connection between the battery cell and the upper cover or between the battery cell and the box body can be maintained fixed through the first adhesion structure with high elongation at break.
In some embodiments, the adhesion member is used for bonding a second surface of at least one of the battery cells to the first surface, and the second adhesion structure covers a central point of the second surface.
Considering that when the battery cell expands, the deformation amount of the central position of the battery cell is larger, and the deformation amount of the edge region is relatively small, that is to say, the distance from the central position of the battery cell to the first surface is smaller than the distance from the edge region to the first surface, so the second adhesion structure with smaller elongation at break and higher strength is provided at the central position, which can cover the central point of the surface of the battery cell where it is located, and can ensure the stability between the battery cell and the first component.
In some embodiments, the first adhesion structure surrounds the periphery of the second adhesion structure.
Considering that when the battery cell expands, the deformation amount of the central position of the battery cell is larger, and the deformation amount of the edge position of the battery cell is smaller, that is to say, the distance from the edge region of the battery cell to the first surface is greater than the distance from the central position to the first surface, so the first adhesion structure with larger elongation at break is provided all around the second adhesion structure, which can reduce the risk of unbonding at the edge region all around the battery cell after the expansion and deformation of the battery cell.
In some embodiments, the adhesion member is used for bonding a second surface of at least one of the battery cells to the first surface, and where the area of the second surface is S0, the contact area of the first adhesion structure with the second surface is S1, the contact area of the second adhesion structure with the second surface is S2, then S0, S1 and S2 satisfy: 0.25≤(S1+S2)/S0<1.
When the contact area of the adhesion member with the first surface or the contact area with the second surface of the battery cell is smaller, the binding force of the adhesion structure to the battery cell is weak, there is a risk of failure due to vibration impact, and the capacity retention rate of the battery cell is poor; whereas when the contact area of the adhesion member with the first surface or the contact area with the second surface of the battery cell is too large, it may cause glue overflow and adhesion to the structural parts such as an electrode terminal of the battery cell or a battery wiring harness, and in turn result in the risk of failure due to vibration impact; therefore, 0.25≤(S1+S2)/S0<1 can ensure that there is no battery failure under vibration, and can also ensure that the capacity retention rate of the battery is in a better range.
In some embodiments, S0, S1, and S2 satisfy: 0.5≤(S1+S2))/S0≤0.85.
Therefore, when 0.5≤(S1+S2)/S0≤0.85, the vibration impact and the capacity retention rate of the battery are better.
In some embodiments, the contact area of the first adhesion structure with the first surface is S1, the contact area of the second adhesion structure with the first surface is S2, and S1 and S2 satisfy: 0.05≤S1/(S1+S2)≤0.85.
In some embodiments, S1 and S2 satisfy: 0.15≤S1/(S1+S2)≤0.55.
By the area ratio of the first adhesion structure to the second adhesion structure set above, the amount of glue used can be reduced as much as possible while ensuring the structural strength.
The gluing area ratio of the first adhesion structure at the edge position has an influence on the structural strength, and increasing the content of the first adhesion structure in a certain range is beneficial to improving the structural strength of the battery and enhancing the capacity retention rate. When S1/(S1+S2) is equal to 1, that is, only the first adhesion structure is used, the adhesion structure has weak binding strength to the battery structure. When S1/(S1+S2) is equal to 0.02, it indicates that the majority of the adhesion structure is the second adhesion structure, which can lead to the unbonding problem. When 0.05≤S1/(S1+S2)≤0.85, it can not only ensure that there is no battery failure under vibration, but also ensure that the capacity retention rate of the battery is in a better range. Especially when 0.15≤S1/(S1+S2)≤0.55, the anti-vibration impact performance of the battery is better.
In some embodiments, the elastic modulus of the first adhesion structure is less than that of the second adhesion structure. The elongation at break of a adhesion structure such as a glue is generally negatively correlated with the elastic modulus, and therefore, setting the elastic modulus of the first adhesion structure to be less than the elastic modulus of the second adhesion structure can also ensure that the elongation at break of the first adhesion structure is greater than the elongation at break of the second adhesion structure, so as to reduce the risk of unbonding at the edge of the battery cell.
In some embodiments, the elastic modulus A2 of the first adhesion structure satisfies: 10 MPa≤A2≤150 MPa; and/or the elastic modulus B2 of the second adhesion structure satisfies: 150 MPa≤B2≤1000 MPa.
In some embodiments, the elastic modulus A2 of the first adhesion structure satisfies: 30 MPa≤A2≤60 MPa; and/or the elastic modulus B2 of the second adhesion structure satisfies: 150 MPa≤B2≤500 MPa.
