JP7215433B2 - battery - Google Patents

Description

The present application discloses a battery.

When connecting a plurality of electrode bodies in series, an insulator may be placed between the electrode bodies to prevent a short circuit. For example, in the technique disclosed in Patent Document 1, by using a combination of a conductive connecting member, an insulating connecting member, and an insulating fixing member, the tabs of the electrode body are connected in series and the tabs of the electrode body are connected. It is compatible with insulation between Further, Patent Literature 2 discloses a technique of ultrasonically welding a positive electrode tab and a negative electrode tab. Furthermore, Patent Document 3 discloses a technique of forming a connection portion of a battery using a conductive material such as solder.

JP 2016-136504 A JP 2014-167881 A JP 2017-152415 A

When a connection member and a fixing member are separately used as in the technology disclosed in Patent Document 1, the weight and volume of the battery are increased. If ultrasonic welding is performed as in the technique disclosed in Patent Document 2, the insulating member may be damaged. By connecting the tabs using a conductive material such as solder as in the technique disclosed in Patent Document 3, it is possible to suppress an increase in the weight and volume of the battery, and to suppress damage to the insulating member. Conceivable. However, when the tabs are connected by melting the solder by heating, the heat may be transferred from the tabs to the electrodes, degrading the battery performance.

As one means for solving the above problems, the present application provides
comprising a plurality of electrode bodies and an insulator disposed between each of the plurality of electrode bodies;
The electrode body includes an electrode portion, and a positive electrode tab and a negative electrode tab protruding from the electrode portion,
The insulator comprises an electrode part insulating part and an insulating tab protruding from the electrode part insulating part,
The thermal conductivity of the insulating tab is higher than the thermal conductivity of the electrode portion insulating portion,
When one of the electrode bodies adjacent to each other with one of the insulators interposed therebetween is a first electrode body and the other electrode body is a second electrode body, the positive electrode tab of the first electrode body and the second electrode body The negative electrode tab of the electrode body is joined by heating, the insulating tab of the insulator is disposed between the negative electrode tab of the first electrode body and the positive tab of the second electrode body, and the first electrode body is The electrode part insulating part of the insulator is arranged between the electrode part and the electrode part of the second electrode body,
Disclose the battery.

According to the battery of the present disclosure, the positive electrode tab and the negative electrode tab are heat-bonded, and there is no need to separately use a connecting member or a fixing member. In addition, in the insulator arranged between the electrode bodies, the insulating tab has a higher thermal conductivity than the insulating part of the electrode part. It is possible to heat and bond in a short time, and it is possible to suppress heat transfer to the electrode part and suppress deterioration of battery performance.

It is the schematic which shows each component of a battery disassembled. The tabs indicated by double arrows are heat-bonded. FIG. 4 is a schematic diagram showing a stacking structure of a side surface of a battery from which tabs protrude; The tabs indicated by double arrows are heat-bonded. FIG. 4 is a schematic diagram showing the appearance of an electrode assembly; FIG. 4 is a schematic diagram showing a laminated structure on the side surface of an electrode body from which a tab protrudes; It is a schematic diagram showing a surface shape of an insulator. FIG. 4 is a schematic diagram showing the structure of the insulator side from which the insulating tab protrudes; It is a schematic diagram showing a manufacturing method of a battery.

1. Battery FIGS. 1-6 schematically illustrate the construction of a battery 100 of the present disclosure. As shown in FIGS. 1 and 2 , battery 100 includes a plurality of electrode bodies 10 and insulators 20 disposed between each of the plurality of electrode bodies 10 . As shown in FIGS. 2 to 4, the electrode body 10 includes an electrode portion 10a, and a positive electrode tab 10b and a negative electrode tab 10c projecting from the electrode portion 10a. As shown in FIGS. 2, 5 and 6, the insulator 20 includes an electrode section insulating portion 20a and an insulating tab 20b protruding from the electrode section insulating portion 20a. Here, the thermal conductivity of the insulating tab 20b is higher than the thermal conductivity of the electrode insulating portion 20a. Further, as shown in FIGS. 1 and 2, in the battery 100, one of the electrode bodies 10 adjacent to each other with one insulator 20 interposed therebetween is the first electrode body (X), and the other electrode body 10 is the second electrode body (X). When the electrode body (Y) is formed, the positive electrode tab 10b of the first electrode body (X) and the negative electrode tab 10c of the second electrode body (Y) are joined by heating, and the negative electrode tab 10c of the first electrode body (X) is joined. and the positive electrode tab 10b of the second electrode body (Y). and the electrode portion insulating portion 20a of the insulator 20 is arranged between them.

