Battery and method for manufacturing the same

Abstract

To provide a highly reliable battery.SOLUTION: A battery 1 includes a laminate 100 having a first electrode layer 110, a second electrode layer 120, and a solid electrolyte layer 130 located between the first electrode layer 110 and the second electrode layer 120, and a shaft 20. The laminate 100 is a wound body 10 wound around a shaft 20. When the length of the laminated body 100 in the axial direction of the shaft 20 is defined as the breadth of the laminated body 100, the breadth W1 at the first portion of the laminated body 100 is shorter than the breadth W2 at the second portion of the laminated body 100, and the first portion is located closer to the end of the winding than the second portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to batteries and methods for manufacturing the same. [Background technology]

[0002] There is a demand for technologies aimed at improving the performance and reliability of batteries. For example, Patent Documents 1 and 2 disclose technologies relating to such batteries, which are constructed by winding a strip-shaped power generating element, which includes an electrode layer, a solid electrolyte layer, and a counter electrode layer in this order, around a core material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-319449 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-113718 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need in the art for a highly reliable battery. Accordingly, the present disclosure provides a highly reliable battery and a method for manufacturing the same. [Means for solving the problem]

[0005] A battery according to one embodiment of the present disclosure includes a laminate having a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer, and a shaft, wherein the laminate is a wound body wound around the shaft, and when the length of the laminate in the axial direction of the shaft is defined as the width of the laminate, the width of a first portion of the laminate is shorter than the width of a second portion of the laminate, and the first portion is located closer to the end of the winding than the second portion.

[0006] A method for manufacturing a battery according to one embodiment of the present disclosure includes the steps of winding a laminate around a shaft, the laminate having a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer, and isostatically pressing the laminate wound around the shaft, wherein when the length of the laminate in the axial direction of the shaft is defined as the width of the laminate, the width of a first portion of the laminate is shorter than the width of a second portion of the laminate, and the first portion is located closer to the end of the winding than the second portion. [Effects of the Invention]

[0007] According to the present disclosure, a highly reliable battery can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a battery according to an embodiment. [Figure 2] FIG. 2 is a top view showing a schematic configuration of a battery according to an embodiment. [Figure 3] FIG. 3 is a perspective view showing a schematic configuration of a laminate wound around a shaft of a battery according to an embodiment. [Figure 4] FIG. 4 is a perspective view showing a schematic configuration of a shaft of a battery according to an embodiment. [Figure 5A] FIG. 5A is a plan view showing a schematic configuration of an example of an unwound laminate according to an embodiment. [Figure 5B] FIG. 5B is a plan view showing a schematic configuration of another example of an unwound laminate according to an embodiment. [Figure 5C] FIG. 5C is a plan view showing a schematic configuration of another example of an unwound laminate according to an embodiment. [Figure 5D] FIG. 5D is a plan view showing a schematic configuration of another example of an unwound laminate according to an embodiment. [Figure 5E] FIG. 5E is a plan view showing a schematic configuration of another example of an unwound laminate according to an embodiment. [Figure 5F]FIG. 5F is a plan view showing a schematic configuration of another example of an unwound laminate according to an embodiment. [Figure 6A] FIG. 6A is a perspective view showing a schematic configuration of another example of a shaft of a battery according to an embodiment. [Figure 6B] FIG. 6B is a perspective view showing a schematic configuration of another example of a shaft of the battery according to the embodiment. [Figure 6C] FIG. 6C is a perspective view showing a schematic configuration of another example of a shaft of the battery according to the embodiment. [Figure 6D] FIG. 6D is a perspective view showing a schematic configuration of another example of a shaft of a battery according to an embodiment. [Figure 6E] FIG. 6E is a perspective view showing a schematic configuration of another example of a shaft of a battery according to an embodiment. [Figure 6F] FIG. 6F is a perspective view showing a schematic configuration of another example of a shaft of a battery according to an embodiment. [Figure 6G] FIG. 6G is a cross-sectional view showing a schematic configuration of another example of a shaft of a battery according to an embodiment. [Figure 6H] FIG. 6H is a cross-sectional view showing a schematic configuration of another example of a shaft of a battery according to an embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a schematic configuration of a battery according to a first modification of the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a schematic configuration of a battery according to the second modification of the embodiment. [Figure 9] FIG. 9 is a top view showing a schematic configuration of a battery according to a third modification of the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a schematic configuration of a battery according to a fourth modification of the embodiment. [Figure 11] FIG. 11 is a perspective view showing a schematic configuration of a laminate wound around a shaft according to the fourth modification of the embodiment. [Figure 12] FIG. 12 is a perspective view showing a schematic configuration of a laminate wound around a shaft according to a fifth modification of the embodiment. [Figure 13] FIG. 13 is a flowchart showing a method for manufacturing a battery according to the embodiment and each of the modifications. [Figure 14A] FIG. 14A is a perspective view illustrating one step of the method for manufacturing the battery according to the embodiment and each of the modifications. [Figure 14B] FIG. 14B is a top view illustrating one step of the method for manufacturing the battery according to the embodiment and each of the modifications. [Figure 14C] FIG. 14C is a top view illustrating one step of the method for manufacturing the battery according to the embodiment and each of the modifications. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Summary of the Disclosure) A battery according to a first aspect of the present disclosure includes a laminate having a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer, and a shaft, wherein the laminate is a wound body wound around the shaft, and when the length of the laminate in the axial direction of the shaft is defined as the width of the laminate, the width of a first portion of the laminate is shorter than the width of a second portion of the laminate, and the first portion is located closer to the end of the winding than the second portion.

[0010] This suppresses short circuits during pressure treatment after winding, resulting in a highly reliable battery. Furthermore, by combining the number of windings with the change in the width of the laminate as a capacity design factor, the design range of capacity can be expanded. Furthermore, unlike the stacked type, the laminate does not require repeated lamination and pressing processes, and instead winds the battery continuously and applies pressure to the battery, resulting in a battery with excellent productivity.

[0011] A battery according to a second aspect of the present disclosure is the battery according to the first aspect of the present disclosure, wherein the width of the laminate decreases continuously from the second region to the first region.

[0012] This allows for handling and winding without concentrating stress on the laminate, thereby preventing short circuits and damage to the laminate. Furthermore, because the capacitance changes continuously, it is easier to predict the capacitance change of the laminate. This makes it easier to design the capacitance.

[0013] A battery according to a third aspect of the present disclosure is the battery according to the first aspect of the present disclosure, wherein the width of the laminate decreases stepwise from the second region to the first region.

[0014] This allows the discontinuous width change area to bite into and catch on the lower layer of the winding, preventing loosening of the wound body after pressure integration. This prevents loosening and shifting of the wound body due to vibration or expansion and contraction during charging and discharging, resulting in a battery with excellent stability of characteristics.

[0015] A battery according to a fourth aspect of the present disclosure is the battery according to any one of the first to third aspects of the present disclosure, wherein the first region and the second region are located at the outermost periphery of the wound body.

[0016] This makes it possible to obtain a highly reliable battery while suppressing a decrease in capacity.

[0017] A battery according to a fifth aspect of the present disclosure is the battery according to any one of the first to fourth aspects of the present disclosure, further comprising a loosening suppression material that suppresses loosening of the wound body.

[0018] This can prevent the wound body from loosening, thereby realizing a battery with excellent stability of characteristics.

[0019] A battery according to a sixth aspect of the present disclosure is the battery according to the fifth aspect of the present disclosure, wherein the slack suppression material is a tape-shaped member.

[0020] This allows any location of the wound body to be fixed with a tape-like member. For example, by using an adhesive tape, it is possible to firmly prevent the wound body from loosening while suppressing increases in weight and volume.

[0021] A battery according to a seventh aspect of the present disclosure is the battery according to the sixth aspect of the present disclosure, wherein the tape-shaped member fixes an end of the winding of the wound body.

[0022] This fixes the end of the wound body, which could be the starting point for loosening, and thus firmly prevents loosening. Furthermore, after the wound body is fixed, the loosening prevention material can also be integrated with the wound body by, for example, isostatic pressing, resulting in an even stronger structure. This allows for the realization of a battery with even more stable characteristics.

[0023] A battery according to an eighth aspect of the present disclosure is the battery according to the sixth or seventh aspect of the present disclosure, wherein the tape-shaped member surrounds the wound body around the axis of the shaft.

[0024] This allows the entire wound body to be more firmly fixed, thereby achieving a battery with even more stable characteristics. The tape-shaped member may be wound around the outermost circumference of the wound body multiple times, or multiple tape-shaped members may be provided. This makes it possible to more firmly prevent loosening at any desired location, such as a location that is prone to loosening.

[0025] A battery according to a ninth aspect of the present disclosure is the battery according to the eighth aspect of the present disclosure, wherein the tape-shaped member is embedded in the outermost periphery of the wound body.

[0026] This allows the tape-shaped member to exhibit a strong anchoring effect, thereby realizing a battery with excellent stability of characteristics. The embedding of the tape-shaped member into the wound body can be performed, for example, by applying pressure to the wound body and the tape-shaped member together.

[0027] A battery according to a tenth aspect of the present disclosure is the battery according to the eighth or ninth aspect of the present disclosure, wherein the tape-shaped member is a heat-shrinkable member.

[0028] This allows the wound body to be stably and easily fixed by, for example, attaching a ring-shaped heat-shrinkable tube to the wound body and heating it to cause it to shrink.

[0029] A battery according to an eleventh aspect of the present disclosure is the battery according to any one of the first to tenth aspects of the present disclosure, wherein the laminate has a chamfered shape at least at one of the starting end and the ending end of the winding.

[0030] This prevents deformation of the winding start or end of the wound body during winding or pressure application, and also prevents short circuits that tend to occur due to deformation. It also prevents delamination at the start or end, which tends to occur due to thermal cycling and thermal shock.

[0031] A battery according to a twelfth aspect of the present disclosure is a battery according to any one of the first to eleventh aspects of the present disclosure, wherein the length of the axis in the axial direction is longer than the width of the laminate at the second portion.

