Patent Application
20240079695
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2022-139559 filed on Sep. 1, 2022, the disclosure of which is incorporated by reference herein.
The present disclosure relates to a battery, a battery module, and a method of manufacturing a battery.
A battery such as a lithium-ion secondary battery is usually provided with an electrode body having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector. The electrode body is sealed, for example, in an internal space surrounded by an exterior material. Japanese Patent Application Laid-Open (JP-A) No. 2011-108623 discloses a lithium polymer secondary battery including an electrode assembly, an exterior material surrounding an exterior of the electrode assembly, and first and second covers sealing the exterior material, and in which a first electrode terminal and a second electrode terminal were drawn out to the exterior via the first cover and the second cover, respectively. Furthermore, Japanese Patent Application Laid-Open (JP-A) No. 2011-108623 describes a laminate film as an exterior material.
As shown in
The present disclosure has been made in view of the foregoing circumstances, and aims to provide a battery, a battery module having the battery, and a method of manufacturing the battery, with which damage at the bent part in the laminate film at the starting point of the fused part at the side of the side face member is suppressed.
A battery of a first aspect of the present disclosure, comprising: an electrode body; a side face member disposed at a side face of the electrode body; and a laminate film covering the electrode body and the side face member, wherein: in a case in which the battery is viewed laterally from a side of the side face member, an outer edge of the side face member is disposed further toward an inner side than an outer edge of the electrode body, the laminate film is disposed so as to cover a face configuring the outer edge of the side face member and a face configuring the outer edge of the electrode body, a fused part, at which respective inner faces of the laminate film are fused together, is disposed on the side face member, and a bent part at a starting point of the fused part at a side of the side face member has a curved shape. A battery of a second aspect according to the present disclosure is the battery of the first aspect, wherein the laminate film has a metal layer and a fusing resin layer at an inner face side that forms the fused part, and the side face member has a coating resin layer at a face that contacts the laminate film.
A battery of a third aspect according to the present disclosure is the battery of the second aspect, wherein a radius of curvature R of the curved shape in the bent part satisfies the following Formula (1) and Formula (3):
R<(((2Δt(a+b+4t1))/(4−π))1/2)−r Formula (1):
R<b/2 Formula (3):
wherein, in the Formula (1) and the Formula (3):
A battery of a fourth aspect according to the present disclosure is the battery of the second aspect or the third aspect, wherein a radius of curvature R of the curved shape in the bent part satisfies the following Formula (2) and Formula (3):
R<(((((a+2t1)(b+2t1)−ab)×0.05)/(4−π))1/2)−r Formula (2):
R<b/2 Formula (3):
wherein, in the Formula (2) and the Formula (3):
A battery of a fifth aspect according to the present disclosure is the battery of any one of the second aspect to the fourth aspect, wherein a radius of curvature R of the curved shape in the bent part is equal to or greater than an average thickness of the metal layer.
A battery of a sixth aspect according to the present disclosure is the battery of any one of the first aspect to the fifth aspect, wherein the fused part does not have a folding crease mark at a region other than the bent part.
A battery of a seventh aspect according to the present disclosure is the battery of any one of the first aspect to the sixth aspect, wherein, in a case in which the battery is viewed in plan view from a thickness direction, the fused part is disposed continuously from an end part position α of the laminate film at the side of the side face member to a position β of the laminate film corresponding to a boundary between the side face member and the electrode body.
A battery of an eighth aspect according to the present disclosure is the battery of any one of the first aspect to the seventh aspect, wherein the fused part is disposed at a corner part of the outer edge of the side face member.
A battery of a ninth aspect according to the present disclosure is the battery of any one of the first aspect to the eighth aspect, wherein, in a case in which the battery is viewed laterally from the side of the side face member, a shape of the side face member is rectangular.
A battery of a tenth aspect according to the present disclosure is the battery of any one of the first aspect to the ninth aspect, wherein a plurality of the fused parts is disposed on the side face member.
A battery of an eleventh aspect according to the present disclosure is the battery of any one of the first aspect to the tenth aspect, wherein the side face member is a current collection terminal.
