Battery and method for manufacturing a battery

Abstract

The present application relates to a battery and a method of manufacturing a battery. At least one of a plurality of first stacking end faces of a first electrode body has an overlapping stacking end face which overlaps, as viewed in a stacking direction, a portion of a second electrode body other than a plurality of second stacking end faces. An end region including the overlapping stacking end face has a thickness which is thinner than a thickness of a region other than the end region.

Description

Technical Field

[0001] This disclosure relates to batteries and methods for manufacturing batteries. Background Technology

[0002] Japan's special lottery 2021-57322 has been published. Figure 7 The stacked battery shown is also referred to as "battery 900". Battery 900 includes multiple power generation elements 900U and multiple positive current collectors 910. The power generation elements 900U are stacked via the positive current collectors 910. Each power generation element 900U is formed by stacking a positive electrode layer 920, a solid electrolyte layer 930, a negative electrode active material layer 940, and a negative electrode current collector 950 in this order in the stacking direction D. The positive electrode layer 920 has a positive electrode active material layer 921 and an insulating layer 922 formed at the ends of the positive electrode active material layer 921. The dimension of at least one direction of the main surface of the positive current collector 910 is smaller than the dimension of the main surface of the positive electrode layer 920 in the same direction. An insulating adhesive 911 is disposed across the ends of the positive current collector 910. The insulating adhesive 911 bonds the main surface of one power generation element 900U to the main surface of adjacent power generation elements 900U. The positive current collector 910, the positive electrode layer 920, the solid electrolyte layer 930, the negative electrode active material layer 940, and the negative electrode current collector 950 have the same thickness. Summary of the Invention

[0003] To reduce interlayer resistance, the battery 900 is typically used under a compressive state by a constraint load F in the stacking direction D. The positive electrode active material layer 921, having the same thickness, has sharp corners (i.e., approximately right angles that are not chamfered). Therefore, due to these sharp corners, stress may concentrate at the portions E930 and E940 of at least one of the solid electrolyte layer 930 and the negative electrode active material layer 940 (hereinafter also referred to as "negative electrode active material layer 940, etc.") corresponding to the end face E921 of the positive electrode active material layer 921. As a result, cracks may occur in the negative electrode active material layer 940, etc. When cracks occur in the negative electrode active material layer 940, etc., the battery performance of the battery 900 deteriorates.

[0004] For example, the power generation element of a battery is sometimes fabricated by alternately stacking electrode bodies and current collectors of the same thickness. Each electrode body includes a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer. Due to the processing of electrode body stacking, etc., there is sometimes electrode body stacking misalignment in the power generation element. "Electrode body stacking misalignment" means that the stacked end faces of adjacent electrode bodies in the stacking direction are not on the same plane. More specifically, "electrode body stacking misalignment" means that in a direction orthogonal to the stacking direction, the distance between the stacked end faces of adjacent electrode bodies in the stacking direction is 0.2 mm or more. If electrode body stacking misalignment exists, due to the sharp angles of the misaligned electrode bodies, as described above, cracks may occur in the structural layers of the electrode bodies, resulting in a decrease in battery performance.

[0005] This disclosure is made in view of the above-mentioned circumstances.

[0006] One embodiment of this disclosure provides a battery that is less prone to cracking of the electrode body even in the event of electrode body stacking misalignment, and a method for manufacturing the battery.

[0007] This disclosure includes the following methods.

[0008] The first aspect of this disclosure relates to a battery having a first electrode, a first current collector, and a second electrode. The first electrode body, the first current collector, and the second electrode body are stacked along the stacking direction in the order of the first electrode body, the first current collector, and the second electrode body. The first electrode body has a first electrode active material layer, an electrolyte layer, and a second electrode active material layer in the order of the stacking direction. The second electrode body has a first electrode active material layer, an electrolyte layer, and a second electrode active material layer in the order of the stacking direction. The first electrode body also has a plurality of first stacked end faces, and the second electrode body also has a plurality of second stacked end faces. At least one of the plurality of first stacked end faces of the first electrode body includes an overlapping stacked end face. When viewed from the stacking direction, the overlapping stacked end face overlaps with a portion of the second electrode body that is different from the second stacked end face. The first electrode body also has an end region and a region different from the end region. The end region includes the overlapping stacked end face of the first electrode body, and the thickness of the end region is thinner than the thickness of the different region.

[0009] In this disclosure, "first electrode active material layer" can refer to one of the positive electrode active material layer and the negative electrode active material layer. "Second electrode active material layer" can refer to the other of the positive electrode active material layer and the negative electrode active material layer. "Positive electrode active material layer" can refer to a layer containing positive electrode active material. "Negative electrode active material layer" can refer to a layer containing negative electrode active material. "Electrolyte layer" can refer to a layer containing electrolyte but not active material (i.e., at least one of positive electrode active material and negative electrode active material). "Electrolyte" can refer to a substance that is located between the positive electrode active material layer and the negative electrode active material layer and conducts charge carrier ions. Specifically, examples of electrolytes include solid electrolytes, non-aqueous electrolytes containing lithium salts (e.g., LiPF6, etc.), non-aqueous gel electrolytes, and ion-conducting polymers. "End region" can also refer to the region between the overlapping stacked end face of the first electrode body and a portion located at a specific distance (e.g., 0.2 mm to 0.5 mm) away from the overlapping stacked end face of the first electrode body when viewed from the stacking direction. "At least a portion of the stacked end face of the first electrode body has the overlapping stacked end face when viewed from the stacking direction" can indicate that there is a stacking offset between the first electrode body and the second electrode body.

[0010] In the first embodiment, the thickness of the end region is thinner than the thickness of the portion of the first electrode that differs from the end region. That is, the first electrode does not have sharp corners. Therefore, in the first embodiment, compared to the case where the first electrode has the same thickness, the stress applied to the portion of the second electrode corresponding to the overlapping end face of the first electrode when a constraint load is applied in the stacking direction is mitigated. As a result, the battery of the first embodiment is one that is less prone to cracking of the electrode body even if there is a stacking misalignment.

[0011] In the battery described in the first aspect of this disclosure, the thickness of the end region may gradually decrease as it moves toward the overlapping end face.

[0012] The aforementioned battery is less prone to cracking of the electrode body even if there is a stacking misalignment of the electrode body.

[0013] In the battery described in the first aspect of this disclosure, the end region may also have a stepped portion where the thickness of the overlapping end face side is thinner than that of other portions of the end region.

[0014] The aforementioned battery is less prone to cracking of the electrode body even if there is a stacking misalignment of the electrode body.

[0015] In the battery described in the first aspect of this disclosure, the overlapping end faces may also be located on a first plane, which is different from the second plane containing one of the second overlapping end faces of the second electrode body.

[0016] "Alternatively, the overlapping end face is located on a first plane, and the first plane is different from the second plane containing one of the second overlapping end faces of the second electrode body." This means that in a direction orthogonal to the stacking direction, the distance between the overlapping end face of the first electrode body and the second overlapping end face of the second electrode body can be 0.2 mm or more.

[0017] The aforementioned battery is less prone to cracking of the electrode body even if there is a stacking misalignment of the electrode body.