[0032] This allows the ends of the laminate to contact the shaft even if there is a variation in width of the laminate, a misalignment in winding, or elongation of the laminate due to lamination or pressing, which sufficiently reduces the possibility of the laminate protruding from the ends in the axial direction, thereby suppressing deformation of the laminate during isostatic pressing and preventing short circuits.

[0033] A battery according to a thirteenth aspect of the present disclosure is the battery according to any one of the first to twelfth aspects of the present disclosure, wherein the shaft includes a conductor.

[0034] This allows the shaft and the wound body to come into contact at the winding start end of the wound body and be electrically connected, so that the shaft also functions as a terminal. This eliminates the need to form a terminal electrode. Furthermore, because the shaft and the wound body, which function as a terminal, are firmly fixed together, the winding body is highly reliable, easy to manufacture, and compact.

[0035] A battery according to a fourteenth aspect of the present disclosure is the battery according to any one of the first to thirteenth aspects of the present disclosure, wherein the shaft includes a porous member.

[0036] This reduces the weight of the shaft, improving the weight energy density. Furthermore, by embedding a portion of the laminate in the pores, the friction on the surface in contact with the laminate increases, suppressing loosening and misalignment of the winding. This results in a battery with high weight energy density and high reliability.

[0037] A battery according to a fifteenth aspect of the present disclosure is the battery according to any one of the first to fourteenth aspects of the present disclosure, wherein the shaft has a hollow portion.

[0038] This reduces the weight of the shaft and improves the weight energy density.

[0039] A battery according to a sixteenth aspect of the present disclosure is the battery according to any one of the first to fifteenth aspects of the present disclosure, wherein the hollow portion is a recess provided at an end of the shaft in the axial direction.

[0040] This reduces the weight of the shaft, improving the weight-energy density. Furthermore, the shaft can be easily rotated by inserting a jig or opening the recess at the end of the shaft. By bringing the shaft into contact with the stack placed on a flat surface and rotating it to wind the stack, handling becomes easier without directly contacting the stack. Therefore, handling can be performed without causing scratches or defects in the stack, resulting in a highly reliable battery.

[0041] A battery according to a seventeenth aspect of the present disclosure is the battery according to any one of the first to fifteenth aspects of the present disclosure, wherein the shaft is a cylindrical body.

[0042] This further reduces the weight of the shaft, improving the weight energy density and making it easier to handle, resulting in a highly reliable battery.

[0043] A battery according to an eighteenth aspect of the present disclosure is the battery according to the seventeenth aspect of the present disclosure, wherein the inner surface of the shaft has a rough surface portion.

[0044] This reduces the risk of slipping when handling a jig inserted inside the cylindrical shaft. This increases the reliability of handling, resulting in a battery with excellent reliability and performance. Furthermore, for example, if an extraction electrode is provided so that it extends from the inner wall of the cylindrical shaft, the connection area between the extraction electrode and the shaft increases, resulting in low resistance and strong connectivity. This results in a battery with high reliability and excellent performance.

[0045] A battery according to a 19th aspect of the present disclosure is a battery according to any one of the first to eighteenth aspects of the present disclosure, wherein, when viewed from the axial direction, the size of one end of the shaft in the axial direction is different from the size of the other end of the shaft in the axial direction.

[0046] This clarifies the orientation of the wound body, making it easier to control the orientation of the wound body during the manufacturing process, improving quality and productivity, and thus enabling high-quality batteries to be produced with good productivity.

[0047] A battery according to a twentieth aspect of the present disclosure is the battery according to any one of the first to nineteenth aspects of the present disclosure, wherein the shaft has a rough surface portion on the surface that comes into contact with the laminate.

[0048] This makes it easier to firmly integrate the wound body and the shaft, improving the shock resistance and vibration resistance of the battery. Furthermore, when the shaft functions as a terminal, the surface area of ​​the electrical connection between the shaft and the wound body increases, reducing connection resistance and improving battery performance.

[0049] A battery according to a twenty-first aspect of the present disclosure is the battery according to any one of the first to twentieth aspects of the present disclosure, wherein the shaft has a resin portion in contact with the laminate.

[0050] This prevents the winding from sliding against the shaft, and the softness of the resin part absorbs stress, preventing deformation of the winding and preventing short circuits and breakage. This also reduces the weight of the shaft, which increases the weight density of capacity and energy.

[0051] A battery according to a twenty-second aspect of the present disclosure is the battery according to any one of the first to twenty-first aspects of the present disclosure, further comprising a flange provided on the shaft.

[0052] This allows the flange to restrict and control the position of the laminate to a predetermined location, thereby preventing misalignment of the wound body during and after winding. This makes it easier to create a uniform wound body. As a result, a highly reliable battery with excellent shock and vibration resistance can be obtained.

[0053] A battery according to a twenty-third aspect of the present disclosure is the battery according to any one of the first to twenty-second aspects of the present disclosure, wherein the shaft has a recess into which the laminate is inserted.

[0054] This allows the winding start end to be stored, preventing loosening of the wound body during and after winding, thereby reducing variations in characteristics and changes in characteristics due to environmental changes such as impacts and thermal cycling, resulting in a highly reliable battery.

[0055] A battery according to a twenty-fourth aspect of the present disclosure is the battery according to the twenty-third aspect of the present disclosure, wherein the shaft has a roughened surface on the inner surface of the recess.

[0056] This strengthens the effect of fixing the position of the laminate inserted into the recess due to increased friction with the laminate, thereby improving the effect of preventing the wound body from loosening and providing a highly reliable battery.

[0057] A battery according to a twenty-fifth aspect of the present disclosure is the battery according to the twenty-third or twenty-fourth aspect of the present disclosure, further comprising a resin member that covers the inner surface of the recess.

[0058] This allows the laminate inserted into the recess to be fixed in place without significantly increasing its weight, resulting in a lightweight, highly reliable battery. Furthermore, the ends of the electrode layers, which are prone to delamination, are fixed with the insulating resin, suppressing delamination from the ends, which is prone to occur due to thermal cycling, etc., resulting in a lightweight, highly reliable battery.

[0059] A battery according to a 26th aspect of the present disclosure is the battery according to any one of the first to 25th aspects of the present disclosure, wherein the shaft has a step absorbing portion that absorbs steps in the winding of the stack.

[0060] This makes it possible to absorb the step at the beginning of the winding, thereby suppressing deformation and breakage of the laminate.

[0061] A battery manufacturing method according to a 27th aspect of the present disclosure includes the steps of winding a laminate around a shaft, the laminate having a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer, and isostatically pressing the laminate wound around the shaft, wherein when the length of the laminate in the axial direction of the shaft is defined as the width of the laminate, the width of a first portion of the laminate is shorter than the width of a second portion of the laminate, and the first portion is located closer to the end of the winding than the second portion.

[0062] This allows the shaft and the laminate to be uniformly and firmly integrated, thereby enabling the manufacture of a highly reliable battery.

[0063] A battery manufacturing method according to a 28th aspect of the present disclosure is a battery manufacturing method according to the 27th aspect of the present disclosure, in which the isostatic pressing step is carried out after covering at least a portion of the laminate wound around the shaft with an elastic body.

[0064] By covering at least a portion of the laminate with the elastic body, the shaft and the laminate can be uniformly and firmly integrated while suppressing deformation and breakage, thereby enabling the production of a highly reliable battery.

[0065] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0066] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing method steps, and process order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not described in the independent claims are described as optional components.

[0067] In addition, the drawings are not necessarily strict illustrations, and the same reference numerals are used to designate substantially the same components in the drawings, and redundant explanations are omitted or simplified.

[0068] In the present specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the axis direction.

[0069] In addition, in this specification, the terms "inside" and "outside" refer to the direction toward the center of the axis as "inside (inward)" and the direction away from the center as "outside (outward)."

[0070] Furthermore, in this specification, the terms "above" and "below" in the stacking structure of a laminate do not refer to the upward direction (vertically upward) and downward direction (vertically downward) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking structure. Furthermore, the terms "above" and "below" are applied not only to a case where two components are arranged with a gap between them and another component exists between the two components, but also to a case where two components are arranged closely together and the two components are in contact with each other.

[0071] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not refer to the number or order of components unless otherwise specified, but are used to avoid confusion and distinguish between components of the same type.

[0072] (Embodiment) [Battery Overview] First, the battery according to the present embodiment will be described.

[0073] FIG. 1 is a cross-sectional view showing a schematic configuration of a battery 1 according to the present embodiment. FIG. 2 is a top view showing a schematic configuration of the battery 1 according to the present embodiment. FIG. 3 is a perspective view showing a schematic configuration of a laminate 100 wound around a shaft 20 of the battery 1 according to the present embodiment. Specifically, FIG. 2 is a plan view seen from the positive side of the z-axis. FIG. 1 shows a cross section at the position indicated by line II in FIG. 2. Note that in FIG. 1, the number of turns of the laminate 100 is simplified as 2 (two turns) to show the layer structure of the laminate 100. The number of turns of the laminate 100 is one or more turns, and may be, for example, 10 or more turns as shown in FIG. 3.

[0074] 1 , the battery 1 includes a laminate 100 and a shaft 20. The laminate 100 is a wound body 10 wound around the shaft 20. The battery 1 further includes a first flange 31, a second flange 32, a first terminal electrode 40, a second terminal electrode 50, and a resin member 60.

[0075] The laminate 100 includes a first electrode layer 110, a solid electrolyte layer 130, and a second electrode layer 120, in this order. The solid electrolyte layer 130 is located between the first electrode layer 110 and the second electrode layer 120. As shown in FIG. 1 , the first electrode layer 110 includes a first active material layer 111 and a first current collector 112. The second electrode layer 120 includes a second active material layer 121 and a second current collector 122.

[0076] The laminate 100 is formed in a strip shape that is long in one direction. The laminate 100 can also be called an electrode plate or an electrode plate. As shown in FIG. 1, the laminate 100 is a wound body 10 wound around a shaft 20 and is integrated with the shaft 20. As shown in FIG. 3, the width of the laminate 100 is narrowed at the last winding at the end of the winding. The width of the laminate 100 refers to the length of the laminate 100 in the axial direction (z-axis direction) of the shaft 20. The specific shape of the laminate 100 and the specific configuration of each layer and each current collector included in the laminate 100 will be described later.

