Secondary battery using bipolar electrodes

Abstract

The problem to be solved by the present invention is to provide a secondary battery using bipolar electrodes, which does not impair productivity due to reasons such as the need for an electrode welding method different from that of ordinary electrodes. In order to solve the above problems, the secondary battery using bipolar electrodes of the present invention comprises: partial power generation elements 22, 23, 24, which are composed of a single-layer stack with bipolar electrodes stacked on at least one side of a solid electrolyte layer 2, or a multi-layer stack formed by stacking a plurality of single-layer stacks, wherein the bipolar electrode has a positive electrode of a polarized electrode formed on one side of a single sheet-like current collector, and a negative electrode of a polarized electrode formed on the other side; and ordinary electrodes 3, 4, which are stacked on one side and the other side of the partial power generation element directly or through a solid electrolyte layer, and have poles of the same polarity formed on both sides of the single sheet-like current collector.

Description

Technical Field

[0001] The present invention relates to a secondary battery using a bipolar electrode. Background Art

[0002] In recent years, various secondary batteries using bipolar electrodes have been proposed (for example, see Patent Document 1, Patent Document 2, and Patent Document 3).

[0003] [Prior technical literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent No. 4501905

[0006] Patent Document 2: Japanese Patent No. 4300310

[0007] Patent document 3: U.S. Patent Specification No. 9972860 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] In order to obtain a desired voltage between output terminals, a secondary battery using a bipolar electrode has a structure in which a plurality of single-layer stacks having bipolar electrodes stacked on at least one side of a solid electrolyte layer are stacked in series.

[0010] However, the bipolar electrode has a problem in productivity because a different electrode welding method is required for the bipolar electrode than for ordinary electrodes.

[0011] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a secondary battery using a bipolar electrode with excellent productivity.

[0012] [Technical means to solve the problem]

[0013] (1) A secondary battery using a bipolar electrode, comprising:

[0014] A partial power generation element, which is composed of a single-layer stack in which a bipolar electrode (for example, a bipolar electrode 17 described below) is stacked on at least one side of a solid electrolyte layer (for example, a solid electrolyte layer 2 described below), or a multilayer stack in which the above-mentioned single-layer stack is stacked in multiple layers, wherein the bipolar electrode has a positive electrode (for example, a positive electrode mixture slurry 19 described below) formed on one side of a single sheet-like current collector (for example, a sheet-like current collector 18 described below) and a negative electrode (for example, a negative electrode mixture slurry 20 described below) formed on the other side; and,

[0015] The common electrode (for example, the positive common electrode 3 and the negative common electrode 4 described later) is in the form of being stacked directly or through the solid electrolyte layer on one side and the other side of the aforementioned partial power generation element, and forming poles of the same polarity on both sides of the single-piece sheet collector.

[0016] (2) A secondary battery using a bipolar electrode as described in (1), wherein the common electrode is any one of the following: a positive common electrode (for example, the positive common electrode 3 described below), which is stacked on one side of the partial power generation element and has a positive polarity formed on both sides of a single sheet-like current collector; and a negative common electrode (for example, the negative common electrode 4 described below), which is stacked on the other side of the partial power generation element and has a negative polarity formed on both sides of a single sheet-like current collector.

[0017] (3) A secondary battery using a bipolar electrode as described in (2), wherein the aforementioned partial power generation elements constitute a series partial power generation element (for example, the later-described series partial power generation elements 26, 26a, 26b, 26c, 26d), and the series partial power generation element is composed of a single stack (for example, the later-described single stack 25) constituting the aforementioned multi-layer stack, which is stacked between the aforementioned positive common electrode and the aforementioned negative common electrode in the direction of the polarity constituting the series connection.

[0018] (4) A secondary battery using a bipolar electrode as described in (3), wherein one of the aforementioned positive common electrodes is used as a positive current collecting electrode (for example, the positive electrode sheet collector 5 described later), and between the aforementioned positive current collecting electrode and the two aforementioned negative common electrodes corresponding thereto, the aforementioned series-connected partial power generating elements clamp the aforementioned positive current collecting electrode and are connected with opposite polarities, thereby forming a first form of parallel connection body (for example, the first form of parallel connection body 27, 27a, 27b, 27d described later) in which the aforementioned series-connected partial power generating elements are connected in parallel between the aforementioned positive current collecting electrode and the two aforementioned negative common electrodes.

[0019] (5) A secondary battery using a bipolar electrode as described in (3), wherein one of the aforementioned negative common electrodes is used as a negative current collecting electrode (for example, the negative electrode sheet collector 7 described later), and between the aforementioned negative current collecting electrode and the two aforementioned positive common electrodes corresponding thereto, the aforementioned series-connected partial power generating elements clamp the aforementioned negative current collecting electrode and are connected with opposite polarities, thereby forming a second form of parallel connection body (for example, the second form of parallel connection body 28 described later) in which the aforementioned series-connected partial power generating elements are connected in parallel between the aforementioned negative current collecting electrode and the two aforementioned positive common electrodes.

[0020] (6) A secondary battery using a bipolar electrode as described in (3), wherein the first form of parallel connection body (for example, the first form of parallel connection body 27, 27a, 27b, 27c, 27d described below) and the second form of parallel connection body (for example, the second form of parallel connection body 28 described below) make the aforementioned series-connected partial power generation elements common between the aforementioned positive electrode collector electrode or the aforementioned negative electrode collector electrode and one of the aforementioned negative electrode common electrodes or the aforementioned positive electrode common electrodes to form a composite parallel connection body (for example, the composite parallel connection body 29, 29a, 29b, 29c, 29d, 29e described below);

[0021] The parallel connection body of the first form is formed by using one of the aforementioned positive common electrodes as a positive current collecting electrode (for example, the positive sheet current collector 5 described later), between the aforementioned positive current collecting electrode and the two aforementioned negative common electrodes corresponding thereto, the aforementioned series partial power generation elements sandwich the aforementioned positive current collecting electrode, and are connected with opposite polarities, and between the aforementioned positive current collecting electrode and the two aforementioned negative common electrodes, the aforementioned series partial power generation elements are connected in parallel;

[0022] The second form of parallel connection body uses one of the aforementioned negative common electrodes as a negative collecting electrode (for example, the negative sheet collector 7 described later), and between the aforementioned negative collecting electrode and the two aforementioned positive common electrodes corresponding thereto, the aforementioned series partial power generation elements clamp the aforementioned negative collecting electrode and are connected with opposite polarities, and between the aforementioned negative collecting electrode and the two aforementioned positive common electrodes, the aforementioned series partial power generation elements are connected in parallel.

