JP3385319B2 - Stacked battery - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a structure of a laminated battery. In particular, the present invention relates to a battery structure that has a high energy density and eliminates dead space by stacking battery cell electrodes.

[0002]

2. Description of the Related Art In a conventional rechargeable battery, first, a coating device is used to coat a positive / negative electrode active material, a polymeric binder and a conductive material so as to coat the current collectors 11a and 11b. The method of coating and assembling the positive / negative electrode plates 10a, 10b is performed by mixing with the positive / negative electrode active materials 12a, 12b. The coating pattern is shown in FIG. 1 or 2.

FIG. 1 shows a single material that is discretely coated, and FIG. 2 is a diagram that shows a single material that is continuously coated. The coated positive / negative electrode plates 10a and 10b are further subjected to pressure to form stripes. Polymeric separator membranes are used to isolate them. It is then rolled into a circular or elliptical structure to make a cylindrical or trabecular battery.

With the recent development of thinner, lighter and smaller devices in electronics, the design of rechargeable batteries has also placed more stringent requirements on weight, energy density and space. ing.
As shown in FIG. 3, the structure of the initial storage battery has an annular shape. The positive electrode plate / polymer separator film / negative electrode plate module is rolled like a spiral 20 and placed in a cylindrical metal case 21. Technically, this spiral structure is relatively well developed. However, it obviously cannot prevent the occurrence of dead space 22 and results in wasted space.

Therefore, a battery having a rectangular case as shown in FIG. 4 was invented thereafter. In general,
The columnar battery is a lithium-ion battery, and
Widely used in the design of nickel metal hydride batteries. By using a rectangular case to stack the battery cells, there was less wasted space. However, even if the positive / negative electrode plates are rounded into an elliptical shape and placed in a rectangular metal case 21a, some dead space 22a is still present.
Is in the battery.

In view of the above, as shown in FIG. 5, modern battery assemblies are stacked and pressured, much like polymer batteries are stacked. In principle, the battery formed by stacking the electrodes 30 achieves open stacking and the space is used more efficiently. By enclosing in the aluminum foil case 31, the total weight of the battery can be reduced. In this way, the energy density of the battery can be increased. However, since the electrode and the polymer separator film (PE, PP or non-woven fabric) are not cohesive with each other in the recent battery design, the recent storage batteries (nickel hydrogen battery, lithium ion battery) are stacked and pressure is not applied. It cannot be built over. And, since a polymer electrolyte membrane similar to a separator membrane produces a stronger binding force, by using it, polymer batteries can be manufactured by stacking and applying pressure. However, since the electrode plates need to be stacked with polymer electrolytes (membranes) and pressure applied, it is necessary to increase the polymer binder on the positive / negative electrode plates. It reduces the proportion of active material on the board. Therefore, polymeric batteries will have a lower energy density than lithium-ion batteries. In addition, the increase in polymeric binder on the electrode plate reduces the conductivity on the electrode plate, resulting in a difficult charge / discharge process for large polymer batteries.

Therefore, the implementation of the closest packing on the positive / negative electrode plate and the polymer separator film which does not increase the amount of the polymer binder on the electrode plate are the most urgent problems at present. ing.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laminated battery structure capable of eliminating the dead space due to the conventional spiral structure of the battery cell electrode plate and increasing the energy density of the battery. .
The present invention uses stacking to eliminate dead space when the electrode plates are rolled into a circle or oval.

Further, in order to increase the energy density of the battery, the laminated battery disclosed in the present invention comprises:
(A) The binder is separated from the active material, and (b) the position of the binder is modified so that the positive / negative electrode plates are polymerized via the binder in the process of stacking and pressing. (C) The percentage of the weight of the active material in each unit is not affected, and no active material is handled for the binding action by stacking and pressing.

[0010]

The above objects of the present invention can be achieved by the following means.