[0077] The shaft 20 is a member that serves as the center of winding of the laminate 100. The shaft 20 can also be called a core material. Specifically, the shaft 20 is a cylindrical body. In the present embodiment, the shaft 20 includes a conductor. Specifically, the shaft 20 is substantially made of metal. More specifically, the shaft 20 is a cylindrical body made of SUS (stainless steel). The shaft 20 is electrically connected to the first electrode layer 110 of the laminate 100. The shaft 20 is, for example, a rigid body having rigidity, and specifically, a member that is harder than the laminate 100.

[0078] The shaft 20 is not a laminate film, and has a Young's modulus higher than that of a general laminate film. For example, the Young's modulus of the shaft 20 is 10 GPa or more. The Young's modulus of a general laminate film is less than 1 GPa. In other words, the Young's modulus of the shaft 20 is one order of magnitude higher than that of a general laminate film. The upper limit of the Young's modulus of the shaft 20 is not particularly limited, but is, for example, 1000 GPa.

[0079] Furthermore, the shaft 20 has a higher thermal conductivity than a typical laminate film. For example, the thermal conductivity of the shaft 20 is 10 W / (m·K) or higher. The thermal conductivity of the shaft 20 is one order of magnitude higher than the thermal conductivity of a typical laminate film. The upper limit of the thermal conductivity of the shaft 20 is not particularly limited, but is, for example, 400 W / (m·K).

[0080] As shown in Fig. 4, shaft 20 includes hollow portion 21 and slit 22. Hollow portion 21 is a space that passes through shaft 20 in the axial direction. Slit 22 is an example of a recess into which laminate 100 is inserted. Specifically, slit 22 is a through-hole that connects the outside of shaft 20 with hollow portion 21, and into which the winding start end of laminate 100 is inserted.

[0081] In this embodiment, since the slits 22 penetrate the hollow portion 21, it is possible to adjust the length of the laminate 100 inserted into the slits 22, i.e., the length of the laminate 100 pulled into the hollow portion 21 of the cylindrical shaft 20. This makes it possible to prevent the laminate 100 from shifting position and coming off the slits 22. Furthermore, by adjusting the degree to which the laminate 100 is pulled in, it is also possible to adjust the capacity of the battery 1 (specifically, to reduce the capacity).

[0082] Slit 22 is large enough to accommodate the operation of inserting and fitting the starting end of laminate 100 and dimensional fluctuations that occur due to expansion and contraction during charging and discharging. For example, the cross-sectional size of the starting end of laminate 100 is used as a reference value, and the length of each side of slit 22 is set to be 105% to 130% of that reference value. The size of slit 22 may be set arbitrarily depending on the accuracy of the operation and the magnitude of dimensional fluctuations that occur due to expansion and contraction.

[0083] Furthermore, the corners and ridges of the slits 22 may be chamfered to prevent damage to the laminate 100 due to contact with the laminate 100. That is, the corners and ridges of the slits 22 may be provided with rounded or curved portions. The C-cut length of the curved portion is, for example, 0.1 mm or more and 1.0 mm or less, and the R radius of the curved portion is, for example, 1 mm or more and 5 mm or less, but is not limited to these.

[0084] The length L of the shaft 20 in the axial direction is longer than the width W2 of the laminate 100. The width W2 is, for example, the maximum width of the laminate 100. Even if the width of the laminate 100 varies or the laminate 100 shifts during winding, or if the laminate 100 stretches due to lamination or pressing, the shaft 20 can contact the laminate 100 up to its end. This sufficiently reduces the possibility of the laminate 100 protruding from its end in the axial direction, thereby suppressing deformation of the laminate 100 during isostatic pressing, etc., and suppressing short circuits.

[0085] The length L of the shaft 20 may be made longer than the width W2 of the laminate 100 by any amount, but is determined taking into account variations in process accuracy and the elongation of the laminate 100. Furthermore, by lengthening the shaft 20, the first flange 31 and the second flange 32 can be provided with ample space. Note that if the length L of the shaft 20 is too long, it will increase the volume and weight of the battery 1, so it should be designed to an appropriate length. For example, the difference between L and W2 is 5 μm or more and 50 mm or less, but is not limited to this.

[0086] The shaft 20 may include a porous member. For example, a porous metal material formed using various metals or alloy materials such as stainless steel, titanium, copper, nickel, and aluminum can be used as the shaft 20. The porosity of the porous metal material is, for example, not less than 5% and not more than 90%.

[0087] The weight of the shaft 20 is reduced, improving the weight energy density of the battery 1. Furthermore, by embedding a portion of the laminate 100 in the pores of the shaft 20, the friction of the surface in contact with the laminate 100 is increased, thereby suppressing loosening and misalignment of the winding. This makes it possible to obtain a battery 1 with high weight energy density and high reliability.

[0088] The material and shape of the shaft 20 are designed according to the intended use, such as the desired weight energy density. The shaft 20 may be formed by combining a plurality of different materials. For example, the surface of the shaft 20 that comes into contact with the laminate 100 may be made of a material (e.g., a material with high conductivity) selected in consideration of electrochemical stability during operation of the battery 1. Specifically, the shaft 20 may include a core material and a plating layer formed on the surface of the core material using a material different from the core material.

[0089] The first flange 31 and the second flange 32 are provided on the shaft 20. The first flange 31 and the second flange 32 are provided at both ends of the shaft 20, respectively, so that the wound body 10 is disposed therebetween. At least one of the first flange 31 and the second flange 32 does not have to be provided. Furthermore, the first flange 31 or the second flange 32 may be provided near the center of the shaft 20, rather than at the end.

[0090] In this embodiment, the first flange 31 and the second flange 32 have the same shape and are made of the same material. Specifically, as shown in Fig. 2, the first flange 31 and the second flange 32 are formed in a disk shape with a through-hole in the center. Note that the first flange 31 and the second flange 32 may be different in at least one of their shapes and materials.

[0091] The provision of the first flange 31 and the second flange 32 makes it possible to suppress misalignment of the laminate 100 during and after winding. Furthermore, the first flange 31 and the second flange 32 can protect the side surfaces of the wound body 10. For example, the first flange 31 and the second flange 32 are larger than the wound body 10 when viewed from the axial direction (z-axis direction). In other words, the height of the first flange 31 and the second flange 32 (i.e., the length in the direction perpendicular to the axial direction of the shaft 20) is equal to or greater than the thickness of the wound body 10.

[0092] The first flange 31 and the second flange 32 are formed using a material different from that of the shaft 20. The first flange 31 and the second flange 32 are formed using an insulating material. In this embodiment, as an example, the first flange 31 and the second flange 32 are attached using flanges made of a Bakelite-based material, which has excellent heat resistance and insulating properties at temperatures of approximately 200°C or higher. In this way, by forming the first flange 31 and the second flange 32 using a resin material that is lighter than metal, the weight of the battery 1 can be reduced. Furthermore, the insulating properties of the first flange 31 and the second flange 32 can prevent short circuits due to contact with the wound body 10. The first flange 31 and the second flange 32 may be integral with the shaft 20 and formed using a metal material. In this case, an insulating layer may be provided on the surface of each of the first flange 31 and the second flange 32 facing the wound body 10.

[0093] At least one of the first flange 31 and the second flange 32 can restrict and control the position of the laminate 100 at a predetermined location, thereby suppressing misalignment of the wound body 10 during and after winding. This makes it easier to create a uniform wound body 10. This allows for the production of a highly reliable battery 1 that is excellent in shock resistance and vibration resistance.

[0094] Both the first terminal electrode 40 and the second terminal electrode 50 are made of conductive materials. For example, the first terminal electrode 40 and the second terminal electrode 50 are made of a metal or alloy such as copper, aluminum, or SUS. The first terminal electrode 40 and the second terminal electrode 50 function as the positive and negative terminals of the battery 1.

[0095] The first terminal electrode 40 is electrically connected to the first electrode layer 110 of the laminate 100. Specifically, the first terminal electrode 40 is electrically connected to the first electrode layer 110 via a conductive shaft 20. For example, the first terminal electrode 40 is in contact with the inner surface of the shaft 20, but it may also be in contact with the outer surface of the shaft 20. The first terminal electrode 40 is joined to the shaft 20 by connection with a conductive resin or solder, or by screwing. The first terminal electrode 40 may be plated with solder such as Sn or AuSn, which makes it easy to solder the first terminal electrode 40 to the shaft 20.

[0096] The second terminal electrode 50 is electrically connected to the second electrode layer 120 of the laminate 100. Specifically, the second terminal electrode 50 is electrically connected to the second electrode layer 120 via an Ag-based highly conductive resin (not shown). For example, the second terminal electrode 50 is connected to the surface of the second electrode layer 120 at the outermost periphery of the wound body 10. The second terminal electrode 50 may be plated with solder such as Sn or AuSn, which allows for easy solder connection to the laminate 100.

[0097] Resin member 60 is provided in hollow portion 21 of shaft 20. In this embodiment, resin member 60 covers the inner surface of slit 22 provided in shaft 20 and the inner surface of shaft 20. Resin member 60 also covers the winding start end of laminate 100. For example, resin member 60 is formed by injecting an insulating resin material or the like into hollow portion 21 using a dispenser (not shown) and curing it. By providing resin member 60, the start end of laminate 100, which is prone to deformation or peeling, can be impregnated with the resin material, and since it is firmly integrated with shaft 20, the reliability of battery 1 can be improved.

[0098] A typical epoxy resin or the like can be used as the resin member 60, as it is a lightweight resin material with excellent sealing properties. This can increase the weight energy density of the battery 1 and improve reliability. Furthermore, for example, the resin member 60 may contain an inorganic filler (powder) with excellent thermal conductivity, such as alumina, boron nitride, magnesium oxide, or yttrium oxide, for the purpose of improving thermal conductivity. This improves the heat dissipation properties of the resin member 60 and suppresses heat generation during battery 1 operation, resulting in a more reliable battery 1. The highly thermally conductive powder can be, for example, any shape with a particle size of 0.1 μm or more and 100 μm or less in maximum width.