[0023] (7) A secondary battery using a bipolar electrode as described in (6), wherein the aforementioned composite parallel connection body has the aforementioned negative common electrodes at both outermost ends in the connection direction thereof.

[0024] (8) A secondary battery using a bipolar electrode as described in (6), wherein the positive common electrode is located at both outermost ends of the composite parallel connection body in the connection direction.

[0025] (9) A secondary battery using bipolar electrodes as described in any one of (6) to (8), wherein the composite parallel connection body has connecting conductors provided on the positive current collecting electrode and the negative current collecting electrode, respectively, and a positive electrode tab (for example, the positive electrode tab 10 described below) and a negative electrode tab (for example, the negative electrode tab 11 described below) for supplying output power to the outside are provided concentratedly on the connecting conductors of the positive polarity and the negative polarity, respectively.

[0026] (10) A secondary battery using bipolar electrodes as described in (9), which is provided with an outer packaging body (for example, the outer packaging body 12 described later) of stacked plate materials, wherein the outer packaging body wraps the aforementioned composite parallel connector and the aforementioned connecting conductors of the positive polarity and the negative polarity, and a portion of the aforementioned positive electrode tab and the negative electrode tab is led out from the aforementioned outer packaging body.

[0027] (Effects of the Invention)

[0028] In the secondary battery using a bipolar electrode of (1), a single-layer stack with bipolar electrodes or a multi-layer stack formed by stacking multiple layers of the aforementioned single-layer stack, that is, one side and the other side of a part of the power generation element are common electrodes. Therefore, the conductor connection for deriving the output of the secondary battery to the outside does not need to correspond to the technology of the bipolar electrode, and can be processed by applying the previous technology. Therefore, it is easy to manufacture.

[0029] In the secondary battery using bipolar electrodes in (2), the common electrode is any one of the following: a positive common electrode (for example, the positive common electrode 3 described later), which is in the form of being stacked on one side of a portion of the power generation element, and having a positive polarity formed on both sides of a single sheet-like current collector; and a negative common electrode (for example, the negative common electrode 4 described later), which is in the form of being stacked on the other side of the aforementioned portion of the power generation element, and having a negative polarity formed on both sides of a single sheet-like current collector. Therefore, the conductor connection for deriving the output of the secondary battery to the outside does not require a new technology corresponding to the bipolar electrode, and can be processed using the conventional technology. Therefore, it is easy to manufacture.

[0030] In the secondary battery using a bipolar electrode of (3), part of the power generation elements constitute a series partial power generation element, and the series partial power generation element is a series connection body of a single stack of a multilayer stack between the positive common electrode and the negative common electrode. Therefore, it is possible to stack in direct contact without interposing other conductors to form a series connection body, and the advantage of reducing internal resistance by using a bipolar electrode can be fully utilized.

[0031] In the secondary battery using bipolar electrodes of (4), the positive electrode connection parts of the first type of parallel connection body can be concentrated on one positive electrode common electrode, that is, the positive electrode collector electrode. Therefore, the number of connection conductors used to constitute the parallel connection body can be reduced.

[0032] In the secondary battery using bipolar electrodes of (5), the connection parts of the negative electrodes of the second type of parallel connection body can be concentrated on one negative electrode collector electrode serving as a negative electrode common electrode. Therefore, the number of connection conductors for constituting the parallel connection body can be reduced.

[0033] In the secondary battery using the bipolar electrode of (6), the number of connection conductors of each parallel connection body constituting the composite parallel connection body can be reduced.

[0034] In the secondary battery using bipolar electrodes of (7), the composite parallel connection body has the aforementioned negative common electrodes at both ends of the outermost part in the connection direction. Therefore, even if no other insulator is inserted between the outer packaging bodies, the potential of the composite parallel connection body at the part in contact with the inner surface of the outer packaging body is the negative electrode and is the same potential, so safety is ensured.

[0035] In the secondary battery using bipolar electrodes of (8), the composite parallel connection body has the aforementioned positive common electrodes at both ends of the outermost part in the connection direction. Therefore, even if no other insulator is inserted between the outer packaging bodies, the potential of the composite parallel connection body at the part in contact with the inner surface of the outer packaging body is the positive electrode and is the same potential, so safety is ensured.

[0036] In the secondary battery using bipolar electrodes of (9), the composite parallel connection body is provided with connecting conductors at the positive collector electrode and the negative collector electrode, respectively, and the positive electrode tab and the negative electrode tab for supplying output power to the outside are provided on the positive and negative connecting conductors, respectively. Therefore, a battery pack that is overall compact and easy to use is provided.

[0037] In the secondary battery using bipolar electrodes of (10), an outer packaging body is provided that encloses the composite parallel connector and the stacked plate materials of the positive and negative connecting conductors, and a portion of the positive electrode tab and the negative electrode tab are led outward from the outer packaging body. Thus, a compact battery pack having a structure suitable for use as an all-solid-state battery is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a cross-sectional view showing a bipolar electrode suitable for use in an embodiment of the present invention.

[0039] Figure 2 FIG. 4 is a schematic structural diagram of a secondary battery using bipolar electrodes according to the present invention.

[0040] Figure 3 This is a diagram for explaining a two-layer stacked body formed by stacking two single-layer stacked bodies in series and the generation of a potential difference between positive and negative electrodes in an embodiment of the present invention.

[0041] Figure 4 This is a diagram for explaining a three-layer stacked body formed by stacking three single-layer stacked bodies in series and the generation of a potential difference between positive and negative electrodes in an embodiment of the present invention.

