Non-aqueous electrolyte batteries

Abstract

To provide a nonaqueous electrolyte battery with high safety, in which the deficiency of an electrolyte in a separator can be suppressed.SOLUTION: An electrode body housed in a cylindrical battery can in a state of being wound in a spiral shape includes sheet shaped positive electrode and negative electrode 5, and separator stacks 6 and 7 having one electrode (in an example in Fig. 2, negative electrode 5) of the positive electrode and negative electrode 5 therebetween. The separator stacks 6 and 7 include two or more (in the example in Fig. 2, two) separators 6a, 6b, 7a, and 7b that are welded to each other in welded regions 6c and 7c provided along a first side in a longitudinal direction and welded regions 6d and 7d provided along a second side in the longitudinal direction facing the first side, and are welded to each other in a welded region 20a provided along the first side and a welded region 20b provided along the second side in the longitudinal direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a non-aqueous electrolyte battery.

Background Art

[0002] As a non-aqueous electrolyte battery, there is one having an electrode body in which a sheet-shaped positive electrode and a sheet-shaped negative electrode are wound via a sheet-shaped separator. Since such a non-aqueous electrolyte battery easily increases the facing area between the positive electrode and the negative electrode, it is suitable for applications using a large current. However, when discharging at a large current, the electrolyte (non-aqueous electrolyte) in the separator may be insufficient, and there may be cases where a sufficient current cannot flow.

[0003] Conventionally, a battery including a separator in which a non-woven fabric capable of holding more electrolyte is overlapped with a microporous film has been proposed (see, for example, Patent Documents 1-5).

[0004] On the other hand, in a non-aqueous electrolyte battery, when the separator cannot keep the positive electrode and the negative electrode separated due to an impact, vibration, abnormal heating, etc. on the battery, a short circuit may occur, leading to heat generation and rupture. For example, a microporous film made of polyethylene (PE) or polypropylene (PP) used as a separator for a lithium (Li) ion secondary battery or a lithium primary battery may shrink easily and significantly by heating, which may cause a short circuit, or a short circuit may occur due to a displacement caused by an impact or vibration.

[0005] Conventionally, in order to prevent a short circuit and improve the liquid absorption property of the electrolyte, a wound battery has been proposed in which both ends of the separators existing on the front and back of either the positive electrode or the negative electrode plate are heat-sealed in a zigzag pattern at a certain interval while winding (see, for example, Patent Document 6).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Conventional non-aqueous electrolyte batteries have room for improvement in terms of safety and electrolyte deficiency within the separator. In one aspect, the present invention aims to provide a non-aqueous electrolyte battery that is highly safe and can suppress the occurrence of electrolyte shortage in the separator. [Means for solving the problem]

[0008] In one embodiment, a non-aqueous electrolyte battery is provided, comprising an electrode body housed in a cylindrical battery case in a spiral winding manner, wherein the electrode body is a laminate having a sheet-like positive electrode and a negative electrode, and two or more separators welded to each other at a first welding region provided along a first longitudinal side and a second welding region provided along a second longitudinal side opposite to the first side, wherein the laminate comprises a first separator laminate and a second separator laminate welded to each other at a third welding region provided along the first longitudinal side and a fourth welding region provided along the second longitudinal side, sandwiching one of the positive or negative electrodes. [Effects of the Invention]

[0009] In one respect, the present invention can provide a non-aqueous electrolyte battery that is highly safe and can suppress the occurrence of electrolyte shortage in the separator. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing an example of a cylindrical non-aqueous electrolyte battery according to this embodiment. [Figure 2] This is a perspective view illustrating an example of a separator laminate. [Figure 3] This figure shows the case where the welding region where two separators of a separator laminate are welded together and the welding region where the two separator laminates are welded together overlap in the short direction. [Figure 4] This figure shows the evaluation results of the difference in characteristics depending on whether or not there is overlap between two types of welded areas. [Figure 5] This figure shows the results of verifying the difference in characteristics based on the number of separators and whether or not welding is performed. [Figure 6] This figure shows examples where the longitudinal length of two types of welded areas is varied. [Figure 7] This figure shows the liquid absorption rate, discharge capacity, and free-fall test results when the longitudinal length of two types of welding regions is varied. [Figure 8] This figure shows an example of the use of a non-welded area. [Figure 9] This is a diagram showing a modified example. [Modes for carrying out the invention]

