Battery

Abstract

To provide a battery with improved vibration resistance.SOLUTION: A battery has a battery element with first and second outer end faces and a cylindrical outer body housing the battery element and having a first inner end face opposite the first outer end face, and a first inner diameter φ1 of the outer body at a position 4 mm away from the first inner end face toward the second outer end face is 0.24 to 0.72% smaller than a second inner diameter φ2 of the outer body at a position 7 mm away from the second outer end face of the battery element toward the first outer end face.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to batteries. [Background technology]

[0002] Batteries are capable of extracting energy produced by chemical reactions or the like as electrical energy, and are used in a variety of applications, including mobile devices such as mobile phones, smartphones, and laptops.

[0003] Conventionally, the battery can (exterior body) of such a battery is formed from a metal plate by the drawing and ironing method (deep drawing method) described in Patent Document 1, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-6087 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the present inventors have found that the above-mentioned battery cannot sufficiently improve vibration resistance.

[0006] Therefore, a primary object of the present disclosure is to provide a battery with improved vibration resistance. [Means for solving the problem]

[0007] The present inventors have attempted to solve the above problems by taking a new approach, rather than simply extending the conventional approach. As a result, they have arrived at a battery according to the present disclosure that achieves the above-mentioned main object. That is, the present disclosure includes the following embodiments.

[0008] In order to solve the above problems, a battery according to an embodiment of the present disclosure comprises: A battery comprising: a battery element having a first outer end surface and a second outer end surface; and a cylindrical exterior body that houses the battery element and has a first inner end surface that faces the first outer end surface, The first inner diameter φ1 of the outer casing at a position 4 mm away from the first inner end surface toward the second outer end surface is 0.24 to 0.72% smaller than the second inner diameter φ2 of the outer casing at a position 7 mm away from the second outer end surface of the battery element toward the first outer end surface. Effect of the Invention

[0009] A battery according to an embodiment of the present disclosure can provide a battery with improved vibration resistance. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view showing the appearance of a battery according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram showing the internal configuration of the battery according to the first embodiment of the present disclosure. [Diagram 3] FIG. 3 is a cross-sectional view showing the battery according to the first embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view showing a battery element and an exterior body in the battery according to the first embodiment of the present disclosure. [Diagram 5] FIG. 5 is a cross-sectional view showing a punch and an exterior body in deep drawing. [Figure 6] FIG. 6 is a cross-sectional view showing a battery according to a second embodiment of the present disclosure. [Figure 7] FIG. 7 is a schematic diagram showing a battery element in a battery according to a second embodiment of the present disclosure. [Figure 8] FIG. 8 is an enlarged cross-sectional view of the vicinity of an end portion of a battery element in a battery according to a second embodiment of the present disclosure. [Figure 9] FIG. 9 is a cross-sectional view showing a battery element and an exterior body in a battery according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The following describes the embodiments of the present disclosure in detail. Please note that the applicant provides the following description and examples to allow those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims. In other words, the present disclosure is not particularly limited to the preferred embodiments described below, and can be modified and implemented as appropriate within the scope of its purpose. In addition, in consideration of the explanation or ease of understanding of the main points, the present invention may be shown in separate embodiments and examples for convenience, but partial replacement and / or combination of the configurations shown in different embodiments is possible. In the description of such embodiments, overlapping explanations of substantially identical matters may be omitted, and only the differences may be described. In particular, similar actions and effects due to similar configurations may not be mentioned sequentially for each embodiment.

[0012] In addition, in the description of the present specification, references to directions or orientations are merely for the convenience of description and are not intended to limit the scope of the present disclosure unless otherwise expressly described. For example, relative terms such as "outside (or outer, external or outer circumference)", "inside (or inner, internal or inner circumference)", and their derivative terms should be understood to refer to the direction as described or illustrated. Similarly, "on" an element includes not only the case of contacting the upper surface of the element, but also the case of not contacting the upper surface of the element. In other words, "on" an element includes not only the position above the element, i.e., the position above the element through another object, or the position above the element with a space therebetween, but also the position directly above the element. In addition, "on" does not necessarily mean the upper side in the vertical direction. "On" merely indicates the relative positional relationship of a certain element. In other words, unless otherwise expressly described, the invention does not need to be limited to a specific direction, orientation, shape, etc. The same applies to terms such as "provided," "disposed," and "connected," as well as their derived terms, and unless otherwise explicitly stated, they are not limited to a direct configuration, but may also refer to a configuration in which other elements, such as intervening objects, are involved.

[0013] Various numerical ranges mentioned in this specification are intended to include the lower and upper limit numerical values ​​themselves, unless a special explanation such as "less than" is added. In other words, for example, a numerical range such as 0.24 to 0.72% is interpreted as including the lower limit of 0.24% and the upper limit of 0.72%.

[0014] The term "battery" in this specification includes not only so-called "secondary batteries" but also "primary batteries" that can only be discharged. In other words, the term "battery" in this specification may be a "secondary battery" that can be repeatedly charged and discharged, or a "primary battery" that can essentially only be discharged. Note that the term "secondary battery" is not overly limited to its name, and may also include, for example, "electricity storage devices."

[0015] Hereinafter, a "battery" according to an embodiment of the present disclosure will be described in detail. Although the description will be made with reference to the drawings as necessary, the contents shown in the drawings are merely shown in a schematic and illustrative manner for understanding the present disclosure, and the appearance and dimensional ratios may differ from the actual product. For example, characteristic parts of the embodiment of the present disclosure may be emphasized.

[0016] For ease of explanation, the battery according to the present disclosure will be explained below mainly using a secondary battery as an example.

[0017] <First embodiment: battery> The first embodiment of the present disclosure relates to a battery (secondary battery) 1. The battery according to the first embodiment will be described with reference mainly to FIG. 1, FIG. 2, and FIG. 3. FIG. 1 is a schematic perspective view showing the appearance of the battery according to the first embodiment. FIG. 2 is a schematic view showing the internal configuration of the battery according to the first embodiment. FIG. 3 is a cross-sectional view of the battery according to the first embodiment. In FIG. 1 to FIG. 3, the direction parallel to the axial direction (battery axial direction) of the battery 1 is the Z direction, the vertical downward direction is the reverse Z direction, and the vertical upward direction is the forward Z direction. In this specification, the battery axis corresponds to the central axis of the cylindrical battery 1. In FIG. 1 to FIG. 3, the symbol "first" is attached to a member arranged on the lower side (reverse Z direction side), and the symbol "second" is attached to a member arranged on the upper side (forward Z direction side).

[0018] In this specification, the term "cylindrical" refers to a cylinder having a large aspect ratio (for example, an aspect ratio of 1 or more) in which the ratio of the height to the diameter of the equivalent circle diameter of the base of the cylinder is large. Here, the equivalent circle diameter of the base refers to the diameter of a circle having the same area as the area of ​​the base.

[0019] 1 to 3, the secondary battery 1 according to the first embodiment is a battery including a battery element (electrode assembly) 10 having a first outer end surface 11 and a second outer end surface 12, and a cylindrical exterior body (battery can) 20 that houses the battery element 10 and has a first inner end surface 21 facing the first outer end surface 11. The secondary battery 1 further includes an electrolyte (not shown) sealed in the exterior body 20.