A battery of a twelfth aspect according to the present disclosure is the battery of any one of the first aspect to the eleventh aspect, wherein the battery comprises a pair of the side face members, and the pair of the side face members is disposed so as to oppose each other relative to the electrode body.
A battery module of a thirteenth aspect according to the present disclosure, comprising the battery of any one of the first aspect to the twelfth aspect, wherein a plurality of the batteries is layered in a thickness direction thereof.
A battery module of a fourteenth aspect according to the present disclosure is the battery module of the thirteenth aspect, wherein, in a pair of the side face members disposed adjacent to each other in the thickness direction, a main face part of the laminate film disposed on one of the pair of side face members does not contact a main face part of the laminate film disposed on the other of the pair of side face members.
A method of manufacturing a battery of a fifteenth aspect according to the present disclosure, the method comprising:
A method of manufacturing a battery of a sixteenth aspect according to the present disclosure is the method of manufacturing a battery of the fifteenth aspect, further comprising, after the preparation process and before the first covering process, a folding process of providing in advance a fold line at a position of the laminate film opposing a corner part of the electrode body,
According to the present disclosure, it is possible to provide a battery in which damage at the bent part at the starting point of the fused part at the side of the side face member in the laminate film is suppressed, a battery module having the battery, and a method of manufacturing the battery.
Hereinafter, a battery according to the present disclosure will be described in detail with reference to the drawings. The drawings shown below are schematically shown, and the sizes and shapes of the respective parts have been appropriately exaggerated for ease of understanding. Furthermore, in the present specification, when expressing an aspect in which a given member is arranged with respect to another member, when simply indicated as “above” or “below”, unless otherwise specified, a case in which the given member is placed directly above or below the other member so as to contact the other member and a case in which the given member is placed above or below the other member via a further member are both included.
A. Battery
In contrast, as shown in
According to the present disclosure, since the bent part 34 at the starting point of the fused part X at the side of the side face member 20 has a curved shape, concentration of stress at a specific location of the bent part 34 is suppressed, and a battery is obtained in which damage to the bent part 34 of the fused part X in the laminate film 30 is suppressed.
1. Battery Configuration
The battery of the present disclosure is provided with at least an electrode body, a side face member, and a laminate film.
(1) Electrode Body
The electrode body of the present disclosure functions as a power generation element of the battery. The shape of the electrode body is not particularly limited, and for example, as shown in
The shape of the top surface part is not particularly limited, and examples thereof include quadrangles such as a square, a rectangle, a diamond, a trapezoid, and a parallelogram. The shape of the top surface part 11 in
(2) Side Face Member
The side face member of the present disclosure is arranged at the side face part of the electrode body. The battery of the present disclosure, relative to one electrode body, may be provided with one side face member, or two or more side face members may be provided. In the latter case, as shown, for example, in
The shape of the side face member is not particularly limited, and examples thereof include quadrangles such as a square, a rectangle, a diamond, a trapezoid, and a parallelogram. The shape of the side face member 20 in
When the battery is viewed from the side of the side face member, the outer edge of the side face member is positioned further toward an inner side than the outer edge of the electrode body. For example, as shown in
For example, in
(3) Laminate Film
The laminate film of the present disclosure covers the electrode body and seals the electrode body together with the side face member. As shown in
Furthermore, as shown in
Furthermore, in
Here, the radius of curvature R of the curved shape of the bent part 34 of the fused part X is described with reference to
In some embodiments, the radius of curvature R of the curved shape in the bent part 34 satisfies the following Formula (1).
R<(((2Δt(a+b+4t1))/(4−π))1/2)−r Formula (1):
The respective symbols in Formula (1) represent the following.
However, the radius of curvature R of the curved shape in the bent part 34 satisfies the following Formula (3); that is, the radius of curvature R is less than ½ of the thickness b of the side face member 20.
R<b/2 Formula (3):
The respective symbols in Formula (3) represent the following.