[0042] Figure 5 This is a diagram for explaining a four-layer stacked body formed by stacking four single-layer stacked bodies in series and the generation of a potential difference between positive and negative electrodes in an embodiment of the present invention.

[0043] Figure 6 This is a diagram for explaining a six-layer stacked body formed by stacking six single-layer stacked bodies in series and the generation of a potential difference between positive and negative electrodes according to an embodiment of the present invention.

[0044] Figure 7 This is a diagram for explaining a structure in which two two-layer stacks formed by stacking two single-layer stacks in series are connected in parallel, and how a potential difference is generated between the positive and negative electrodes of each of the two-layer stacks, in accordance with an embodiment of the present invention.

[0045] Figure 8 This is a diagram for explaining a structure in which two three-layer stacks formed by stacking three single-layer stacks in series are connected in parallel, and how a potential difference is generated between the positive and negative electrodes of each of the three-layer stacks, in accordance with an embodiment of the present invention.

[0046] Fig. 9 This is a diagram for explaining a structure in which two six-layer stacks formed by stacking six single-layer stacks in series are connected in parallel, and how a potential difference is generated between the positive and negative electrodes of each of the six-layer stacks, in accordance with an embodiment of the present invention.

[0047] Fig.10 This is a diagram for explaining a structure in which three six-layer stacks, each of which is formed by stacking six single-layer stacks in series, are connected in parallel, and how a potential difference is generated between the positive and negative electrodes of each of the six-layer stacks, in accordance with an embodiment of the present invention.

[0048] Fig.11 This is a diagram for explaining a structure in which four six-layer stacks, each of which is formed by stacking six single-layer stacks in series, are connected in parallel, and how a potential difference is generated between the positive and negative electrodes of each of the six-layer stacks, in accordance with an embodiment of the present invention.

[0049] Fig.12 This is a diagram illustrating an embodiment of the present invention, which illustrates a structure in which four 12-layer stacks formed by stacking 12 single-layer stacks in series are connected in parallel, a situation in which a potential difference is generated between the positive and negative electrodes of each of the 12-layer stacks, and the wiring configuration of the positive terminal collector plate and the negative terminal collector plate.

[0050] Fig.13 This is a diagram illustrating an embodiment of the present invention, which illustrates a structure in which eight six-layer stacks are formed by stacking six single-layer stacks in series and connected in parallel, a situation in which a potential difference is generated between the positive and negative electrodes of each of the six-layer stacks, and a form of wiring of a positive terminal collector plate and a negative terminal collector plate.

[0051] Fig.14This is a diagram illustrating a structure in which twelve single-layer stacks formed by stacking four of them in series are connected in parallel, the generation of a potential difference between the positive and negative electrodes of each of the four-layer stacks, and the wiring configuration of the positive terminal collector plate and the negative terminal collector plate in an embodiment of the present invention.

[0052] Fig.15 This is an exploded conceptual diagram for explaining the physical structure of a multilayer laminated body in which a plurality of single-layer laminated bodies are stacked in series in accordance with an embodiment of the present invention.

[0053] Fig.16 yes Fig.15 Conceptual diagram of the stacked body after stacking.

[0054] Fig.17 It is a drawing that will Fig.16 Figure 2 shows a battery pack in which a stacked body is housed in an outer packaging body.

[0055] Fig.18 yes Fig.17 Projection diagram of the battery pack in the stacking direction of the stack.

[0056] Fig.19 A diagram showing a solid-state battery consisting of common electrodes and a solid electrolyte.

[0057] Fig. 20 It is to put multiple Fig.19 A diagram illustrating the wiring configuration of a positive terminal collector plate and a negative terminal collector plate in a power generation unit formed by connecting solid batteries in parallel.

[0058] Fig.21 It is to connect multiple Fig.19 A diagram illustrating the wiring configuration of a positive terminal collector plate, a negative terminal collector plate, and an intermediate potential connection portion in a power generation unit formed by connecting a plurality of partial power generation units formed by a solid battery in series. DETAILED DESCRIPTION

[0059] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0060] A secondary battery using a bipolar electrode as one embodiment of the present invention includes a bipolar electrode and a common electrode.

[0061] Fig.19 1 is a diagram showing a solid battery 1 including a common electrode and a solid electrolyte. The solid battery 1 is configured such that a positive common electrode 3 is stacked on one side of a plate-like solid electrolyte layer 2, and a negative common electrode 4 is stacked on the other side.

[0062] The positive common electrode 3 is a common electrode in the form of a positive pole formed by coating a positive electrode mixture 6 on both sides of a collector foil such as aluminum, that is, a single positive electrode sheet collector 5. The positive electrode mixture 6 is formed by further containing a conductive aid or a binder in a positive electrode active material such as lithium cobalt oxide or lithium phosphate.

[0063] The negative electrode 4 is a common electrode in the form of a negative electrode formed by coating a negative electrode mixture 8 on both sides of a copper collector foil, i.e., a single negative electrode sheet collector 7. The negative electrode mixture 8 is formed by further containing a binder in a negative electrode active material such as graphite or lithium titanate.

[0064] The solid battery 1 generates an electromotive force E between the positive electrode sheet-shaped current collector 5 and the negative electrode sheet-shaped current collector 7. The solid battery 1 is a plurality of series-connected bodies in which the same type of solid batteries are electrically connected in series to generate a specific electromotive force, and are connected in parallel to form a power generation element. The series-connected bodies of solid batteries constituting such a power generation element and the parallel-connected bodies of the series-connected bodies constitute a partial power generation element with respect to the above-mentioned power generation element.

[0065] In this specification, the positive electrode sheet-like current collector 5 and the negative electrode sheet-like current collector 7 generating the electromotive force E are counted as one electrode surface (p=1). In addition, the parallel connection of these electrode surfaces is referred to as p parallel connections.