1.1 Electrode Body As shown in FIGS. 2 to 4, the electrode body 10 includes an electrode portion 10a, and a positive electrode tab 10b and a negative electrode tab 10c projecting from the electrode portion 10a.

1.1.1 Electrode Section Electricity is generated by causing an electrochemical reaction in the electrode section 10a. The configuration of the electrode portion 10a may be the same as the conventional one. For example, as shown in FIG. 4, the electrode part 10a includes a positive electrode current collector 1 having a positive electrode tab 10b, a negative electrode current collector 2 having a negative electrode tab 10c, a positive electrode active material layer 3, a negative electrode active material layer 4, and an electrolyte layer. 5 may be provided.

The positive electrode current collector 1 may be made of metal foil, metal mesh, or the like. From the standpoint of excellent handleability, the positive electrode current collector 1 may be a metal foil. The positive electrode current collector 1 may consist of a plurality of sheets of metal foil. Examples of metals forming the positive electrode current collector 1 include Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, and the like. The positive electrode current collector 1 may have some kind of coating layer on its surface for the purpose of adjusting the resistance. Moreover, when the positive electrode current collector 1 is composed of a plurality of metal foils, there may be some layer between the plurality of metal foils. The thickness of the positive electrode current collector 1 is not particularly limited. For example, it may be 0.1 μm or more, 1 μm or more, 1 mm or less, or 100 μm or less.

The negative electrode current collector 2 may be made of metal foil, metal mesh, or the like. From the viewpoint of excellent handleability, etc., the negative electrode current collector 2 may be a metal foil. The negative electrode current collector 2 may consist of a plurality of sheets of metal foil. Examples of metals forming the negative electrode current collector 2 include Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, and stainless steel. The negative electrode current collector 2 and the positive electrode current collector 1 may be made of the same material, or may be made of different materials. The negative electrode current collector 2 may have some kind of coating layer on its surface for the purpose of adjusting the resistance. Moreover, when the negative electrode current collector 2 is composed of a plurality of metal foils, some layer may be provided between the plurality of metal foils. The thickness of the negative electrode current collector 2 is not particularly limited. For example, it may be 0.1 μm or more, 1 μm or more, 1 mm or less, or 100 μm or less.