Examples of the laminate film 30 include an embodiment having a metal layer and a fusing resin layer 30A at an inner surface side, forming a fusing part. Furthermore, in order to enhance the sealing property with the laminate film 30, examples include an embodiment in which the side face member 20 has a coating resin layer 20A at the surface that contacts the laminate film 30. When the bent part 34 at the starting point of the fused part X at the side of the side surface member 20 is configured with a curved shape, a space S is formed inside the curved shape of the bent part 34. In some embodiments, this space S is filled with resin from the fusing resin layer 30A of the laminate film 30 and the coating resin layer 20A of the side face member 20, such that no cavity is produced. In this regard, when the radius of curvature R of the curved shape in the bent part 34 satisfies Formula (1), the space S can be favorably filled with resin, whereby generation of cavities can be suppressed.
For example, in a case in which:
In some embodiments, the radius of curvature R of the curved shape in the bent part 34 satisfies the following Formula (2).
R<(((((a+2t1)(b+2t1)−ab)×0.05)/(4−π))1/2)−r Formula (2):
The respective symbols in Formula (2) represent the following.
However, the radius of curvature R of the curved shape in the bent part 34 satisfies the following Formula (3); that is, the radius of curvature R is less than ½ of the thickness b of the side face member 20.
R<b/2 Formula (3):
In a case in which the bent part 34 at the starting point of the fused part X at the side of the side face member 20 is configured with a curved shape, a space S is formed inside the curved shape of the bent part 34, and this space S is filled with resin from the fusing resin layer 30A and the coating resin layer 20A. In some embodiments, since resins easily absorb moisture, from the viewpoint of water barrier properties in batteries, the volume of the space S (that is, the amount of resin filling the space S) may be small. In some embodiments, an increase in the water absorption amount due to an increase in the volume of the space S may be 5% or less. In this regard, when the radius of curvature R of the curved shape in the bent part 34 satisfies Formula (2), the amount of water absorbed by the resin filling the space S can be reduced, and water barrier properties can be maintained.
For example, in a case in which:
In some embodiments, conversely, the lower limit value of the radius of curvature R of the curved shape in the bent part 34 is equal to or greater than the average thickness of the metal layer in the laminate film. As the radius of curvature R decreases (the curvature becomes tighter), stress concentration occurs, whereby damage to the laminate film is more likely to occur; however, when the radius of curvature R is greater than or equal to the average thickness of the metal layer, damage to the laminate film can be more favorably suppressed.
In some embodiments, as shown in
In
As shown in
As shown in
In the present disclosure, when the battery 100 has plural fused parts X, in one or more fused parts X, the bent part at the starting point at the side of the side face member 20 has a curved shape. In some embodiments, the bent part at the starting point at the side of the side face member 20 has a curved shape in plural fused parts X. In some embodiments, the bent part at the starting point at the side of the side face member 20 has a curved shape in all of the fused parts X.
As shown in
2. Battery Members
The battery of the present disclosure includes an electrode body, a side face member, and a laminate film.
(1) Electrode Body
The electrode body of the present disclosure generally has a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector in this order in the thickness direction. For example, the electrode body 10 shown in
The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the positive electrode active material include oxide active materials. Examples of the oxide active materials include rock-salt layered active materials such as LiNi1/3Co1/3Mn1/3O2, spinel-type active materials such as LiMn2O4, and olivine-type active materials such as LiFePO4. Furthermore, sulfur (S) may be used as the positive electrode active material. The shape of the positive electrode active material is, for example, particulate.
Examples of the conductive material include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or may be an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Furthermore, the liquid electrolyte contains, for example, a support salt such as LiPF6 and a solvent such as a carbonate-based solvent. Examples of the binder include rubber-based binders and fluoride-based binders.
The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and oxide active materials such as Li4Ti5O12. The shape of the negative electrode active material is, for example, particulate or foil-shaped. The conductive material, the electrolyte, and the binder are the same as those described above.
The electrolyte layer is arranged between the positive electrode active material layer and the negative electrode active material layer, and contains at least an electrolyte. The electrolyte may be a solid electrolyte or a liquid electrolyte. The electrolyte is the same as the content described above. The electrolyte layer may have a separator.
The positive electrode current collector performs collection of current at the positive electrode active material layer. Examples of the material of the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of the shape of the positive electrode current collector include foil-shaped and mesh-shaped. The positive electrode current collector may have a positive electrode tab for connection to a positive electrode current collection terminal.