[0018] In the battery described in the first aspect of this disclosure, the first plane where at least one of the plurality of first stacked end faces of the first electrode body is located may be the same as the second plane where one of the second stacked end faces of the second electrode body is located.

[0019] "At least one of the plurality of stacked end faces of the first electrode" refers to a stacked end face that is cut together with one of the second stacked end faces of the second electrode. Furthermore, "first plane" can also refer to a plane that is within 0.1 mm of the second plane in a direction orthogonal to the stacking direction.

[0020] Compared to cases where the multiple stacked end faces of the first electrode do not have a stacked end face that is on the same plane as the stacked end face of the second electrode, the above-described battery exhibits superior structural efficiency. "Structural efficiency" can be expressed as the ratio of the volume of the power-generating element contained within the battery to the total volume of the battery.

[0021] In the battery according to the first aspect of this disclosure, the thickness of the end region of the first electrode active material layer may be thinner than the thickness of the different region of the first electrode active material layer that is different from the end region, and the electrolyte layer and the second electrode active material layer may each have a uniform thickness.

[0022] The battery described above is one that is not prone to cracking of the electrode body even if there is a stacking misalignment of the electrode body.

[0023] In the battery described in the first aspect of this disclosure, the first electrode body may also have the following layers in the stacking direction: first electrode active material layer, electrolyte layer, second electrode active material layer, second current collector, second electrode active material layer, electrolyte layer, and first electrode active material layer in that order.

[0024] The aforementioned battery has superior structural efficiency.

[0025] In the battery according to the first aspect of this disclosure, the end offset in the cross section of the battery cut along the stacking direction is shorter than the length of the end region in the orthogonal direction orthogonal to the stacking direction, where the end offset represents the length of the orthogonal direction between the overlapping stacked end face of the first electrode body and the stacked end face of the second electrode body.

[0026] The aforementioned battery is less prone to cracking of the electrode body even if there is a stacking misalignment of the electrode body.

[0027] In the battery described in the first aspect of this disclosure, the battery may also have at least one first electrode and a plurality of second electrodes.

[0028] The aforementioned battery has superior structural efficiency.

[0029] In the battery described in the first aspect of this disclosure, the electrolyte layer may also comprise a solid electrolyte.

[0030] The safety of the above-mentioned batteries is superior to those with an electrolyte layer that does not contain a solid electrolyte.

[0031] In the battery described in the first aspect of this disclosure, the different regions may also be adjacent to the end regions in a direction perpendicular to the stacking direction.

[0032] In the battery according to the first aspect of this disclosure, the thickness of the end region may also gradually decrease in the direction from the different regions toward the overlapping end face as it moves toward the overlapping end face.

[0033] The second aspect of this disclosure relates to a method for manufacturing the aforementioned battery, comprising: preparing a first electrode body semi-finished product, the first electrode body semi-finished product having, along the stacking direction, in the order of a first electrode active material layer, an electrolyte layer, and a second electrode active material layer, a first electrode active material layer having a uniform thickness, an electrolyte layer having a uniform thickness, and a second electrode active material layer having a uniform thickness; and reducing the thickness of at least one of the first electrode active material layer of the first electrode body semi-finished product and the second electrode active material layer of the first electrode body semi-finished product in the end region.

[0034] In the battery manufacturing method of the second aspect of this disclosure, the end region may include at least one of the end of the first electrode active material layer of the first electrode body semi-finished product and the end of the second electrode active material layer of the first electrode body semi-finished product.

[0035] The above-described battery manufacturing method can efficiently manufacture batteries that are less prone to cracking even if there is a stacking misalignment of the electrode bodies.

[0036] According to this disclosure, a battery that is not prone to cracking in the electrode body even if there is a stacking misalignment of the electrode body, and a method for manufacturing the battery are provided. Attached Figure Description

[0037] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which like reference numerals denote like elements, and wherein: Figure 1 This is a perspective view of the battery according to the first embodiment.

[0038] Figure 2 yes Figure 1 A cross-sectional view along line II-II of the battery according to the first embodiment.

[0039] Figure 3 yes Figure 1 A cross-sectional view along line III-III of the battery according to the first embodiment.

[0040] Figure 4 yes Figure 1 A cross-sectional view along line IV-IV of the power generation element of the first embodiment.

[0041] Figure 5 yes Figure 1 A VV-line cross-sectional view of the power generation element of the first embodiment.

[0042] Figure 6 This is a cross-sectional view of the first electrode body in the second embodiment.

[0043] Figure 7 This is a cross-sectional view of a traditional stacked battery. Detailed Implementation

[0044] In this disclosure, the numerical range indicated by "~" refers to the range encompassed by the values ​​recorded before and after "~" as the minimum and maximum values, respectively. In the numerical ranges recorded in stages in this disclosure, the upper or lower limit value recorded in a certain numerical range can also be replaced by the upper or lower limit value of other numerical ranges recorded in stages. In this disclosure, a combination of two or more preferred methods is a more preferred method. In this disclosure, the term "process" is not only an independent process, but is sometimes included in this terminology when it cannot be clearly distinguished from other processes.

[0045] Hereinafter, embodiments of the battery of this disclosure will be described with reference to the accompanying drawings. In the drawings, the same or equivalent parts are labeled with the same reference numerals without being described again.

[0046] The batteries disclosed herein include all-solid-state batteries using a solid electrolyte as the electrolyte, and semi-solid-state batteries having a gel layer containing an electrolyte and a polymer between the electrode and the solid electrolyte. The solid electrolyte may contain less than 10% by mass of electrolyte relative to the total electrolyte volume. It should be noted that the solid electrolyte may be a composite solid electrolyte comprising an inorganic solid electrolyte and a polymer electrolyte. Preferably, all-solid-state batteries are used.

[0047] 1 First Implementation Method

[0048] 1.1 Battery

[0049] The battery 1A in the first embodiment is a solid-state battery. For example... Figure 1 As shown, battery 1A includes a power generation element 10A, an outer casing 20, and an electrical insulator 30 (see reference). Figure 2 It has two positive terminals 41 and two negative terminals 42. The power generation element 10A is a cuboid shape.

[0050] In the first embodiment, the long side direction of the main surface S10A of the power generation element 10A is defined as the X-axis direction. The short side direction of the main surface S10A of the power generation element 10A is defined as the Y-axis direction. The thickness direction of the power generation element 10A is defined as the Z-axis direction (an example of the stacking direction). The X-axis, Y-axis, and Z-axis are all orthogonal to each other. Furthermore, these orientations do not limit the orientation in which the battery of this disclosure is used. In addition, the stacking direction can also be represented as the stacking direction D.

[0051] The positive terminal 41, the power generation element 10A, and the negative terminal 42 are arranged in this order along the X-axis. The positive terminal 41 and the negative terminal 42 are electrically connected to the power generation element 10A. An electrical insulator 30 is located between the power generation element 10A and the outer casing 20. The power generation element 10A and the electrical insulator 30 are sealed by the outer casing 20, the positive terminal 41, and the negative terminal 42.

[0052] 1.1.1 Power generation components

[0053] The power generation element 10A functions as the power generation element of the battery 1A.