[0020] (Mechanism of action) The battery 1 according to the first embodiment has improved vibration resistance, the reason for which is presumed to be as follows. As shown in FIG. 3, the first inner diameter φ1 of the exterior body 20 at a position 4 mm away from the first inner end surface 21 toward the second outer end surface 12 is 0.24 to 0.72% smaller than the second inner diameter φ2 of the exterior body 20 at a position 7 mm away from the second outer end surface 12 toward the first outer end surface 11 of the battery element 10.

[0021] Since the inner diameter ratio [(φ2-φ1) / φ2] is 0.72% or less, the clearance between the inner diameter of the exterior body 20 and the outer surface of the battery element 10 does not differ significantly between the first inner diameter φ1 and the second inner diameter φ2. Furthermore, since the inner diameter ratio [(φ2-φ1) / φ2] is 0.24% or more, the clearance between the inner diameter of the exterior body 20 and the outer surface of the battery element 10 is sufficiently small. This makes it difficult for the battery element 10 to vibrate within the entire exterior body 20. Therefore, the battery 1 according to the first embodiment has improved vibration resistance.

[0022] Furthermore, the battery 1 according to the first embodiment can improve vibration resistance and reduce the defective rate in battery production, the reason for which is presumed to be as follows, in addition to the reasons mentioned above. Since the inner diameter of the exterior body 20 decreases along the insertion direction of the battery element 10 from the second inner diameter φ2 side to the first inner diameter φ1 side of the exterior body 20, the battery element 10 can be easily inserted smoothly into the exterior body 20 during the manufacture of the battery 1. This makes it possible to reduce the defective rate during the manufacture of the battery 1. Therefore, the battery 1 according to the first embodiment can achieve both "improved vibration resistance" and the opposing goal of "reducing the defective rate in battery manufacturing."

[0023] (Calculation method for the inner diameter ratio of battery elements) The method of calculating the inner diameter ratio of the battery element 10 is as follows. The (finished) battery 1 is disassembled. The first outer end surface 11 side of the battery element 10 of the battery 1 is opened, and the position of the second outer end surface 12 of the battery element 10 is marked on the inner surface of the exterior body 20. The exterior body 20 is removed. A probe of a three-dimensional measuring machine ("three-dimensional measuring machine" manufactured by Mitutoyo Corporation) is inserted into the inside of the removed exterior body 20. The inner diameter of a predetermined position (a position 4 mm away from the first inner end surface 21 toward the second outer end surface 12 side for the first inner diameter φ1, and a position 7 mm away from the second outer end surface 12 of the battery element 10 toward the first outer end surface 11 side for the first inner diameter φ2) is measured. The inner diameter ratio [(φ2-φ1) / φ2] is calculated from the obtained inner diameters (φ1 and φ2).

[0024] Such an inner diameter ratio of the exterior body 20 can be adjusted, for example, by processing in multiple stages (at least two stages) using punches with different diameters in deep drawing in the manufacturing method of the battery 1. An example will be described with reference to FIG. 5. FIG. 5 is a cross-sectional view showing a punch and an exterior body in deep drawing. As shown in the upper diagram of FIG. 5, a metal plate is deep drawn using a punch 31 with an outer diameter φ2. As a result, a space with an inner diameter φ2 is formed inside the exterior body 20. Next, as shown in the lower diagram of FIG. 4, the metal plate is further deep drawn using a punch 32 with an outer diameter φ1 (<φ2). As a result, an exterior body 20 having a predetermined inner diameter ratio [(φ2-φ1) / φ2] is produced therein.

[0025] The above has been explained in terms of the inner diameter ratio, but it can also be explained in terms of the inner diameter difference. In a preferred embodiment, the difference (φ2-φ1) between the first inner diameter φ1 and the second inner diameter φ2 is 0.05 to 0.15 mm. The difference (φ2-φ1) is calculated from the first inner diameter φ1 and the second inner diameter φ2 measured in the calculation method of the battery element 10. When the difference (φ2-φ1) is 0.05 mm or more, the clearance between the inner diameter of the exterior body 20 and the outer surface of the battery element 10 does not differ greatly between the first inner diameter φ1 and the second inner diameter φ2. In addition, since the difference (φ2-φ1) is 0.15 mm or less, the clearance between the inner diameter of the exterior body 20 and the outer surface of the battery element 10 is sufficiently small. As a result, the battery element 10 is less likely to vibrate within the entire exterior body 20.

[0026] In a preferred embodiment, in the range of the inner diameter ratio [(φ2-φ1) / φ2] of 0.24 to 0.72%, the outer casing 20 preferably has an inner diameter on the second outer end surface 12 side larger than that on the first outer end surface 11 side. The cross-sectional shape of the outer casing 20 has at least one shape selected from the group consisting of curved and straight shapes in at least a part of the cross-sectional shape in a cross-sectional view parallel to the battery axis, for example. A specific example of the cross-sectional shape is a trumpet shape having a curved shape. The inner diameter of the outer casing 20 may be partly constant with respect to the battery axis. For example, the inner diameter of the outer casing 20 may simply increase from the first outer end surface 11 of the battery element 10 to the first outer end surface 11 as shown in FIG. 3. Alternatively, the inner diameter of the outer casing 20 may simply increase in part from the first outer end surface 11 of the battery element 10 to the first outer end surface 11 as shown in the lower diagram of FIG. 5.

[0027] (Element fixing part) As shown in Fig. 2, the battery element (electrode assembly) 10 includes an electrode layer including a positive electrode 13, a negative electrode 14, and a separator 15. The battery element 10 further includes an element fixing part 17 on its outer circumferential surface. The element fixing part 17 fixes an end of the electrode layer having a wound structure. In this way, the element fixing part 17 prevents the electrode layer from loosening or coming undone.

[0028] The element fixing part 17 is located on the outer side surface of the battery element 10. The lower end of the element fixing part 17 is located in a region within 4 mm from the first inner end face 21 towards the second outer end face 12, and the upper end is located in a region within 7 mm from the second outer end face 12 towards the first outer end face 11. When viewed from a direction perpendicular to the battery axis, the element fixing part 17 is located at least at the end of the electrode configuration layer, and may or may not go around the outer periphery (side peripheral surface) of the battery element 10.

[0029] The element fixing part 17 can swell and function as a spacer in the presence of the electrolyte in the exterior body 20. That is, the element fixing part 17 fills the clearance between the outer surface of the battery element 10 and the inner surface of the exterior body 20. This increases the area of ​​contact with the inner surface of the exterior body 20. In addition, the element fixing part 17 can have viscosity due to swelling, and therefore the adhesion with the inner surface of the exterior body 20 increases. Therefore, the battery element 10 is further fixed in the exterior body 20, and vibration resistance can be further improved.

[0030] As the resin constituting the element fixing portion 17, for example, polyurethane resin is mentioned, from the viewpoint that swelling occurs easily due to the electrolyte and the viscosity is easily increased due to the swelling.

[0031] [Battery configuration] As described above, the battery 1 according to the first embodiment includes the battery element 10, the exterior body 20 that houses the battery element, and an electrolyte (not shown). Each of the components will be described below.