In some embodiments, the strength of the first adhesion structure is less than the strength of the second adhesion structure. The strength of a adhesion structure such as a glue is generally positively correlated with the elastic modulus, while the elongation at break is negatively correlated with the elastic modulus; therefore, a greater strength of the second adhesion structure can ensure the stability of the battery cell, while a greater strength and a greater elongation at break of the first adhesion structure can reduce the risk of unbonding at the edge of the battery cell.
In some embodiments, the strength A3 of the first adhesion structure satisfies: 2 MPa≤A3≤15 MPa; and/or,
The strength B3 of the second adhesion structure satisfies: 6 MPa≤B3≤25 MPa.
In some embodiments, the strength A3 of the first adhesion structure satisfies: 6 MPa≤A3≤15 MPa; and/or the strength B3 of the second adhesion structure satisfies: 8 MPa≤B3≤25 MPa.
In some embodiments, the battery comprises a plurality of battery cell groups arranged in a first direction perpendicular to the first surface, each battery cell group of the plurality of battery cell groups comprises at least two battery cells arranged in a second direction perpendicular to the first direction, and the adhesion member is provided between a first battery cell group of the plurality of battery cell groups and the first surface.
In some embodiments, a plurality of the adhesion members are provided between the first battery cell group and the first surface, and the plurality of the adhesion members correspond to the battery cells in the first battery cell group on a one-to-one basis. In this way, the stability of each battery cell can be better ensured when the battery cell expands and deforms.
In some embodiments, one of the adhesion members is provided between the first battery cell group and the first surface to simplify the course of processing.
In some embodiments, a gap is provided between the first adhesion structure and the second adhesion structure.
In the above solution, when materials of the same system with different characteristics are selected for the first adhesion structure and the second adhesion structure, there may be mutual influence between the two; for example, glues of the same polyurethane system with different characteristics are selected as the materials for the first adhesion structure and the second adhesion structure, and the two may react to influence each other. A gap is provided between the first adhesion structure 51 and the second adhesion structure 52, which can reduce the mutual influence between the first adhesion structure 51 and the second adhesion structure 52.
In some embodiments, a blocking member is provided between the first adhesion structure and the second adhesion structure.
It is possible to better avoid the mutual influence between the first adhesion structure and the second adhesion structure by providing the blocking member.
In some embodiments, the material of the first adhesion structure includes at least one of: epoxy resin, polyurethane, acrylic resin and silicone rubber; and/or the material of the second adhesion structure includes at least one of: epoxy resin, polyurethane and acrylic resin.
In some embodiments, the battery comprises a first box body and a second box body that are snap-fitted to form an accommodating space for accommodating the battery cell, and the first component comprises the first box body and/or the second box body.
In some embodiments, the battery comprises the upper cover, the first box body and the second box body, the first box body and the second box body are snap-fitted to form the accommodating space for accommodating the battery cell, the upper cover is provided within the accommodating space and covers the battery cell, and the first component comprises the upper cover.
In some embodiments, the surface of the first box body and/or the second box body with the largest area is the first surface.
With the provision of the above solution, the bonding area between the first component and the battery cell can be increased, and the bonding strength between them can be improved.
In some embodiments, the battery cell comprises: an electrode assembly; a case provided with an opening and having a cavity for accommodating the electrode assembly; and a cover plate for covering the opening of the case.
In some embodiments, the adhesion member is provided between a side wall of the case having the largest area and the first surface.
With the provision of the above solution, the bonding area between the adhesion member and the battery cell can be increased, and the bonding strength between them can be improved.
In a second aspect, there is provided an electrical apparatus comprising: the battery of the first aspect for providing electric energy.
In some embodiments, the electrical apparatus is a vehicle, a ship or a spacecraft.
In a third aspect, there is provided a method for making a battery, comprising: providing a battery cell; providing a first component, wherein a first surface of the first component is connected to at least one of the battery cells through an adhesion member, the adhesion member comprises a first adhesion structure and a second adhesion structure, the first adhesion structure is located at the periphery of the second adhesion structure, and the first adhesion structure has an elongation at break greater than that of the second adhesion structure.
In a fourth aspect, there is provided an apparatus for making a battery, comprising a module for performing the method of the third aspect above.
In the drawings, the drawings are not drawn to actual scale.
Implementation of the present application will be described in further detail below in connection with the drawings and embodiments. The following detailed description of the embodiments and the drawings are used to illustrate the principles of the present application exemplarily, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.
In the description of the present application, it should be noted that, unless otherwise stated, “plurality of” means two or more; the orientations or positional relationships indicated by the terms “upper”, “lower”, “left”, “right”, “inner” and “outer” are only for facilitating the description of the present application and simplifying the description, rather than indicating or implying that the apparatus or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application. In addition, the terms “first”, “second”, “third”, and the like are used for descriptive purposes only, and cannot be construed as indicating or implying relative importance. “Perpendicular” is not strictly perpendicular, but within an allowable range of errors. “Parallel” is not strictly parallel, but within an allowable range of errors.