[0011] The embodiments for carrying out the invention will be described below with reference to the drawings. Figure 1 is a cross-sectional view showing an example of a cylindrical non-aqueous electrolyte battery according to this embodiment. The non-aqueous electrolyte battery 1 is, for example, a lithium primary battery in which lithium metal or lithium alloy is used as the negative electrode active material and manganese dioxide or copper oxide is used as the positive electrode active material. Alternatively, the non-aqueous electrolyte battery 1 may also be a lithium secondary battery in which graphite or silicon is used as the negative electrode active material and lithium cobalt oxide (LiCoO2) is used as the positive electrode active material.

[0012] The non-aqueous electrolyte battery 1 includes an electrode body 10 housed together with a non-aqueous electrolyte 3 in a bottomed cylindrical battery can 2 in a state of being wound in a spiral shape. The electrode body 10 is wound around the cylindrical axis 2a of the battery can 2 as a winding axis.

[0013] The electrode body 10 has sheet-shaped positive electrode 4 and negative electrode 5, and separator laminates 6, 7 that sandwich one of the electrodes of the positive electrode 4 and the negative electrode 5 (negative electrode 5 in the example of FIG. 1) and are welded to each other at welding regions provided along two sides in the longitudinal direction as described later.

[0014] The non-aqueous electrolyte 3 is obtained by adding an additive to a non-aqueous solvent. As the non-aqueous solvent, for example, a mixture of propylene carbonate (PC), ethylene carbonate (EC), and 1,2-dimethoxyethane (DME) at a weight ratio of PC:EC:DME = 10:10:80 can be used. As the additive, for example, supporting salts such as lithium trifluoromethanesulfonate (LiCF3SO3), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), and lithium perchlorate (LiClO4) can be used.

[0015] The positive electrode 4 is, for example, obtained by rolling a positive electrode mixture (for example, a mixture of a positive electrode active material, a conductive material, and a binder) onto a core body, cutting it into a predetermined size, and then drying it to form a sheet shape. As the core body, for example, a lath plate, a plain woven wire mesh, an expanded metal, a metal foil, etc. can be used. As the material of the core body, it is desirable that it has corrosion resistance against the positive electrode potential. Examples of such materials include SUS316 and SUS444, but it is not limited thereto.

[0016] The negative electrode 5 is formed by shaping lithium metal or a lithium alloy into a sheet shape. As the lithium alloy, for example, a lithium-aluminum (Al) alloy, a lithium-magnesium (Mg) alloy, a lithium-tin (Sn) alloy, a lithium-zinc (Zn) alloy, a lithium-antimony (Sb) alloy, a lithium-silicon (Si) alloy, etc. can be used.

[0017] Furthermore, a metal that alloys with lithium may be placed on the surface of the negative electrode 5 to form an alloyed layer. For example, aluminum foil may be placed on the surface of the negative electrode 5 to alloy with lithium. The metal placed on the surface of the negative electrode 5 is not particularly limited as long as it is an element that can be alloyed; for example, magnesium, tin, zinc, silicon, etc., can be used. Moreover, the material placed on the surface of the negative electrode 5 is not limited to metal foil, but may also be a plate, powder, or a processed version thereof.

[0018] Examples of separator laminates 6 and 7 will be described later (see Figure 2). The non-aqueous electrolyte battery 1 further includes a sealing plate 11, a negative electrode terminal 12, a metal washer 13, a resin gasket 14, a positive electrode tab 15, and a negative electrode tab 16.