[0099] [Planar shape of laminate (wound body)] Next, a specific planar shape of the laminate 100 and modifications thereof will be described with reference to Figures 5A to 5F. Figures 5A to 5F are plan views each showing a schematic configuration of an example of an unwound laminate according to this embodiment. In describing the common features of the laminates 100A to 100F shown in Figures 5A to 5F, there is no need to distinguish between the laminates 100A to 100F, and therefore the laminates will be described as the laminate 100.

[0100] In each figure, the starting end is the starting end of the winding of the laminate 100. In other words, the starting end of the laminate 100 and its vicinity are in contact with the shaft 20. The ending end is the ending portion of the winding of the laminate 100. The starting end is the inner peripheral end of the wound laminate 100. The ending end is the outer peripheral end of the wound laminate 100. From the starting end toward the ending end, the laminate 100 moves away from the shaft 20, and the ending portion of the laminate 100 is located at the outermost periphery of the winding. In each figure, the area shaded with dots corresponds to the outermost periphery of the winding. The outermost periphery is the part that is not covered by the laminate 100 when the laminate 100 is wound around the shaft 20 and is exposed.

[0101] As shown in FIGS. 5A to 5F, the laminate 100 has portions with different widths. Specifically, the width W1 of the first portion P1 of the laminate 100 is shorter than the width W2 of the second portion P2 of the laminate 100. For example, the width W1 is 50% or more but less than 95% of the width W2, e.g., 80% of the width W2. The first portion P1 is located closer to the end of the winding than the second portion P2. In the wound state, the first portion P1 is located farther from the axis 20 than the second portion P2. In the example shown in each figure, the first portion P1 is the end of the winding, and the second portion P2 corresponds to the first position where the width of the laminate 100 becomes shorter than the width of the starting portion when tracing the direction from the starting end to the ending end of the laminate 100. In each of the laminates 100A to 100F in each figure, the range from the second portion P2 to the first portion P1 is considered to be a narrow width portion.

[0102] In the laminate 100A shown in FIG. 5A, the width continuously decreases from the second portion P2 to the first portion P1. Specifically, the width of the laminate 100A continuously decreases evenly from both sides from the second portion P2 to the first portion P1. The rate of width reduction is constant, but may vary. That is, the shape of the narrow portion 101A is an isosceles trapezoid rotated 90 degrees, but the legs of the trapezoid may be curved inward or outward. Furthermore, the rate of width reduction may differ for each leg.

[0103] In the laminate 100B shown in FIG. 5B, the width continuously decreases from the second portion P2 to the first portion P1. Specifically, the width of the laminate 100B continuously decreases at a constant rate from one side to the first portion P1. The shape of the narrow portion 101B is a trapezoid rotated 90 degrees, with one leg perpendicular to the upper and lower bases. The remaining leg is a straight line segment, but may be curved outward or inward.

[0104] In the laminate 100C shown in FIG. 5C, the width decreases in a stepwise manner from the second portion P2 to the first portion P1. Specifically, in the laminate 100C, the width changes from width W2 to width W1 at the second portion P2. In other words, the width of the laminate 100C changes in one step. The narrow portion 101C is a rectangle with a side length of W1.

[0105] In the laminate 100D shown in FIG. 5D, the width decreases in stages from the second portion P2 to the first portion P1. Specifically, in the laminate 100D, the width changes in two stages from the second portion P2 to the first portion P1. The narrow portion 101D includes a first narrow portion 102D having a side length of W3 and a second narrow portion 103D having a side length of W1. The relationship W2>W3>W1 is satisfied.

[0106] In laminate 100D, first narrow portion 102D may have a width that changes continuously from second portion P2 to third portion P3, as in narrow portion 101A shown in FIG. 5A or narrow portion 101B shown in FIG. 5B. Alternatively, second narrow portion 103D may have a width that changes continuously from third portion P3 to first portion P1. In other words, laminate 100 may include a combination of a portion where the width decreases stepwise and a portion where the width decreases continuously. The number of steps in the width decrease is not particularly limited.

[0107] The laminate 100E shown in FIG. 5E has a chamfered shape at least at one of the start and end of the winding. Specifically, the laminate 100E has a rounded portion 104r at each of the start and end. The rounded portion 104r is formed, for example, by forming the laminate 100A shown in FIG. 5A and then performing rounded chamfering on the four corners. The rounded portion 104r has a radius of, for example, 1 mm or more and 5 mm or less, but is not limited thereto.

[0108] The laminate 100F shown in FIG. 5F has a chamfered shape at least at one of the start and end of the winding. Specifically, the laminate 100F has a C-shaped portion 104c at each of the start and end. The C-shaped portion 104c is formed, for example, by forming the laminate 100A shown in FIG. 5A and then chamfering the four corners. The C-cut length of the C-shaped portion 104c is, for example, 0.1 mm or more and 1 mm or less, but is not limited thereto. The inclination of the C-cut is 45°, but is not limited thereto and may be, for example, 30° or more and 60° or less.

[0109] In the case of the laminates 100E and 100F having chamfered edges, the widths W1 and W2 are defined as the widths without chamfered edges. The rounded portions 104r and the curved portions 104c are formed using a cutter, a mold, or laser processing. The radius of the rounded portion 104r or the length of the curved portion 104c is set arbitrarily in consideration of the characteristics, reliability, and processability of the battery 1.

[0110] In each figure, at least a portion of the narrow width portions 101A to 101D is located in the outermost peripheral portion of the laminate 100. For example, in the laminate 100A shown in FIG. 5A, the entire narrow width portion 101A is located in the outermost peripheral portion. Specifically, the second portion P2 of the laminate 100A is the starting point of the outermost peripheral portion, and both the second portion P2 and the first portion P1 are located in the outermost peripheral portion. Furthermore, in the laminate 100B shown in FIG. 5B, for example, only a portion of the narrow width portion 101B is located in the outermost peripheral portion. In other words, while the first portion P1 of the laminate 100B is located in the outermost peripheral portion, the second portion P2 of the laminate 100B is not located in the outermost peripheral portion.

[0111] The outermost periphery of the laminate 100 wound around the shaft 20 is the part that is most likely to stretch when pressure is applied. By providing narrow width portions 101A to 101D at the outermost periphery, even if narrow width portions 101A to 101D are deformed by pressure, they are less likely to protrude in the width direction of the laminate 100. If protrusion does occur, it can cause a short circuit and deterioration of characteristics at the protruding portion. Therefore, by using the laminates 100A to 100F shown in each figure, the reliability of the battery 1 can be improved.

[0112] The rate of width reduction of the laminate 100 is, for example, 20% per winding, but is not limited to this. It may be set taking into consideration fluctuations in the manufacturing process and operation of the battery 1, such as winding accuracy, the amount of expansion of the laminate 100 when pressure is applied, or expansion and contraction due to charge and discharge operations. For example, if the amount of widthwise deviation during winding is 0% to 10% and the amount of widthwise expansion of the laminate 100 when pressure is applied is 0% to 10%, a width reduction of approximately 20% can improve the reliability of the battery 1 during manufacturing.

[0113] The positional relationship between the outermost periphery and the narrow portions 101A to 101D is not limited to the examples shown in the figures. For example, in each figure, the second portion P2 may be the starting point of the outermost periphery. Also, in each figure, the starting point of the outermost periphery may be a position closer to the end point of the winding than the second portion P2. Alternatively, in each figure, the starting point of the outermost periphery may be a position closer to the start point of the winding than the second portion P2. In this case, the second portion P2 is located closer to the start point than the midpoint between the start and end points of the outermost periphery. In other words, the narrow portions 101A to 101D occupy more than half of the outermost periphery. This improves the reliability of the battery 1.

[0114] [Layer structure of laminate (wound body)] Next, a description will be given of the specific configuration of each layer included in the laminate 100. In the following, an example will be described in which the first electrode layer 110 is a positive electrode layer and the second electrode layer 120 is a negative electrode layer, but the first electrode layer 110 may be a negative electrode layer and the second electrode layer 120 may be a positive electrode layer.

[0115] 1, the first electrode layer 110 includes a first active material layer 111 and a first current collector 112. The first active material layer 111 is provided in contact with a main surface of the first current collector 112. The first active material layer 111 is in contact with the solid electrolyte layer 130 on the main surface opposite to the main surface in contact with the first current collector 112.

[0116] The first active material layer 111 is disposed in contact with one surface of the first current collector 112 and is configured as a positive electrode active material layer. The first active material layer 111 includes at least a positive electrode active material. The first active material layer 111 is a layer mainly composed of a positive electrode material such as a positive electrode active material. The positive electrode active material is a substance in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystal structure at a potential higher than that of the negative electrode, and oxidation or reduction occurs accordingly. The type of positive electrode active material can be appropriately selected depending on the type of battery, and any known positive electrode active material can be used as long as it can maintain its properties as a positive electrode active material even after undergoing manufacturing processes such as heat treatment.

[0117] The positive electrode active material may be a compound containing lithium and a transition metal element, such as an oxide containing lithium and a transition metal element, or a phosphate compound containing lithium and a transition metal element. Examples of oxides containing lithium and a transition metal element include LiNi x M 1-x Lithium nickel composite oxides such as LiO2, lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), layered oxides such as lithium manganese oxide (LiMn2O4), and lithium manganese oxides with a spinel structure such as LiMn2O4, Li2MnO3, and LiMO2 are used. x M 1-xIn O2, M is at least one element among Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W. Also, 0 < x ≤ 1. As the phosphate compound containing lithium and transition metal elements, for example, lithium iron phosphate (LiFePO4) having an olivine structure is used. Further, sulfides such as sulfur (S) and lithium sulfide (Li2S) can also be used as the positive electrode active material. In this case, a material obtained by coating or adding lithium niobate (LiNbO3) or the like to the positive electrode active material particles can be used as the positive electrode active material. Note that only one of these materials may be used as the positive electrode active material, or two or more of these materials may be combined and used. Also, as the positive electrode active material, one or two or more of the above-described materials may be combined and used.