[0054] The power generation element 10A is a cuboid shape. For example... Figure 2 As shown, the power generation element 10A has a main surface S10A, a main surface S10B, a side surface S10C, a side surface S10D, and a side surface S10E (see reference). Figure 3 ) and the side S10F (refer to Figure 3 Main surface S10A is opposite to main surface S10B in the Z-axis direction. Side surface S10C is opposite to side surface S10D in the Y-axis direction. Side surface S10E is opposite to side surface S10F in the X-axis direction.

[0055] For details regarding the 10A power generation element, please refer to [link / reference]. Figure 4 and Figure 5 To be discussed later.

[0056] 1.1.2 Exterior body

[0057] The outer casing 20 houses the power generation element 10A.

[0058] The outer casing 20 is a cuboid shape. In the first embodiment, the outer casing 20 is a can. The outer casing 20 has a metal cylindrical body 21, a pair of metal caps 22, and an electrical insulator 23. The metal cylindrical body 21 has a pair of openings R21. The metal caps 22 block the openings R21 of the metal cylindrical body 21. The pair of metal caps 22 are fixed to the metal cylindrical body 21 by known methods (e.g., welding and mechanical fastening). The electrical insulator 23 is located between the positive terminal 41 and the negative terminal 42 and the metal caps 22.

[0059] The metal cylindrical body 21 has a hollow portion extending along the X-axis. A pair of openings R21 are connected via the hollow portion in the X-axis direction. The metal cylindrical body is made of metal (e.g., aluminum, copper, stainless steel (SUS), and nickel).

[0060] The metal cap 22 is plate-shaped. For example... Figure 3 As shown, multiple metal caps 22 have a pair of through holes R22 extending along the X-axis. The positive terminal 41 protrudes from one through hole R22 of the pair of metal caps 22. The negative terminal 42 protrudes from the other through hole R22 of the pair of metal caps 22. The caps are made of metal (e.g., aluminum, copper, stainless steel (SUS), or nickel).

[0061] The electrical insulator 23 prevents electrical contact between the positive terminal 41 and the negative terminal 42 and the metal cover 22. The shape of the electrical insulator 23 is not particularly limited, as long as it falls somewhere between the shapes of the positive terminal 41 and the negative terminal 42 and the metal cover 22. The material of the electrical insulator can be a known resin (thermoplastic resin or thermosetting resin, etc.). Thermoplastic resin can be an elastomer.

[0062] 1.1.3 Electrical Insulators

[0063] An electrical insulator 30 electrically insulates the power generation element 10A from the outer casing 20. The electrical insulator 30 is located between the power generation element 10A and the outer casing 20. The electrical insulator 30 covers the entire surface of the main surfaces S10A and S10B, and the side surfaces S10C and S10D of the power generation element 10A. The electrical insulator 30 is in physical contact with both the power generation element 10A and the outer casing 20. The material of the electrical insulator 30 is not particularly limited as long as it is a resin capable of electrically insulating the power generation element 10A from the outer casing 20; it can be any known resin (thermoplastic resin or thermosetting resin, etc.). Thermoplastic resins can be elastomers.

[0064] 1.1.4 Positive extreme

[0065] The positive terminal 41 is used to conduct electricity generated by the power generation element 10A to the outside of the battery 1A. For example... Figure 3 As shown, the positive terminal 41 has two positive terminal components 411, a positive current collector plate 412, and a positive current collector sheet 413. The two positive terminal components 411, the positive current collector plate 412, and the positive current collector sheet 413 are electrically connected. The positive current collector sheet 413 is electrically connected to the power generation element 10A. The positive current collector sheet 413 is cut in such a way that it physically contacts three parts of the positive current collector plate 412. Examples of materials for the positive terminal components 411, the positive current collector plate 412, and the positive current collector sheet 413 include metals (e.g., aluminum, stainless steel (SUS), and nickel). The materials of the positive terminal components 411, the positive current collector plate 412, and the positive current collector sheet 413 can be the same or different. Details of the positive current collector sheet 413 will be described later.

[0066] 1.1.5 Negative extremes

[0067] The negative terminal 42 is used to conduct electricity generated by the power generation element 10A to the outside of the battery 1A. The negative terminal 42 has two negative terminal components 421, a negative current collector plate 422, and a negative current collector sheet 423. The two negative terminal components 421, the negative current collector plate 422, and the negative current collector sheet 423 are electrically connected. The negative current collector sheet 423 is electrically connected to the power generation element 10A. Examples of materials for the negative terminal components 421, the negative current collector plate 422, and the negative current collector sheet 423 include metals (e.g., aluminum, stainless steel (SUS), and nickel). The materials of the negative terminal components 421, the negative current collector plate 422, and the negative current collector sheet 423 can be the same or different. Details regarding the negative current collector sheet 423 will be described later.

[0068] 1.1.6 Details of the power generation components

[0069] like Figure 4 and Figure 5 As shown, the power generation element 10A includes a plurality of first electrode bodies 11A, a plurality of first electrode bodies 11B, a plurality of positive current collectors 12 (an example of a first current collector), and a plurality of second electrode bodies 13. The first electrode bodies 11A, 11B and the positive current collectors 12 are stacked in this order along the Z-axis direction.

[0070] From the perspective of improving the structural efficiency of battery 1A, it is preferable to have fewer first electrode bodies 11A and 11B respectively. The number of each of the first electrode bodies 11A and 11B can be one.

[0071] Each first electrode body 11A has a pair of stacked end faces S11AC and S11AD opposite each other in the Y-axis direction (see reference). Figure 4 ) and a pair of stacked end faces S11AE and S11AF opposite each other in the X-axis direction (refer to Figure 5 Each first electrode body 11B has a pair of stacked end faces S11BC and S11BD opposite each other in the Y-axis direction (see reference). Figure 4 ) and a pair of stacked end faces S11BE and S11BF opposite each other in the X-axis direction (refer to Figure 5 Each second electrode body 13 has a pair of stacked end faces S13C and S13D opposite each other in the Y-axis direction (see reference). Figure 4 ) and a pair of stacked end faces S13E and S13F opposite each other in the X-axis direction (refer to Figure 5 ).

[0072] The side surface S10C of the power generation element 10A includes laminated end faces S11AC, S11BC, and S13C. The side surface S10D of the power generation element 10A includes laminated end faces S11AD, S11BD, and S13D. The side surface S10E of the power generation element 10A includes laminated end faces S11AE, S11BE, and S13E. The side surface S10F of the power generation element 10A includes laminated end faces S11AF, S11BF, and S13F.

[0073] 1.1.6.1 First Electrode

[0074] The first electrode 11A has a unipolar structure. The first electrode 11A is formed by stacking a positive electrode active material layer 111 (an example of a first electrode active material layer), an electrolyte layer 112 (an example of an electrolyte layer), a negative electrode active material layer 113 (an example of a second electrode active material layer), and a negative electrode current collector 114 (an example of a second current collector) in this order along the Z-axis. Details of the positive electrode active material layer 111, electrolyte layer 112, negative electrode active layer 113, and negative electrode current collector 114 will be described later.

[0075] In the first embodiment, such as Figure 4 As shown, viewed from the Z-axis direction, the stacked end face S11AC of the first electrode body 11A is an overlapping stacked end face (hereinafter also referred to as "overlapping stacked end face S11AC") that overlaps with the stacked end face S13C of the second electrode body 13 at a different location. That is, the overlapping stacked end face S11AC and the stacked end face S13C of the second electrode body 13 are not on the same plane.