(1) A laminated battery according to the present invention comprises a positive electrode plate, a negative electrode plate, and a polymer separator film arranged between the positive electrode plate and the negative electrode plate, and comprises a plurality of the positive electrode plates and the negative electrode. A laminated battery in which plates are stacked to form a battery cell, wherein the positive electrode plate and the negative electrode plate include current collectors, and surfaces of the positive electrode plate and the negative electrode plate are coated with an electrode layer and are adjacent to each other. The opposite surfaces of the positive electrode plate and the negative electrode plate are coated with a binder layer for binding with the polymer separator film, and the binder layer coats an edge of the electrode layer.
Characterized in that that

(2) The laminated battery of the present invention has a positive electrode plate.
And a negative electrode plate, and arranged between the positive electrode plate and the negative electrode plate.
A plurality of positive electrode plates.
And a laminated bar in which the negative electrode plates are laminated to form a battery cell.
The positive electrode plate and the negative electrode plate are collectors.
The positive electrode plate and the negative electrode plate have a surface
Adjacent positive plates that are coated with layers
And the opposite surface of the negative electrode plate is the polymer separator.
Coated with a binder layer to bond with the
The binder layer coats the electrode layer surface along a diagonal line.
It is characterized by tinging.

(3) The binder layer is coated on the surface of the electrode layer.
To sing.

(4) The binder layer symmetrically coats the two sides of the electrode layer.

(5) The binder layer is formed by die coating.
Is formed.

(6) The binder layer is used for screen printing.
Therefore, it is formed.

(7) The positive electrode plate and the negative electrode plate are heated and
And the polymer separator membrane under pressure.
Is bound with.

(8) The material of the binder layer is a rubber binder.
Agent, sulfide compound, epoxy resin, polyester,
Ethylene acetate polyvinyl, ethylene-acrylic
Reester, polyethylene, polypropylene, kraton
(Shell Chemical Co., Ltd.), acrylic binder, cyanide acetone
Tate ester binder, aromatic polyamine binder, silicone
Corn binder, polybenzimidazoles, polyquinoki
Sarins, polyphenylquinoxalines, and poly
Selected from the group consisting of quinolines.

[0019]

[0020]

In a preferred embodiment of the present invention, a binder layer is formed on a single surface of a current collector on a battery electrode plate by die coating or screen printing. In another preferred embodiment of the present invention, the binder layer is formed on both surfaces of the current collector on the battery electrode by die coating or screen printing.

In another more preferred embodiment of the present invention,
Since the positive / negative electrode plate can be strongly bonded to the polymer separator film, the binder layer is formed on the periphery of the electrode plate material or on two symmetrical lateral edges, or Arranged diagonally on the surface of.

The structure of the laminated battery disclosed in the present invention achieves the following actions.

1. The binder layer is formed on the surface of the current collector of the battery so as to be bonded to the positive / negative electrode plate and the polymer separator film. Therefore, since the active material is not handled in the lamination and the pressure binding, many materials can be used as the binder layer and the polymer separator film.

2. The present invention is a lithium ion battery,
It is applicable to lithium polymer batteries, nickel hydrogen batteries, and capacitors.

3. The energy density of a battery can be increased by stacking battery electrode plates.

4. The problem of dead space caused by forming a spiral shape can be solved.

Further areas of applicability of the present invention will become apparent from the following description. However, the preferred embodiments of the present invention are not limited to the detailed description given with reference to the drawings and what is understood in the specific examples, and are based on the detailed description within the scope of the technical idea of the present invention. Those skilled in the art can make various changes and improvements.

The electrode plate 10 of the laminated battery according to the present invention,
Reference is made to FIGS. 6 and 7 which show cross-sectional views of 10 '. The main technique featured in the present invention is to cover the surface of the active material on any surface of the current collector 11 to form the electrode layer 13. The binder layer 14 is attached to all edges or a plurality of edges of the surfaces of the adjacent electrode layers of the positive / negative electrode plates 10 and 10 ′ facing each other. Alternatively, the binder layer 1
4'can also be applied along the edge of the upper surface of the electrode layer 13. The positive / negative electrode plate 10 can be bound to almost all polymer separator films (not shown) by binding using a binder, heat, and pressure. Thus, in principle, close packing is achieved without the need to change the composition of the active material on the battery electrodes 10.

The apparatus used in the present invention performs (1) die coating and (2) screen printing. Therefore, the battery of the present invention is characterized in that the polymer separator film is easily attached onto the electrode plate 10 by die coating or screen printing.

Possible coating patterns include the following methods.