[0032] (Battery element) As shown in FIG. 2, the battery element (electrode assembly) 10 includes an electrode layer including a positive electrode 13, a negative electrode 14, and a separator 15. The electrode layer may have a wound structure wound into a roll (hereinafter, also referred to as a "wound electrode body" or a "wound structure"). The electrode assembly 10 has a configuration in which the positive electrode 13, the negative electrode 14, and the separator 15 disposed between the positive electrode 13 and the negative electrode 14 are wound together. In the secondary battery 1, such an electrode assembly 10 is enclosed in an exterior body 20 together with an electrolyte (e.g., a non-aqueous electrolyte).

[0033] -Positive and negative electrodes- The battery element 10 has current collectors (positive electrode current collector and negative electrode current collector), electrode material layers (positive electrode material layer and negative electrode material layer) laminated with the current collectors, and electrode current collectors. The positive electrode 13 is composed of at least a positive electrode material layer and a positive electrode current collector. In the positive electrode 13, the positive electrode material layer is provided on at least one side of the positive electrode current collector. The positive electrode material layer contains a positive electrode active material as an electrode active material. For example, each of the multiple positive electrodes 13 in the electrode assembly 10 may have a positive electrode material layer provided on both sides of the positive electrode current collector, or may have a positive electrode material layer provided only on one side of the positive electrode current collector.

[0034] The negative electrode 14 is composed of at least a negative electrode material layer and a negative electrode current collector. In the negative electrode 14, the negative electrode material layer is provided on at least one side of the negative electrode current collector. The negative electrode material layer contains a negative electrode active material as an electrode active material. For example, each of the multiple negative electrodes 14 in the electrode assembly 10 may have a negative electrode material layer provided on both sides of the negative electrode current collector, or may have a negative electrode material layer provided only on one side of the negative electrode current collector.

[0035] The electrode active materials contained in the positive electrode 13 and the negative electrode 14, that is, the positive electrode active material and the negative electrode active material, respectively, are materials directly involved in the transfer of electrons in the secondary battery, and are the main materials of the positive and negative electrodes that are responsible for charging and discharging, that is, the battery reaction. More specifically, ions are brought to the electrolyte due to the "positive electrode active material contained in the positive electrode material layer" and the "negative electrode active material contained in the negative electrode material layer", and such ions move between the positive electrode 13 and the negative electrode 14 to transfer electrons and charge and discharge. The positive electrode material layer and the negative electrode material layer may be layers that can absorb and release lithium ions in particular. In other words, the secondary battery 1 according to the first embodiment may be a non-aqueous electrolyte secondary battery in which lithium ions move between the positive electrode 13 and the negative electrode 14 via the non-aqueous electrolyte to charge and discharge the battery 1. When lithium ions are involved in charging and discharging, the secondary battery 1 according to the first embodiment corresponds to a so-called "lithium ion battery", and has layers that can absorb and release lithium ions as the positive electrode 13 and the negative electrode 14.

[0036] In view of the lithium ion battery, the positive electrode active material may be a material that contributes to the absorption and release of lithium ions. In other words, the positive electrode layer may contain any one or more of positive electrode materials that can absorb and release lithium. From this perspective, the positive electrode active material may be, for example, a lithium-containing compound. The type of lithium-containing compound is not particularly limited, but examples thereof include lithium-containing composite oxides and lithium-containing phosphate compounds. This is because high energy density is easily obtained.

[0037] The lithium-containing composite oxide is a general term for oxides containing lithium and one or more other elements (elements other than lithium) as constituent elements, and may have any of the crystal structures of layered rock salt type and spinel type. The lithium-containing phosphate compound is a general term for phosphate compounds containing lithium and one or more other elements as constituent elements, and may have any of the crystal structures of olivine type. The type of the other element is not particularly limited as long as it is one or more of any element. In particular, the other element is preferably one or more of elements belonging to groups 2 to 15 of the long period periodic table. More specifically, the other element is, for example, nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), etc. This is because a high voltage is easily obtained.

[0038] The lithium-containing composite oxide having a layered rock-salt type crystal structure may be, for example, a compound represented by each of the following formulas (1) to (3). Li a Mn (1-b-c) Ni b M11 c O (2-d) F e (1) (M11 is at least one of cobalt (Co), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), zirconium (Zr), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). a to e satisfy 0.8 ≤ a ≤ 1.2, 0 < b < 0.5, 0 ≤ c ≤ 0.5, (b + c) < 1, -0.1 ≤ d ≤ 0.2, and 0 ≤ e ≤ 0.1. However, the composition of lithium varies depending on the charge-discharge state, and a is the value in the fully discharged state.) Li a Ni (1-b) M12 b O (2-c) F d ···(2) (M12 is at least one of cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). a to d satisfy 0.8 ≤ a ≤ 1.2, 0.005 ≤ b ≤ 0.5, -0.1 ≤ c ≤ 0.2, and 0 ≤ d ≤ 0.1. However, the composition of lithium varies depending on the charge-discharge state, and a is the value in the fully discharged state.) Li a Co (1-b) M13 b O (2-c) F d ···(3) (M13 is at least one of nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). a to d satisfy 0.8≦a≦1.2, 0≦b<0.5, -0.1≦c≦0.2, and 0≦d≦0.1. However, the composition of lithium varies depending on the charge / discharge state, and a is the value in a fully discharged state.) Specific examples of lithium-containing composite oxides having a layered rock salt type crystal structure include LiNiO2, LiCoO2, and LiCoO 0.98 Al 0.01 Mg 0.01 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.33 Co 0.33 Mn 0.33 O2, Li 1.2 Mn 0.52 Co 0.175 Ni 0.1 O2 and Li 1.15 (M 0.65 Ni 0.22 Co 0.13 )O2, etc. When the lithium-containing composite oxide having a layered rock-salt crystal structure contains nickel, cobalt, manganese and aluminum as constituent elements, the atomic ratio of nickel is preferably 50 atomic % or more, because a high energy density is easily obtained.

[0039] The lithium-containing composite oxide having a spinel-type crystal structure may be, for example, a compound represented by the following formula (4). Li a Mn (2-b) M14 b O c F d (4) (M14 is at least one of cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). a to d satisfy 0.9≦a≦1.1, 0≦b≦0.6, 3.7≦c≦4.1, and 0≦d≦0.1. However, the composition of lithium varies depending on the charge / discharge state, and a is the value in a fully discharged state.) A specific example of the lithium-containing composite oxide having a spinel type crystal structure may be LiMn2O4.

[0040] The lithium-containing phosphate compound having an olivine type crystal structure is, for example, a compound represented by the following formula (5). Li a M15PO4···(5) (M15 is at least one of cobalt (Co), manganese (Mn), iron (Fe), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), niobium (Nb), copper (Cu), zinc (Zn), molybdenum (Mo), calcium (Ca), strontium (Sr), tungsten (W) and zirconium (Zr). a satisfies 0.9≦a≦1.1. However, the composition of lithium varies depending on the charge / discharge state, and a is the value in a fully discharged state.) Specific examples of lithium-containing phosphate compounds having an olivine crystal structure include LiFePO4, LiMnPO4, and LiFe 0.5 Mn 0.5 PO4 and LiFe 0.3 Mn 0.7 It may be PO4, etc.