[0076] The thickness L1 of the end region R11A1 including the overlapping end face S11AC (refer to) Figure 4The thickness L2 of the region R11A2 (hereinafter also referred to as "non-end region R11A2") that is different from the end region R11A1 of the first electrode body 11A (refer to) Figure 4 The thickness L1 of the end region R11A1 gradually decreases towards the overlapping end face S11AC. That is, the positive electrode active material layer 111 of the end region R11A1 has a pointed shape. Specifically, the thickness L3 of the end region R11A1 of the positive electrode active material layer 111 (refer to...) Figure 4 The thickness L4 of the non-end region R11A2 (refer to) Figure 4 Thin. That is, the electrolyte layer 112 and the negative electrode active material layer 113 each have the same thickness.

[0077] like Figure 4 As shown, in the cross-section of battery 1A cut along the Z-axis, the end offset L5 is shorter than the length L6 of the end region R11A1 in the Y-axis direction. The end offset L5 represents the length in the Y-axis direction of the overlapping end face S11AC of the first electrode body 11A and the overlapping end face S13C of the second electrode body 13. The end offset L5 can be 0.5 mm, and the length L6 can be 0.6 mm.

[0078] The stacked end face S11AD of the first electrode body 11A and the stacked end face S13D of the second electrode body 13 are located on the same plane.

[0079] 1.1.6.2 First Electrode

[0080] The first electrode 11B has a unipolar structure. The stacked structure of the first electrode 11B is the same as that of the first electrode 11A. The first electrode 11B is formed by stacking the positive electrode active material layer 111, the electrolyte layer 112, the negative electrode active material layer 113, the negative electrode current collector 114, the negative electrode active material layer 113, the electrolyte layer 112, and the positive electrode active material layer 111 in this order along the Z-axis direction.

[0081] like Figure 4 As shown, viewed from the Z-axis direction, the stacked end face S11BD of the first electrode body 11B is an overlapping stacked end face (hereinafter also referred to as "overlapping stacked end face S11BD") that overlaps with the stacked end face S13D of the second electrode body 13 at a different location. That is, the overlapping stacked end face S11BD and the stacked end face S13D of the second electrode body 13 are not on the same plane.

[0082] The thickness L7 of the end region R11B1, including the overlapping end face S11BD, is (refer to) Figure 4 The thickness L8 of the region R11B2 (hereinafter also referred to as "non-end region R11B2") that is different from the end region R11B1 of the first electrode body 11B (refer to) Figure 4The thickness L7 of the end region R11B1 gradually decreases towards the overlapping end face S11BD. That is, the positive electrode active material layer 111 of the end region R11B1 has a pointed shape. Specifically, the thickness L9 of the end region R11B1 of the positive electrode active material layer 111 (refer to...) Figure 4 The thickness L10 of the non-end region R11B2 (refer to) Figure 4 The electrolyte layer 112 and the negative electrode active material layer 113 are each of the same thickness.

[0083] Thickness L7 can be the same as or different from thickness L1. Thickness L8 is the same as thickness L2. The ratio of thickness L7 to thickness L8 can also be within the same range as the ratio of thickness L1 to thickness L2. The ratio of thickness L7 to thickness L8 can be the same as or different from the ratio of thickness L1 to thickness L2. Thickness L9 can be the same as or different from thickness L3. Thickness L10 is the same as thickness L4. The ratio of thickness L9 to thickness L10 can be within the same range as the ratio of thickness L3 to thickness L4. The ratio of thickness L9 to thickness L10 can be the same as or different from the ratio of thickness L3 to thickness L4.

[0084] like Figure 4 As shown, in the cross-section of battery 1A cut along the Z-axis, the end offset L11 is shorter than the length L12 of the end region R11B1 in the Y-axis direction. The end offset L11 represents the length in the Y-axis direction of the overlapping end face S11BD of the first electrode body 11B and the overlapping end face S13D of the second electrode body 13. The end offset L11 can be within the same range as the example end offset L5. The end offset L11 can be the same as or different from the end offset L5. The length L12 can be within the same range as the length L6. The length L12 can be the same as or different from the length L6. The end offset L11 can be 0.5 mm, and the length L12 can be 0.6 mm.

[0085] The stacked end face S11BC of the first electrode body 11B and the stacked end face S13C of the second electrode body 13 are located on the same plane. In addition, the first plane containing at least one of the stacked end faces S11AC, S11AD, S11AE, S11AF, S11BC, S11BD, S11BE, and S11BF of the first electrode bodies 11A, 11B, and 11C may also be the same as the second plane containing one of the stacked end faces S13C and S13D of the second electrode body 13.

[0086] 1.1.6.3 Positive Current Collector

[0087] The positive current collector 12 collects current from the positive active material layer 111. The material of the positive current collector is not particularly limited; examples include stainless steel, aluminum, copper, nickel, iron, titanium, carbon, and aluminum alloys. The positive current collector can be made of aluminum. The shape of the positive current collector can be, for example, foil or mesh. The positive current collector can have a structure with a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on its surface.

[0088] 1.1.6.4 Second Electrode

[0089] The second electrode 13 has a unipolar structure. The stacked structure of the second electrode 13 is the same as that of the first electrode 11A. The second electrode 13 is formed by stacking the positive electrode active material layer 111, the electrolyte layer 112, the negative electrode active material layer 113, the negative electrode current collector 114, the negative electrode active material layer 113, the electrolyte layer 112, and the positive electrode active material layer 111 in this order along the Z-axis direction.

[0090] 1.1.6.5 Layers of the electrode body

[0091] 1.1.6.5.1 Positive Electrode Active Material Layer

[0092] The positive electrode active material layer 111 contains a positive electrode active material. The positive electrode active material layer 111 may contain at least one of a solid electrolyte for positive electrodes, a conductive additive, and a binder, as needed.

[0093] The preferred positive electrode active material is a lithium composite oxide. The lithium composite oxide may contain at least one element selected from F, Cl, N, S, Br, and I. Furthermore, the lithium composite oxide may have a crystal structure belonging to at least one space group selected from R-3m, Immm, and P63-mmc. Additionally, the lithium composite oxide may have a dominant O2-type structure with transition metal, oxygen, and lithium. The positive electrode active material can be a known positive electrode active material.

[0094] The solid electrolyte for the positive electrode preferably comprises one selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. The solid electrolyte can be a known solid electrolyte. At least a portion of the surface of the positive electrode active material is preferably coated with a sulfide solid electrolyte, an oxide solid electrolyte, or a halide solid electrolyte.

[0095] As a sulfide solid electrolyte, it preferably contains sulfur (S) element as the main component of the anionic element, and preferably further contains, for example, lithium (Li) element and element A in addition to S element. Element A is at least one selected from the group consisting of P, As, Sb, Si, Ge, Sn, B, Al, Ga and In. The sulfide solid electrolyte may further contain at least one of O and a halogen element. Examples of the halogen element (X) include F, Cl, Br, I and the like. The composition of the sulfide solid electrolyte is not particularly limited, and examples thereof include xLi₂S·(100-x)P₂S₅ (70≤x≤80), and yLiI·zLiBr·(100-y-z)(xLi₂S·(1-x)P₂S₅) (0.7≤x≤0.8, 0≤y≤30, 0≤z≤30). The sulfide solid electrolyte may have a composition represented by the following general formula (1).