[0066] Fig. 20 It is to put multiple Fig.19 A diagram illustrating the wiring configuration of a positive terminal collector plate (positive electrode tab) 10 and a negative terminal collector plate (negative electrode tab) 11 in a power generation unit formed by connecting solid batteries in parallel. Fig. 20 In the power generation unit 9, P solid batteries 1 are electrically connected in parallel between the positive electrode tab 10 and the negative electrode tab 11 for supplying output power to the outside. In the figure, this connection state is recorded as p-pole parallel. Fig. 20 In the figure, the potential difference PD between each solid battery 1 is schematically drawn with a thick solid line in the middle position in the vertical direction of each solid battery 1. Because it is connected in parallel, the electromotive force E generated between the positive electrode tab 10 and the negative electrode tab 11 is equivalent to the electromotive force of each solid battery 1. Because it is connected in parallel, as shown in the figure, P wirings are connected to the positive electrode tab 10, and P+1 wirings are connected to the negative electrode tab 11. The power generation unit 9 can also be regarded as a partial power generation unit, which utilizes the series or parallel connection of the same type of power generation units to form a high-voltage power generation unit with more layers. In addition, the power generation unit 9 is housed in the outer packaging body 12 of the stacked plate.

[0067] Fig.21 Connect multiple Fig.19A diagram illustrating the wiring configuration of the positive electrode tab, the negative electrode tab, and the intermediate potential connection portion in other power generation units formed by connecting multiple partial power generation units formed by solid batteries in series. Fig. 20 The power generation unit 9 has the same p-pole connected in parallel as a partial power generation unit, and two of the partial power generation units are connected in series. In this example, p = 24. The value of the electromotive force E between the positive electrode tab 10 and the negative electrode tab 11 of the power generation unit 13 is Fig. 20 The number of wiring sheets of the positive electrode tab 10 and the negative electrode tab 11 is P sheets and P+1 sheets, which is the same as Fig. 20 The number of power generation units 9 is the same. On the other hand, the number of wirings of the intermediate potential connection portion 14 when two partial power generation units are connected in series is (2P+1)+1. In addition, the power generation unit 13 is housed in the outer packaging body 12 of the laminate. An intermediate insulating sheet 15 is inserted between the partial power generation unit 9a on the positive electrode tab 10 side and the partial power generation unit 9b on the negative electrode tab 11 side, and an outer packaging body inner insulating sheet 16 is inserted between the partial power generation unit 9a and the outer packaging body 12.

[0068] Figure 1 The bipolar electrode 17 is an electrode having a positive electrode mixture slurry 19 formed on one side of a single sheet-shaped current collector (current collector foil) 18, and a negative electrode mixture slurry 20 formed on the other side of the single sheet-shaped current collector (current collector foil) 18, which is a positive electrode of a bipolar electrode.

[0069] Figure 2 : is a schematic diagram of the structure of a secondary battery using bipolar electrodes of the present invention. Figure 2 In the embodiment, a unit cell, that is, a secondary battery 21, is constituted as a multilayer stack formed by stacking a plurality of layers of single-layer stacks in series. In detail, a positive common electrode 3 is provided at the outermost end of the positive electrode side of the secondary battery 21, and a negative common electrode 4 is provided at the outermost end of the negative electrode side. In this example, the stacking is as follows: two bipolar electrodes 17 are provided between the positive common electrode 3 and the negative common electrode 4. From the positive common electrode 3 side to the negative common electrode 4 side, a solid electrolyte layer 2 is sandwiched between the positive common electrode 3 and one bipolar electrode 17, between two bipolar electrodes 17, and between another bipolar electrode 17 and the negative common electrode 4.

[0070] That is, a partial unit cell 22 of the first form is formed by sandwiching a solid electrolyte layer 2 between the positive common electrode 3 and a bipolar electrode 17. A partial unit cell 23 of the second form is formed by sandwiching a solid electrolyte layer 2 between two bipolar electrodes 17 of one bipolar electrode 17 and another bipolar electrode 17. Furthermore, a partial unit cell 24 of the third form is formed by sandwiching a solid electrolyte layer 2 between another bipolar electrode 17 and the negative common electrode 4.

[0071] The electromotive force of each partial unit cell 24 of the third form, the partial unit cell 23 of the second form, and the partial unit cell 22 of the first form stacked in sequence from the negative common electrode 4 side to the positive common electrode 3 side is equivalent to E0 (for example, 3.7 volts). In addition, the partial unit cell 24 of the third form, the partial unit cell 23 of the second form, and the partial unit cell 22 of the first form are stacked in sequence from the negative common electrode 4 side to the positive common electrode 3 side, so as to form a series connection body. Therefore, the electromotive force E of the secondary battery (unit cell) 21 is E0×3 (for example, 11.7 volts).

[0072] Hereinafter, the first, second, and third partial unit cells 22, 23, and 24 are collectively referred to as a single-layer stack 25. The single-layer stack 25 is a partial power generation element that constitutes a power generation element in a secondary battery either as a single unit or as a collection thereof.

[0073] Figures 3 to 6 The diagrams are diagrams showing different examples of the number of series connection of some unit cells of the secondary battery (unit cell) 21. Figures 3 to 6 In the above Figure 2 The corresponding parts are marked with the same symbols. Figures 3 to 6 In FIG. 1 , a potential difference PD between each unit cell is schematically shown by a thick solid line at the middle position in the vertical direction of each unit cell.

[0074] Figures 3 to 6 In any case, a series partial power generation element 26 (26a, 26b, 26c, 26d) is constituted, and the series partial power generation element is composed of a single-layer stack 25 constituting a multi-layer stack, which is stacked between the positive common electrode 3 and the negative common electrode 4 in the direction of the polarity constituting the series connection.

[0075] exist Figure 3 In the case of , a two-layer stack formed by stacking two layers of the single-layer stack 25 in series is formed, that is, the series partial power generation element 26a. The generation of the potential difference in the series partial power generation element 26a corresponding to the stacking of the single-layer stack 25 is represented by the bold line as the potential difference PD.