First method: As shown in FIG. 8, the binder layer 1 is formed by die coating or screen printing.
4a is attached on a single surface or both surfaces of the current collector 11c. The electrode material is distributed in blocks to form the electrode layer 13a, and the binder layer 14a is the electrode layer 13a.
Attached along a single or multiple sides of the. For example, the binder layer 14a is covered along the edge of the electrode layer 13a. Positive / negative electrode plate layer 13a and binder layer 14a
The block with is cut off by abutting,
Then, while being heated and pressed, the positive electrode plate, the negative electrode plate, and the polymer separator membrane module are bonded. The polymer separator film includes PP (polypropylene), PE (polyethylene), a PP / PE composite layer, and a non-woven fabric. Due to the special structure of the electrode 10c,
In the binding between the electrode 10c and the polymer separator film, the binding ability is determined only by the binding force between the binder layer 14a and the polymer separator film. Has nothing to do with Therefore, many materials can be selectively applied to the binder layer 14a and the polymer separator film. For example, the binder layer 14a
The materials are rubber binder, sulfide, epoxy resin, polyester, ethylene-acetate polyvinyl, ethylene-acrylic polyester, PE, P
P, Kraton (ShellChem. CO),
Acrylic binders, cyanide acetate ester binders, aromatic polyamine binders, silicone binders, polybenzimidazoles ), Polyquinoxalines (pol
yquinoxalines), polyphenylquinoxalines (polyphe
nyl quinoxalines) and polyquinoline
ine), and so on.

Second method: The electrode plate 10d shown in FIG.
The active material and the binder layer 14b are die-coated or screen-printed on one surface or both surfaces of the current collector 11d. The electrode layer 13b formed by the electrode material and the binder layer 14b is covered in the lateral direction. Then, the electrode layer 13b is replaced with the binder layer 14
By cutting or striping so that b is evenly arranged on both sides of the electrode layer 13b, a sheet-shaped positive / negative electrode plate 10d is obtained. The positive electrode plate, the polymeric separator film, and the negative electrode plate are bonded together under heat and pressure to form a rechargeable battery cell.

Third method: electrode plate 10e shown in FIG.
Is prepared by die-coating or screen-printing the active material and the binder layer 14c on the single surface or both surfaces of the current collector 11e. The electrode layer 13c formed by the electrode material and the binder layer 14c is laterally covered so that the binder layer 14c is evenly arranged on both sides of the electrode layer 13c. Then, the electrode layer 13c is
It is cut or striped to form a sheet-shaped or striped positive / negative electrode plate 10e. The positive electrode, the polymeric separator membrane, and the negative electrode are bonded together under heat and pressure to form a rechargeable battery cell.

Fourth method: electrode plate 10f shown in FIG.
Is prepared by die coating or screen printing the active material and the binder layer 14d on a single surface or both surfaces of the current collector 11f. Binder layer 14d
Are arranged along the diagonal of the surface of the electrode layer 13d formed of the electrode material. The positive / negative electrode plate 10f is cut off by abutting or cutting. The positive electrode, the polymeric separator membrane, and the negative electrode are combined under heat and pressure to form a rechargeable battery cell.

The laminated battery structure obtained using the above four methods is applicable to lithium ion batteries, lithium polymer batteries, nickel hydrogen batteries, and capacitors.

The coating on the positive plate was 85% Li.
CoO ₂ and 10% conductive agent ks6 (Timcal Company: Ti
mcal) and 5% of PVdF (polyvinylidene fluoride) binder are mixed, and the mixture is used as a solvent for NMP.
It is carried out by dissolving in a solution containing (N-methylpyrrolidone). The binder may be PE or an epoxy resin dissolved in NMP which will be the solution for later coating. The positive electrode material and the binder are coated simultaneously or stepwise by die coating or screen printing according to the above-mentioned first method, second method and third method.

The coating on the negative plate is 90% MC
MB (mesocarbon microbeads) powder and 10% P
VdF binder is mixed, and the mixture is used as a solvent for NM
It is carried out by dissolving in a solution containing P (N-methylpyrrolidone). The binder may be PE or an epoxy resin dissolved in NMP which will be the solution for later coating. The negative electrode material and the binder are coated simultaneously or stepwise by injection mold die coating or screen printing according to the above-mentioned first method, second method and third method.

<Embodiment 1> As shown in FIG.
The positive electrode plate formed by the method of 1. is cut together with the binder layer 14 by pressure molding or cutting, and the size thereof is W1 (4.0 + 0.5 cm) × L1.
(7.0 + 0.5 cm). Here, the size of the positive electrode layer 16 is W2 (4.0 cm) × L2 (7.0 cm), and the remaining range having a width of t = 0.25 cm is coated with the binder layer 14.