[0041] The lithium-containing composite oxide may be a compound represented by the following formula (6). (Li2MnO3) x(LiMnO2) 1-x (6) (x satisfies 0≦x≦1. However, the lithium composition varies depending on the charge / discharge state, and x is the value in a fully discharged state.)

[0042] In addition, the positive electrode material may be, for example, one or more of oxides, disulfides, chalcogenides, conductive polymers, etc. The oxides may be, for example, titanium oxide, vanadium oxide, manganese dioxide, etc. The disulfides may be, for example, titanium disulfide, molybdenum sulfide, etc. The chalcogenides may be, for example, niobium selenide, etc. The conductive polymers may be, for example, sulfur, polyaniline, polythiophene, etc. However, the positive electrode material is not particularly limited and may be other materials than those mentioned above.

[0043] The positive electrode layer may contain a binder. In addition, the positive electrode layer may contain a positive electrode conductive agent to facilitate the transfer of electrons that promote the battery reaction. The binder of the positive electrode may contain, for example, one or more of synthetic rubber and polymer compounds. Examples of synthetic rubber include styrene butadiene rubber, fluorine-based rubber, and ethylene propylene diene. Examples of polymer compounds include polyvinylidene fluoride and polyimide. The positive electrode conductive agent may contain, for example, one or more of carbon materials. Examples of the carbon materials may include graphite, carbon black, acetylene black, and ketjen black. However, the positive electrode conductive agent may be a metal material, a conductive polymer, or the like, as long as it is a material that has conductivity.

[0044] Similarly, the negative electrode active material of the negative electrode layer may be a material that contributes to the absorption and desorption of lithium ions. That is, the negative electrode layer may contain any one or more types of negative electrode materials that can absorb and desorb lithium. From this perspective, the negative electrode active material may be, for example, various carbon materials, metal materials, and / or other materials.

[0045] When a carbon material is used as the negative electrode active material, the change in the crystal structure during lithium absorption and desorption is very small, so that a high energy density can be stably obtained. In addition, the carbon material also functions as a negative electrode conductive agent, so that the conductivity of the negative electrode layer can be easily improved.

[0046] Specific examples of carbon materials include graphitizable carbon, non-graphitizable carbon, and / or graphite. More specifically, the carbon material may be, for example, pyrolytic carbons, cokes, glassy carbon fiber, organic polymer compound sintered bodies, activated carbon, and carbon blacks. The cokes may include pitch coke, needle coke, and petroleum coke. The organic polymer compound sintered bodies are, for example, substances in which polymer compounds such as phenol resins and furan resins are sintered (carbonized) at an appropriate temperature. In addition, the carbon material may be low-crystalline carbon that has been heat-treated at a temperature of about 1000° C. or less, or may be amorphous carbon. The shape of the carbon material is not particularly limited, and may be at least one of fibrous, spherical, granular, and scaly shapes.

[0047] The "metal-based material" used as the negative electrode active material is a general term for a material containing one or more of metal elements and metalloid elements as constituent elements. When a carbon material is used as the negative electrode active material, a high energy density is easily obtained. The metal-based material may be a single substance, an alloy, a compound, or two or more of them, or may be a material containing at least one or more phases of them. However, the alloy may include a material containing one or more metal elements and one or more metalloid elements in addition to a material consisting of two or more metal elements. The alloy may also contain a nonmetallic element. The structure of this metal-based material may be, for example, a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or a coexistence of two or more of them. Such a metal element and metalloid element may be, for example, one or more of metal elements and metalloid elements that can form an alloy with lithium. Specifically, the metal element and the metalloid element may be, for example, magnesium (Mg), boron (B), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), bismuth (Bi), cadmium (Cd), silver (Ag), zinc, hafnium (Hf), zirconium, yttrium (Y), palladium (Pd) and / or platinum (Pt). In a preferred embodiment, the metal element is silicon and tin. This is because they have excellent lithium absorption and release capabilities and are easy to obtain higher energy density. The material containing silicon as a constituent element may be silicon alone, a silicon alloy, a silicon compound, or two or more selected from them, or may be a material that contains one or more of these phases at least in a part. Similarly, a material containing tin as a constituent element may be a simple substance of tin, a tin alloy, a tin compound, or two or more of these, or may be a material that contains at least one or more of these phases in part. The term "simple substance" as used herein refers to a simple substance in the general sense, and may contain a trace amount of impurities.That is, the purity of the single substance is not necessarily limited to 100%. The silicon alloy may contain, for example, any one or more of tin, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, and chromium as constituent elements other than silicon. The silicon compound may contain, for example, any one or more of carbon and oxygen as constituent elements other than silicon. Note that the silicon compound may contain any one or more of the series of elements described for the silicon alloy as constituent elements other than silicon. Specific examples of the silicon alloy and specific examples of the silicon compound include SiB4, SiB6, MgSi, Ni2Si, TiSi2, MoSi2, CoSi2, NiSi2, CaSi2, CrSi2, Cu5Si, FeSi2, MnSi2, NbSi2, TaSi2, VSi2, WSi2, ZnSi2, SiC, Si3N4, Si2N2O, SiO. v (0 < v ≤ 2), and / or LiSiO, etc. can be mentioned. Note that SiO v The v in it may be 0.2 < v < 1.4. The tin alloy may contain, for example, any one or more of silicon, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, and chromium as constituent elements other than tin. The tin compound may contain, for example, any one or more of carbon and oxygen as constituent elements other than tin. Note that the tin compound may contain any one or more of the series of elements described for the tin alloy as constituent elements other than tin. Specific examples of the tin alloy and specific examples of the tin compound include SnO w(0 < w ≤ 2), SnSiO3, LiSnO, and / or Mg2Sn, etc. can be mentioned. In particular, a material containing tin as a constituent element may be, for example, a material (tin-containing material) containing a second constituent element and a third constituent element together with tin which is the first constituent element. The second constituent element may be, for example, any one or more of cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium, zirconium, niobium, molybdenum, silver, indium, cesium (Ce), hafnium (Hf), tantalum, tungsten, bismuth, and silicon. The third constituent element may be, for example, any one or more of boron, carbon, aluminum, and phosphorus. This is because high battery capacity and excellent cycle characteristics, etc. are easily obtained. Among them, the tin-containing material may be a material (tin cobalt carbon-containing material) containing tin, cobalt, and carbon as constituent elements. This is because a high energy density is easily obtained. In the tin cobalt carbon-containing material, at least a part of the carbon which is a constituent element may be combined with a metal element or a metalloid element which is another constituent element. This is because aggregation of tin and crystallization of tin, etc. are easily suppressed. Such a tin cobalt carbon-containing material is not limited to a material (SnCoC) whose constituent elements are only tin, cobalt, and carbon. This tin cobalt carbon-containing material may contain, for example, in addition to tin, cobalt, and carbon, any one or more of silicon, iron, nickel, chromium, indium, niobium, germanium, titanium, molybdenum, aluminum, phosphorus, gallium, and bismuth as constituent elements. In addition to the tin cobalt carbon-containing material, a material (tin cobalt iron carbon-containing material) containing tin, cobalt, iron, and carbon as constituent elements may also be used.