[0076] exist Figure 4 In the case of , a three-layer stack formed by stacking three layers of single-layer stacks 25 in series is formed, namely, a series partial power generation element 26b. The generation of a potential difference in the series partial power generation element 26b corresponding to the stacking of the single-layer stack 25 is indicated by a bold line as a potential difference PD.

[0077] exist Figure 5 In the case of , a four-layer stack formed by stacking four layers of single-layer stacks 25 in series is formed, namely a series partial power generation element 26c. The generation of a potential difference in the series partial power generation element 26c corresponding to the stacking of the single-layer stack 25 is indicated by a bold line as a potential difference PD.

[0078] exist Figure 6 In the case of , a six-layer stack consisting of six layers of single-layer stacks 25 stacked in series is formed, namely a series partial power generation element 26d. The generation of a potential difference in the series partial power generation element 26d corresponding to the stacking of the single-layer stack 25 is indicated by a bold line as a potential difference PD.

[0079] Figures 7 to 9 They respectively represent a first form of parallel connection body, in which a positive common electrode is used as a positive collecting electrode, and between the positive collecting electrode and the two corresponding negative common electrodes, some power generation elements are connected in series to clamp the positive collecting electrode and are connected with opposite polarities, and between the positive collecting electrode and the two negative common electrodes, some power generation elements are connected in series in parallel.

[0080] exist Figure 7 In the case of, a positive common electrode 3 is used as a positive collector electrode 3a, between two negative common electrodes 4, 4 corresponding to the positive collector electrode 3a, Figure 3 The series partial power generation elements 26a sandwich the positive collector electrode 3a and are connected with opposite polarities. This connection forms a first form of parallel connection body 27 (27a) in which the series partial power generation elements 26a are connected in parallel between the positive collector electrode 3a and the two negative common electrodes 4, 4. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the first form of parallel connection body 27a is represented by a bold line as a potential difference PD.

[0081] exist Figure 8 In the case of, a positive common electrode 3 is used as a positive collector electrode 3a, between two negative common electrodes 4, 4 corresponding to the positive collector electrode 3a, Figure 4The series partial power generation elements 26b are connected with opposite polarities by sandwiching the positive collector electrode 3a. This connection forms a first form of parallel connection body 27 (27b) in which the series partial power generation elements 26b are connected in parallel between the positive collector electrode 3a and the two negative common electrodes 4, 4. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the first form of parallel connection body 27b is represented by a bold line as a potential difference PD.

[0082] exist Fig. 9 In the case of, a positive common electrode 3 is used as a positive collector electrode 3a, between two negative common electrodes 4, 4 corresponding to the positive collector electrode 3a, Figure 6 The series partial power generation elements 26d are connected with opposite polarities by sandwiching the positive collector electrode 3a. This connection forms a first form of parallel connection body 27 (27d) in which the series partial power generation elements 26d are connected in parallel between the positive collector electrode 3a and the two negative common electrodes 4, 4. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the first form of parallel connection body 27d is represented by a bold line as a potential difference PD.

[0083] Fig.10 and Fig.11 Draw the Figure 6 The series connection part of the power generating element 26d and Fig. 9 The parallel connection bodies are formed by connecting the parallel connection bodies 27d of the first form in parallel. These parallel connection bodies can be regarded as a combination of the parallel connection body 27 of the first form and the parallel connection body 28 of the second form with a different form.

[0084] The second form of parallel connection body 28 means that one negative common electrode 4 is used as a negative collector electrode 4a, and between the negative collector electrode 4a and the two corresponding positive common electrodes 3, 3, a series connection of partial power generation elements 26 is sandwiched between the negative collector electrode 4a, and the polarities are reversed. That is, the second form of parallel connection body 28 (28a) is a connection body in which a series connection of partial power generation elements 26 is connected in parallel between the negative collector electrode 4a and the two positive common electrodes 3, 3.

[0085] exist Fig.10 In the case of , it is a structure in which three six-layer stacks formed by stacking six layers in series are connected in parallel, which can be regarded as a connection body formed by connecting three groups of six poles in series in parallel. In addition, it can be regarded as a composite parallel connection body 29 (29a), which is a structure in which Fig. 9The first form of parallel connection body 27d is combined with the second form of parallel connection body 28a in which one negative common electrode 4 is used as the negative collector electrode 4a. At this time, in the composite parallel connection body 29a, the series-connected part power generation element 26 is shared between the positive collector electrode 3a or the negative collector electrode 4a and one of the negative common electrodes 4 or the positive common electrode 3. The generation of the potential difference corresponding to the stacking of the single stack body 25 in the composite parallel connection body 29a is represented by the bold line as the potential difference PD.

[0086] exist Fig.11 In the case of , the structure is a structure in which four six-layer stacks formed by stacking six layers in series are connected in parallel, which can be regarded as a connection body formed by connecting four groups of six poles in series in parallel. In addition, it can be regarded as a composite parallel connection body 29 (29b), which is a structure in which the negative electrode collector electrode 4a is used as a junction and a negative electrode common electrode 4 is connected to the junction with the opposite polarity. Fig. 9 At this time, in the composite parallel connection body 29b, the series-connected partial power generation element 26 is also shared between the positive collector electrode 3a or the negative collector electrode 4a and one of the negative common electrodes 4 or the positive common electrode 3. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the composite parallel connection body 29b is represented by a bold line as the potential difference PD.

[0087] Figure 12 to Figure 14 The figures respectively illustrate the structure of connecting a multilayer stack formed by stacking more single-layer stacks in series in parallel, the generation of a potential difference between the positive and negative electrodes of the multilayer stacks, and the wiring form of the positive terminal collector plate and the negative terminal collector plate.

[0088] Fig.12 It is a structure in which four 12-layer stacks formed by stacking 12 layers in series are connected in parallel, and can be regarded as a composite parallel connection body 29 (29c) formed by connecting four groups of 12 poles in series in parallel. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the composite parallel connection body 29c is represented by a bold line as the potential difference PD. The wiring form of the positive pole tab 10 connected to each positive terminal collector plate, and the wiring form of the negative pole tab 11 connected to each negative terminal collector plate are shown as the number of wiring welding pieces (abbreviated as NWS). The output electromotive force E is obtained between the positive pole tab 10 and the negative pole tab 11. At Fig.12 When four groups of 12 electrodes are connected in series and then connected in parallel, the NWS of the positive electrode tab 10 is 2, and the NWS of the negative electrode tab 11 is 3. The composite parallel connection body 29c is housed in the outer packaging body 12 of the laminated plates.