[0019] The sealing plate 11 has a disc-shaped portion with an opening in the center, and the edge of the disc-shaped portion is bent upward. The negative terminal 12 and the washer 13 are crimped together via a gasket 14. The edge of the sealing plate 11 and the upper edge of the battery can 2 are welded together by laser welding or the like. This seals the opening of the battery can 2 and seals the inside of the battery can 2.

[0020] The negative electrode 5 and the lower surface of the negative electrode terminal 12 are electrically connected via the negative electrode tab 16. Additionally, the positive electrode 4 and the inner surface of the battery can 2 are electrically connected via the positive electrode tab 15. Figure 2 is a perspective view illustrating an example of a separator laminate. Figure 2 shows a portion of the longitudinal direction of the separator laminates 6 and 7 before winding.

[0021] In the example shown in Figure 2, the separator laminate 6 is a laminate having two separators 6a and 6b, and the separator laminate 7 is also a laminate having two separators 7a and 7b. Note that the separator laminates 6 and 7 may each have three or more separators.

[0022] Separators 6a and 6b are welded to each other by a welding region 6c provided along a first longitudinal edge and a welding region 6d provided along a second edge opposite the first edge. Similarly, separators 7a and 7b are welded to each other by a welding region 7c provided along a first longitudinal edge and a welding region 7d provided along a second edge opposite the first edge.

[0023] Furthermore, the separator laminates 6 and 7 are welded to each other by a welding region 20a provided along the first edge in the longitudinal direction, with the negative electrode 5 in between, and a welding region 20b provided along the second edge opposite the first edge.

[0024] The welding regions 6c, 6d, 7c, 7d, 20a, and 20b are all located in areas that do not face the upper (and lower) surface of the negative electrode 5. For example, separators 6a and 7a are microporous films made of polyolefin, and separators 6b and 7b are nonwoven fabrics (for example, sheet-like resin nonwoven fabrics (such as polypropylene nonwoven fabrics)) with a melting point higher than that of separators 6a and 7a. Examples of resin nonwoven fabrics include polyethylene, polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and cellulose. Microporous films are preferably capable of shutting down at lower temperatures.

[0025] Welding in welding regions 6c, 6d, 7c, and 7d is performed in advance, and then welding in welding regions 20a and 20b is performed with the negative electrode 5 sandwiched between separator laminates 6 and 7.

[0026] Ultrasonic welding is preferred as the welding method, but other methods such as heat welding can also be used. Note that welding is not required in the short direction of the separator laminates 6 and 7 compared to the long direction, as separator displacement is less likely to occur in that direction. However, for applications requiring greater safety, welding may be performed in the short direction of the separator laminates 6 and 7.

[0027] Furthermore, the welded regions 20a and 20b do not necessarily have to be provided along the entire length of the separator laminates 6 and 7. Non-welded regions for removing the negative electrode tab 16 and reducing winding wrinkles may be provided as shown in Figure 1 (see Figure 8). As will be described later, providing non-welded regions at appropriate intervals can be expected to reduce winding wrinkles and improve the liquid absorption (liquid absorption rate) of the non-aqueous electrolyte 3. The welded regions 6c, 6d, 7c, and 7d also do not necessarily have to be provided along the entire length of the separator laminates 6 and 7 (see Figure 9).

[0028] As described above, in the non-aqueous electrolyte battery 1 of this embodiment, since there are two or more separators interposed between the positive electrode 4 and the negative electrode 5 (two in the example of Figure 2), the space in which the non-aqueous electrolyte 3 is held is larger than the space in the case where there is only one separator. For example, the non-aqueous electrolyte 3 is held in the space between separators 6a and 6b and in the space between separators 7a and 7b. This suppresses the occurrence of electrolyte shortage in the separators and maintains the high current characteristics of the non-aqueous electrolyte battery 1.

[0029] Furthermore, in the non-aqueous electrolyte battery 1, the negative electrode 5 is sandwiched between a separator stack 6 made of separators 6a and 6b fixed in welding regions 6c and 6d, and a separator stack 7 made of separators 7a and 7b fixed in welding regions 7c and 7d, and the separator stacks 6 and 7 are welded together in welding regions 20a and 20b. This suppresses the shrinkage of separators 6a, 6b, 7a, and 7b due to a rapid rise in temperature, and prevents short circuits caused by displacement due to shock or vibration, thereby enhancing safety.