[0096] Li 4-x Ge 1-x P x S₄ (0<x<1) ··· Formula (1)

[0097] In the formula (1), at least a part of Ge may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V and Nb. Furthermore, at least a part of P may also be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V and Nb. A part of Li may be substituted with at least one selected from the group consisting of Na, K, Mg, Ca and Zn. A part of S may be substituted with halogen. The halogen is at least one of F, Cl, Br and I.

[0098] A halide solid electrolyte may have a composition represented by the following general formula (2) (LTAF).

[0099] Li 6-(4-x)b (Ti 1-x Al x ) b F₆ (0<x<1, 0<b≤1.5) ··· Formula (2)

[0100] Examples of the conductive auxiliary agent include carbon materials (for example, carbon black, carbon nanotubes, graphite, carbon fluoride and the like), metal materials (for example, aluminum powder, conductive whiskers and the like), and conductive polymer materials (for example, polyaniline, polypyrrole, polythiophene and the like).

[0101] Examples of the binder include halogenated vinyl resins (for example, polyvinylidene fluoride (PVdF) and the like), rubbers (for example, acrylate butadiene rubber (ABS), styrene-butadiene rubber (SBR) and the like), and polyolefin resins (for example, polyethylene (PE), polypropylene (PP) and the like).

[0102] 1.1.6.5.2 Solid Electrolyte Layer

[0103] Electrolyte layer 112 comprises a solid electrolyte. The solid electrolyte is not particularly limited and can be an aggregate of multiple particles. Preferably, the solid electrolyte comprises one selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. The solid electrolyte can be a known solid electrolyte. As a sulfide solid electrolyte, examples include the same sulfide solid electrolyte exemplified as a sulfide solid electrolyte used as a positive electrode solid electrolyte.

[0104] The solid electrolyte layer may further include an adhesive. The adhesive can be used for bonding between the particles of the solid electrolyte. The adhesive can also be used for bonding the solid electrolyte to the positive electrode active material layer 111 or the negative electrode active material layer 113.

[0105] 1.1.6.5.3 Negative Electrode Active Material Layer

[0106] The negative electrode active material layer 113 contains a negative electrode active material. The negative electrode active material layer 113 may contain at least one of a solid electrolyte for negative electrodes, a conductive additive, and a binder, as needed.

[0107] Examples of negative electrode active materials include Li-based active materials (such as lithium metal), carbon-based active materials (such as graphite), oxide-based active materials (such as lithium titanate), and Si-based active materials (such as elemental Si).

[0108] As a solid electrolyte for the negative electrode, the same material as that exemplified as a solid electrolyte for the positive electrode contained in the positive electrode active material layer can be used. At least a portion of the surface of the negative electrode active material is preferably coated with a sulfide solid electrolyte, an oxide solid electrolyte, or a halide solid electrolyte.

[0109] As a conductive additive, the same conductive additives as those exemplified as conductive additives that can be used in the positive electrode active material layer can be cited.

[0110] As an adhesive, the same adhesives exemplified as those used as adhesives in the positive electrode active material layer can be cited.

[0111] 1.1.6.5.4 Negative current collector

[0112] The negative electrode current collector 114 collects current from the negative electrode active material layer 113. The material of the negative electrode current collector is not particularly limited; examples include stainless steel, aluminum, copper, nickel, iron, titanium, and carbon. The negative electrode current collector can be made of aluminum. The shape of the negative electrode current collector can be, for example, foil or mesh. The negative electrode current collector can have a structure with a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on its surface.

[0113] 1.1.6.5.5 Positive current collector

[0114] The positive current collector 413 electrically connects the positive current collector 12 to the positive current collector plate 412. For example... Figure 3 As shown, the positive current collector 413 protrudes towards the negative X-axis direction relative to the side S10F of the power generation element 10A. The positive current collector 413 is cut in such a way that it physically contacts three parts of the positive current collector plate 412. A bundle containing multiple positive current collectors 413 is electrically connected to the positive current collector plate 412. The positive current collector 413 and the positive current collector 12 can be separate or an identical integrated unit.

[0115] 1.1.6.5.6 Negative electrode current collector

[0116] The negative current collector 423 electrically connects the negative current collector 114 to the negative current collector plate 422. For example... Figure 3 As shown, the negative current collector 423 protrudes towards the positive X-axis direction relative to the side S10E of the power generation element 10A. The negative current collector 423 is cut in such a way that it physically contacts three parts of the negative current collector plate 422. A bundle containing multiple negative current collectors 423 is electrically connected to the negative current collector plate 422. The negative current collector 423 and the negative current collector 114 can be separate or an identical integrated unit.

[0117] 1.1.7 Applications

[0118] Examples of applications for battery 1A include power sources for electrical equipment (e.g., vehicles, electronic devices, and electrical storage systems). For vehicles, examples include electric four-wheeled vehicles, electric two-wheeled vehicles, gasoline-powered cars, and diesel-powered cars. For electric four-wheeled vehicles, examples include battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs). For electric two-wheeled vehicles, examples include electric motorcycles and electric-assisted bicycles. For electronic devices, examples include handheld devices (e.g., smartphones, tablets, and audio players), mobile devices (e.g., laptops and CD (Compact Disc) players), and movable devices (e.g., power tools and business cameras). Preferably, battery 1A is used as a power source for driving hybrid electric vehicles, plug-in hybrid electric vehicles, or electric vehicles.

[0119] 1.2 Battery manufacturing method

[0120] The battery manufacturing method of the first embodiment is a method for manufacturing battery 1A. This method includes a power generation element fabrication step, an electrical insulator formation step, an insertion step, and a sealing step. The power generation element fabrication step, the insertion step, and the sealing step can be performed in this order.

[0121] 1.2.1 Manufacturing Process of Power Generation Components

[0122] In the process of manufacturing a power generation element, a power generation element with a current collector is manufactured. The power generation element with a current collector has a power generation element 10A, a positive current collector 413 electrically connected to the power generation element 10A, and a negative current collector 423 electrically connected to the power generation element 10A.

[0123] The manufacturing process of power generation components includes a preparation process, an end-processing process, a stacking process, and a cutting process. The preparation process, end-processing process, stacking process, and cutting process can be performed in this order.

[0124] 1.2.1.1 Preparation process

[0125] In the preparation process, electrode sheets and positive current collector sheets are prepared. The electrode sheets are the materials for the first electrode 11A, the first electrode 11B, and the second electrode 13. The positive current collector sheet is the material for the positive current collector 12 having a positive current collector sheet 413. Each electrode sheet is formed by stacking the positive active material layer 111, the electrolyte layer 112, the negative active material layer 113, the negative current collector 114 having a negative current collector sheet 423, the negative active material layer 113, the electrolyte layer 112, and the positive active material layer 111 along the Z-axis in this order. Each layer constituting the electrode sheet has the same thickness. That is, a first electrode body semi-finished product can also be prepared by stacking a positive electrode active material layer 111 with uniform thickness, an electrolyte layer 112 with uniform thickness, and a negative electrode active material layer 113 with uniform thickness along the stacking direction D in the order of positive electrode active material layer 111, electrolyte layer 112, and negative electrode active material layer 113.