The positive electrode active material layer 3 is a layer containing at least a positive electrode active material. When the battery 100 is a solid battery, in addition to the positive electrode active material, it can optionally contain a solid electrolyte, a binder, a conductive aid, and the like. Moreover, when the battery 100 is an electrolytic solution-based battery, in addition to the positive electrode active material, a binder, a conductive aid, and the like can be optionally included. A known active material may be used as the positive electrode active material. Among known active materials, two substances having different potentials (charge/discharge potentials) at which predetermined ions are occluded and released are selected. Each can be used as a negative electrode active material. For example, when constructing a lithium ion battery, various kinds of lithium cobalt oxide, lithium nickel oxide, LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , lithium manganate, spinel-based lithium compounds, etc. are used as the positive electrode active material. A lithium-containing composite oxide can be used. When the battery 100 is a solid battery, the surface of the positive electrode active material may be covered with an oxide layer such as a lithium niobate layer, a lithium titanate layer, or a lithium phosphate layer. Moreover, when the battery 100 is a solid battery, the solid electrolyte may be an inorganic solid electrolyte. Inorganic solid electrolytes have higher ionic conductivity than organic polymer electrolytes. In addition, it has excellent heat resistance as compared with organic polymer electrolytes. Furthermore, compared to the organic polymer electrolyte, it is hard and excellent in rigidity, and the battery 100 can be constructed more easily. Examples of inorganic solid electrolytes include oxide solid electrolytes such as lithium lanthanum zirconate, LiPON, Li _1+X Al _X Ge _2-X (PO ₄ ) ₃ , Li—SiO glass, and Li—Al—S—O glass. _Li2SP2S5 , _{Li2S - SiS2} , LiI _{- Li2S - SiS2} , LiI _{- Si2SP2S5} , _{Li2SP2S5 -} LiI _- LiBr, Sulfide solids such as LiI-Li ₂ SP ₂ S ₅ , LiI-Li ₂ SP ₂ O ₅ , LiI-Li ₃ PO ₄ -P ₂ S ₅ , Li ₂ SP ₂ S ₅ -GeS ₂ Electrolytes can be exemplified. In particular, a sulfide solid electrolyte is preferred, and a sulfide solid electrolyte containing Li ₂ SP ₂ S ₅ is more preferred. Examples of binders that can be contained in the positive electrode active material layer 3 include butadiene rubber (BR) binders, butylene rubber (IIR) binders, acrylate butadiene rubber (ABR) binders, polyvinylidene fluoride (PVdF) binders, polytetra Examples include fluoroethylene (PTFE) binders. Examples of conductive aids that can be contained in the positive electrode active material layer 3 include carbon materials such as acetylene black and Ketjenblack, and metal materials such as nickel, aluminum, and stainless steel. The content of each component in the positive electrode active material layer 3 may be the same as the conventional one. The shape of the positive electrode active material layer 3 may also be the same as the conventional one. In particular, the sheet-like positive electrode active material layer 3 is preferable from the viewpoint that the battery 100 can be easily constructed. The thickness of the positive electrode active material layer 3 is not particularly limited. For example, it may be 0.1 μm or more and 2 mm or less. The lower limit may be 1 μm or more, and the upper limit may be 1 mm or less.

The negative electrode active material layer 4 is a layer containing at least a negative electrode active material. When the battery 100 is a solid battery, in addition to the negative electrode active material, it can optionally contain a solid electrolyte, a binder, a conductive aid, and the like. Further, when the battery 100 is an electrolytic solution-based battery, in addition to the negative electrode active material, a binder, a conductive aid, and the like can be optionally included. A known active material may be used as the negative electrode active material. For example, when constructing a lithium ion battery, silicon-based active materials such as Si, Si alloys and silicon oxides as negative electrode active materials; carbon-based active materials such as graphite and hard carbon; various oxide-based active materials such as lithium titanate. Substance: metal lithium, lithium alloy, or the like can be used. The solid electrolyte, the binder, and the conductive aid can be appropriately selected and used from those exemplified as those used for the positive electrode active material layer 3 . The content of each component in the negative electrode active material layer 4 may be the same as the conventional one. The shape of the negative electrode active material layer 4 may also be the same as the conventional one. In particular, the sheet-like negative electrode active material layer 4 is preferable from the viewpoint of facilitating the construction of the battery 100 . The thickness of the negative electrode active material layer 4 is not particularly limited. For example, it may be 0.1 μm or more and 2 mm or less. The lower limit may be 1 μm or more, and the upper limit may be 1 mm or less.

The electrolyte layer 5 is a layer containing at least an electrolyte. If the battery 100 is a solid battery, the electrolyte layer 5 can be a solid electrolyte layer containing a solid electrolyte and optionally a binder. The solid electrolyte is preferably the above inorganic solid electrolyte, particularly a sulfide solid electrolyte. The binder can be appropriately selected and used from those exemplified as those used for the positive electrode active material layer 3 . The content of each component in the solid electrolyte layer may be the same as in the conventional case. The shape of the solid electrolyte layer may also be the same as the conventional one. In particular, a sheet-like solid electrolyte layer is preferable from the viewpoint that the battery 100 can be easily constructed. In this case, the thickness of the solid electrolyte layer may be, for example, 0.1 μm or more and 2 mm or less. The lower limit may be 1 μm or more, and the upper limit may be 1 mm or less. On the other hand, when the battery 100 is an electrolyte-based battery, the electrolyte layer 5 may include an electrolyte and a separator. Known electrolytes and separators may be used.