[0030] Furthermore, because the separator laminates 6 and 7 have separators 6b and 7b, which are nonwoven fabrics with a higher melting point than separators 6a and 7a, which are microporous films, shrinkage of the separator laminates 6 and 7 due to temperature rise is suppressed, and the shape of the separator laminates 6 and 7 can be maintained.

[0031] Furthermore, since separators 6a and 7a, which are microporous films with a lower melting point than separators 6b and 7b, are positioned in contact with the negative electrode 5, the melting of the microporous films facilitates thermal fusion of the separator laminates 6 and 7, thereby improving productivity.

[0032] Furthermore, since the welding regions 6c, 7c and welding region 20a, and the welding regions 6d, 7d and welding region 20b are located at different positions in the short direction, welding can be easily performed, and defects such as holes in the separator laminates 6, 7 during welding can be suppressed.

[0033] (Evaluation results of battery characteristics) The following shows the evaluation results of the battery characteristics of the non-aqueous electrolyte battery 1 when various types of separators 6a, 6b, 7a, and 7b, as well as the positions and shapes of the welding regions 6c, 7c, 20a, and 20b are changed.

[0034] The non-aqueous electrolyte battery 1 used in the evaluation is a cylindrical lithium primary battery with a diameter of 17 mm and a height of 33.5 mm. The positive electrode 4 is made by rolling a positive electrode mixture, which is a mixture of electrolytic manganese dioxide (EMD), a conductive material (carbon (C)), and a fluorine-based binder in a mass ratio of 90:5:5, onto a lath core, cutting it to a predetermined size, and then drying it to form a sheet. The negative electrode 5 is a lithium aluminum alloy. The non-aqueous electrolyte 3 is made by mixing propylene carbonate, ethylene carbonate, and 1,2-dimethoxyethane in a weight ratio of PC:EC:DME = 10:10:80, to which 0.5 M lithium trifluoromethanesulfonate support salt is added as a support salt.

[0035] Welding in welding regions 6c, 7c, 20a, and 20b was performed by ultrasonic welding. The battery characteristics evaluated were the discharge capacity, the number of free falls required for the non-aqueous electrolyte battery 1 to experience a voltage drop during the free-fall test, and the absorption rate by the welded regions 20a and 20b as the non-aqueous electrolyte permeates through the welded regions 20a and 20b.

[0036] A 560Ω resistor was used as the load to verify the discharge capacity. The free-fall test was performed under the same conditions as the Z-axis direction in Test J as specified in IEC (International Electrotechnical Commission) 60086. The liquid absorption rate was evaluated using the JIS L 1907 / Baileck method.

[0037] Figure 3 shows a case where the welding region where two separators of a separator laminate are welded together and the welding region where the two separator laminates are welded together overlap in the short direction. Figure 3 shows an example where welding regions 6c, 7c and welding region 20a overlap in the short direction. Note that welding regions 6d, 7d, and 20b are not shown in Figure 3.

[0038] Figure 4 shows the evaluation results of the difference in characteristics depending on whether or not the two types of welded regions overlap. In Figure 4, Comparative Example 1 is the case where the two types of welded regions—the welded region where the two separators of the separator laminate are welded together (welded regions 6c and 7c in the example of Figure 3) and the welded region where the two separator laminates are welded together (welded region 20a in the example of Figure 3)—overlap in the short direction (they are in the same position). Example 1 is the case where the two types of welded regions described above do not overlap in the short direction (they are in different positions) (as shown in Figure 2).

[0039] In Comparative Example 1, tears and holes were observed in the separator laminates 6 and 7 during welding in welding regions 20a and 20b. Also in Comparative Example 1, the number of free-fall cycles until a voltage drop occurred in the non-aqueous electrolyte battery 1 was 500. In Comparative Example 1, it is thought that the overlapping of the two types of welding regions made the shape of each welding region unstable, and the displacement of separators 6a, 6b, 7a, and 7b during free-fall caused an internal short circuit, making a voltage drop more likely.