[0118] As described above, the first active material layer 111 only needs to contain at least the positive electrode active material, and may be a composite layer composed of a composite of the positive electrode active material and other additive materials. As other additive materials, for example, solid electrolytes such as inorganic solid electrolytes or sulfide solid electrolytes, conductive aids such as acetylene black, and binders such as polyethylene oxide or polyvinylidene fluoride can be used. By mixing the positive electrode active material and other additive materials such as solid electrolytes at a predetermined ratio, the lithium ion conductivity in the first active material layer 111 can be improved, and the electron conductivity can also be improved.

[0119] The thickness of the first active material layer 111 is, for example, 5 μm or more and 300 μm or less.

[0120] The first current collector 112 contacts the shaft 20 at or near the winding start end of the main surface opposite the surface in contact with the first active material layer 111. This electrically connects the shaft 20 to the first current collector 112. The first current collector 112 contains a conductor. For example, a conductor metal or conductor alloy such as Al, Fe, Ni, or Cu can be used as the first current collector 112. Using a conductor metal with high conductivity can reduce resistance loss and heat generation in the battery. Any conductor metal that satisfies electrochemical stability and mechanical strength can be selected and used as the first current collector 112. The first current collector 112 may have a layered structure made of multiple metals, such as a clad material.

[0121] The second electrode layer 120 is disposed opposite the first electrode layer 110 and functions as a counter electrode of the first electrode layer 110. The second electrode layer 120 includes a second active material layer 121 and a second current collector 122. The second active material layer 121 is provided in contact with a main surface of the second current collector 122. The second active material layer 121 is in contact with the solid electrolyte layer 130 on the main surface opposite to the main surface in contact with the second current collector 122.

[0122] The second active material layer 121 is configured as a negative electrode active material layer, serving as a counter electrode to the first active material layer 111. The second active material layer 121 is disposed in contact with one surface of the second current collector 122. The second active material layer 121 contains at least a negative electrode active material. The second active material layer 121 is a layer mainly composed of a negative electrode material such as a negative electrode active material. A negative electrode active material is a substance in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystal structure at a potential lower than that of the positive electrode, and oxidation or reduction occurs accordingly. The type of negative electrode active material can be appropriately selected depending on the type of battery, and known negative electrode active materials can be used.

[0123] The negative electrode active material may be, for example, TiNb2O7, lithium titanate (Li4Ti5O 12 ), zinc oxide (ZnO), and silicon oxide (SiO xThe type of negative electrode active material may be any material that can maintain its function as a negative electrode active material even after undergoing manufacturing processes such as heat treatment. For example, carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, or resin-baked carbon, and alloy-based materials that are mixed with a solid electrolyte may be used. Examples of alloy-based materials include LiAl, LiZn, Li3Bi, Li3Cd, Li3Sb, Li4Si, and Li 4.4 Pb, Li 4.4 Sn, Li 0.17 C or lithium alloys such as LiC6, zinc oxide (ZnO), and silicon oxide (SiO x ) and other metal oxides can be used. As the negative electrode active material, only one of these materials may be used, or two or more of these materials may be used in combination. As the negative electrode active material, one or two or more of the above-mentioned materials may be used in combination.

[0124] As described above, the second active material layer 121 may contain at least a negative electrode active material, and may be a mixture layer composed of a mixture of the negative electrode active material and other additive materials. Examples of other additive materials that can be used include solid electrolytes such as inorganic solid electrolytes or sulfide solid electrolytes, conductive additives such as acetylene black, and binders such as polyethylene oxide or polyvinylidene fluoride. By mixing the negative electrode active material and other additive materials, such as the solid electrolyte, in a predetermined ratio, the second active material layer 121 can improve both the lithium ion conductivity and the electronic conductivity.

[0125] The thickness of the second active material layer 121 is, for example, not less than 5 μm and not more than 300 μm.

[0126] The second current collector 122 is in contact with the insulating layer 160 on a main surface opposite to the surface in contact with the second active material layer 121. The second current collector 122 contains a conductor. For example, similar to the first current collector 112, the second current collector 122 can be made of a conductive metal or a conductive alloy such as Al, Fe, Ni, or Cu.

[0127] In this specification, the first current collector 112 and the second current collector 122 may be collectively referred to simply as "current collectors."

[0128] The solid electrolyte layer 130 is located between the first electrode layer 110 and the second electrode layer 120. Specifically, the solid electrolyte layer 130 is disposed between the first active material layer 111 and the second active material layer 121 and is in contact with each of them.

[0129] The solid electrolyte layer 130 includes at least a solid electrolyte. The solid electrolyte layer 130 includes, for example, a solid electrolyte as a main component. The solid electrolyte may be any known solid electrolyte for batteries that has ionic conductivity. For example, a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions may be used as the solid electrolyte. The type of solid electrolyte may be appropriately selected depending on the type of conductive ions. For example, an inorganic solid electrolyte such as an oxide-based solid electrolyte, a halide-based solid electrolyte, or a sulfide-based solid electrolyte may be used as the solid electrolyte. An example of an oxide-based solid electrolyte is Li7La3Zr2O 12 , Li7Pr3Zr2O 12 Lithium-containing metal oxides such as Li2O-SiO2 or Li2O-SiO2-P2O5, Li x P y O 1-z N z Examples of usable solid electrolytes include lithium-containing metal nitrides such as lithium phosphate (Li3PO4), lithium transition metal oxides such as lithium titanium oxide, and lithium phosphate (Li3PO4). Examples of usable halide solid electrolytes include Li3AlF6 and Li2TiF6. Examples of usable sulfide solid electrolytes include lithium-containing sulfides such as Li2S-P2S5, Li2S-SiS2, Li2S-B2S3, Li2S-GeS2, Li2S-SiS2-LiI, Li2S-SiS2-Li3PO4, Li2S-Ge2S2, Li2S-GeS2-P2S5, and Li2S-GeS2-ZnS. As the solid electrolyte, only one of these materials may be used, or two or more of these materials may be used in combination.

[0130] In addition to the above solid electrolyte material, the solid electrolyte layer 130 may contain an adhesive binder such as polyethylene oxide or polyvinylidene fluoride.

[0131] The thickness of the solid electrolyte layer 130 is, for example, not less than 5 μm and not more than 150 μm.

[0132] The solid electrolyte material may be composed of an aggregate of particles or a sintered structure.

[0133] In the present embodiment, the first active material layer 111, the first current collector 112, the second active material layer 121, the second current collector 122, and the solid electrolyte layer 130 all have the same size and shape, but are not limited to this. For example, the first active material layer 111 may be larger than the first current collector 112, and the second active material layer 121 may be larger than the second current collector 122. Furthermore, the second active material layer 121, which is the negative electrode active material layer, may be larger than the first active material layer 111, which is the positive electrode active material layer. Furthermore, the solid electrolyte layer 130 may be larger than the first active material layer 111. The first active material layer 111, the second active material layer 121, and the solid electrolyte layer 130 may each have a circular or elliptical shape.

[0134] As shown in FIG. 1 , the laminate 100 is provided with an insulating layer 160. The insulating layer 160 is disposed between the first current collector 112 of the first electrode layer 110 and the second current collector 122 of the second electrode layer 120, and is provided to prevent the first electrode layer 110 and the second electrode layer 120 from coming into contact with each other and causing a short circuit. Specifically, the insulating layer 160 is provided on the main surface of the second current collector 122 opposite to the main surface that contacts the second active material layer 121. Note that, although the insulating layer 160 is not provided on the outermost peripheral portion of the wound body 10 in FIG. 1 , the insulating layer 160 may be provided on the outermost peripheral portion of the wound body 10.

[0135] The insulating layer 160 has electronic insulation properties. The insulating layer 160 need only have electronic conductivity and may have ionic conductivity. For example, the insulating layer 160 may be formed using the same solid electrolyte as the solid electrolyte layer 130. For example, the insulating layer 160 may be formed using various solid electrolytes or insulating materials made of inorganic or resin materials that have substantially no electronic conductivity. Note that by using a material softer than the active material, such as a resin material or a sulfide- or halogen-based solid electrolyte, for the insulating layer 160, expansion and contraction accompanying the charge and discharge operations of the battery 1 can be absorbed. This makes it possible to suppress loosening of the winding and the occurrence of structural defects such as delamination or cracks. This results in a highly reliable battery 1.

[0136] The insulating layer 160 may be formed using a material different from that of the solid electrolyte layer 130. For example, the insulating layer 160 may be a coating using aluminum oxide powder. A coating using aluminum oxide powder is formed by applying a paste dispersed in an organic solvent or the like using a doctor blade method or the like. The aluminum oxide powder may have any particle size and any shape, such as a particle size of 0.1 μm or more and 10 μm or less.

[0137] An insulating oxide powder such as aluminum oxide sinks into the current collector foil, which is softer than aluminum oxide, during winding, which has the effect of more strongly integrating the wound body 10. Furthermore, aluminum oxide has high thermal conductivity and excellent heat dissipation performance, which suppresses heat generation in the battery 1 and further improves reliability.

[0138] Instead of forming the insulating layer 160 using aluminum oxide powder, the insulating layer 160 may contain particles with excellent thermal conductivity, such as yttrium oxide, magnesium oxide, silicon nitride, or boron nitride. This provides the same effects as when aluminum oxide is used. Alternatively, the insulating layer 160 may be formed using the same material as the solid electrolyte layer 130 and contain aluminum oxide. In this case, the same anchoring effect and heat dissipation effect can be obtained.

[0139] The insulating layer 160 may also include a polyimide film. The polyimide film can be formed in a state where it protrudes from the edge of the laminate 100, thereby achieving higher insulation. Commercially available polyimide films can be used, and films of any thickness, for example, 10 μm to 90 μm, can be used. The insulating layer 160 may include various insulating films, such as a PET (polyethylene terephthalate) film or a PEN (polyethylene naphthalate) film, instead of or in addition to a polyimide film. These insulating films, such as a polyimide film, are lightweight, and therefore can improve reliability without deteriorating the weight energy density of the battery 1.