[0048] In addition, the negative electrode material may be, for example, any one or more of metal oxides and polymer compounds. The metal oxide may be, for example, iron oxide, ruthenium oxide, and molybdenum oxide. The polymer compound may be, for example, polyacetylene, polyaniline, and polypyrrole.

[0049] The negative electrode material layer may contain a binder. Furthermore, the negative electrode material layer may contain a negative electrode conductive agent to facilitate the transfer of electrons that promote the battery reaction. The binder that may be contained in the negative electrode material layer is not particularly limited, but at least one selected from the group consisting of styrene butadiene rubber, polyacrylic acid, polyvinylidene fluoride, polyimide resins, and polyamideimide resins can be mentioned. The negative electrode conductive agent that may be contained in the negative electrode material layer is not particularly limited, but at least one selected from carbon black such as thermal black, furnace black, channel black, ketjen black, and acetylene black, carbon fibers such as graphite, carbon nanotubes, and vapor-grown carbon fibers, metal powders such as copper, nickel, aluminum, and silver, and polyphenylene derivatives can be mentioned. The negative electrode material layer may contain a component resulting from a thickener component (e.g., carboxymethyl cellulose) used during battery production.

[0050] The positive electrode current collector and the negative electrode current collector used in the positive electrode 13 and the negative electrode 14 are members that contribute to collecting and supplying electrons generated in the electrode active material due to the battery reaction. Such an electrode current collector may be a sheet-shaped metal member. The electrode current collector may be a single layer or a multilayer. Furthermore, the electrode current collector may have a porous or perforated form. For example, the current collector may be a metal foil, a punched metal, a net, an expanded metal, or the like. The positive electrode current collector used in the positive electrode 13 may be made of a metal foil containing at least one selected from the group consisting of aluminum, nickel, stainless steel, and the like. On the other hand, the negative electrode current collector used in the negative electrode 14 may be made of a metal foil containing at least one selected from the group consisting of copper, aluminum, nickel, stainless steel, and the like.

[0051] -Separator- The separator 15 used for the positive electrode 13 and the negative electrode 14 is a member provided from the viewpoint of preventing a short circuit caused by contact between the positive and negative electrodes, retaining an electrolyte, etc. In other words, the separator 15 is a member that separates the positive electrode 13 and the negative electrode 14, and allows ions (e.g., lithium ions) to pass through while preventing a short circuit of current caused by contact between the two electrodes. For example, the separator 15 may be a porous or microporous insulating member, and may have a membrane form due to its small thickness.

[0052] The separator 15 may be, for example, one or more of a porous film such as a synthetic resin and / or a ceramic, or may be a laminated film of two or more of porous films. Examples of synthetic resins used for the separator 15 include polytetrafluoroethylene, polypropylene, and polyethylene. For example, the separator may include a porous film (substrate layer) and a polymer compound layer provided on one or both sides of the substrate layer. Since the adhesion of the separator 15 to the positive electrode 13 can be improved and the adhesion of the separator 15 to the negative electrode 14 can be improved, the distortion of the wound electrode body can be easily suppressed. The polymer compound layer may include, for example, one or more of a polymer compound such as polyvinylidene fluoride. The polymer compound layer has excellent physical strength and is easily electrochemically stable. The polymer compound layer may include, for example, one or more of insulating particles such as inorganic particles. The type of inorganic particles may be, for example, aluminum oxide and / or aluminum nitride. In the first embodiment, the separator should not be limited to a particular name, and may be a solid electrolyte, a gel electrolyte, and / or insulating inorganic particles having a similar function.

[0053] -Electrolytes- Typically, the electrolyte is an electrolytic solution that includes a solvent and an electrolyte salt. The electrolytic solution may further include any one or more of other materials such as additives. In a preferred embodiment, the separator is impregnated with the electrolytic solution, and the positive electrode 13 and / or the negative electrode 14 may also be impregnated with the electrolytic solution.

[0054] The solvent may include any one or more of non-aqueous solvents such as organic solvents. An electrolyte solution including a non-aqueous solvent may be a so-called non-aqueous electrolyte solution. The non-aqueous solvent may be, for example, a cyclic carbonate ester, a chain carbonate ester, a lactone, a chain carboxylate ester, and / or a nitrile (e.g., mononitrile). This is because it is easy to obtain better battery capacity, cycle characteristics, and / or storage characteristics. The cyclic carbonate ester may be, for example, ethylene carbonate, propylene carbonate, and / or butylene carbonate. The chain carbonate ester may be, for example, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and / or methyl propyl carbonate. The lactone may be, for example, γ-butyrolactone and / or γ-valerolactone. The chain carboxylate ester may be, for example, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, and / or ethyl trimethyl acetate. The nitrile may be, for example, acetonitrile, methoxyacetonitrile, and / or 3-methoxypropionitrile. In addition, the non-aqueous solvent may be, for example, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, N,N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N,N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, and / or dimethyl sulfoxide. Among them, the non-aqueous solvent preferably contains one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. This is because it is easy to bring about a higher battery capacity, better cycle characteristics, and / or better storage characteristics. Furthermore, the non-aqueous solvent may be, for example, an unsaturated cyclic carbonate, a halogenated carbonate, a sulfonate, an acid anhydride, a dicyano compound (a dinitrile compound), a diisocyanate compound, a phosphate ester, and / or a chain compound having a carbon-carbon triple bond.This is because the chemical stability of the electrolyte solution is easily improved. The term "unsaturated cyclic carbonate" as used herein refers to a cyclic carbonate having one or more unsaturated bonds (carbon-carbon double bonds or carbon-carbon triple bonds). Examples of the unsaturated cyclic carbonate include vinylene carbonate, vinylethylene carbonate, and / or methyleneethylene carbonate. The term "halogenated carbonate" refers to a cyclic or chain-like carbonate containing one or more halogen elements as constituent elements. When the halogenated carbonate contains two or more halogens as constituent elements, the type of the two or more halogens may be only one type or may be two or more types. Examples of the cyclic halogenated carbonate include 4-fluoro-1,3-dioxolane-2-one and / or 4,5-difluoro-1,3-dioxolane-2-one. Examples of the chain-like halogenated carbonate include fluoromethyl methyl carbonate, bis(fluoromethyl) carbonate, and / or difluoromethyl methyl carbonate. The sulfonate ester may be, for example, a monosulfonate ester and / or a disulfonate ester. The monosulfonate ester may be, for example, a cyclic monosulfonate ester or a chain monosulfonate ester. The cyclic monosulfonate ester may be, for example, a sultone such as 1,3-propane sultone and / or 1,3-propene sultone. The chain monosulfonate ester is, for example, a compound in which a cyclic monosulfonate ester is cut in the middle. The disulfonate ester may be, for example, a cyclic disulfonate ester or a chain disulfonate ester. The acid anhydride may be, for example, a carboxylic acid anhydride, a disulfonic acid anhydride and / or a carboxylic acid sulfonic acid anhydride. The carboxylic acid anhydride may be, for example, succinic acid anhydride, glutaric acid anhydride and / or maleic acid anhydride. The disulfonic acid anhydride may be, for example, ethane disulfonic acid anhydride and / or propane disulfonic acid anhydride. The carboxylic acid sulfonic acid anhydride may be, for example, sulfobenzoic anhydride, sulfopropionic anhydride, and / or sulfobutyric anhydride, etc. The dinitrile compound may be, for example, NC-R1-CN (R1 is either an alkylene group or an arylene group).) is a compound represented by the formula: The dinitrile compound may be, for example, succinonitrile (NC-C2H4-CN), glutaronitrile (NC-C3H6-CN), adiponitrile (NC-C4H8-CN), phthalonitrile (NC-C6H4-CN), etc. The diisocyanate compound is, for example, a compound represented by the formula: OCN-R2-NCO (R2 is either an alkylene group or an arylene group). The diisocyanate compound is, for example, hexamethylene diisocyanate (OCN-C6H. 12 The phosphate ester may be, for example, trimethyl phosphate and triethyl phosphate. The chain compound having a carbon-carbon triple bond is a chain compound having one or more carbon-carbon triple bonds (-C≡C-). The chain compound having a carbon-carbon triple bond may be, for example, propargyl methyl carbonate (CH≡C-CH2-OC(=O)-O-CH3) and propargyl methylsulfonate (CH≡C-CH2-OS(=O)2-CH3).