1.1.2 Positive Electrode Tab The material of the positive electrode tab 10b may be the same as that of the positive electrode current collector 1, or may be different. The thickness of the positive electrode tab 10b may be the same as the thickness of the positive electrode current collector 1, or may be different. The positive electrode tab 10b may have any shape as long as it protrudes from the positive electrode current collector 1 . Various shapes such as a polygonal shape, a semicircular shape, and a linear shape can be adopted for the projecting shape of the positive electrode tab 10b. The method of providing the positive electrode tab 10b on the positive electrode current collector 1 is not particularly limited. For example, the positive electrode tab 10b may be formed by partially notching the positive electrode current collector 1, or the positive electrode tab 10b may be joined to the positive electrode current collector 1 by welding or the like.

1.1.3 Negative Electrode Tab The material of the negative electrode tab 10c may be the same as that of the negative electrode current collector 2, or may be different. The thickness of the negative electrode tab 10c may be the same as or different from the thickness of the negative electrode current collector 1 . The negative electrode tab 10c may have any shape as long as it protrudes from the negative electrode current collector 2 . Various shapes, such as a polygonal shape, a semicircular shape, and a linear shape, can be adopted for the projecting shape of the negative electrode tab 10c. The method of providing the negative electrode tab 10c on the negative electrode current collector 2 is not particularly limited. For example, the negative electrode tab 10c may be formed by partially notching the negative electrode current collector 2, or the negative electrode tab 10c may be joined to the negative electrode current collector 2 by welding or the like.

1.1.4 Supplementary The electrode body 10 can be produced by a known method. In the case of an all-solid-state battery, for example, an active material layer A is laminated on one side of a current collector by a dry or wet method, and a solid electrolyte layer is laminated on one side of the active material layer A by a dry or wet method. , the electrode body 10 is obtained by laminating the active material layer B on one side of the solid electrolyte layer by a dry or wet method, and further laminating a current collector on one side of the active material layer B. The stacking order of each layer is not limited to this.

1 to 4, the negative electrode active material layers 4, 4 are provided on both sides of one negative electrode current collector 2, and the electrolyte layers 5, 5 are provided on the respective negative electrode active material layers 4, 4. The positive electrode active material layers 3, 3 are provided on the electrolyte layers 5, 5, and the positive electrode current collectors 1, 1 are provided on the positive electrode active material layers 3, 3, respectively. It is not limited to this. An electrode body may be constructed by sequentially providing positive electrode active material layers 3, 3, electrolyte layers 5, 5, negative electrode active material layers 4, 4, and negative electrode current collectors 2, 2 on both sides of one positive electrode current collector 1. Alternatively, the electrode body may be configured by providing a positive electrode active material layer 3, a solid electrolyte layer 5, and a negative electrode active material layer 4 between one positive electrode current collector layer 1 and one negative electrode current collector 2. . Alternatively, a bipolar electrode body may be configured by providing a bipolar current collector between the positive electrode current collector layer 1 and the negative electrode current collector 2 .

1.2. Insulator As shown in FIGS. 2, 5 and 6, the insulator 20 comprises an electrode section insulation portion 20a and an insulation tab 20b protruding from the electrode section insulation portion 20a. Here, the thermal conductivity of the insulating tab 20b is higher than the thermal conductivity of the electrode insulating portion 20a.

1.2.1 Electrode Insulating Portion The electrode insulating portion 20a is arranged between the electrode portions 10a of the electrode body 10 to prevent conduction between the electrode portions 10a. Confining pressure may be applied to the electrode portion 10a, and in this case, the electrode portion insulating portion 20a is required not to be damaged even when a high load is applied. In consideration of suppressing heat transfer between the electrode bodies 10, the electrode section insulating section 20a may be made of a material having a large thermal resistance. For example, the electrode section insulating section 20a can be made of a resin such as polyethylene terephthalate or polyimide. The shape of the electrode portion insulating portion 20a can be, for example, a sheet shape. The thickness of the electrode insulating portion 20a is not particularly limited as long as it is possible to prevent contact and conduction between the electrode portions 10a. For example, the thickness of the electrode portion insulating portion 20a may be 0.1 μm or more and 2 mm or less. The thermal conductivity of the material forming the electrode insulating portion 20a may be, for example, 0.1 W/mK or more and 1.0 W/mK or less.