The negative electrode current collector performs collection of current at the negative electrode active material layer. Examples of the material of the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include foil-shaped and mesh-shaped. The negative electrode current collector may have a negative electrode tab for connection to a negative electrode current collection terminal.
(2) Side Face Member
The side face member of the present disclosure is disposed at a side face part of the electrode body. The side face member is not particularly limited as long as it is a member that is disposed at a side face part of the electrode body, but in some embodiments is a current collection terminal. A current collection terminal refers to a terminal of at which at least a part is a current collection part. The current collection part is electrically connected, for example, to a tab in the electrode body. The current collection terminal may be entirely a current collection part, or may be partially a current collection part. Furthermore, the side face member may be an exterior member which does not have a current collection function.
Examples of the material of the side face member include a metal such as SUS. Furthermore, examples of the side face member include an embodiment in which the coating resin layer is provided at a face on the surface thereof that contacts the laminate film. Examples of the material of the coating resin layer include olefinic resins such as polypropylene (PP) and polyethylene (PE). The thickness of the coating resin layer is, for example, from 40 μm to 150 μm.
(3) Laminate Film
The laminate film of the present disclosure has at least a structure in which a fusing resin layer (heat fusion layer) and a metal layer are laminated; that is, it has a structure in which a fusing resin layer (heat fusion layer) is provided on one surface of the metal layer (inner surface side that forms the fused part). Furthermore, the laminate film may have a fusing resin layer (heat fusion layer), a metal layer, and a resin layer in this order along the thickness direction. Examples of the material of the fusing resin layer (heat fusion layer) include olefinic resins such as polypropylene (PP) and polyethylene (PE). Examples of the material of the metal layer include aluminum, an aluminum alloy, and stainless steel. Examples of the material of the resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the fusing resin layer (heat fusion layer) is, for example, from 40 μm to 100 μm. The thickness of the metal layer is, for example, from 30 μm to 60 μm. The thickness of the resin layer is, for example, from 20 μm to 60 μm. The thickness of the entire laminate film is, for example, from 70 μm to 220 μm.
(4) Battery
The battery of the present disclosure is typically a lithium-ion secondary battery. Examples of the application of the battery include hybrid vehicles (HEVs), plug-in hybrid vehicles (PHEVs), electric vehicles (BEVs), gasoline vehicles, and power supply for vehicles such as diesel vehicles. In some embodiments, it is used as a power supply for driving a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), or an electric vehicle (BEV). Furthermore, the battery of the present disclosure may be used as a power source for a moving body other than an automobile (for example, a railway, a ship, or an aircraft), and it may be used as a power source for an electrical product such as an information processing apparatus.
B. Battery Module
According to the present disclosure, by using the battery described above, the battery module is such that damage at a bent part at a starting point of the fused part in the laminate film at the side of the side face member is suppressed.
Since the battery of the present disclosure is the same as described above under “A. Battery”, description thereof is omitted. Furthermore, the battery module of the present disclosure may have a restraining jig which restrains the plural batteries in the thickness direction. The type of restraining jig is not particularly limited, and examples thereof include a jig which applies a restraining torque via a bolt. The restraining pressure applied by the restraining jig is, for example, from 1 MPa to 50 MPa.
As shown in
C. Method of Manufacturing Battery
A method of manufacturing a battery according to the present disclosure is a method for producing the battery described above, and includes: a preparation process of preparing a structure having the electrode body described above and the side face member described above; a first covering process of covering the above-described outer edge of the above-described electrode body in the above-described structure with the above-described laminate film; and a second covering process of covering the above-described outer edge of the above-described side face member in the above-described structure with the above-described laminate film, the fused part being formed in the above-described second covering process by using a jig capable of surface contact with a surface configuring the above-described outer edge of the above-described side face member. In the preparation process, in a case in which the battery is viewed from the side of the side face member, the shape of the side face member is rectangular, and a structure having a first side, a second side adjacent to the first side, and a third side adjacent to the second side and opposing the first side, and a fourth side adjacent to the third side and opposing the second side, may be prepared as the rectangular shape. In this case, the second covering process has a first adhesion process in which a first jig and a third jig are pushed inward from the side of the first side and the side of the third side of the side face member, respectively, and the laminate film is adhered to the first side and the third side, respectively, and after the first adhesion process, a second adhesion process in which a second jig and a fourth jig are pushed inward from the side of the second side and the side of the fourth side of the side face member, respectively, and the laminate film is adhered to the second side and the fourth side, respectively, and, in some embodiments, at least one of the first jig and the third jig has a chamfered shape at a portion that forms the curved shape of the bent part at the fused part.