[0126] The preparation method for the electrode body can be a known method. The preparation method for the positive current collector body can be a known method.

[0127] Hereinafter, the electrode sheet that will also become the material for the first electrode body 11A will be referred to as the "first electrode body semi-finished product". Hereinafter, the electrode sheet that will also become the material for the first electrode body 11B will be referred to as the "second electrode body semi-finished product".

[0128] 1.2.1.2 End-processing procedure

[0129] In the end-processing process, end-processing is performed on the first and second first electrode body semi-finished products.

[0130] Specifically, in the end-processing step, the first electrode body semi-finished product with the same thickness L4 (refer to) is cut. Figure 4 The thickness of the end region R11A1 of the positive electrode active material layer 111 is determined by the thickness of the end region R11A1 of the positive electrode active material layer 111. Therefore, the thickness L3 of the end region R11A1 of the positive electrode active material layer 111 is thinner than the thickness L4. Alternatively, the end region R11A1 may also include at least one of the end of the positive electrode active material layer 111 of the first electrode body semi-finished product and the end of the negative electrode active material layer 113 of the first electrode body semi-finished product.

[0131] In the end-processing step, the second and first electrode body semi-finished products with the same thickness L10 (refer to) are cut. Figure 4The thickness of the end region R11B1 of the positive electrode active material layer 111 is determined by the thickness of the end region R11B1 of the positive electrode active material layer 111. Therefore, the thickness L9 of the end region R11B1 of the positive electrode active material layer 111 is thinner than the thickness L10. Alternatively, the end region R11B1 may also include at least one of the end of the positive electrode active material layer 111 of the second first electrode body semi-finished product and the end of the negative electrode active material layer 113 of the second first electrode body semi-finished product.

[0132] There are no particular limitations on the end processing method. Examples include laser processing (e.g., laser trimming) and machining (e.g., stamping using a pair of rollers and cutting using an end mill). The method for reducing the thickness of the end regions R11A1 and R11B1 of the positive electrode active material layer 111 can be a known method.

[0133] 1.2.1.3 Lamination process

[0134] In the lamination process, the first and second semi-finished electrode bodies, the positive current collector sheet, and the electrode body sheet are stacked in this order along the Z-axis direction. Thus, a laminate is obtained.

[0135] There are no particular restrictions on the stacking method; any well-known method can be used.

[0136] 1.2.1.4 Cutting process

[0137] In the cutting process, the laminate is cut along the Z-axis direction. This yields a power generation element with current collector plates. The cut surfaces of the laminate are a pair of opposing side surfaces S10C and S10D of the power generation element 10A in the Y-axis direction.

[0138] There are no particular restrictions on the cutting method; any well-known method can be used.

[0139] 1.2.2 Electrical Insulator Formation Process

[0140] In the electrical insulator forming process, an electrical insulator 30 is formed on at least one of the power generation element 10A and the outer casing 20.

[0141] The method for forming the electrical insulator 30 can be a known method. The material of the electrical insulator 30 can be a film-like processed product (i.e., a self-supporting film) or a paste.

[0142] 1.2.3 Insertion Process

[0143] During the insertion process, the power generation element 10A is inserted into the outer casing 20.

[0144] The insertion method of the power generation element 10A can be any known method.

[0145] 1.2.4 Sealing process

[0146] In the sealing process, the power generation element 10A inside the outer casing 20 is sealed. Thus, battery 1A is obtained.

[0147] The sealing method can be any known method.

[0148] 1.3 Effects

[0149] For reference Figures 1-5As explained, battery 1A comprises a first electrode body 11A, 11B, a positive current collector 12, and a second electrode body 13 in the following order along the stacking direction. That is, along the stacking direction D, the first electrode body 11A, the positive current collector 12, and the second electrode body 13 can also be stacked in the order of first electrode body 11A, positive current collector 12, and second electrode body 13. Alternatively, the first electrode body 11B, the positive current collector 12, and the second electrode body 13 can also be stacked in the order of first electrode body 11B, positive current collector 12, and second electrode body 13. The first electrode bodies 11A, 11B, and the second electrode body 13 each comprise a positive active material layer 111, an electrolyte layer 112, and a negative active material layer 113 in the following order along the Z-axis direction. That is, the first electrode bodies 11A and 11B can each have a positive active material layer 111, an electrolyte layer 112, and a negative active material layer 113 in the order of positive active material layer 111, electrolyte layer 112, and negative active material layer 113 along the stacking direction D. Similarly, the second electrode body 13 can also have a positive active material layer 111, an electrolyte layer 112, and a negative active material layer 113 in the order of positive active material layer 111, electrolyte layer 112, and negative active material layer 113 along the stacking direction D. Viewed from the Z-axis direction, the four stacked end faces of the first electrode bodies 11A and 11B have overlapping stacked end faces S11AC and S11BD that overlap with portions of the second electrode body 13 that are different from the stacked end faces S13C and S13D. That is, the first electrode body 11A may also have multiple stacked end faces, and these multiple stacked end faces of the first electrode body 11A may be stacked end faces S11AC, S11AD, S11AE, and S11AF. Similarly, the first electrode body 11B may also have multiple stacked end faces, and these multiple stacked end faces of the first electrode body 11B may be stacked end faces S11BC, S11BD, S11BE, and S11BF. Furthermore, the second electrode body 13 may have multiple stacked end faces, and these multiple stacked end faces of the second electrode body 13 may be stacked end faces S13C, S13D, S13E, and S13F. The thicknesses L1 and L7 of the end regions R11A1 and R11B1 of the overlapping stacked end faces S11AC and S11BD of the first electrode bodies 11A and 11B are thinner than the thicknesses L2 and L8 of the non-end regions R11A2 and R11B2 of the first electrode bodies 11A and 11B. That is, the first electrode body 11A may also have an end region R11A1 and a non-end region R11A2 that is a region different from the end region R11A1. Similarly, the first electrode body 11B may also have an end region R11B1 and a non-end region R11B2 that is a region different from the end region R11B1. Furthermore, the end region R11A1 may include an overlapping end face S11AC, and the end region R11B1 may include an overlapping end face S11BD.In addition, non-end region R11A2 can also be adjacent to end region R11A1 in the Y-axis direction, and non-end region R11B2 can also be adjacent to end region R11B1 in the Y-axis direction.

[0150] That is, the first electrode bodies 11A and 11B do not have sharp corners. Therefore, compared to the case where the first electrode bodies 11A and 11B have the same thickness, when a constraint load is applied in the Z-axis direction, the stress applied to the portion of the second electrode body 13 corresponding to the overlapping stacked end faces S11AC and S11BD of the first electrode bodies 11A and 11B is alleviated. As a result, even if there is a stacking misalignment between the first electrode bodies 11A and 11B and the second electrode body 13 in the battery 1A, the electrode bodies 11A, 11B, and 13 are less prone to cracking.