[0089] Fig.13It is a structure in which eight six-layer stacks formed by stacking six layers in series are connected in parallel, and can be regarded as a composite parallel connection body 29 (29d) formed by connecting eight groups of six poles in series in parallel. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the composite parallel connection body 29d is represented by a bold line as the potential difference PD. The wiring form of the positive pole tab 10 connected to each positive terminal collector plate and the wiring form of the negative pole tab 11 connected to each negative terminal collector plate are shown as the number of wiring welding pieces (abbreviated as NWS). An output electromotive force E is obtained between the positive pole tab 10 and the negative pole tab 11. At Fig.13 When four groups of six electrodes are connected in series and then connected in parallel, the NWS of the positive electrode tab 10 is 4, and the NWS of the negative electrode tab 11 is 5. The composite parallel connection body 29d is housed in the outer packaging body 12 of the laminated plates.

[0090] Fig.14 It is a structure in which twelve 4-layer stacks formed by stacking 4 layers in series are connected in parallel, and can be regarded as a composite parallel connection body 29 (29e) formed by connecting 12 groups of 4 poles in series in parallel. The generation of the potential difference corresponding to the stacking of the single-layer stack 25 in the composite parallel connection body 29e is represented by a bold line as the potential difference PD. The wiring form of the positive electrode tab 10 connected to each positive terminal collector plate and the wiring form of the negative electrode tab 11 connected to each negative terminal collector plate are shown as the number of wiring welding pieces (abbreviated as NWS). The output electromotive force E is obtained between the positive electrode tab 10 and the negative electrode tab 11. At Fig.14 When 12 sets of four electrodes are connected in series and then connected in parallel, the NWS of the positive electrode tab 10 is 6, and the NWS of the negative electrode tab 11 is 7. In addition, the composite parallel connection body 29e is housed in the outer packaging body 12 of the laminated plate.

[0091] Fig.15 This is an exploded conceptual diagram for explaining the physical structure of a multilayer stack formed by stacking a plurality of layers of single-layer stacks in series. In the illustrated example, a negative electrode sheet-like collector 7 having a negative electrode 7a is located at the top layer. The negative electrode sheet-like collector 7 is a form of a negative electrode common electrode 4. From the negative electrode sheet-like collector 7, a single-layer stack (partial power generation element) including a first form of bipolar electrode 17a and a solid electrolyte layer 2 is repeatedly stacked in the manner shown in the figure.

[0092] The first embodiment of the bipolar electrode 17a is a bipolar electrode of the following embodiment: Fig.15 The positive electrode material (positive electrode mixture slurry 19 ) is applied to the upper layer side of the single-layer stack in the stacking direction, and the negative electrode material (negative electrode mixture slurry 20 ) is applied to the lower layer side.

[0093] A positive electrode sheet-like collector 5 having a positive electrode 5a is stacked at the end of the repeated stacking of a single-layer stack (partial power generation element) including a bipolar electrode 17a and a solid electrolyte layer 2 of the first form. A single-layer stack (partial power generation element) including a bipolar electrode 17b and a solid electrolyte layer 2 of the second form is repeatedly stacked from the positive electrode sheet-like collector 5 to the lower layer in the manner shown in the figure.

[0094] The second embodiment of the bipolar electrode 17b is a bipolar electrode of the following embodiment: Fig.15 The negative electrode material (negative electrode mixture slurry 20 ) is applied to the upper layer side of the single-layer stack in the stacking direction, and the positive electrode material (positive electrode mixture slurry 19 ) is applied to the lower layer side.

[0095] At the end of the repetition of stacking of the single-layer stack (partial power generation element) including the second form of bipolar electrode 17b and solid electrolyte layer 2, the negative electrode sheet-like collector 7 having the negative electrode 7a is stacked again. The stacking is repeated from the stacked negative electrode sheet-like collector 7 having the negative electrode 7a to the lower layer in sequence as shown in the figure, and the positive electrode sheet-like collector 5 having the positive electrode 5a is stacked at the bottom layer.

[0096] Fig.16 It is shown Fig.15 As shown in the figure, the positive electrodes 5a of each positive electrode sheet-like collector 5 overlap in the projection position in the stacking direction of the stack. Similarly, the negative electrodes 7a of each negative electrode sheet-like collector 7 overlap in the projection position in the stacking direction of the stack.

[0097] Fig.17 It is a drawing that will Fig.16 Figure 1 shows a battery pack in which the stacked body is housed in an outer packaging body. Fig.17 In the battery pack, Fig.16 As shown, the positive electrodes 5a of the positive electrode sheet-like current collectors 5 located at positions where the projection positions in the stacking direction of the stacked body overlap are connected in parallel with the current collecting conductors in the illustrated battery by an imaginary line, and are concentrated at the positive electrode tab 10 and led out to the outside of the outer packaging body 12. Similarly, the negative electrodes 7a of the negative electrode sheet-like current collectors 7 located at positions where the projection positions in the stacking direction of the stacked body overlap are connected in parallel with the current collecting conductors in the illustrated battery by an imaginary line, and are concentrated at the negative electrode tab 11 and led out to the outside of the outer packaging body 12.

[0098] Fig.18 yes Fig.17 As shown in the figure, the positive electrode tab 10 and the negative electrode tab 11 are led out from the same side surface of the square outer packaging body 12 in parallel to the outside. Fig.18 The arrows in the figure schematically indicate the direction of the current.

[0099] According to the secondary battery using the bipolar electrode of this embodiment, the following effects are achieved.