[0140] [shaft] Next, modified examples of the shaft 20 will be described using Fig. 6A to Fig. 6H. Fig. 6A to Fig. 6F are perspective views each showing a schematic configuration of another example of the shaft of the battery 1 according to the present embodiment. Fig. 6G and Fig. 6H are cross-sectional views each showing a schematic configuration of another example of the shaft of the battery 1 according to the present embodiment. In the description of the shafts 20A to 20H shown in each figure, differences from the shaft 20 shown in Fig. 4 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0141] A shaft 20A shown in FIG. 6A differs from the shaft 20 shown in FIG. 4 in that it has rough surface portions 23 and 24.

[0142] Rough surface portion 23 is provided on the inner surface of shaft 20A. Rough surface portion 23 is provided on the entire inner surface of cylindrical shaft 20A, but is not limited to this. For example, rough surface portion 23 may be provided only on the portion of the inner surface of shaft 20A that comes into contact with laminate 100 and its vicinity.

[0143] The rough surface portion 24 is provided on the inner surface of the slit 22. It is provided on the entire inner surface of the slit 22, but is not limited to this. For example, the rough surface portion 24 may be provided only on the portion of the inner surface of the slit 22 that comes into contact with the laminate 100 and its vicinity.

[0144] Rough surface portions 23 and 24 are formed, for example, by roughening the inner surface of shaft 20A and the inner surface of slit 22. Examples of roughening methods include physical treatment such as sandblasting, or chemical treatment using acid or chemicals. Alternatively, roughening may be performed by plating a film made of rough particles. The specific method for roughening is not particularly limited. The same applies to the method for forming rough surface portion 25, which will be described later with reference to FIG. 6D.

[0145] By providing at least one of the rough surface portions 23 and 24, the frictional force between the starting end of the laminate 100 and the shaft 20A can be increased. This can prevent the laminate 100 from shifting out of position. The surface roughness Rz of the rough surface portions 23 and 24 is equal to or less than the thickness of the current collector, and is, for example, 0.3 μm to 30 μm, but is not limited to this. The surface roughness Rz of the rough surface portions 23 and 24 may be 0.5 μm to 10 μm, or may be 1 μm to 3 μm. The roughness of the rough surface portions 23 and 24 should be set so that the laminate 100 is not damaged.

[0146] The shaft 20B shown in Fig. 6B is a cylindrical shaft. The shaft 20B does not have a hollow portion 21 or a slit 22. By fixing the starting end of the laminate 100 to the outer surface of the shaft 20B using a resin member 60, the laminate 100 can be wound around the shaft 20B that does not have a hollow portion 21 or a slit 22. The shaft 20B may have a recess into which the starting end of the laminate 100 is inserted.

[0147] The shaft 20C shown in FIG. 6C differs from the shaft 20B shown in FIG. 6B in that it has two hollow portions 21C. The hollow portions 21C are recesses provided at the ends of the shaft 20C in the axial direction. The hollow portions 21C are recesses whose inner surfaces have a curved surface that convexly curves in a direction toward the center of the shaft 20C, and may be, for example, hemispherical recesses, but are not limited to this. The hollow portions 21C are recesses whose inner surfaces have a curved surface that convexly curves in a direction away from the center of the shaft 20C, and may be, for example, funnel-shaped recesses. The hollow portions 21C may also be conical or polygonal pyramidal, or truncated conical or polygonal pyramidal recesses.

[0148] The provision of the hollow portion 21C reduces the weight of the shaft 20C, thereby improving the weight energy density. Furthermore, the hollow portion 21C, which is a recess, can be used to insert a jig (tool) and easily rotate the shaft 20C. By bringing the shaft 20C into contact with the laminate 100 placed on a flat surface and rotating and winding the shaft 20C, the laminate 100 can be easily handled without directly contacting it. Therefore, the laminate 100 can be handled without causing scratches or defects, and the reliability of the battery 1 can be improved.

[0149] Shaft 20D shown in FIG. 6D differs from shaft 20B shown in FIG. 6B in that it has a rough surface portion 25. Rough surface portion 25 is provided on the outer surface of shaft 20D. Rough surface portion 25 is provided on the entire outer surface of shaft 20D, but is not limited to this. For example, rough surface portion 25 may be provided only on the portion of the outer surface of shaft 20D that comes into contact with laminate 100 and its vicinity.

[0150] By providing the rough surface portion 25, the frictional force between the starting end of the laminate 100 and the shaft 20D can be increased. This can suppress misalignment of the laminate 100. The surface roughness Rz of the rough surface portion 25 is equal to or less than the thickness of the current collector, and is, for example, but not limited to, 0.3 μm to 30 μm. The surface roughness Rz of the rough surface portion 25 may be 0.5 μm to 10 μm, or may be 1 μm to 3 μm. The degree of roughness of the rough surface portion 25 should be set so that the laminate 100 is not damaged.

[0151] Shaft 20E shown in Fig. 6E differs from shaft 20B shown in Fig. 6B in that it includes resin portion 26 that contacts laminate 100. Resin portion 26 is formed, for example, in a layer shape so as to cover the outer surface of the metal core material of shaft 20E. The thickness of resin portion 26 is, for example, not less than 0.5 µm and not more than 50 µm, but is not limited to this.

[0152] The provision of resin portion 26 can strengthen the contact between shaft 20E and laminate 100. In addition, the elasticity of resin portion 26 can absorb stress in laminate 100, thereby preventing laminate 100 from being damaged.

[0153] The resin portion 26 may be formed using a conductive resin material. For example, an epoxy-based thermosetting resin containing metal conductor particles can be used as the conductive resin material. By using a conductive resin material, the shaft 20E and the laminate 100 can be electrically connected.

[0154] Shaft 20F shown in Fig. 6F is a cylindrical shaft having hollow portion 21, similar to shaft 20 shown in Fig. 4. Shaft 20F does not have slits 22, but may have slits 22. When viewed from the axial direction, the size of one end of shaft 20F in the axial direction is different from the size of the other end of shaft 20F in the axial direction. Specifically, shaft 20F has end 27 that is different in size from the other end.

[0155] By varying the size of the ends of shaft 20F in the axial direction in this way, the directionality of wound body 10 can be clarified, making it easier to manage the directionality of wound body 10 during the manufacturing process, improving quality and productivity. As a result, high-quality batteries 1 can be produced with good productivity.

[0156] In the example shown in Fig. 6F, end 27 is smaller than the other end and has a truncated cone shape, but this is not limiting. End 27 may also have a cylindrical shape. End 27 may also be larger than the other end.

[0157] The shaft 20G shown in FIG. 6G differs from the shaft 20 shown in FIG. 4 in that it includes a step absorbing portion 28. The step absorbing portion 28 is provided to absorb steps in the winding of the laminate 100. Specifically, the step absorbing portion 28 is part of the inner surface of the slit 22 and is a curved surface that is curved along the winding direction of the laminate 100. As shown in FIG. 6G, by arranging the laminate 100 so that it is in contact with the step absorbing portion 28, steps in the winding of the laminate 100 can be absorbed. This reduces stress locally applied to the starting end of the laminate 100 or its vicinity, thereby preventing damage to the laminate 100.

[0158] The shaft 20H shown in FIG. 6H differs from the shaft 20 shown in FIG. 4 in that it includes a step absorbing portion 29. The step absorbing portion 29 is provided to absorb steps that occur during the winding of the laminate 100. Specifically, the step absorbing portion 29 is a protrusion provided on the outer surface of the shaft 20H. The step absorbing portion 29 forms a step corresponding to the thickness of the laminate 100 between the portion of the outer surface of the shaft 20H where the starting end of the laminate 100 is located. As a result, as shown in FIG. 6G, there is almost no step between the outer surface of the starting end of the laminate 100 and the step absorbing portion 29, allowing the second turn of the laminate 100 to be wound smoothly. This reduces stress locally applied to the starting end of the laminate 100 or its vicinity, thereby preventing damage to the laminate 100.

[0159] As described above, shaft 20 and shafts 20A to 20H have been described, but the respective features may be combined. For example, step absorbing portion 29 shown in shaft 20H may be applied to rod-shaped shaft 20B, etc. Also, for example, shaft 20 and shafts 20A to 20H may be formed using a porous material. In shafts made of a porous material, the pore size is, for example, 1 μm to 10 mm, and the porosity is 10% to 90%. By using a porous material, the weight of the shaft can be reduced, and the weight energy density of battery 1 can be improved.

[0160] [Effects, etc.] Comparing the configuration of the battery 1 according to the present embodiment with that of the batteries described in Patent Documents 1 and 2, the battery 1 according to the present embodiment differs in that the width of the laminate 100 is narrower at the end of the winding. In the batteries described in Patent Documents 1 and 2, the width of the laminate is constant. In this case, structural defects in the surface layer of the wound body, which is prone to deformation, are likely to cause short circuits and deterioration of characteristics. In contrast, in the battery 1 according to the present embodiment, the width of the laminate 100 is narrower, which suppresses short circuits during pressure treatment after winding. This results in a highly reliable battery 1.

[0161] In the battery 1 according to this embodiment, the starting end of the laminate 100 is pulled into and accommodated in the hollow portion 21 of the shaft 20 via the slit 22. This provides a strong anchoring effect, thereby preventing the starting end from shifting position, winding misalignment, and loosening of the winding during winding. Furthermore, the shaft 20 having the hollow portion 21 reduces the weight of the battery 1, thereby increasing the energy weight density. Thus, according to this embodiment, a battery 1 with high performance and high reliability can be realized.

[0162] Furthermore, by combining the number of windings with the change in width of the laminate 100 as a capacity design factor, the design range of capacity can be expanded. Furthermore, unlike the laminate type, the lamination process and the pressing process are not repeated, and by continuously winding and pressing the laminate 100 together, a battery 1 with excellent productivity can be realized.