The orientation words appearing in the following description are all the directions shown in the drawings, and do not limit the specific structure of the present application. In the description of the present application, it is also to be noted that, unless otherwise expressly specified and restricted, the terms “installed”, “linked” and “connected” should be understood in a broad sense, for example, as a fixed connection, or as a detachable connection, or as an integral connection; alternatively as a direct connection or as an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.
In the present application, the battery cell may include a primary battery and a secondary battery, for example, it may be a lithium-ion battery, a lithium-sulfur batter, a sodium/lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or the like, which are not limited in the embodiments of the present application. The battery cell may have a shape of cylinder, flat body, rectangular parallelepiped or other shapes, which are not limited either in the embodiments of the present application. Battery cells are generally divided into three types according to the encapsulating mode: cylindrical battery cells, square battery cells and soft pack battery cells, which are not limited either in the embodiments of the present application.
The battery mentioned in the embodiments of the present application refers to a single physical module comprising one or more battery cells for providing higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. A battery pack generally comprises a box body for encapsulating one or more battery cells. The box body can prevent liquids or other foreign matters from affecting the charging or discharging of the battery cell.
The battery cell comprises an electrode assembly and an electrolyte solution, and the electrode assembly comprises a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the portion of the current collector not coated with the positive electrode active material layer protrudes from the portion of the current collector already coated with the positive electrode active material layer, and the portion of the current collector not coated with the positive electrode active material layer serves as a positive tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the portion of the current collector not coated with the negative electrode active material layer protrudes from the portion of the current collector already coated with the negative electrode active material layer, and the portion of the current collector not coated with the negative electrode active material layer serves as a negative tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that a large current is passed without fusing, there are a plurality of positive tabs which are laminated together, and there are a plurality of negative tabs which are laminated together. The material of the separator may be PP, PE, or the like. In addition, the electrode assembly may have a wound structure or a laminated structure, which are not limited in the embodiments of the present application.
Additionally, in order to improve the safety performance of the battery cell, a pressure relief mechanism is generally also provided for the battery cell. The pressure relief mechanism refers to an element or component that is actuated to relieve an internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a predetermined threshold. The predetermined threshold can be adjusted depending on the design requirements. The predetermined threshold may depend on the materials of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte solution and the separator in the battery cell. The pressure relief mechanism may use such elements or components that are sensitive to pressure or temperature, that is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure relief mechanism is actuated, thus forming a passage through which the internal pressure or temperature can be relieved.
The development of battery technology should consider various design factors at the same time, for example, energy density, cycling life, discharge capacity, charge/discharge rate, and other performance parameters, in addition to the safety of the battery.
The safety of the battery includes many aspects, among which, in the aspect of securing the battery cells, in order to improve the stability and safety of the battery cells within the battery, a plurality of battery cells are generally fixedly installed within the box body through an adhesion structure. Taking an example of using a structural glue between the battery cell and a certain surface of the box body, and fixing the battery cell within the box body by gluing, two types of structural glue are usually included in selection. One is to use a “high-strength glue”, which has high bonding strength and is firmly bonded to the box body, and a synchronous deformation of the box body and the battery cell can be realized through the high strength of the “high-strength glue”; however, during the use of the battery cell, the battery cell may expand and deform, and this “high-strength glue” solution is limited by the strength of the glue; after the expansion and deformation of the battery cell, the edge thereof is likely to have a risk of unbonding, and the high-strength glue also has a risk of unbonding under the impact of low temperature vibration. The other is to use a “high-elastic glue”, which has high elasticity, high elongation and strong glue deformability, and can be extended along with deformation, thereby realizing synchronous deformation between the box body and the battery cell through the deformation of the glue; however, this “high-elastic glue” solution has a lower relative strength due to the high glue elongation, resulting in that the overall stiffness of the battery is lower, the structure is unstable, and during the use of the battery, the stability between the battery cell and the box body is not enough, and there is a risk of structural failure.
Therefore, the battery monomer stable with the case, the adhesion member provided on the surface of the battery cell in the embodiments of the present application comprises two adhesion structures, wherein the first adhesion structure is located at the periphery of the second adhesion structure, and the elongation at break of the first adhesion structure is greater than the elongation at break of the second adhesion structure, so that the overall stiffness and stability of the battery cell within the battery can be ensured, and there is no unbonding due to the expansion and deformation of the battery cell, thereby avoiding the battery failure due to vibration impact after unbonding.