[0151] For reference Figures 1-5 As explained, the thicknesses L1 and L7 of the end regions R11A1 and R11B1 gradually decrease towards the overlapping end faces S11AC and S11BD. That is, the thickness L1 of the end region R11A1 can gradually decrease towards the overlapping end face S11AC in the direction from the non-end region R11A2 towards the overlapping end face S11AC, and the thickness L7 of the end region R11B1 can also gradually decrease towards the overlapping end face S11BD in the direction from the non-end region R11B2 towards the overlapping end face S11BD.

[0152] Therefore, even if there is a stacking offset between the first electrode bodies 11A, 11B and the second electrode body 13, it is more difficult for cracks to occur in the electrode bodies 11A, 11B and 13.

[0153] For reference Figures 1-5 As explained, the overlapping stacked end face S11AC and the stacked end face S13C of the second electrode body 13 are not on the same plane. The overlapping stacked end face S11BD and the stacked end face S13D of the second electrode body 13 are not on the same plane. That is, the overlapping stacked end faces S11AC and S11BD can also be located on the first plane, and the first plane can also be different from the second plane where one of the stacked end faces S13C, S13D, S13E, and S13F of the second electrode body 13 is located.

[0154] Therefore, even if there is a stacking offset between the first electrode bodies 11A, 11B and the second electrode body 13, it is more difficult for cracks to occur in the electrode bodies 11A, 11B and 13.

[0155] For reference Figures 1-5As explained, one of the four stacked end faces of the first electrode body 11A has a stacked end face S11AD located in the same plane as the stacked end face S13D of the second electrode body 13. One of the four stacked end faces of the first electrode body 11B has a stacked end face S11BC located in the same plane as the stacked end face S13C of the second electrode body 13.

[0156] Therefore, compared with the case where the four stacked end faces of the first electrode bodies 11A and 11B do not have stacked end faces that are on the same plane as the stacked end face of the second electrode body 13, the volumetric efficiency of battery 1A is excellent.

[0157] For reference Figures 1-5 As explained, the thicknesses L3 and L9 of the end regions R11A1 and R11B1 of the positive electrode active material layer 111 are thinner than the thicknesses L4 and L10 of the non-end regions R11A2 and R11B2 of the positive electrode active material layer 111. The electrolyte layer 112 and the negative electrode active material layer 113 each have the same thickness.

[0158] Therefore, even if there is a stacking offset between the first electrode bodies 11A, 11B and the second electrode body 13, it is more difficult for cracks to occur in the electrode bodies 11A, 11B and 13.

[0159] For reference Figures 1-5 As explained, the first electrode bodies 11A and 11B have, along the Z-axis direction, a positive electrode active material layer 111, an electrolyte layer 112, a negative electrode active material layer 113, a negative electrode current collector 114, a negative electrode active material layer 113, an electrolyte layer 112, and a positive electrode active material layer 111 in the following order.

[0160] Therefore, the structural efficiency of battery 1A is superior.

[0161] For reference Figures 1-5 As explained, in the cross-section of battery 1A cut along the Z-axis, the end offsets L5 and L11 are shorter than the Y-axis lengths L6 and L12 of the end regions R11A1 and R11B1.

[0162] Therefore, even if there is a stacking offset between the first electrode bodies 11A, 11B and the second electrode body 13, it is more difficult for cracks to occur in the electrode bodies 11A, 11B and 13.

[0163] For reference Figures 1-5 As described, electrolyte layer 112 contains a solid electrolyte.

[0164] Therefore, the safety of battery 1A is superior to that of batteries without a solid electrolyte layer.

[0165] For reference Figures 1-5As explained, the battery manufacturing method of the first embodiment includes an end processing step.

[0166] Therefore, it is possible to efficiently manufacture a battery 1A that is less prone to cracking in the electrode bodies 11A, 11B, and 13 even if there is a stacking misalignment between the first electrode bodies 11A, 11B and the second electrode body 13.

[0167] 2 Second Implementation Method

[0168] 2.1 Battery

[0169] The battery 1B according to the second embodiment is the same as the battery 1A according to the first embodiment, except that the shape of the end region of the first electrode body is different.

[0170] Battery 1B includes a power generation element 10B, an outer casing 20, an electrical insulator 30, a positive terminal 41, and a negative terminal 42.

[0171] The power generation element 10B includes a plurality of first electrode bodies 11C, a plurality of first electrode bodies 11B, a plurality of positive current collectors 12, and a plurality of second electrode bodies 13. The first electrode bodies 11C, 11B and the positive current collectors 12 are stacked in this order along the Z-axis direction.

[0172] The first electrode body 11C is identical to the first electrode body 11A except for a change in the shape of the end region R11A1. The thickness L1 of the end region R11A1 (refer to...) Figure 6 The thickness L2 of the non-end region R11A2 of the first electrode body 11C (refer to) Figure 6 The end region R11A1 has a thin step with a thickness L13 on the side of the overlapping laminate end face S11AC. Specifically, the end region R11A1 continuously has a front end region R11A11 and a connecting region R11A12 along the Y-axis direction. The front end region R11A11 is located on the side of the overlapping laminate end face S11AC. The positive electrode active material layer 111 of the front end region R11A11 has the same thickness L13. The connecting region R11A12 is the part that connects the non-end region R11A2 to the front end region R11A11. The thickness of the positive electrode active material layer 111 of the connecting region R11A12 gradually decreases towards the front end region R11A11. The step is formed by the front end region R11A11 and the connecting region R11A12. Alternatively, the first electrode 11B, the positive current collector 12, and the second electrode 13 can be stacked in the order of first electrode 11B, positive current collector 12, and second electrode 13. Furthermore, the first electrode 11C, the positive current collector 12, and the second electrode 13 can also be stacked along the stacking direction D in the order of first electrode 11C, positive current collector 12, and second electrode 13.

[0173] 2.2 Effects

[0174] Battery 1B is identical to battery 1A except that the pointed shape of the end region R11A1 is changed to a step. Therefore, battery 1B performs the same function as battery 1A.

[0175] For reference Figure 6 As explained, in battery 1B, the end region R11A1 of the first electrode body 11C has a thin stepped portion with a thickness L13 on the side of the overlapping layered end face S11AC.

[0176] Therefore, even if there is a stacking offset of electrode bodies 11C, 11B, and 13, it is more difficult for cracks to occur in electrode bodies 11C, 11B, and 13.

[0177] 3. Variations

[0178] In a first embodiment, the thicknesses L3 and L9 of the end regions R11A1 and R11B1 of the first electrode bodies 11A and 11B gradually thin towards the overlapping end faces S11AC and S11BD. In a second embodiment, the end region R11A1 of the first electrode body 11C has a stepped portion with a thinner thickness L13 on the side of the overlapping end face S11AC. This disclosure is not limited thereto. The shape of the end region of the first electrode body is not limited as long as the thickness of the end region of the first electrode body is thinner than the thickness of the region of the first electrode body that is different from the end region. The shape of the end region of the first electrode body may have an athemble shape.

[0179] In the first and second embodiments, one of the four stacked end faces of the first electrode bodies 11A, 11B, and 11C has stacked end faces S11AD and S11BC that are on the same plane as the stacked end faces S13C and S13D of the second electrode body 13, but this disclosure is not limited to this. Multiple stacked end faces of the first electrode body may not have stacked end faces that are on the same plane as the stacked end faces of the second electrode body.