[0055] The electrolyte salt contained in the electrolytic solution may include, for example, one or more of salts such as lithium salt. The electrolyte salt may include, for example, a salt other than lithium salt. Such salt other than lithium may be, for example, a salt of a light metal other than lithium. Examples of the lithium salt include lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium tetraphenylborate (LiB(C6H5)4), lithium methanesulfonate (LiCH3SO3), lithium trifluoromethanesulfonate (LiCF3SO3), lithium tetrachloroaluminate (LiAlCl4), dilithium hexafluorosilicate (Li2SiF6), lithium chloride (LiCl) and / or lithium bromide (LiBr). This is because it is easier to obtain better battery capacity, cycle characteristics and / or storage characteristics. Among these, any one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, and lithium hexafluoroarsenate may be used.

[0056] -Lead- The positive electrode lead 161 is connected to the end of the positive electrode 13 of the wound body, and the negative electrode lead 162 is connected to the end of the negative electrode 14 of the wound body, and the terminals are taken out to the outside of the battery element 10.

[0057] -Element fixing part- The element fixing portion 17 is located on a side surface of the battery element 10 and fixes an end of the electrode configuration layer having a wound structure, thereby preventing the electrode configuration layer from loosening or coming undone.

[0058] (Exterior body) The exterior body (battery can) 20 corresponds to a member that encases the electrode assembly 10 in which electrode constituent layers including the positive electrode 13, the negative electrode 14, and the separator 15 are laminated. The battery can 20 may have, for example, a hollow structure with one end closed and the other end (open end) open. The battery can 20 may be a metal can containing any one or two or more of metal materials such as iron, aluminum, stainless steel, and alloys thereof, without being particularly limited thereto. The surface of the battery can may be plated with any one or two or more of metal materials such as nickel.

[0059] [Battery manufacturing method] A method for manufacturing the battery 1 according to the present disclosure will be described as an example by taking the method for manufacturing the battery 1 as an example. The battery 1 according to the first embodiment can be manufactured, for example, by the following procedure.

[0060] In the preparation of the positive electrode 13, a positive electrode active material and, if necessary, a positive electrode binder and a positive electrode conductor are mixed to obtain a positive electrode mixture. Next, the positive electrode mixture is dispersed in an organic solvent or the like to obtain a paste-like positive electrode mixture slurry. Then, the positive electrode mixture slurry is applied to one or both sides of a positive electrode current collector, and the positive electrode mixture slurry is dried to form a positive electrode active material layer. Thereafter, if necessary, the positive electrode active material layer may be compression molded using a roll press or the like. In such a case, the positive electrode active material layer may be heated, or the compression molding may be repeated multiple times. In the same manner, the negative electrode 14 can be prepared. Specifically, a negative electrode active material is mixed with a negative electrode binder, a negative electrode conductor, and the like to obtain a negative electrode mixture, and then the negative electrode mixture is dispersed in an organic solvent or the like to obtain a paste-like negative electrode mixture slurry. Next, the negative electrode mixture slurry is applied to one or both sides of the negative electrode current collector, and then the negative electrode mixture slurry is dried to form a negative electrode active material layer. Thereafter, if necessary, the negative electrode active material layer is compression molded using a roll press or the like.

[0061] A metal plate is deep-drawn in multiple stages (at least two stages) to form exterior body 20. For example, as shown in the upper diagram of Fig. 5, punch 31 having an outer diameter φ2 and punch 32 having an outer diameter φ1 are used to perform deep-drawing in multiple stages, thereby forming spaces with second inner diameters φ1 and φ2 in exterior body 20.

[0062] When assembling the battery 1, the positive electrode lead is connected to the positive electrode current collector by welding or the like, and the negative electrode lead is connected to the negative electrode current collector by welding or the like. Next, the positive electrode 13 and the negative electrode 14 are laminated via the separator 15, and then the positive electrode 13, the negative electrode 14, and the separator 15 are wound to form a wound electrode body. Next, a center pin is inserted into the winding space of the wound electrode body. Then, while sandwiching the wound electrode body between a pair of insulating plates, the wound electrode body together with the pair of insulating plates is stored inside the exterior body. In this case, one end of the positive electrode lead is connected to an external terminal by welding or the like, and one end of the negative electrode lead is connected to the exterior body 20 by welding or the like. Next, an electrolyte is injected into the interior of the exterior body 20, and the electrolyte is impregnated into the wound electrode body. Finally, one end of the exterior body 20 is sealed. This completes the battery 1.

[0063] <Second embodiment: battery> The battery according to the second embodiment is different from the battery 1 according to the first embodiment in the manner of electrical connection with the battery element 10. In other words, the battery according to the second embodiment does not have leads (positive electrode lead and negative electrode lead), and the current collector is extended to take out the terminals from the battery element 10 at the current collector plate, which is different from the battery 1 according to the first embodiment. Hereinafter, this different configuration will be mainly described. In the second embodiment, the same reference numerals as those in the first embodiment have the same configuration as the first embodiment, and therefore, in principle, the description thereof will be omitted.

[0064] Hereinafter, the battery according to the second embodiment will be described with reference to Fig. 6, Fig. 7, and Fig. 8. Fig. 6 shows the battery according to the second embodiment. Fig. 7 shows a battery element in the battery according to the second embodiment. Fig. 8 shows the vicinity of an end of the battery element in the battery according to the second embodiment.

[0065] In the battery 1A according to the second embodiment, the battery element 10A further includes negative and positive current collectors 181, 182 as shown in Fig. 7. The negative and positive current collectors 181, 182 are electrically connected to the electrode configuration layers via current collectors. The negative and positive current collectors 181, 182 provide terminals to the outside of the battery element 10A.