[0100] (1) The secondary battery using a bipolar electrode of the present embodiment comprises: a partial power generation element 25, which is composed of a single-layer stack in which a bipolar electrode 17 is stacked on at least one side of a solid electrolyte layer 2, or a multi-layer stack in which the above-mentioned single-layer stack is stacked on multiple layers, wherein the bipolar electrode 17 is coated with a positive electrode mixture slurry 19 on one side of a sheet-like collector (collector foil) 18, and is coated with a negative electrode mixture slurry 20 on the other side; and a positive electrode common electrode 3 and a negative electrode common electrode 4, which are stacked on one side and the other side of the partial power generation element 25 directly or through the solid electrolyte layer 2, and form poles of the same polarity on both sides of the single-piece sheet-like collector (collector foil) 18.

[0101] In this structure, the positive common electrode 3 and the negative common electrode 4 are located on one side and the other side of the partial power generation element 25, that is, the part where the battery output is output to the outside. Therefore, in order to connect the conductor for outputting the battery output to the outside, no special technology corresponding to the bipolar electrode is required, and the conventional welding technology can be applied, so the manufacturing is easy.

[0102] In the secondary battery 1 using bipolar electrodes of (2), the common electrode is either the positive common electrode 3 stacked on one side of the partial power generation element 25 or the negative common electrode 4 stacked on the other side of the partial power generation element 25 .

[0103] Therefore, for the connection of the conductor for outputting the battery to the outside on either one side or the other side of the partial power generation element 25, there is no need to use special technology corresponding to the cladding material of the bipolar electrode, and conventional welding technology can be applied, thereby facilitating manufacturing.

[0104] In the secondary battery using bipolar electrodes in (3), some of the power generation elements constitute series-connected partial power generation elements 26, 26a, 26b, 26c, and 26d, and the series-connected partial power generation elements are composed of a single-layer stack 25 that constitutes a multi-layer stack, which is stacked between the positive common electrode 3 and the negative common electrode 4 in the direction of the polarity constituting the series connection.

[0105] Therefore, the partial unit cells 22 of the first form, the partial unit cells 23 of the second form, and the partial unit cells 24 of the third form can be stacked in direct contact without interposing other conductors to form a series connection body, and the advantage of reducing the internal resistance of the bipolar electrode can be fully utilized.

[0106] In the secondary battery using bipolar electrodes (4), a positive common electrode 3 is used as a positive collecting electrode, that is, a positive sheet collector 5. Between the positive sheet collector 5 and the two corresponding negative common electrodes 4, 4, some power generation elements are connected in series to clamp the positive sheet collector 5 and are connected with opposite polarities, thereby forming a first form of parallel connection body 27, 27a, 27b, 27d in which some power generation elements are connected in series in parallel between the positive sheet collector 5 and the two negative common electrodes 4, 4.

[0107] Therefore, the conductor part on the positive electrode side for connecting the two series partial power generation elements in parallel is necessary for each series partial power generation element, and in this structure, one positive electrode sheet-shaped collector 5 functions as a conductor common to the two series partial power generation elements. Therefore, the number of conductor parts on the positive electrode side for parallel connection is small, and the structure is simplified.

[0108] In the secondary battery 1 using bipolar electrodes in (5), a negative common electrode 4 is used as a negative collecting electrode, that is, a negative sheet collector 7. Between the negative sheet collector 7 and the two corresponding positive common electrodes 3, 3, some power generation elements are connected in series, clamping the negative sheet collector 7 and connected with opposite polarities, thereby forming a second form of parallel connection body 28 in which some power generation elements are connected in series in parallel between the negative sheet collector 7 and the two positive common electrodes 3, 3.

[0109] Therefore, the conductor part on the negative electrode side for connecting the two series partial power generation elements in parallel is necessary for each series partial power generation element, and in this structure, one negative electrode sheet-shaped collector 7 functions as a conductor common to the two series partial power generation elements. Therefore, the number of conductor parts on the negative electrode side for parallel connection is small, and the structure is simplified.

[0110] In the secondary battery 1 using bipolar electrodes of (6), the first type of parallel connection bodies 27, 27a, 27b, 27d and the second type of parallel connection body 28 make the series-connected part of the power generation elements common between the positive electrode sheet-like collector 5 or the negative electrode sheet-like collector 7 and one of the negative electrode common electrodes 4 or the positive electrode common electrode 3 to form composite parallel connection bodies 29, 29a, 29b, 29c, 29d, 29e,

[0111] The parallel connection bodies 27, 27a, 27b, 27d of the first form use a positive common electrode 3 as a positive current collecting electrode, that is, a positive sheet-shaped current collector 5. Between the positive sheet-shaped current collector 5 and the two corresponding negative common electrodes 4, 4, a series of partial power generation elements sandwich the positive sheet-shaped current collector 5 and are connected with opposite polarities. Between the positive sheet-shaped current collector 5 and the two negative common electrodes 4, 4, the series of partial power generation elements are connected in parallel to form the parallel connection body of the first form.

[0112] The second form of parallel connection body 28 uses a negative common electrode 4 as a negative collecting electrode, that is, a negative sheet collector 7. Between the negative sheet collector 7 and the two corresponding positive common electrodes 3, 3, the negative sheet collector 7 is clamped by a series of partial power generation elements, which are connected with opposite polarities. Between the negative sheet collector 7 and the two positive common electrodes 3, 3, the series part of the power generation elements are connected in parallel to form a second form of parallel connection body.

[0113] Therefore, as described in (4) and (5) above, the number of conductor parts on the positive electrode side and the negative electrode side for parallel connection is small, and the structure is simplified.

[0114] In the secondary battery 1 using bipolar electrodes of (7), the composite parallel connection body has negative common electrodes 4, 4 at both outermost ends in the connection direction.

[0115] Therefore, even if no separate insulator is inserted between the outer packaging bodies 12 , the potential of the composite parallel connection body at the portion in contact with the inner surface of the outer packaging body 12 is the negative electrode potential and is the same potential, so safety can be ensured.

[0116] In addition, this configuration is realized when the parallel number of the complex parallel connection body is an even number.