1. Preparation Process
The preparation process in the present disclosure is a process of preparing a structure having the above-described electrode body and the above-described side face member. The electrode body and the side face member are the same as those described above under “A. Battery”, and therefore, description thereof is omitted.
2. Folding Process
In the present disclosure, prior to performing the first covering process, a process of applying a fold line in advance to the laminate film at a position opposing a corner part of the electrode body-specifically, a folding process in which folding is performed in advance in accordance with the shape of the electrode body—may be included.
However, as shown in
3. First Covering Process
In the first covering process of the present disclosure, the above-described outer edge of the above-described electrode body in the above-described structure is covered with the above-described laminate film. For example, as shown in
Furthermore, in the first covering process, normally, as shown in
4. Second Covering Process
In the second covering process of the present disclosure, the surface configuring the above-described outer edge of the above-described side face member is covered with the above-described laminate film. Further, in the second covering process, the fused part is formed.
In the second covering process, the side face member and the laminate film are adhered to each other using a jig capable of surface contact with the surface configuring the outer edge of the side face member.
In the jig 44 of the present disclosure, a part (a part opposing the bent part) 44A, which forms the curved shape of the bent part of the fused part X, has a chamfered shape. In other words, as shown in
In some embodiments, the radius of curvature C of the chamfered portion of the jig satisfies the following formulae (1′) and (3′).
C<(((2Δt(a+b+4t1))/(4−π))1/2)−r Formula (1′):
C<b/2 Formula (3′):
The respective symbols in Formula (1′) and Formula (3′) represent the following.
Furthermore, in some embodiments, the radius of curvature C of the chamfered portion of the jig satisfies the following formulae (2′) and (3′).
C<(((((a+2t1)(b+2t1)−ab)×0.05)/(4−π))1/2)−r Formula (2′):
C<b/2 Formula (3′):
The respective symbols in Formula (2′) and Formula (3′) represent the following.
Further, in some embodiments, the radius of curvature C of the chamfered portion of the jig be equal to or greater than the average thickness of the metal layer.
Here, an embodiment in which the jig 41, the jig 42, the jig 43, and the jig 44 are pushed in toward the laminate film 30 and the side face member 20 is described. When the side view shape of the side face member is rectangular, the second covering process may have a first adhesion process and a second adhesion process.
For example, as shown in
First, the jig 42 and the jig 44 are pushed in from the side of the first side and the third side of the side face member 20, respectively. As a result, the laminate film 30 is adhered to the first side and the third side, respectively (first adhesion process). Next, the jig 41 and the jig 43 are pushed in from the side of the second side and the fourth side of the side face member 20, respectively. As a result, the laminate film 30 is adhered to the second side and the fourth side, respectively (second adhesion process). As a result, as shown in
In some embodiments of the present disclosure, the first side and the third side correspond to short sides configuring the outer edge of the side face member 20, and the second side and the fourth side correspond to long sides configuring the outer edge of the side face member 20. In this case, in the first adhesion process, the jig 42 and the jig 44, which are not heated, may be pushed in, and in the second adhesion processing, the heated jig 41 and the jig 43 may be pushed in. By heating the entire periphery of the outer edge of the side face member 20 only by heat input from the jigs on the long sides (the jig 41 and the jig 43), the structure of the sealing machine can be simplified.
5. Battery
The battery obtained by the above-described processes is the same as the battery described above under “A. Battery”, and therefore, description thereof is omitted.
The present disclosure is not limited to the embodiments described above. The above-described embodiments are exemplary, and embodiments having substantially the same configuration as the technical concepts recited in the claims of the present disclosure and exhibiting the same action and effect are all encompassed by the technical scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-139559 | Sep 2022 | JP | national |