As shown in FIG. 13, the negative electrode plate formed by the first method is cut together with the binder layer 14 by pressure molding or cutting the electrode plate, and its size is W1 '(4.1 + 0). 0.5 cm) x L1 '(7.1+
0.5 cm). Here, the size of the negative electrode layer 17 is W
2 '(4.1 cm) x L2' (7.1 cm), t
The remaining range having a width of 0.25 cm is the binder layer 1
4 coated.

3. With the above positive and negative electrode plates and dimensions of 4.
The 7 cm × 7.7 cm PE separator membrane is heated and pressed at 140 ° C. for 5 minutes. After the conductive plate is soldered and the resulting module is placed in an aluminum foil back or metal case, the ME is
X2 (Mitsui Petrochemical Co., Ltd.) electrolyte solution is filled. The single-layer battery is completed by enclosing it in an aluminum foil bag. The charge / discharge diagram is shown in Figure 14.
Shown in.

<Second Embodiment> As shown in FIG.
The positive electrode formed by the method of 1. is cut out by pressure molding or cutting the electrode plate together with the binder layer 14, and the size thereof is W1 (4.0 + 0.5 cm) × L1.
(7.0 + 0.5 cm). Here, the size of the positive electrode layer 16 is W1 (4.0 cm) × L2 (7.0 cm), and the remaining range having a width of t = 0.25 cm is coated with the binder layer 14.

As shown in FIG. 16, the negative electrode plate formed by the second method is cut together with the binder layer 14 by pressure molding or cutting, and the size thereof is W1 '(4.1 + 0). 0.5 cm) x L1 '(7.1+
0.5 cm). Here, the size of the negative electrode layer 17 is W
1 ′ (4.1 cm) × L2 ′ (7.1 cm), and t =
The remaining area having a width of 0.25 cm is the binder layer 14
Is coated with.

3. With the above positive and negative electrode plates and dimensions of 4.
The 7 cm × 7.7 cm PE separator membrane is heated and pressed at 140 ° C. for 5 minutes. After the conductive plate is soldered and the resulting module is placed in an aluminum foil back or metal case, the ME is
X2 (Mitsui Petrochemical Co., Ltd.) electrolyte solution is filled. The single-layer battery is completed by enclosing it in an aluminum foil bag. The charge / discharge diagram is shown in Figure 17.
Shown in.

<Third Embodiment> As shown in FIG.
The positive electrode formed by the method of 1. is cut out by pressure molding or cutting the electrode plate together with the binder layer 14, and the size thereof is W1 (4.0 + 0.5 cm) × L1.
(7.0 + 0.5 cm). Here, the size of the positive electrode layer 16 is W2 (4.0 cm) × L1 (7.0 cm), and the remaining range having a width of t = 0.25 cm is coated with the binder layer 14.

As shown in FIG. 19, the negative electrode plate formed by the third method is cut out together with the binder layer 14 by pressure molding or cutting, and its size is W1 ′ (4.1 + 0). 0.5 cm) x L1 '(7.1+
0.5 cm). Here, the size of the negative electrode layer 17 is W
2 '(4.1 cm) x L1' (7.1 cm), t
The remaining range having a width of 0.25 cm is the binder layer 1
4 coated.

The positive and negative electrode plates described above, with dimensions of 4.
The 7 cm × 7.7 cm PE separator membrane is heated and pressed at 140 ° C. for 5 minutes. After the conductive plate is soldered and the module is placed in the aluminum foil back or metal case, it is vacuum-perfused to MEX2.
(Mitsui Petrochemical Co., Ltd.) Filled with electrolyte. The single-layer battery is completed by enclosing it in an aluminum foil bag. A charge / discharge diagram is shown in FIG.

The battery structure shown in the above embodiment is a single battery cell (positive electrode plate / polymer separator film /
Negative electrode plate) and wrapped together by heat and pressure, nevertheless, a plurality of battery cells (eg positive electrode plate / polymer separator membrane / negative electrode plate / polymer separator membrane / positive electrode) It can be stacked by pressure to form a stacked battery structure.

Although the present invention has been described above, it is obvious that it can be modified in various ways. Variations of the above are possible without departing from the spirit and scope of the invention. And such changes obvious to those skilled in the art are included in the technical scope of the claims.

[Brief description of drawings]

FIG. 1 is a schematic view of a conventional coating.

FIG. 2 is a schematic view of another conventional coating.

FIG. 3 is a diagram showing a schematic structure of a conventional cylindrical battery.

FIG. 4 is a diagram showing a schematic structure of a conventional rectangular battery.