The technical solutions described in the embodiments of the present application are applicable to various apparatuses using batteries, such as a mobile phone, a portable device, a laptop, a battery car, an electric toy, an electric tool, an electric vehicle, a ship, a spacecraft, and the like, for example, the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, and the like.
It should be understood that the technical solutions described in the embodiments of the present application are applicable not only to the above-mentioned devices, but also to all devices using batteries; however, for the sake of simplicity of description, the following embodiments are all illustrated with electric vehicles as examples.
For example, as shown in
In order to meet different power demands, the battery can comprise a plurality of b attery cells, wherein the plurality of battery cells can be connected in series or in parallel or in parallel-series connection, and the parallel-series connection refers to the mixing of series connection and parallel connection. The battery may also be referred to as a battery pack. In some embodiments, a plurality of battery cells can first be connected in series or in parallel or in parallel-series connection to form a battery module, and then a plurality of battery modules are connected in series or in parallel or in parallel-series connection to form a battery. That is to say, a plurality of battery cells can directly form a battery, or they can form battery modules first, and then the battery modules form a battery.
For example, as shown in
In some embodiments, the battery 10 may further comprise other structures, which will not be repeated here. For example, the battery 10 may further comprise a bus member for electrically connecting the plurality of battery cells 20, such as in parallel or in series or in parallel-series connection. Specifically, the bus member can electrically connect the battery cells 20 by connecting the electrode terminals of the battery cells 20. Further, the bus member can be fixed to the electrode terminals of the battery cells 20 by welding. The electric energy of the plurality of battery cells 20 can further be extracted by passing a conductive mechanism through the box body.
The number of battery cells 20 in the battery module 200 can be set to any numerical value according to different power demands. The plurality of battery cells 20 can be connected in series, in parallel, or in parallel-series connection to achieve a larger capacity or power. Since the number of battery cells 20 comprised in each battery 10 may be large, for convenience of installation, the battery cells 20 are arranged in groups, and each group of battery cells 20 constitutes a battery module 200. The number of the battery cells 20 comprised in the battery module 200 is not limited, and can be set as required.
The battery cell 20 may further comprise two electrode terminals 214, which can be provided on the cover plate 212. The cover plate 212 is generally in the shape of a flat plate, the two electrode terminals 214 are fixed on the flat plate surface of the cover plate 212, and the two electrode terminals 214 are a first electrode terminal 214a and a second electrode terminal 214b, respectively. The two electrode terminals 214 are opposite in polarity. For example, when the first electrode terminal 214a is a positive electrode terminal, the second electrode terminal 214b is a negative electrode terminal. Each electrode terminal 214 is respectively provided with a corresponding connection member 23, which is located between the cover plate 212 and the electrode assembly 22, for electrically connecting the electrode assembly 22 to the electrode terminal 214.
As shown in
In the battery cell 20, according to the actual use requirements, one or more electrode assemblies 22 can be provided; as shown in
In addition, in order to improve the safety of the battery cell 20, a pressure relief mechanism can be provided on one wall of the battery cell 20, for example, a pressure relief mechanism can be provided on a first wall of the battery cell 20, wherein the first wall may be any wall of the battery cell 20. The pressure relief mechanism is used to actuate when an internal pressure or temperature of the battery cell 20 reaches a threshold to relieve the internal pressure or temperature. Specifically, when too much gas generated in the battery cell 20 causes the internal pressure of the case 211 to rise and reach a threshold or the heat generated by the internal reaction in the battery cell 20 causes the internal temperature of the battery cell 20 to rise and reach a threshold, the pressure relief mechanism may rupture to cause the inside and outside of the case 211 to be inter-communicated, and the gas pressure and temperature are released to the outside through the rupture of the pressure relief mechanism, thus preventing the explosion of the battery cell 20.
In the embodiments of the present application, the battery cell 20 needs to be fixed within the box body, for example, taking as an example that a structural glue is provided on the surface of the battery cell 20 to fix the battery cell 20, two types of structural glue are usually included in selection. One is to use a “high-strength glue”, which has high bonding strength, so that the battery cell 20 is firmly bonded to the box body, and a synchronous deformation of the box body and the battery cell 20 can be realized through the high strength of the “high-strength glue”; however, during the use of the battery cell 20, the battery cell 20 may expand and deform, and this “high-strength glue” solution is limited by the strength of the glue; after the expansion and deformation of the battery cell 20, the edge thereof is likely to have a risk of unbonding, and the high-strength glue also has a risk of unbonding under the impact of low temperature vibration. The other is to use a “high-elastic glue”, which has high elasticity, high elongation and strong glue deformability, and can be extended along with deformation, thereby realizing synchronous deformation between the box body and the battery cell 20 through the deformation of the glue; however, this “high-elastic glue” solution has a lower relative strength due to the high glue elongation, resulting in that the overall stiffness of the battery 10 is lower, the structure is unstable, and during the use of the battery 10, the stability between the battery cell 20 and the box body is not enough, and there is a risk of structural failure.