[0163] [Variations] Next, a battery according to a modification of the embodiment will be described. The following description will focus on the differences from the embodiment, and the description of the commonalities will be omitted or simplified.

[0164] <Variation 1> 7 is a cross-sectional view showing a schematic configuration of a battery 2 according to a first variation of the embodiment. The battery 2 shown in FIG. 7 differs from the battery 1 shown in FIG. 1 mainly in that the battery 2 does not have a first flange 31 or a second flange 32. Furthermore, the battery 2 does not have a slit 22 in the shaft 20. Therefore, the starting end of the laminate 100 is provided in contact with the outer surface of the shaft 20.

[0165] If the first flange 31 and the second flange 32 were provided to fit the width of the laminate 100, and the laminate 100 included a portion where the width was locally increased, the laminate 100 might not be able to be accommodated between the first flange 31 and the second flange 32, resulting in deformation of the laminate 100. In contrast, the battery 2 according to this modification does not include the first flange 31 and the second flange 32, so deformation of the laminate 100 can be suppressed, and short circuits and deterioration of characteristics can be suppressed. The degree of freedom in the shape of the laminate 100 can also be increased.

[0166] <Variation 2> Fig. 8 is a cross-sectional view showing a schematic configuration of a battery 3 according to Modification 2 of the embodiment. The battery 3 shown in Fig. 8 differs from the battery 2 shown in Fig. 7 mainly in that it includes a molding member 70.

[0167] The molding member 70 is a member for sealing the wound body 10 together with the shaft 20. The molding member 70 is used as an exterior material. For example, the molding member 70 seals the entire wound body 10 and at least a portion of the shaft 20. When the starting end of the wound body 10 is located within the hollow portion 21 of the shaft 20, the molding member 70 is also provided within the hollow portion 21. When the first flange 31 and the second flange 32 are provided, the molding member 70 may seal the first flange 31 and the second flange 32. Note that "sealing" means separating the wound body 10 from the external space without exposing the wound body 10 to the outside.

[0168] The molding member 70 exposes at least a portion of each of the first terminal electrode 40 and the second terminal electrode 50. This makes it possible to ensure that the positive electrode and the negative electrode can be removed from the wound body 10.

[0169] The molding member 70 is made of, for example, a thermosetting epoxy resin material. However, other materials can also be used for the molding member 70 as long as it has insulating properties. For example, the wound body 10, which has been heated to a temperature close to its curing temperature (e.g., 120°C), is impregnated with epoxy resin powder having a diameter of 50 μm to 300 μm. This causes the epoxy resin powder to become viscous and adhere to the wound body 10. By repeating this process multiple times, a molding resin layer of, for example, 1 mm to 5 mm is formed to cover the wound body 10. After the molding resin layer of the desired coating thickness is formed, the molding resin layer is allowed to harden for approximately 30 minutes to 1 hour. This produces a battery 3 including a molding member 70 that completely seals the wound body 10. The thus-covered molding member 70 is a laminated film formed by repeatedly applying thin films. Pores or defects (e.g., cracks) present in the single-layer film are blocked by the lamination process, resulting in a highly airtight molding member 70.

[0170] Battery 3 according to this modification can protect wound body 10 from external shock and from outside air containing gas or moisture that may deteriorate the characteristics of wound body 10. This further improves the reliability of battery 3.

[0171] <Variation 3> Fig. 9 is a top view showing a schematic configuration of battery 4 according to a third variation of the embodiment. Battery 4 shown in Fig. 9 differs from battery 1 shown in Fig. 1 mainly in that it includes shaft 20I and first flange 33 instead of shaft 20 and first flange 31. Specifically, shaft 20I and first flange 33 differ from shaft 20 and first flange 31 in that they are each substantially square in plan view. Although not shown in Fig. 9, battery 4 may include a second flange similar to first flange 33 instead of second flange 32.

[0172] The shaft 20I is a rectangular cylindrical shaft. The corners (ridges) of the shaft 20I are rounded. This makes it possible to prevent damage to the laminate 100 wound around the shaft 20I due to stress concentration. Note that a chamfered portion may be provided instead of the rounded portion. The corners of the shaft 20I do not need to be chamfered. For example, the corners may be protected by a relatively soft material such as an insulating film.

[0173] The first flange 33 is a rectangular plate-shaped flange. The corners of the first flange 33 are provided with rounded portions. Note that C-shaped portions may be provided instead of the rounded portions. Also, the corners of the first flange 33 do not necessarily have to be chamfered.

[0174] According to this modification, when multiple batteries 4 are arranged side by side, the volume density is improved. Specifically, when multiple batteries 4 are arranged side by side so that their axial directions are parallel to each other, packing arrangement is facilitated. For example, by arranging multiple batteries 4 side by side and connecting them in parallel, a battery pack with high energy density can be realized.

[0175] The shapes of shaft 20I and first flange 33 when viewed in the axial direction are not limited to a square, but may be other regular polygons or polygons such as a regular hexagon or a regular octagon. For example, by using a regular hexagonal shaft 20I and first flange 33, the packing ratio can be increased when multiple batteries 4 are arranged.

[0176] <Variation 4> Fig. 10 is a cross-sectional view showing a schematic configuration of a battery 5 according to Modification 4 of the embodiment. Fig. 11 is a perspective view showing a schematic configuration of a laminate 100 wound around a shaft 20 according to Modification 4 of the embodiment.

[0177] The battery 5 shown in Fig. 10 differs from the battery 1 shown in Fig. 1 in that it includes a loosening-preventing material 80. Another difference is that an insulating layer 160 is also provided on the outermost periphery of the wound body 10.

[0178] The slack suppressing material 80 suppresses slack in the wound body 10. The slack suppressing material 80 is a tape-shaped member that surrounds the wound body 10 around the axis of the shaft 20. For example, the slack suppressing material 80 is a heat-shrinkable member that shrinks when heated. As the heat-shrinkable member, a common material such as polyolefin or fluorine-based polymer can be used. In this modification, as shown in FIGS. 10 and 11 , two slack suppressing materials 80 are arranged to sandwich the center of the wound body 10 in the z-axis direction.

[0179] For example, after winding the annular unshrunk loosening suppression material 80 around the wound body 10, the loosening suppression material 80 is shrunk by heating it to a predetermined temperature (e.g., 70°C). As a result, the loosening suppression material 80 is embedded in the outermost peripheral portion of the wound body 10. After the loosening suppression material 80 and the wound body 10 are integrated, the loosening suppression material 80, the wound body 10, and the shaft 20 can be firmly fixed together by isostatic pressure.

[0180] In the battery 5 according to this modification, the provision of the loosening-preventing material 80 can further prevent loosening of the wound body 10. Therefore, the reliability of the battery 5 can be improved.

[0181] <Variation 5> Fig. 12 is a perspective view showing a schematic configuration of the laminate 100 wound around the shaft 20 according to Modification 5 of the embodiment. As shown in Fig. 12, in this modification, a slack suppression material 81 is provided instead of the slack suppression material 80 shown in Fig. 10.

[0182] The slack suppressing material 81 suppresses slack in the wound body 10. The slack suppressing material 81 is a tape-shaped member that secures the terminal end of the winding of the wound body 10. For example, the slack suppressing material 81 is an adhesive tape that secures the terminal end of the wound body 10 and the starting end of the outermost periphery of the wound body 10.

[0183] The slack suppression material 81 is, for example, a tape-shaped member having a thickness of 5 μm to 50 μm. Any material can be used as the slack suppression material 81, such as polyimide, cellophane, PET, PEN, PPS (polyphenylene sulfide), or Teflon (registered trademark), which has insulating properties. For example, in terms of environmental resistance to thermal cycles, polyimide, which has excellent heat resistance strength, or PEN, which has small thermal expansion, is used.

[0184] According to this modification, the provision of the loosening suppression material 81 can further suppress loosening of the wound body 10. This can improve the reliability of the battery.

[0185] [Battery manufacturing method] Next, a method for manufacturing the batteries according to the above-described embodiment and each of the modifications will be described, taking the method for manufacturing battery 1 as a representative example.

[0186] Fig. 13 is a flowchart showing a method for manufacturing the battery 1 according to the present embodiment. As shown in Fig. 13, the method for manufacturing the battery 1 includes a step (S10) of winding the laminate 100 around the shaft 20, and a step (S20) of isostatically pressing the laminate 100 wound around the shaft 20. Each step will be described in more detail below.

[0187] In the winding step, first, the laminate 100 is prepared. Specifically, slurries are prepared to be used for forming the first active material layer 111, which is the positive electrode active material layer, the second active material layer 121, which is the negative electrode active material layer, the solid electrolyte layer 130, and the insulating layer 160. More specifically, as the solid electrolyte raw material used for the mixture of the first active material layer 111 and the second active material layer 121, for example, a glass powder of Li2S-P2S5-based sulfide having an average particle size of about 1 μm and containing triclinic crystals as the main component is prepared. As this glass powder, for example, 1×10 -3 S / cm or more, 5×10 -3 A soft sulfide-based solid electrolyte having high ionic conductivity of about S / cm or less can be used.

[0188] As the positive electrode active material, for example, a layered Li, Ni, Co, Al composite oxide (LiNi 0.8 Co 0.15 Al 0.05 A mixture containing the above-mentioned positive electrode active material and the above-mentioned solid electrolyte powder is dispersed in an organic solvent or the like to prepare a slurry for a positive electrode active material layer.

[0189] Furthermore, as the negative electrode active material, for example, Li4Ti5O 12 In this way, a negative electrode active material that expands and contracts little during charge and discharge is used. Next, a mixture containing the above-mentioned negative electrode active material and the above-mentioned solid electrolyte powder is dispersed in an organic solvent or the like to prepare a slurry for a negative electrode active material layer in the same manner.