[0066] 8, a plurality of positive current collectors 131 are extended and bundled together near the first outer end surface 11 of the battery element 10A. The connection between the negative current collector 181 and the negative current collector 141 is similar to the connection between the positive current collector 182 and the positive current collector 131.

[0067] The extending portion 132 of the positive current collector 131 forms a high density region 133 where the extending portions 132 are present at a high density. The current collectors (positive current collector 182 and negative current collector 181) are connected to the high density region 133 in a planar manner. That is, the extending portions 132 are bundled and electrically connected to the positive current collector 182. In the second embodiment, the positive current collector 182 forms the second outer end surface 12. In the battery 1 according to the first embodiment, the lead has a linear structure and is linearly connected to the current collector at the end of the winding structure. Therefore, in the battery 1A, the contact area is larger than that in the battery 1 according to the first embodiment, and the connection resistance can be reduced.

[0068] Furthermore, since the wound body does not have leads, it has a structure closer to a perfect circle when viewed from a direction perpendicular to the battery axis. This makes it easier to make the clearance between the inner surface of the exterior body 20 and the outer circumferential surface of the battery element 10 more uniform, which makes it easier for the battery element 10 to be fixed inside the exterior body 20 and improves vibration resistance. In addition, because the wound body has a structure closer to a perfect circle, the battery element 10 can be housed in the exterior body 20 more smoothly in the manufacture of the battery 1A, and the defective rate in the battery manufacture is further reduced.

[0069] <Third embodiment: battery> The battery according to the third embodiment differs from the battery 1 according to the first embodiment in the arrangement of the element fixing part 17. This different configuration will be mainly described below. In the third embodiment, the same reference numerals as those in the first and second embodiments indicate the same configuration as those in the first and second embodiments, and therefore the description thereof will be omitted in principle.

[0070] The battery according to the third embodiment will be described below with reference to Fig. 9. Fig. 9 shows a battery element in the battery according to the third embodiment.

[0071] In the battery element 10B of the battery 1B according to the third embodiment, the element fixing part 17B is not disposed at a position 4 mm away from the first inner end face 21 toward the second outer end face 12 as shown in FIG. 9. That is, the lower end of the element fixing part 17B is located 4 mm away from the first inner end face toward the second outer end face in the forward Z direction. Since the element fixing part 17B is not disposed at a position 4 mm away from the first inner end face 21 toward the second outer end face 12, the position 4 mm away from the first inner end face 21 toward the second outer end face 12 may be the narrowest region in the inner diameter of the exterior body 20. By not locating the element fixing part 17B in this region, the battery element 10 can be more smoothly accommodated in the exterior body 20 in the manufacture of the battery 1B while maintaining the vibration resistance of the battery element 10 in the exterior body 20, and the battery element 10 can be more smoothly accommodated in the exterior body 20 in the manufacture of the battery 1A, thereby further reducing the defective rate.

[0072] <Other embodiments> Although the embodiments of the present disclosure have been described above, the above-mentioned embodiments are merely exemplary examples. The present disclosure is not limited to the above-mentioned embodiments, and design changes are possible without departing from the gist of the present disclosure. In addition, the configurations in the first, second, and third embodiments may be combined in various ways.

[0073] For example, in the second embodiment, both the positive electrode 13 and the negative electrode 14 of the battery element 10 are taken out to the outside of the battery element 10 by the extension of the current collector, but this is not limited thereto. Only one of the positive electrode and the negative electrode may be taken out by the extension of the current collector. In this case, the electrode that does not have the extension of the current collector may have a lead.

[0074] The aspects of the battery according to the present disclosure are as follows. <1> A battery comprising: a battery element having a first outer end surface and a second outer end surface; and a cylindrical exterior body that houses the battery element and has a first inner end surface that faces the first outer end surface, A battery in which the first inner diameter φ1 of the outer casing at a position 4 mm away from the first inner end face toward the second outer end face is 0.24 to 0.72% smaller than the second inner diameter φ2 of the outer casing at a position 7 mm away from the second outer end face of the battery element toward the first outer end face. <2> The difference (φ2-φ1) between the first inner diameter φ1 and the second inner diameter φ2 is 0.05 to 0.15 mm. <1> 2. The battery according to claim 1 . <3> The battery element further has an element fixing portion on its outer circumferential surface, the element fixing portion is not disposed at a position 4 mm away from the first inner end face toward the second outer end face, <1> or <2> 2. The battery according to claim 1 . <4> the battery element includes a current collector having an extension portion, an electrode member layer laminated with the current collector, and an electrode current collector plate constituting the first outer end surface and the second outer end surface, The extension portions are bundled together to be electrically connected to the electrode current collector plate. <1> ~ <3> 2. A battery according to claim 1 . <5> The cross section of the exterior body has at least one shape selected from the group consisting of a curved shape and a linear shape in at least a part of the cross section parallel to the battery axis. <1> ~ <4> 2. A battery according to claim 1 . EXAMPLES

[0075] The present invention will be described in more detail below using examples, but the present disclosure is not limited to the following examples.

[0076] <Example 1> [1. Preparation of test battery] A secondary battery having the following specifications was prepared. The configuration of Example 1 is summarized in Table 1. Shape: Cylinder (diameter: approx. 22 cm, axial length: approx. 70 mm) Positive and negative electrodes of the electrode assembly: Positive and negative electrodes capable of absorbing and releasing lithium ions The electrode assembly has leads (positive and negative leads) disposed therein, The embodiment in which the electrode assembly includes a lead is indicated as "internal current collection specification" in the "tab structure specification" column of Table 1. The electrode assembly had a wound structure in which multiple sheets were wound, and the ends of the wound structure were fixed with an element fixing tape (element fixing portion). The element fixing tape was positioned so as not to be located 4 mm from the can bottom (bottom of the exterior body: first inner end face) toward the first end face. This embodiment is indicated as "none" in the "Element fixing tape" column in Table 1. ·Nominal capacity: approx. 4100mAh Nominal voltage: 3.6V Inner diameter of exterior body: The inner diameter is constant within 4 mm from the first inner end face Inner diameter increases from 4mm to 10mm along the cell axis The inner diameter remains constant within a range of 10 mm or more from the first inner end face Contact between the inner circumferential surface of the exterior body and the outer circumferential surface of the battery element: Contact at least at a point 4 mm from the first inner end surface (Materials of each component) Exterior: Metal (metal containing aluminum)

[0077] [Table 1]

[0078] 2. Evaluation method (2-1. Vibration Test) Vibration tests were conducted in accordance with the UN38.3 standard at room temperature and pressure (23±2°C, 1 atm). The battery of Example 1, which is 10% thinner than the element system specification of the battery element, was fully discharged. Specifically, it was discharged to a constant voltage of 2.5 V at a temperature of 23±2° C. and a constant current of 4.0 A. Using a battery tester (HIOKI Battery Tester 3561, AC voltmeter), the electrical resistance (AC resistance) of the battery after discharge was measured (measurement number n=1000). In detail, a constant AC current with a frequency of 1 kHz was applied and the voltage value was measured. The internal resistance value of the battery was calculated from the obtained voltage value. The average of the multiple internal resistance values ​​was calculated, and the obtained average value was defined as the "electrical resistance value before vibration application."