FIG. 5 is a schematic view of a laminated battery formed by lamination and pressure treatment.

FIG. 6 is a sectional view of an electrode plate of the laminated battery of the present invention.

FIG. 7 is a cross-sectional view of an electrode plate of another laminated battery of the present invention.

FIG. 8 is a schematic view of a first coating pattern of the present invention.

FIG. 9 is a schematic view of a second coating pattern of the present invention.

FIG. 10 is a schematic view of a third coating pattern of the present invention.

FIG. 11 is a schematic view of a fourth coating pattern of the present invention.

FIG. 12 is a schematic view showing the size of the positive electrode plate according to the first embodiment of the present invention.

FIG. 13 is a schematic view showing the size of the negative electrode plate according to the first embodiment of the present invention.

FIG. 14 is a diagram showing charging / discharging of the first embodiment of the present invention.

FIG. 15 is a schematic view showing the size of a positive electrode plate according to a second embodiment of the present invention.

FIG. 16 is a schematic view showing the size of a negative electrode plate according to a second embodiment of the present invention.

FIG. 17 is a diagram showing charging / discharging of the second embodiment of the present invention.

FIG. 18 is a schematic view showing the size of a positive electrode plate according to a third embodiment of the present invention.

FIG. 19 is a schematic view showing the size of a negative electrode plate according to a third embodiment of the present invention.

FIG. 20 is a diagram showing charging / discharging of the third embodiment of the present invention.

[Explanation of symbols]

10, 10'10a to 10f ... Positive / negative electrode plate, 11, 11a to 11f ... Current collector, 13, 13a to 13d ... Electrode layer, 14, 14 ', 14a to 14d ... Binder.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 10-289732 (JP, A) JP 10-172606 (JP, A) JP 2000-149997 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01M 10/04 H01M 4/02 H01M 4/62 H01M 10/40

Claims (8)

(57) [Claims] 1. A positive electrode plate, a negative electrode plate, and a polymer separator film disposed between the positive electrode plate and the negative electrode plate, wherein a plurality of the positive electrode plates and the negative electrode plate are stacked to form a battery cell. A laminated battery, wherein the positive electrode plate and the negative electrode plate include current collectors, the surfaces of the positive electrode plate and the negative electrode plate are coated with an electrode layer, and the adjacent positive electrode plate and the negative electrode plate face each other. surfaces, said binder layer for binding a polymer separator film is coated, the binder layer is laminated battery, wherein the this <br/> coating the edges of the electrode layer . 2. A positive electrode plate, a negative electrode plate, the positive electrode plate, and
A polymer separator film disposed between the negative electrode plates
A plurality of positive electrode plates and negative electrode plates are stacked to form a bar.
A laminated battery that becomes a battery cell, wherein the positive electrode plate and the negative electrode plate include current collectors, and the surfaces of the positive electrode plate and the negative electrode plate are formed by an electrode layer.
Coated, positive and negative electrode plates facing each other
The surface is a binder for bonding with the polymer separator film.
And a binder layer coated on the surface of the electrode layer along a diagonal line.
A laminated battery, which is characterized by the following features. 3. The binder layer coats the surface of the electrode layer.
3. The method according to claim 1 or 2, wherein
Stacked battery. 4. A binder layer, according to claim, characterized in that symmetrically coating two sides of the electrode layers 1 or
The laminated battery according to claim 2 . 5. The binder layer is formed by die coating.
It is formed in Claim 1 or Claim 2 characterized by the above-mentioned.
The laminated battery described. 6. The binder layer is formed by screen printing.
It is formed according to claim 1 or claim 2.
The laminated battery according to. 7. The positive electrode plate and the negative electrode plate are heated and
Under pressure, it binds to the polymer separator membrane.
Serial to claim 1 or請 Motomeko 2, characterized in that it is worn
Mounted laminated battery. 8. The material of the binder layer is a rubber binder or a suture.
Ruffido compound, epoxy resin, polyester, ethyl
Vinyl acetate, ethylene-acrylic polyester
Tell, polyethylene, polypropylene, kraton
Le Chemical Co.), acrylic binder, cyanated acetate
Ester binder, aromatic polyamine binder, silicone
Binder, polybenzimidazoles, polyquinoxaline
, Polyphenylquinoxalines, and polyquinoli
Specially selected from a group consisting of
Laminated battery according to claim 1 or claim 2
Li.