[0040] On the other hand, in Example 1, no tears or holes were observed in the separator laminates 6 and 7 during welding in welding regions 20a and 20b. Also, in Example 1, the number of free-fall cycles until a voltage drop occurred in the non-aqueous electrolyte battery 1 during the free-fall test was 2900. In Example 1, by positioning the welding regions 6c and 7c and welding region 20a, and welding regions 6d and 7d and welding region 20b at different positions in the short-side direction, welding was made easier, which is thought to reduce the likelihood of defects such as holes. Therefore, it can be seen that internal short circuits are less likely to occur in Example 1, and a high level of safety is achieved.

[0041] Figure 5 shows the results of confirming the difference in properties depending on the number of separators and whether or not they are welded. In Figure 5, Comparative Example 2 uses separators 6a and 7a, which are microporous polyethylene films with a thickness of 15 μm and a melting point of 120°C, and does not use separators 6b and 7b. Comparative Example 3 uses the same separators 6a and 7a as in Comparative Example 2, but uses separators 6b and 7b, which are polypropylene nonwoven fabrics with a thickness of 35 μm and a melting point of 165°C, but separates 6a, 6b and separators 7a and 7b are not bonded together by welding. Example 1 uses the same separators 6a and 7a as in Comparative Examples 2 and 3, and the same separators 6b and 7b as in Comparative Example 3, but separates 6a, 6b and separators 7a and 7b are bonded together by welding (as shown in Figure 2).

[0042] The discharge capacity was 1550 mAh in Comparative Example 2, which did not use separators 6b and 7b, while it increased to 1700 mAh in Comparative Example 3 and Example 1, which used separators 6b and 7b as well as separators 6a and 7a. This is thought to be due to the effect of the non-aqueous electrolyte 3 being retained in the spaces between separators 6a and 6b, and between separators 7a and 7b, thereby suppressing electrolyte shortage.

[0043] On the other hand, in the free-fall test, the number of free-fall cycles required for a voltage drop to occur in the non-aqueous electrolyte battery 1 was 500 in Comparative Examples 2 and 3, compared to 2900 in Example 1. This is thought to be due to the effect of suppressing displacement of separators 6a, 6b, 7a, and 7b caused by shocks and vibrations during free fall, by bonding separators 6a, 6b and separators 7a, 7b together by welding.

[0044] In other words, it can be seen that a high level of safety is achieved by welding separators 6a and 6b together in welding regions 6c and 6d, and separators 7a and 7b together in welding regions 7c and 7d.

[0045] Next, we show the evaluation results of how the battery characteristics change when the longitudinal length of the two types of welded regions is varied. Figure 6 shows examples of varying the longitudinal length of two types of welded regions.

[0046] Figure 6 shows cases where the welded areas 6c and 7c are reduced (shortening their longitudinal length) and cases where the welded area 20a is reduced (shortening its longitudinal length). For the case where the welded area 20a is reduced, two examples are shown: one where the longitudinal length of the welded area 20a is 40% or more and 80% or less of the longitudinal length of the separator laminates 6 and 7, and another where it is 20% or less.

[0047] Although welding regions 6d, 7d, and 20b are not shown in Figure 6, their longitudinal lengths can also be changed in the same way. Figure 7 shows the liquid absorption rate, discharge capacity, and free-fall test results when the longitudinal length of two types of welding regions is varied.

[0048] Figure 7 shows eight examples with different proportions of welded areas 6c, 6d, 7c, 7d, 20a, and 20b provided along the longitudinal direction of the separator laminates 6 and 7. Note that the length (welding width) of the welded areas 6c, 6d, 7c, 7d, 20a, and 20b in the short direction is a constant value depending on the welding equipment.