[0079] A sweep-type vibration was applied to the battery after discharge. Specifically, the frequency was swept from 7 Hz (minimum) to 200 Hz (maximum) to 7 Hz (minimum) over a period of 15 minutes. This frequency change constitutes one cycle, and was performed 12 times in each of the three directions of the XYZ axes (XYZ axes shown in Figure 1). The amplitude was 0.8 (mm). The electrical resistance value of the battery after vibration application was measured (measurement number n = 1000). The average value of the multiple electrical resistance values ​​was calculated, and the obtained average value was defined as the "electrical resistance value after vibration application."

[0080] From the electrical resistance values ​​obtained before and after the vibration application (1): Rate of increase in electrical resistance (%) = [(electrical resistance value after application of vibration - electrical resistance value before application of vibration) / electrical resistance value before application of vibration] × 100 (1) The rate of increase in electrical resistance due to vibration application was calculated using the formula: The vibration resistance of the battery of Example 1 was evaluated according to the rate of increase in electrical resistance, using the following evaluation criteria. The evaluation results of vibration resistance are summarized in Table 1. [Evaluation Criteria] A (Pass: Good): The increase in electrical resistance is less than 10%. B (Fail: Poor): The increase in electrical resistance is 10% or more.

[0081] (2-2. Reducing assembly defects) In the manufacture of the battery of Example 1, the battery element was housed in a cylindrical exterior body with an opening on the first end face side, with the first outer end face facing vertically downward, and the state of the battery element being housed was observed by image. Then, it was determined whether the second end face of the battery element protruded from the first open end of the exterior body. The number of protruding parts was counted out of the measurement number n=100,000. (2): Assembly defect rate (ppm) = (number of protruding parts / number of measurements n) x 10 6 The assembly defect rate (element insertion defect rate) was calculated using the formula expressed as follows. Based on the assembly defect rate, the reduction in assembly defects of the battery of Example 1 was evaluated using the following evaluation results. The evaluation results for the reduction in assembly problems are summarized in Table 1. [Evaluation Criteria] A (pass: good): Assembly defect rate is less than 2500 ppm B (Failed: Poor): Assembly defect rate is 2500ppm or more.

[0082] <Examples 2 to 5 and Comparative Examples 1 to 2> [1. Preparation of test battery] Test batteries were produced in the same manner as in Example 1, except that the battery configuration was changed to the configuration shown in Table 1. Specifically, in Examples 2 to 5 and Comparative Examples 1 and 2, the inner diameter ratio was changed.

[0083] In Example 4 and Comparative Example 1, the element fastening tape (battery element fixing portion) on the outer surface of the battery element was arranged at a position 4 mm away from the can bottom (first inner end face of the exterior body) toward the second outer end face. This embodiment is indicated as "present" in the "Element Fastening Tape" column in Table 1.

[0084] Moreover, in Example 5, a collector specification without a lead in the electrode assembly was adopted. In this collector specification, the extensions of the collectors of both the positive and negative electrodes were bundled to form a high-density region and were electrically connected to the collector plate.

[0085] [2. Evaluation] For the batteries of Examples 2 to 5 and Comparative Examples 1 and 2, a vibration test and an assembly defect rate were carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0086] <Results: Examples 1 to 5 and Comparative Examples 1 to 2> In the batteries of Examples 1 to 5, the second inner diameter of the exterior body was smaller than the first inner diameter by 0.24 to 0.72%, as shown in Table 1. Furthermore, the results of the vibration test for the batteries of Examples 1 to 5 were all A (pass). On the other hand, in the batteries of Comparative Examples 1 and 2, the second inner diameter of the exterior body was less than 0.24 or greater than the first inner diameter by more than 0.72%, as shown in Table 1. Moreover, the results of the vibration test of the batteries of Comparative Examples 1 and 2 were all B (fail).

[0087] From the above, it is clear that the batteries of Examples 1 to 5, which are included in the scope of the invention defined in claim 1, have improved vibration resistance compared to Comparative Examples 1 and 2, which are outside the scope of the invention defined in claim 1.

[0088] Note that the effects of the above embodiment are merely exemplary, and the present disclosure is not limited to the above, and may have additional effects. [Industrial Applicability]

[0089] The batteries (primary batteries, secondary batteries, etc.) according to the present disclosure can be used in applications that typically require the use of electrical energy. For example, the (secondary) batteries according to the present disclosure can be used in various fields where power storage is expected. By way of example only, the (secondary) battery of the present disclosure can be used in the electrical, information, and communication fields in which electrical and electronic devices are used (for example, electrical and electronic devices fields or mobile device fields including mobile phones, smartphones, notebook computers, digital cameras, activity meters, arm computers, electronic paper, wearable devices, and small electronic devices such as RFID tags, card-type electronic money, and smart watches), household and small industrial applications (for example, power tools, golf carts, household, nursing care, and industrial robots), large industrial applications (for example, forklifts, elevators, and port cranes), transportation systems (for example, hybrid cars, electric cars, buses, trains, electrically assisted bicycles, and electric motorcycles), power system applications (for example, various types of power generation, road conditioners, smart grids, and general household installation-type power storage systems), medical applications (medical devices such as earphone hearing aids), pharmaceutical applications (medical management systems), as well as the IoT field, and space and deep sea applications (for example, space probes, submersible research vessels, and the like). [Explanation of symbols]

[0090] 1,1A battery 10, 10A, 10B Battery element 11 First outer end surface 12 Second outer end surface 13 Positive electrode 131 Positive electrode current collector 132 (Positive electrode current collector) extension 14 Negative electrode 141 Negative electrode current collector 17 Element fixing part 181 Negative current collector 182 Positive current collector 20 Exterior body 21 First inner end surface φ1 1st inner diameter φ2 Second inner diameter

Claims

1. A battery comprising: a battery element having a first outer end surface and a second outer end surface; and a cylindrical exterior body that houses the battery element and has a first inner end surface that faces the first outer end surface, A first inner diameter φ of the exterior body at a position 4 mm away from the first inner end surface toward the second outer end surface. １ is the second inner diameter φ of the exterior body at a position 7 mm away from the second outer end surface of the battery element toward the first outer end surface. ２ The battery is 0.24 to 0.72% smaller than the previous model.

2. Said first inner diameter φ １ and the second inner diameter φ ２ Difference from (φ ２ -φ １ 2. The battery of claim 1, wherein the thickness of the first electrode is 0.05 to 0.15 mm.

3. The battery element further has an element fixing portion on its outer circumferential surface, The battery according to claim 1 , wherein the element fixing portion is not disposed at a position 4 mm away from the first inner end face towards the second outer end face.

4. the battery element includes a current collector having an extension portion, an electrode member layer laminated with the current collector, and an electrode current collector plate constituting the first outer end surface and the second outer end surface, The battery according to claim 1 , wherein the extensions are bundled together and electrically connected to the electrode current collector plate.

5. 3. The battery according to claim 1, wherein a cross section of the exterior body has at least one shape selected from the group consisting of a curved shape and a straight shape in at least a part thereof when viewed in a cross section parallel to a battery axis.

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