1.2.2 Insulating Tab The insulating tab 20b is arranged between the tabs of the electrode body 10 to prevent conduction between the tabs 10b and 10c. The insulating tab 20b has insulating properties and is made of a material having a higher thermal conductivity than the electrode insulating portion 20a. For example, the insulating tab 20b can be made of a mixture of thermally conductive filler and resin. Thermally conductive fillers include inorganic oxide particles such as alumina particles. Examples of resins include polyethylene terephthalate, polyimide, and silicone. The insulating tab 20b only needs to protrude with respect to the electrode part insulating portion 20a, and various shapes such as a polygonal shape and a semicircular shape can be adopted for the projecting shape. The insulating tab 20b may have a shape corresponding to that of the tabs 10b and 10c so as to prevent conduction between the tabs 10b and 10c. Also, insulating tab 20b may have a larger area than tabs 10b and 10c. The thickness of the insulating tab 20b may be the same as or different from the thickness of the electrode insulating portion 20a. The thickness of the insulating tab 20b may be less than or equal to the thickness of the electrode insulating portion 20a. The thermal conductivity of the material forming the insulating tab 20b may be, for example, more than 1.0 W/mK and less than or equal to 10.0 W/mK.

1.2.3 Supplementary Information The insulator 20 can be produced by known means and methods. For example, while obtaining the electrode portion insulating portion 20a by molding a resin into a film, a resin composition containing a thermally conductive filler is formed into a tab shape to form an insulating tab 20b, and the insulating tab 20b is adhered or adhered to the electrode portion insulating portion 20a. The insulator 20 may be produced by welding, or the insulator 20 may be produced by integrally molding the resin forming the electrode insulating portion 20a and the resin composition containing the thermally conductive filler forming the insulating tab 20b at the same time. You may

1.3. Arrangement Structure and Bonding Structure of Electrode Body and Insulator As shown in FIGS. 10x in FIG. 2) and the other electrode body 10 is the second electrode body (for example, 10y in FIG. 2), the positive electrode tab 10b of the first electrode body 10x and the negative electrode tab 10c of the second electrode body 10y are heat-bonded, the insulating tab 20b of the insulator 20 is arranged between the negative electrode tab 10c of the first electrode body 10x and the positive electrode tab 10b of the second electrode body 10y, and the electrode portion 10a of the first electrode body 10x and the second An electrode portion insulating portion 20a of the insulator 20 is arranged between the electrode portion 10a of the two-electrode body 10y.

As indicated by the double arrows in FIGS. 1 and 2, the positive electrode tab 10b of the first electrode body 10x and the negative electrode tab 10c of the second electrode body 10y are thermally joined to each other, thereby forming the first electrode body 10x and the second electrode body 10x. The electrode body 10y is connected in series. Whether or not the tabs 10b and 10c are heat-bonded can be easily visually determined. The tabs 10b and 10c may be joined by heating via a conductive material such as solder that melts when heated. On the other hand, an insulating tab 20b is arranged between the negative electrode tab 10c of the first electrode body 10x and the positive electrode tab 10b of the second electrode body 10y. It is insulated from the tab 10b.

The battery 100 is provided with a plurality of such combinations of the first electrode body 10x, the second electrode body 10y, and the insulator 20 disposed between the first electrode body 10x and the second electrode body 10y. As shown in FIGS. 1 and 2, the front and back sides of the first electrode body 10x and the second electrode body 10y may be opposite to each other. That is, when the surface of the first electrode body 10x faces forward, the surface of the second electrode body 10y may face backward. In this manner, the electrode bodies 10x and 10y having the same shape are stacked upside down with the insulator 20 interposed therebetween, so that the battery 100 can be configured more easily.

In addition, in the battery 100, the number of the electrode bodies 10 is not particularly limited. The number of electrode bodies 10 may be appropriately determined according to the intended battery performance.