[0180] In the first and second embodiments, the thicknesses L3 and L9 of the end regions R11A1 and R11B1 of the positive electrode active material layer 111 are thinner than the thicknesses of the non-end regions R11A2 and R11B2. The electrolyte layer 112 and the negative electrode active material layer 113 each have the same thickness, but this disclosure is not limited thereto. The positive electrode active material layer 111 may have the same thickness. The thickness of the end region of at least one of the electrolyte layer and the negative electrode active material layer may be thinner than the thickness of the non-end region.

[0181] In the first and second embodiments, the first electrode bodies 11A, 11B, and 11C have a positive active material layer 111, an electrolyte layer 112, a negative active material layer 113, a negative current collector 114, a negative active material layer 113, an electrolyte layer 112, and a positive active material layer 111 in the Z-axis direction, but this disclosure is not limited thereto. That is, the first electrode bodies 11A, 11B, and 11C may each have a positive active material layer 111, an electrolyte layer 112, a negative active material layer 113, a negative current collector 114, a negative active material layer 113, an electrolyte layer 112, and a positive active material layer 111 in the stacking direction D. The first electrode may have, along the Z-axis, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, a positive electrode current collector, another positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in the following order. Alternatively, the first electrode may have only a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer.

[0182] In the first and second embodiments, in the cross-sections of batteries 1A and 1B cut along the Z-axis, the end offsets L5 and L11 are shorter than the lengths L6 and L12, but this disclosure is not limited to this. The end offsets L5 and L11 may be the same length as L6 and L12, or they may be longer than L6 and L12.

[0183] In the first and second embodiments, batteries 1A and 1B include a plurality of first electrode bodies 11A and 11B and a plurality of second electrode bodies 13, but this disclosure is not limited thereto. The number of second electrode bodies may be one.

[0184] In the first and second embodiments, the electrolyte layer comprises a solid electrolyte, but this disclosure is not limited thereto. The electrolyte layer may not contain a solid electrolyte. The electrolyte layer may contain an electrolyte different from a solid electrolyte. Examples of electrolytes different from solid electrolytes include non-aqueous electrolytes containing lithium salts (e.g., LiPF6), non-aqueous gel electrolytes, and ion-conducting polymers.

[0185] In the first and second embodiments, the power generation element 10A includes two types of first electrode bodies 11A and 11B, and the power generation element 10B includes two types of first electrode bodies 11C and 11B, but the present invention is not limited thereto. The power generation element may include one type of first electrode body, or it may include three or more types of first electrode bodies. The first electrode body 11A may also have an end region R11B1.

[0186] In the first and second embodiments, the first electrode body 11A has an end region R11A1 only on the stacked end face S11AC side, but it may also have an end region R11A1 on the stacked end face S11AD side.

[0187] In the first and second embodiments, the outer casing 20 is a square can, but this disclosure is not limited to this. The outer casing can be a battery can (e.g., cylindrical or coin-shaped) or a laminated outer casing.

[0188] In the first and second embodiments, the first electrode bodies 11A, 11B, 11C and the second electrode body 13 are unipolar structures, but this disclosure is not limited thereto. The first electrode body and the second electrode body can be bipolar structures.

[0189] In the first and second embodiments, the charge carrier ion is a lithium ion, but this disclosure is not limited thereto. In this disclosure, the charge carrier ion may be an alkali metal ion (e.g., sodium ion) or an alkaline earth metal ion (e.g., calcium ion and magnesium ion) that is different from lithium ions.

Claims

1. A battery, characterized in that, have: First electrode body; First collector; as well as The second electrode body, wherein... The first electrode, the first current collector, and the second electrode are stacked along the stacking direction in the order of the first electrode, the first current collector, and the second electrode. The first electrode body has, along the stacking direction, a first electrode active material layer, an electrolyte layer, and a second electrode active material layer in that order. The second electrode body has, along the stacking direction, a first electrode active material layer, an electrolyte layer, and a second electrode active material layer in the order of the first electrode active material layer, the electrolyte layer, and the second electrode active material layer. The first electrode body also has multiple first stacked end faces. The second electrode body also has multiple second-layered end faces. At least one of the plurality of first stacked end faces of the first electrode body includes an overlapping stacked end face, which, when viewed from the stacking direction, overlaps with a portion of the second electrode body that is different from the second stacked end face. The first electrode body also has an end region and a region different from the end region. The end region includes the overlapping end face of the first electrode body. The thickness of the end region is thinner than the thickness of the different regions.

2. The battery according to claim 1, characterized in that, The thickness of the end region gradually decreases as it moves toward the overlapping end face.

3. The battery according to claim 1, characterized in that, The end region has a stepped portion with a thickness on the overlapping end face side that is thinner than other parts of the end region.

4. The battery according to claim 1, characterized in that, The overlapping end face is located on a first plane, which is different from the second plane where one of the second overlapping end faces of the second electrode body is located.

5. The battery according to claim 1, characterized in that, The first plane containing at least one of the plurality of first stacked end faces of the first electrode body is the same as the second plane containing one of the second stacked end faces of the second electrode body.

6. The battery according to claim 1, characterized in that, The thickness of the end region of the first electrode active material layer is thinner than the thickness of the different regions of the first electrode active material layer that are different from the end region. The electrolyte layer and the second electrode active material layer each have a uniform thickness.

7. The battery according to claim 6, characterized in that, The first electrode body has, along the stacking direction, the first electrode active material layer, the electrolyte layer, the second electrode active material layer, the second current collector, the second electrode active material layer, the electrolyte layer, and the first electrode active material layer in that order.

8. The battery according to claim 1, characterized in that, In a cross-section of the battery cut along the stacking direction, the end offset is shorter than the length of the end region in an orthogonal direction orthogonal to the stacking direction. The end offset represents the length of the orthogonal direction between the overlapping end face of the first electrode and the overlapping end face of the second electrode.

9. The battery according to claim 1, characterized in that, The battery has at least one first electrode and a plurality of second electrodes.

10. The battery according to claim 1, characterized in that, The electrolyte layer contains a solid electrolyte.

11. The battery according to claim 1, characterized in that, The different regions are adjacent to the end regions in a direction perpendicular to the stacking direction.

12. The battery according to claim 11, characterized in that, The thickness of the end region gradually decreases in the direction from the different regions toward the overlapping end face as it moves toward the overlapping end face.

13. A method for manufacturing a battery, comprising manufacturing the battery of claim 1, characterized in that, include: Prepare a first electrode body semi-finished product, which is formed by stacking a first electrode active material layer with uniform thickness, an electrolyte layer with uniform thickness, and a second electrode active material layer with uniform thickness along the stacking direction in the order of the first electrode active material layer, the electrolyte layer, and the second electrode active material layer. as well as The thickness of the end region of at least one of the first electrode active material layer and the second electrode active material layer of the first electrode body semi-finished product is reduced.

14. The method for manufacturing a battery according to claim 13, characterized in that, The end region includes at least one of the end of the first electrode active material layer of the first electrode body semi-finished product and the end of the second electrode active material layer of the first electrode body semi-finished product.

Images