[0049] The above percentage is calculated as follows: if there is a partially non-welded area in the longitudinal direction, the percentage (%) = (total longitudinal length of the welded area excluding the non-welded area / longitudinal length of separator laminates 6 and 7) × 100.

[0050] In Comparative Example 4, the above percentages for both welded areas 6c, 6d, 7c, 7d and welded areas 20a, 20b are 100%. In Examples 1-4 and Comparative Example 5, the above percentages for welded areas 6c, 6d, 7c, 7d are 100%, but the above percentages for welded areas 20a, 20b are 80% for Example 1, 60% for Example 2, 40% for Example 3, 20% for Example 4, and 0% for Comparative Example 5. Note that in welded areas 20a and 20b, the non-welded areas are located in the same position in the short direction (see Figure 8). In Comparative Examples 6 and 7, the above percentages for welded areas 20a and 20b are 100%, but the above percentages for welded areas 6c, 6d, 7c, 7d are 80% for Comparative Example 6 and 40% for Comparative Example 7. Furthermore, in the welded areas 6c, 7c and welded areas 6d, 7d, the non-welded areas are located in the same position in the short-side direction.

[0051] As shown in Figure 7, the absorption rate increases as the proportion of the welded areas 20a and 20b decreases, as is clear from the comparison of Comparative Example 4, Comparative Example 5, and Examples 1-4. This is because the non-aqueous electrolyte 3 penetrates from the longitudinal direction, and the smaller the proportion, the faster the penetration. Thus, a faster absorption rate can reduce manufacturing man-hours.

[0052] However, if the above ratio is too small for the welded regions 20a and 20b (for example, 20% in Example 4), the results of the free-fall test will deteriorate, so it is desirable that the above ratio be between 40% and 80% (see Figure 6).

[0053] On the other hand, as is clear from the comparison of Comparative Examples 4, 6, and 7, when the above proportions for welding regions 6c, 6d, 7c, and 7d decrease, the liquid absorption rate remains unchanged, but the results of the free-fall test worsen. For this reason, it is desirable that the above proportions for welding regions 6c, 6d, 7c, and 7d be 100%. However, if the above proportions for welding regions 6c, 6d, 7c, and 7d are less than 100%, and the above proportions for welding regions 20a and 20b are also less than 100%, the liquid absorption rate may improve (see Figure 9).

[0054] Furthermore, the discharge capacity values ​​remained unchanged for the above eight cases. Incidentally, as mentioned above, the non-welded areas where there are no welded areas 20a and 20b can be used for removing the negative electrode tab 16 as shown in Figure 1, or for reducing winding wrinkles.

[0055] Figure 8 shows an example of the use of a non-welded area. In the example shown in Figure 8, non-welded regions 30 and 31 are provided where there is no welded region 20b, and the negative electrode tab 16, which is electrically connected to the negative electrode 5, is brought out to the outside of the bonded structure made of separator laminates 6 and 7 via the non-welded region 30.

[0056] On the other hand, the non-welded region 31 has the function of reducing winding wrinkles. On the welding region 20a side, a non-welded region 32 is provided in the same position as the non-welded region 30 in the longitudinal direction and has the same length as the non-welded region 30, and a non-welded region 33 is provided in the same position as the non-welded region 31 in the longitudinal direction and has the same length as the non-welded region 31.

[0057] (modified version) Figure 9 shows a modified example. Figure 9 shows four variations of the welded region 6c, 7c and the welded region 20a, each periodically arranged in the longitudinal direction. These variations are shown based on combinations of cases where the longitudinal lengths of the welded regions 6c, 7c and the welded region 20a are the same and different, and where the phases in which the welded regions 6c, 7c and the welded region 20a are provided are the same and different in the longitudinal direction.

[0058] For these four modified versions, we conducted tests to confirm the liquid absorption rate and perform free-fall tests as shown in Figure 7. No significant differences were observed among the four modified versions in the free-fall test results.