As described above, according to the battery 100, the positive electrode tab 10b and the negative electrode tab 10c are joined by heating, and separate members such as connecting members and fixing members are unnecessary. In the insulator 20 arranged between the electrode bodies 10, 10, the insulating tab 20b has a higher thermal conductivity than the electrode part insulating part 20a. The tabs 10b and 10c are preferentially heated over the tabs 10a, and heat bonding can be performed in a short time. As a result, heat transfer to the electrode portion 10a is suppressed, and deterioration of battery performance due to heat is suppressed.

When the battery 100 is in operation, the tabs 10b and 10c may generate heat due to energization. Therefore, it is considered that the heat transfer to the electrode portion 10a can be suppressed. That is, it is considered that the battery 100 exhibits not only the effect of suppressing thermal deterioration of the electrode portion 10a during battery manufacturing, but also the effect of suppressing thermal deterioration of the electrode portion 10a during battery operation.

2. Method of Manufacturing Battery As described above, in the battery 100 of the present disclosure, some tabs of the plurality of electrode bodies 10 are heat-bonded to each other, and the insulator 20 is arranged between some of the tabs for insulation. Such a battery 100 can be manufactured, for example, through a method as shown in FIG.

First, a plurality of the electrode bodies 10 described above are prepared, and a plurality of the insulators 20 described above are prepared, and the electrode bodies 10 and the insulators 20 are alternately laminated to obtain the laminate 30 . In the laminate 30, one electrode body 10 (first electrode body 10x) and the other electrode body 10 (second electrode body 10y), which are adjacent to each other with one insulator 20 interposed therebetween, are oriented opposite to each other. and That is, the electrode bodies 10x and 10y are laminated with the insulator 20 interposed therebetween so that the front and back sides are reversed. Needless to say, in the laminate 30, the tabs of the electrode bodies 10x and 10y protrude in the same direction. The tabs of the laminated body thus obtained are heat-bonded by soldering or the like.

At the time of heat bonding, it is preferable to heat at least the portion of the laminate 30 where the tabs are present from both sides in the stacking direction, and heat bond a plurality of tabs protruding from the side surfaces of the laminate at a time. For example, as shown in FIG. 7, a heat bar is arranged on each of one end side and the other end side of the stack in the stacking direction, and by heating the tab portion from both ends in the stacking direction toward the center, the tab of the stack 30 is heated. A plurality of them can be heat-bonded at once. Here, in the insulator 20 constituting the laminate 30, the insulating tab 20b has a higher thermal conductivity than the electrode insulating portion 20a as described above. The tabs 10b and 10c transfer heat more quickly in the stacking direction than the tabs 10a, and the tabs 10b and 10c are heat-bonded in a short time. Therefore, heat transfer from the tabs 10b and 10c to the electrode portion 10a can be suppressed, and deterioration of battery performance due to heat can be suppressed.

The battery of the present disclosure can be widely used from small power sources for mobile devices to large power sources for vehicles. In particular, it is suitable as a large-sized power source for mounting on a vehicle.

REFERENCE SIGNS LIST 10 Electrode body 10a Electrode part 1 Positive electrode current collector 2 Negative electrode current collector 3 Positive electrode active material layer 4 Negative electrode active material layer 5 Electrolyte layer 10b Positive electrode tab 10c Negative electrode tab 20 Insulator 20a Electrode part insulating part 20b Insulating tab 100 Battery

Claims (1)

comprising a plurality of electrode bodies and an insulator disposed between each of the plurality of electrode bodies;
The electrode body includes an electrode portion, and a positive electrode tab and a negative electrode tab protruding from the electrode portion,
The insulator comprises an electrode part insulating part and an insulating tab protruding from the electrode part insulating part,
The thermal conductivity of the insulating tab is higher than the thermal conductivity of the electrode portion insulating portion,
When one of the electrode bodies adjacent to each other with one of the insulators interposed therebetween is a first electrode body and the other electrode body is a second electrode body, the positive electrode tab of the first electrode body and the second electrode body The negative electrode tab of the electrode body is joined by heating, the insulating tab of the insulator is disposed between the negative electrode tab of the first electrode body and the positive tab of the second electrode body, and the first electrode body is The electrode part insulating part of the insulator is arranged between the electrode part and the electrode part of the second electrode body,
battery.

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