Therefore, the embodiments of the present application provide a battery capable of solving the above-mentioned problems.
Therefore, in the battery 10 according to the embodiments of the present application, the adhesion member 50 comprising two adhesion structures is provided between the battery cell 20 and the first component to fix the battery cell 20, wherein the first component may comprise a box body of the battery 10 or an upper cover 113 within the box body, so that the first adhesion structure 51 with a higher elongation at break is located at the periphery of the second adhesion structure 52 with a lower elongation at break, so that after the expansion and deformation of the battery cell 20, the edge position is the first adhesion structure 51 with high elongation at break, which is able to maintain the connection between the battery cell 20 and the upper cover 113 or between the battery cell 20 and the box body fixed, thus improving the stability of the battery cell 20 within the battery 10, and in turn improving the safety of the battery 10.
It should be understood that in the embodiments of the present application, providing the first adhesion structure 51 at the periphery of the second adhesion structure 52 may comprise: the first adhesion structure 51 surrounding the periphery of the second adhesion structure 52, or the first adhesion structure 51 being provided in a local region around the second adhesion structure 52 and not completely surrounding the second adhesion structure 52, and the embodiments of the present application are not limited thereto. For convenience of illustration, the embodiments of the present application are mainly described with the first adhesion structure 51 surrounding the second adhesion structure 52 as an example.
Moreover, the shape of the second adhesion structure 52 in the embodiments of the present application can be set according to the actual application, for example, the second adhesion structure 52 may be rectangular or circular; and correspondingly, the shape of the first adhesion structure 51 can also be set according to the actual application, for example, the first adhesion structure 52 can be set as a square ring or a circular ring, and the embodiments of the present application are not limited thereto. For convenience of illustration, the embodiments of the present application are mainly described with the first adhesion structure 51 being a square ring and the second adhesion structure 52 being square as an example.
It should be understood that the first surface of the first component of the embodiments of the present application may refer to any surface of the first component that is connected to the battery cell 20, and the first component may comprise one or more first surfaces 1111. Specifically, the first component may comprise the box body, which may comprise a first box body 111 and a second box body 112, and the first surface 1111 may be any surface of the first box body 111 or the second box body 112; and in some embodiments, the first component may further comprise the upper cover 113, and the first surface 1111 may also be a surface of the upper cover 113.
In some embodiments, as shown in
In some embodiments, if the upper cover 113 is not comprised in the battery 10, the battery cell 20 can be fixed and connected to the first box body 111 through the adhesion member 50, that is, the first box body 111 has the first surface 1111; and moreover, the adhesion member 50 can also be provided between the battery cell 10 and the second box body 112, that is, the second box body 112 may also have the first surface 1111, but the embodiments of the present application are not limited thereto.
It should be understood that for convenience of description, the drawings of the present application take as an example that the battery 10 has the upper cover 113 and take as an example that the first surface 1111 comprises an inner surface of the second box body 112 shown in
It should be understood that the battery 10 in the embodiments of the present application may comprise a plurality of battery cells 20, and the provision direction of each battery cell 20 in the plurality of battery cells 20 can be flexibly set according to the actual application. Specifically, a rectangular parallelepiped battery cell 20 as shown in
As shown in
In the embodiments of the present application, the adhesion member 50 is provided between the first battery cell group in the plurality of battery cell groups and the first surface 1111, that is, the adhesion member 50 is provided between a second surface 201 of the battery cell 20 in the first battery cell group and the first surface 1111. Specifically, the plurality of battery cell groups may comprise one or more first battery cell groups. For example, as shown in
It should be understood that the battery cell 20 in the embodiments of the present application is a rectangular parallelepiped, and the adhesion member 50 is provided between the second surface 201 of the battery cell 20 in the first battery cell group and the first surface 1111, wherein the second surface 201 may be one surface of each battery cell 20 with the largest surface area, so as to increase the bonding area between the adhesion member 50 and the battery cell 20, and improve the bonding strength between the two. For example, as shown in
In the embodiments of the present application, one or more adhesion members 50 can be provided between the first battery cell group and the first surface 1111. For convenience of description, the adhesion member 50 according to the embodiments of the present application will be described in detail below in connection with the accompanying drawings, taking as an example that a plurality of adhesion members 50 are provided between the first battery cell group and the first surface 1111.