[0059] On the other hand, the fastest liquid absorption rate was observed when the longitudinal lengths of the welded regions 6c and 7c and the welded region 20a were the same, and the phases in which the welded regions 6c and 7c and the welded region 20a were located were the same in the longitudinal direction (i.e., the longitudinal positions of the non-welded regions for the welded regions 6c and 7c and the non-welded region for the welded region 20a were the same). The next fastest liquid absorption rates were observed in two modified cases where the longitudinal lengths of the welded region 20a were different.

[0060] In Figure 9, welding regions 6d, 7d, and 20b are omitted from the illustration, but the same points as above apply to these regions as well. The above describes one aspect of the non-aqueous electrolyte battery of the present invention based on embodiments, but these are merely examples and the invention is not limited to those described above.

[0061] For example, although the above description assumes that the negative electrode 5 is sandwiched between the separator stacks 6 and 7 as shown in Figure 2, the positive electrode 4 may also be sandwiched between the separator stacks 6 and 7. In that case, in the non-aqueous electrolyte battery 1 shown in Figure 1, the negative electrode 5 is located on the outermost circumference of the electrode body 10 housed in the battery case 2 in a spiral winding state. Then, a positive electrode tab electrically connected to the positive electrode 4 is used instead of the negative electrode tab 16, a negative electrode tab electrically connected to the negative electrode 5 is used instead of the positive electrode tab 15, and a positive electrode terminal is used instead of the negative electrode terminal 12. [Explanation of Symbols]

[0062] 1 Nonaqueous electrolyte battery 2 Battery cans 2a cylindrical shaft 3 Nonaqueous electrolyte 4 Positive electrode 5 negative electrode 6,7 Separator laminate 6a, 6b, 7a, 7b Separators 6c,6d,7c,7d,20a,20b welding area 10 Electrode body 11 Sealing plate 12 Negative terminal 13 Washers 14 Gasket 15 Positive Tab 16 Negative Electrode Tabs 30~33 Non-welded area

Claims

1. It is equipped with an electrode body that is wound in a spiral shape and housed in a cylindrical battery case, The electrode body is Each consists of a sheet-shaped positive electrode and a negative electrode, A first separator laminate and a second separator laminate are welded together at a first welding region provided along a first longitudinal side, sandwiching one of the positive or negative electrodes, and at a second welding region provided along a second longitudinal side opposite the first side. It has, The first separator laminate has two or more separators welded to each other in a third welding region provided along the first edge and a fourth welding region provided along the second edge. The second separator laminate has two or more separators welded to each other at a fifth welded region provided along the first edge and in non-welded contact with the third welded region, and a sixth welded region provided along the second edge and in non-welded contact with the fourth welded region. Nonaqueous electrolyte battery.

2. The third welding region and the fifth welding region are located in the short-side direction of the first separator laminate and the second separator laminate, at positions different from the first welding region. The non-aqueous electrolyte battery according to claim 1, wherein the fourth welding region and the sixth welding region are provided in positions different from the second welding region in the short direction.

3. The tab is electrically connected to one of the electrodes, In the longitudinal direction of the first separator laminate and the second separator laminate, there are a first non-welded region and a second non-welded region, respectively, where there is no first welded region or second welded region. The tab is removed from the bonded structure formed by the first separator laminate and the second separator laminate via the first non-welded region. A non-aqueous electrolyte battery according to claim 1 or 2.

4. The non-aqueous electrolyte battery according to any one of claims 1 to 3, wherein the longitudinal lengths of the first welded region and the second welded region are 40% or more and 80% or less of the longitudinal lengths of the first separator laminate and the second separator laminate.

5. The non-aqueous electrolyte battery according to any one of claims 1 to 4, wherein the two or more separators include at least a first separator made of a microporous film and a second separator made of a nonwoven fabric, and the melting point of the second separator is higher than the melting point of the first separator.

6. The non-aqueous electrolyte battery according to claim 5, wherein the first separator of the first separator and the second separator is in contact with one of the electrodes.

7. The negative electrode has lithium metal or a lithium alloy. The aforementioned one electrode is the negative electrode. A non-aqueous electrolyte battery according to any one of claims 1 to 6.

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