[0117] In the secondary battery 1 using bipolar electrodes of (8), the composite parallel connection body has positive common electrodes 4, 4 at both outermost ends in the connection direction.

[0118] Therefore, even if no separate insulator is inserted between the outer packaging bodies 12 , the potential of the composite parallel connection body at the portion in contact with the inner surface of the outer packaging body 12 is the positive electrode potential and is the same potential, so safety can be ensured.

[0119] In addition, this configuration is realized when the parallel number of the complex parallel connection body is an even number.

[0120] In the secondary battery 1 using bipolar electrodes of (9), the composite parallel connection body is provided with connecting conductors on the positive electrode sheet collector 5 and the negative electrode sheet collector 7, respectively, and the connecting conductors of the positive polarity and the negative polarity are respectively concentrated, and a positive electrode tab 10 and a negative electrode tab 11 for supplying output power to the outside are provided.

[0121] Therefore, a battery pack which is compact as a whole and easy to use is provided.

[0122] In the secondary battery 1 using bipolar electrodes of (10), an outer casing 12 is provided which wraps the composite parallel connection body and the stacked plate materials of the positive and negative connection conductors, and a part of the positive electrode tab 10 and the negative electrode tab 11 are led out from the outer casing 12 to the outside.

[0123] Therefore, a compact battery pack suitable for being a configuration of an all-solid-state battery is provided.

[0124] The above describes the embodiments of the present invention, but the present invention is not limited thereto. The structure of the details can be appropriately changed within the scope of the present invention. For example, a structure having a mechanism for exerting a pressing force on the battery in the stacking direction can be used as an outer packaging body.

[0125] Reference numerals

[0126] 1 Solid-state battery

[0127] 2 Solid electrolyte layer

[0128] 3 Positive common electrode

[0129] 3a Positive current collecting electrode

[0130] 4 Negative common electrode

[0131] 4a Negative collector electrode

[0132] 5. Positive electrode sheet collector

[0133] 5a Positive electrode

[0134] 6 Positive electrode mixture

[0135] 7 Negative electrode sheet collector

[0136] 7a Negative electrode

[0137] 8 Negative electrode mixture

[0138] 9 Power generation units

[0139] 10 Positive electrode tab

[0140] 11 Negative electrode tab

[0141] 12 Outer packaging

[0142] 13 (Other) power generation units

[0143] 14 Intermediate potential connection

[0144] 15 Intermediate insulation sheet

[0145] 16 Insulation sheet inside the outer packaging

[0146] 17 Bipolar Electrode

[0147] 18. Sheet current collector (current collector foil)

[0148] 19. Positive electrode mixture slurry

[0149] 20 Negative electrode mixture slurry

[0150] 21 Secondary battery (unit battery)

[0151] 22 Part of the first form of unit cells

[0152] 23 Part of the second form of the unit cell

[0153] 24 Part of the third form of unit cells

[0154] 25 Single-layer stack (partial power generation element)

[0155] 26 (26a, 26b, 26c, 26d) Partial power generation elements connected in series

[0156] 27 (27a, 27b, 27d) Parallel connection body of the first form

[0157] 28 Second form of parallel connection

[0158] 29 (29a, 29b, 29c, 29d, 29e) Composite parallel connection

Claims

1. A secondary battery using a bipolar electrode, comprising: A partial power generation element, which is composed of a single-layer stack having a bipolar electrode stacked on at least one side of a solid electrolyte layer, or a multilayer stack having multiple layers stacked on the single-layer stack, wherein the bipolar electrode has a positive electrode of a polarizable electrode formed on one side of a single sheet-like current collector and a negative electrode of a polarizable electrode formed on the other side thereof; and, The common electrode is in the form of being stacked on one side and the other side of the aforementioned partial power generation element directly or through the aforementioned solid electrolyte layer, and having electrodes of the same polarity formed on both sides of a single sheet-like current collector, in, The common electrode is any one of the following: a positive common electrode, which is stacked on one side of the partial power generation element and has a positive polarity formed on both sides of a single sheet-like current collector; and a negative common electrode, which is stacked on the other side of the partial power generation element and has a negative polarity formed on both sides of a single sheet-like current collector. The aforementioned partial power generation element constitutes a series partial power generation element, and the series partial power generation element is formed by stacking a single stack constituting the aforementioned multilayer stack between the aforementioned positive common electrode and the aforementioned negative common electrode in the direction of polarity constituting a series connection; Furthermore, the parallel connection body of the first form and the parallel connection body of the second form make the aforementioned series-connected partial power generation elements common between the positive collector electrode or the negative collector electrode and one of the aforementioned negative common electrodes or the aforementioned positive common electrodes to form a composite parallel connection body; The parallel connection body of the first form is formed by using one of the positive common electrodes as a positive collector electrode, and between the positive collector electrode and the two corresponding negative common electrodes, the series partial power generation elements sandwich the positive collector electrode and are connected with opposite polarities, and between the positive collector electrode and the two negative common electrodes, the series partial power generation elements are connected in parallel; The parallel connection body of the second form is formed by using one of the aforementioned negative common electrodes as a negative collector electrode, between the aforementioned negative collector electrode and the two aforementioned positive common electrodes corresponding thereto, the aforementioned series partial power generation elements sandwich the aforementioned negative collector electrode, and are connected with opposite polarities, and between the aforementioned negative collector electrode and the two aforementioned positive common electrodes, the aforementioned series partial power generation elements are connected in parallel; Moreover, the aforementioned composite parallel connection body has the aforementioned negative common electrodes at both outermost ends in the connection direction thereof.

2. The secondary battery using a bipolar electrode according to claim 1, wherein: The composite parallel connection body is provided with connection conductors on the positive collector electrode and the negative collector electrode, respectively, and positive and negative pole tabs for supplying output power to the outside are provided on the positive and negative connection conductors respectively. The secondary battery using bipolar electrodes is provided with an outer packaging body of laminated plates, which wraps the composite parallel connection body and the positive and negative connection conductors and leads part of the positive and negative electrode tabs to the outside from the outer packaging body.

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