In some embodiments, as an embodiment, a plurality of adhesion members 50 can be provided between the first battery cell group and the first surface 1111, for example, as shown in
Corresponding to
It should be understood that the adhesion member 50 may be located in any region of the second surface 201 of one battery cell 20. For example, as shown in
In some embodiments, the area of the second surface 201 of one battery cell 20 is denoted as S0, and correspondingly, the contact area of the first adhesion structure 51 with the second surface 201 is denoted as S1 (correspondingly, the contact area of the first adhesion structure 51 with the first surface 1111 can also be denoted as S1), and the contact area of the second adhesion structure 52 with the second surface 201 is denoted as S2 (correspondingly, the contact area of the second adhesion structure 52 with the first surface 1111 can also be denoted as S2), then S0, S1 and S2 can be set to satisfy: 0.25≤(S1+S2)/S0<1. For example, S0, S1 and S2 can be set to satisfy: 0.5≤(S1+S2)/S0≤0.85. Further, S1 and S2 can also be set to satisfy: 0.05≤S1/(S1+S2)≤0.85, for example, S1 and S2 can be set to satisfy: 0.15≤S1/(S1+S2)≤0.55.
In some embodiments, the first adhesion structure 51 surrounds the periphery of the second adhesion structure 52 in
Corresponding to
In some embodiments, the blocking member 53 may be a foam, a plastic part, or the like to block the mutual influence between the first adhesion structure 51 and the second adhesion structure 52. Moreover, the shape of the blocking member 53 can be set according to the actual application. For example, depending on the shapes of the first adhesion structure 51 and the second adhesion structure 52, the shape of the blocking member 53 can be correspondingly set, for example, the blocking member 53 is a square ring in
In some embodiments, to avoid the mutual influence between the first adhesion structure 51 and the second adhesion structure 52, where the blocking member 53 is not provided, a gap may then be provided between the first adhesion structure 51 and the second adhesion structure 52, so that no additional components are needed, and the setting method is relatively simple. For example, the position in
It should be understood that in the presence of the blocking member 53 or the gap, the ratio of the first adhesion structure 51 to the second adhesion structure 52 can still be assigned according to the relationship satisfied by S0, S1 and S2 described above, which will not be repeated here.
For each of the embodiments in
Taking as an example that the battery cells 20 are in one-to-one correspondence with the adhesion members 50 and the blocking member 53 is provided, the battery 10 is tested, wherein as an example, the first adhesion structure 51 and the second adhesion structure 52 can both be made of polyurethane material. Specifically, before the test, the area ratios of the adhesion members 50 are first set according to the parameters described in the “Initial ratio (S1+S2)/S0” in Table 1, respectively, moreover, the area ratio S1/(S1+S2) of the first adhesion structure 51 to the second adhesion structure 52 is set to 0.15, and the test condition is 60° C. Wherein, considering that the adhesion member 50 is provided on the surface of one side wall of one battery cell 20, the ratio of the contact area of the adhesion member 50 with the surface to the area of the surface cannot be greater than 1, and therefore, the values of the “Initial ratio (S1+S2)/S0” in Table 1 are all less than or equal to 1. In a cyclic test experiment, the voltage range is 2.8V to 4.2V, charging is performed at a rate of 2C, then discharging is performed at a rate of 3C, and after 800 cycles, a cycling capacity retention rate is obtained, wherein the cycling capacity retention rate is the ratio of the 3C discharge capacity of the 800th cycle relative to the 3C discharge capacity of the 2nd cycle, which is the “capacity retention rate” in Table 1; and moreover, after 800 cycles, a coupled temperature vibration impact test is performed to determine the results of the “vibration impact” in Table 1; if the vibration impact test is passed, the area ratio of the remaining adhesion member 50 on the surface of the battery cell 20 is determined by an ultrasonic detector, that is, the last column of the “remaining cohesive glue area ratio” in Table 1 is correspondingly obtained, and the remaining cohesive glue area ratio is still set as (S1+S2)/S0.
As can be seen from Table 1, when the contact area of the adhesion member 50 with the first surface 1111 or the contact area with the second surface 201 of the battery cell 20 is smaller, especially when the area ratio (S1+S2)/S0 is less than 0.25, for example (S1+S2)/S0 is equal to 0.2, the binding force of the adhesion structure 50 to the battery cell 20 is weak, there is a risk of failure due to vibration impact, and the capacity retention rate of the battery cell 20 is poor; whereas when the contact area of the adhesion member 50 with the first surface 1111 or the contact area with the second surface 201 of the battery cell 20 is too large, such as for example when the area ratio (S1+S2)/S0 is equal to 1, it may cause glue overflow and adhesion to the structural parts such as an electrode terminal of the battery cell 20 or a battery wiring harness, and in turn result in the risk of failure due to vibration impact; therefore, 0.25≤(S1+S2)/S0<1 can ensure that there is no battery failure under vibration, and can also ensure that the capacity retention rate of the battery is in a better range.