[0190] Next, a Cu foil having a thickness of, for example, 12 μm is prepared as the metal foil to be used for the first current collector 112, which is the positive electrode current collector. A Ni foil having a thickness of, for example, 12 μm is prepared as the metal foil to be used for the second current collector 122, which is the negative electrode current collector. Both main surfaces of each of these current collectors are subjected to, for example, a surface roughening treatment. Roughening both main surfaces improves bonding with the active material or insulating layer, resulting in a highly reliable battery. The degree of surface roughening is not particularly limited, but may be, for example, Rz of about 0.1 μm or more and about 10 μm or less.

[0191] Next, the above-mentioned solid electrolyte powder is dispersed in an organic binder component, an organic solvent, etc. to prepare a slurry for the solid electrolyte layer to be used for the solid electrolyte layer.

[0192] Next, the slurry for the positive electrode active material layer is applied to a thickness of approximately 50 μm on the first current collector 112 by a doctor blade method, and then air-dried to form a first active material layer 111 (positive electrode active material layer) to a thickness of approximately 30 μm on the first current collector 112. Thereafter, similarly, the paste for the solid electrolyte layer is applied to a thickness of approximately 40 μm on the first active material layer 111 and air-dried to form a solid electrolyte layer 130 to a thickness of approximately 25 μm. Thereafter, the paste for the negative electrode active material layer is applied to a thickness of approximately 50 μm on the solid electrolyte layer 130 and air-dried to form a second active material layer 121 (negative electrode active material layer) to a thickness of approximately 30 μm. Next, the slurry for the solid electrolyte layer for the insulating layer is applied to one side of the second current collector 122 to a thickness of approximately 10 μm, and then air-dried to form an insulating layer 160 to a thickness of approximately 6 μm.

[0193] Then, the second current collector 122 is placed on the second active material layer 121, and the second active material layer 121 and the second current collector 122 are pressed together using a roll press with a linear pressure of approximately 2 t / cm. This produces a long laminate 100. The shapes of the laminates 100A to 100F described with reference to FIGS. 5A to 5F can be formed by cutting or otherwise processing a portion of the end of the laminate 100 into a predetermined shape. Alternatively, current collectors having the shapes of the laminates 100A to 100F may be prepared in advance as the first current collector 112 and the second current collector 122. Furthermore, in the coating process for forming the insulating layer 160, it is not necessary to coat the end of the laminate 100 corresponding to the outermost periphery of the wound body 10. This allows for the formation of a configuration in which the insulating layer 160 is not present in the outermost periphery.

[0194] Next, the laminate 100 manufactured as described above is inserted into the slit 22 of the shaft 20, as shown in FIGS. 14A and 14B. FIG. 14A is a perspective view illustrating one step of the method for manufacturing a battery according to the embodiment and each modified example. FIGS. 14B and 14C are top views illustrating one step of the method for manufacturing a battery according to the embodiment and each modified example. Note that, although the first flange 31 and the second flange 32 are attached to the shaft 20 in advance, at least one of the first flange 31 and the second flange 32 may not be provided.

[0195] 14C, an epoxy-based thermosetting insulating resin is injected into the end of the laminate 100 inserted through the slit 22 using, for example, a dispenser, and is then thermally cured by heating at approximately 120° C. This forms a resin member 60, which fixes and integrates the shaft 20 and the starting end of the laminate 100.

[0196] The outer and inner surfaces of shaft 20, as well as the inner surfaces of slits 22, may be roughened. In this case, the surface area is increased by the roughening, thereby increasing the bonding surface between shaft 20 and laminate 100 and resin member 60, thereby firmly bonding them. The degree of roughening is not particularly limited, but for example, by making the roughening equal to or less than the thickness of the current collector, a strong anchor effect can be obtained while suppressing damage to the current collector. The degree of roughening of the inner and outer surfaces of shaft 20 may be different or the same. When using a shaft without slits 22, such as shaft 20B shown in FIG. 6B, the starting end of laminate 100 can be fixed to the outer surface of the shaft.

[0197] Next, the laminate 100 is wound around the shaft 20. After the laminate 100 is wound, the slack suppression material 80 or 81 may be attached. When the slack suppression material 80 is a heat-shrinkable material, it is shrunk by heating. This allows the wound laminate 100, i.e., the wound laminate 100 and the shaft 20, to be firmly fixed together.

[0198] After the laminate 100 is wound around the shaft 20 as described above, isostatic pressing is performed as shown in FIG. 13. The isostatic pressing is warm isotropic pressing (WIP). For example, the WIP temperature is 70°C and the pressure is 400 MPa, but this is not limited thereto. Alternatively, the isostatic pressing may be cold isostatic pressing (CIP). The pressure is about 3 t / cm, but this is not limited thereto.

[0199] Furthermore, for example, isostatic pressing may be performed after at least a portion of the laminate 100 wound around the shaft 20 is covered with an elastic body. The elastic body is, for example, a soft bag made of silicone rubber. After the bag is vacuum-suctioned to remove air and sealed, CIP may be performed.

[0200] Next, the first terminal electrode 40 and the second terminal electrode 50 made of SUS are attached to the shaft 20 and the second current collector 122 at the outermost periphery of the laminate 100 using an Ag-based thermosetting conductive resin. This completes the manufacture of the battery 1 shown in FIG.

[0201] After this, a thermosetting epoxy resin may be applied to a thickness of approximately 300 μm, taking care not to apply the resin to the exposed portions of the first terminal electrode 40 and the second terminal electrode 50. The resin is then thermally cured by heating to approximately 120°C in an inert gas such as nitrogen (N2) gas. This allows the molding member 70 to be formed as in the battery 3 shown in FIG. 8.

[0202] The above manufacturing method is merely an example, and the processing in each step can be changed as appropriate.

[0203] (Other embodiments) While the battery according to the present disclosure has been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by those skilled in the art to the embodiments and other forms constructed by combining some of the components of the embodiments are also included in the scope of the present disclosure.

[0204] For example, the width may be larger at the end of the winding of the laminate. That is, the first portion P1 having a smaller width may be located closer to the start end than the end of the winding of the laminate.

[0205] Furthermore, the above-described embodiments can be modified, substituted, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0206] The battery according to the present disclosure can be used, for example, as a secondary battery such as an all-solid-state battery used in various electronic devices or automobiles. [Explanation of symbols]

[0207] 1, 2, 3, 4, 5 batteries 10. Wound body 20, 20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20I axis 21, 21C Hollow part 22 Slit 23, 24, 25 Rough surface area 26 Resin part 27 End 28, 29 Step absorption section 31, 33 First Tsuba 32 Second Tsuba 40 1st terminal electrode 50 2nd terminal electrode 60 Resin parts 70 Molded parts 80, 81 Loosening prevention material 100, 100A, 100B, 100C, 100D, 100E, 100F laminate 101A, 101B, 101C, 101D Narrow part 102D First narrow section 103D 2nd narrow part 104c C processing section 104r R processing section 110 1st electrode layer 111 First active material layer 112 First current collector 120 Second electrode layer 121 Second active material layer 122 Second current collector 130 Solid electrolyte layer 160 Insulating Layer

Claims

1. a laminate including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer; a shaft; the laminate is a wound body wound around the shaft, When the length of the stack in the axial direction of the shaft is defined as the width of the stack, the width of the stack at a first portion is shorter than the width of the stack at a second portion, The first portion is located closer to the end of the winding than the second portion. battery.

2. The width of the laminate decreases continuously from the second portion to the first portion. The battery of claim 1 .

3. The width of the laminate decreases stepwise from the second portion to the first portion. The battery of claim 1 .

4. the first portion and the second portion are located at the outermost periphery of the wound body. The battery of claim 1 .

5. A loosening suppression material that suppresses loosening of the wound body is provided. The battery according to any one of claims 1 to 4.

6. The slack suppression material is a tape-shaped member. The battery of claim 5.

7. the tape-shaped member fixes the winding end of the wound body; The battery of claim 6.

8. the tape-shaped member surrounds the wound body around the axis of the shaft; The battery of claim 6.

9. the tape-shaped member is embedded in the outermost peripheral portion of the wound body; The battery of claim 8.

10. The tape-shaped member is a heat-shrinkable member. The battery of claim 8.

11. The laminate has a chamfered shape at least at one of a starting end and an ending end of the winding. The battery according to any one of claims 1 to 4.

12. a length of the axis in the axial direction is longer than a width of the laminate in the second region; The battery according to any one of claims 1 to 4.

13. the shaft includes a conductor; The battery according to any one of claims 1 to 4.

14. the shaft includes a porous member; The battery according to any one of claims 1 to 4.

15. The shaft has a hollow portion. The battery according to any one of claims 1 to 4.

16. The hollow portion is a recess provided at an end portion of the shaft in the axial direction.

16. The battery of claim 15.

17. The shaft is a cylindrical body. The battery according to any one of claims 1 to 4.

18. The shaft has a roughened surface on its inner surface.

18. The battery of claim 17.

19. When viewed from the axial direction, a size of one end of the shaft in the axial direction is different from a size of the other end of the shaft in the axial direction. The battery according to any one of claims 1 to 4.

20. The shaft has a rough surface portion on the surface that comes into contact with the laminate. The battery according to any one of claims 1 to 4.

21. The shaft has a resin portion that contacts the laminate. The battery according to any one of claims 1 to 4.

22. A flange is provided on the shaft. The battery according to any one of claims 1 to 4.

23. The shaft has a recess into which the laminate is inserted. The battery according to any one of claims 1 to 4.

24. The shaft has a rough surface on the inner surface of the recess.

24. The battery of claim 23.

25. a resin member covering the inner surface of the recess; 24. The battery of claim 23.

26. The shaft has a step absorbing portion that absorbs steps in the winding of the laminate. The battery according to any one of claims 1 to 4.

27. a step of winding a laminate including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer around a shaft; and isostatically pressing the laminate wound around the shaft, When the length of the stack in the axial direction of the shaft is defined as the width of the stack, the width of the stack at a first portion is shorter than the width of the stack at a second portion, The first portion is located closer to the end of the winding than the second portion. How batteries are manufactured.

28. The isostatic pressing step is performed after at least a portion of the laminate wound around the shaft is covered with an elastic body.

28. A method for manufacturing the battery of claim 27.

Images