As can be seen from the data of Example 1-Example 2, when (S1+S2)/S0 is equal to 0.25, the battery capacity retention rate is reduced as compared to the battery capacity retention rate of Example 2 and Example 3, and the remaining cohesive glue area ratio is also reduced. Therefore, when 0.5≤(S1+S2)/S0≤0.85, the vibration impact and the capacity retention rate of the battery are better.
Further, similar to the test conditions in Table 1, the embodiments of
As can be seen from Table 2, the gluing area ratio of the first adhesion structure 51 at the edge position has an influence on the structural strength, and increasing the content of the first adhesion structure 51 in a certain range is beneficial to improving the structural strength of the battery 10 and enhancing the capacity retention rate. When S1/(S1+S2) is equal to 1, there is a failure of the battery 10 due to vibration impact, indicating that with only the first adhesion structure 51, the binding strength of the adhesion structure 50 to the battery 10 is weak. When S1/(S1+S2) is equal to 0.02, there is a failure of the battery 10 due to vibration impact, indicating that when the majority of the adhesion structure 50 is the second adhesion structure 52, it still can lead to the unbonding problem. When 0.05≤S1/(S1+S2)≤0.85, it can not only ensure that there is no failure of the battery 10 under vibration, but also ensure that the capacity retention rate of the battery 10 is in a better range. Comparing Example 5-Example 9, it can be seen that when 0.15≤S1/(S1+S2)≤0.55, the remaining cohesive glue area ratio is 0.62-0.82, and the anti-vibration impact performance of the battery 10 is better.
It should be understood that the thickness h of the adhesion member 50 can be set as 0.02 cm≤h≤1 cm, for example, it can be set as 0.05 cm≤h≤0.5 cm.
It should be understood that the above
In some embodiments, as another embodiment, a plurality of battery cells 20 in the embodiments of the present application may be correspondingly provided with one adhesion member 50. For example,
Specifically,
It should be understood that when comparing the difference between
It should be understood that one adhesion member 50 may be located at any region of the second surface 201 of the plurality of battery cells 20. For example, as shown in
In some embodiments, referring to the embodiments of
In some embodiments, in the case where one adhesion member 50 is provided on the surfaces of a plurality of battery cells 20, that is, when one adhesion member 50 is provided between the second surface 201 jointly formed by the plurality of battery cells 20 and the first surface 1111, the area of the second surface 201 is denoted as S0, the contact area of the first adhesion structure 51 with the second surface 201 is denoted as S1 (correspondingly, the contact area of the first adhesion structure 51 with the first surface 1111 can also be denoted as S1), and the contact area of the second adhesion structure 52 with the second surface 201 is denoted as S2 (correspondingly, the contact area of the second adhesion structure 52 with the first surface 1111 can also be denoted as S2), and S0, S1 and S2 satisfy: 0.25≤(S1+S2)/S0<1. For example, S0, S1 and S2 can be set to satisfy: 0.5≤(S1+S2)/S0≤0.85. Further, S1 and S2 can also be set to satisfy: 0.05≤S1/(S1+S2)≤0.85, for example, S1 and S2 can be set to satisfy: 0.15≤S1/(S1+S2)≤0.55.
Similar to the effects of the embodiments of
In some embodiments, the thickness h of the adhesion member 50 can be set as 0.02 cm≤h≤1 cm, for example, it can be set as 0.05 cm≤h≤0.5 cm.
It should be understood that the positions where the adhesion member 50 of the embodiments of the present application and the like are described above in connection with the accompanying drawings, and the materials of the adhesion member 50 will be described in detail below.
In the embodiments of the present application, the elongation at break of the first adhesion structure 51 is greater than the elongation at break of the second adhesion structure 52. Specifically, the elongation at break A1 of the first adhesion structure 51 can be set to satisfy: 100%≤A1≤500%; and/or the elongation at break B1 of the second adhesion structure 52 can be set to satisfy: 10%≤B1≤150%. For example, the elongation at break A1 of the first adhesion structure 51 satisfies: 150%≤B1≤400%; and/or the elongation at break B1 of the second adhesion structure 52 satisfies: 60%≤B1≤120%.
In some embodiments, the elongation at break of the first adhesion structure 51 and the second adhesion structure 52 in the embodiments of the present application can be tested with reference to ISO 527-2, a fully cured adhesive tape is used, wherein the stretching speed is 10 mm/min.
For example, the first adhesion structure 51 and the second adhesion structure 52 can be peeled off from the first surface 1111 or the second surface 201 by cutting or freezing, cut into blocks of 10 mm*20 mm with a thickness of 1 mm, and tested for elongation at break by a tensile machine, referring to ISO 527-2 for the specific test method.
It should be understood that the first adhesion structure 51 and the second adhesion structure 52 can also be configured to satisfy other relationships, considering that for such adhesion structure as a glue or the like, the strength is generally positively correlated with the elastic modulus, and the elongation at break is negatively correlated with the elastic modulus.
In some embodiments, the elastic modulus of the first adhesion structure 51 can be set to be smaller than the elastic modulus of the second adhesion structure 52. Specifically, the elastic modulus A2 of the first adhesion structure 51 can be set to satisfy: 10 MPa≤A2≤150 MPa; and/or the elastic modulus B2 of the second adhesion structure 52 can be set to satisfy: 150 MPa≤B2≤1000 MPa. For example, the elastic modulus A2 of the first adhesion structure 51 is set to satisfy: 30 MPa≤A2≤60 MPa; and/or the elastic modulus B2 of the second adhesion structure 52 is set to satisfy: 150 MPa≤B2≤500 MPa.
It should be understood that the elastic modulus in the embodiments of the present application is an elastic modulus at normal temperature, and the elastic modulus can be tested with reference to IPC-TM-650 2.4.24.4, which is a standard test method for testing glue strength using dynamic thermomechanical analysis (DMA).
In some embodiments, the strength of the first adhesion structure 51 can also be set to be less than the strength of the second adhesion structure 52. Specifically, the strength A3 of the first adhesion structure 51 can be set to satisfy: 2 MPa≤A3≤15 MPa; and/or the strength B3 of the second adhesion structure 52 can be set to satisfy: 6 MPa≤B3≤25 MPa. For example, the strength A3 of the first adhesion structure 51 satisfies: 6 MPa≤A3≤15 MPa; and/or the strength B3 of the second adhesion structure 52 satisfies: 8 MPa≤B3≤25 MPa.
It should be understood that the strength in the embodiments of the present application may include bulk strength and/or shear strength. Specifically, the bulk strength is tested with reference to ISO 527-2, a fully cured adhesive tape is used, and the stretching speed is 10 mm/min. The shear strength is tested with reference to GB/T 7124.
In some embodiments, the material of the first adhesion structure 51 of the embodiments of the present application may be selected to be a material that is liquid or pasty before solidification, for example, at least one of the following materials may be selected: epoxy resin, polyurethane, acrylic resin and silicone rubber; and/or the material of the second adhesion structure 52 may also be selected to be a material that is liquid or pasty before solidification, for example, at least one of the following materials may be selected: epoxy resin, polyurethane and acrylic resin.
It should be understood that when selecting the materials of the first adhesion structure 51 and the second adhesion structure 52, if materials of the same system with different characteristics are selected, there may be mutual influence between the two, for example, glues of the same polyurethane system with different characteristics are selected as the materials for the first adhesion structure 51 and the second adhesion structure 52, the two may react and influence each other, so it is necessary to provide a blocking member 53 or a gap between the first adhesion structure 51 and the second adhesion structure 52; and if the materials of the first adhesion structure 51 and the second adhesion structure 52 are selected such that they do not react nor influence each other, for example, silicone rubber and polyurethane-based structural glue are selected respectively, then the blocking member 53 and the gap may not be provided, and the embodiments of the present application are not limited thereto.
Therefore, in the battery 10 according to the embodiments of the present application, the adhesion member 50 comprising two adhesion structures is provided between the battery cell 20 and the first component to fix the battery cell 20, wherein the first component may comprise a box body of the battery 10 or an upper cover 113 within the box body, so that the first adhesion structure 51 with a higher elongation at break is located at the periphery of the second adhesion structure 52 with a lower elongation at break, so that after the expansion and deformation of the battery cell 20, the edge position is the first adhesion structure 51 with high elongation at break, which is able to maintain the connection between the battery cell 20 and the upper cover 113 or between the battery cell 20 and the box body fixed, thus improving the stability of the battery cell 20 within the battery 10, and in turn improving the safety of the battery 10.
The battery 10 according to the embodiments of the present application has been described above, and a method and an apparatus for making a battery according to the embodiments of the present application will be described below, in which the portions not described in detail can be found in the foregoing embodiments.
While the present application has been described with reference to the preferred embodiments, various improvements can be made and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, the technical features mentioned in the various embodiments can be combined in any way as long as there are no structural conflicts. The present application is not limited to the particular embodiments disclosed herein, but rather includes all technical solutions falling within the scope of the claims.
The present application is a continuation of International Application PCT/CN2021/117625, filed Sep. 10, 2021 and entitled “BATTERY, ELECTRICAL APPARATUS, AND METHOD AND APPARATUS FOR MAKING BATTERY”, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2021/117625 | Sep 2021 | US |
Child | 18536262 | US |