JP2005149961A - Non-aqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-aqueous electrolyte battery having a high capacity, superior characteristics, from a medium load to a light load, and high safety. <P>SOLUTION: The cylindrical non-aqueous electrolyte battery houses an electrode rolling body for rolling a sheet-like positive electrode and a sheet-like cathode via a separator, and a non-aqueous electrolyte in a bottomed cylindrical exterior can having an upper opening. Then, a metal foil is employed for the cathode as collector; a metal lithium or a lithium alloy is arranged on both the surfaces of the metal foil or one-sided surface; the metal lithium or the lithium alloy is partially crimped or is not crimped to the metal foil at all; and therewith, the nonaqueous electrolyte battery is formed, by setting the ratio between the cathode capacity and the positive electrode capacity, to be the cathode electrode capacity/positive electrode capacity =0.93 to 1.03. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a non-aqueous electrolyte battery, and more particularly, to a high-capacity, safe, and highly reliable cylindrical non-aqueous electrolyte battery suitable for use under medium loads.

  Lithium primary batteries that use metallic lithium as the negative electrode active material need to have a large electrode area for applications that require heavy load characteristics, such as cameras, and between thin and long positive and negative electrodes. Generally, a structure in which a separator is interposed and wound about 6 to 10 turns is adopted.

  In the case of adopting such a winding structure, the metallic lithium is taken out as a current collecting lead such as ribbon-like nickel that is crimped to the metallic lithium and connected to the outer can by resistance welding or the like. There is a problem that the resistance between the lead and the terminal lithium is increased because the metal is consumed and thinned.

  For this reason, in the conventional technology, in a battery having a winding structure that places importance on heavy load characteristics such as camera applications, by designing the metal lithium to be excessively filled with respect to the positive electrode capacity, the electrical power of the entire metal lithium is reached until the end of discharge. The connection was maintained. This is because when the ratio of negative electrode capacity / positive electrode capacity is 1 or less or close to 1, the end of discharge is reached, the discharge reaction concentrates at the portion where the degree of tension of the positive and negative electrodes is the highest, and the lithium is cut off. This is based on an attempt to prevent the battery capacity from being filled because the connection cannot be made and a portion that does not contribute to the discharge is formed. For example, a battery that emphasizes heavy load characteristics such as a camera application is designed such that the ratio of negative electrode capacity / positive electrode capacity is 1.2 to 1.5. However, when the capacity of the negative electrode is excessive as described above, a capacity shortage is caused, and the problem based on the capacity becomes more noticeable as the load becomes lighter. In applications that require functions, a large capacity shortage will be caused. That is, when the metal lithium capacity of the negative electrode is excessive with respect to the positive electrode capacity, the metal lithium that does not participate in the discharge occupies a large volume, which hinders an increase in capacity under a light load. Conversely, if there is no excess metallic lithium, the end of the metallic lithium is disconnected at the end of discharge and becomes unusable, which also hinders high capacity under light loads.

In addition, it has been proposed to disperse the heat of the high-heated portion by disposing a copper layer having no through hole inside the metallic lithium (Patent Document 1).
JP 58-165256 A

However, in this patent document 1, since the area of the copper layer is set to 25 to 80% of the lithium area, when the discharge proceeds, lithium is cut along the periphery of the copper layer, and the electrical connection is cut off. The capacity was reduced and could not be a solution to the above problem. For the same purpose as described above, it has also been proposed to dispose a metal foil having a plurality of through holes inside metallic lithium.
Japanese Patent Laid-Open No. 11-195415

  However, according to this method, lithium is cut off and remains along the through hole, resulting in a decrease in capacity. In this case as well, it cannot be a solution to the above problem.

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a non-aqueous electrolyte battery having a high capacity, excellent medium load to light load characteristics, and high safety.

  The present invention accommodates a non-aqueous electrolyte and an electrode winding body in which a sheet-like positive electrode and a sheet-like negative electrode are wound through a separator in a bottomed cylindrical outer can having an upper opening. In the cylindrical nonaqueous electrolyte battery, a metal foil is used as a current collector for the negative electrode, and metal lithium or a lithium alloy is disposed on both sides or one side of the metal foil, and the metal lithium or lithium alloy is partly on the metal foil. The above-mentioned problem is solved by making pressure bonding or not pressing at all and setting the ratio of negative electrode capacity to positive electrode capacity to negative electrode capacity / positive electrode capacity = 0.93 to 1.03.

  In the present invention, as described above, when metal lithium or a lithium alloy is disposed on a metal foil, the explanation will be made by taking metal lithium as an example. Do not crimp or do not crimp at all. In the case where only a part of the metal lithium is crimped to the metal foil, it is preferable that only the winding start end is set (see the T portion in FIG. 3B). If the entire surface of the metal lithium is crimped to the metal foil, the inner metal lithium (4b in FIG. 3) bends as it is wound, causing wrinkles on the surface of the metal lithium and lowering the capacity. Adversely affect. However, in the present invention, the metallic lithium is not crimped to the metal foil at all, or only the winding start end (see the T portion in FIG. 3B) is crimped to the metal foil. Thus, the above problem can be solved.

  In the present invention, since the negative electrode capacity and the positive electrode capacity are set to negative electrode capacity / positive electrode capacity = 0.93 to 1.03, the capacity can be increased because there is no excess lithium relative to the positive electrode. Moreover, since almost no lithium remains after discharge, even if the battery is accidentally crushed, it can be prevented from igniting, and the safety is also improved.

  According to the present invention, it is possible to prevent lithium from being cut during the discharge and the electrical connection from being cut off so as not to contribute to the discharge even in the middle load to the light load discharge. In addition, according to the present invention, since excess lithium is not charged, the capacity can be increased, and since the lithium is hardly left even after discharge, the battery is accidentally crushed. It is possible to ensure safety without causing ignition. Therefore, according to the present invention, it is possible to provide a non-aqueous electrolyte battery having high capacity, excellent medium load to light load characteristics, and high safety. Furthermore, according to the present invention, it is possible to prevent the metallic lithium from being bent and wrinkles (wrinkles) from being generated with the winding, and this also contributes to an increase in capacity.

  One embodiment of the non-aqueous electrolyte battery of the present invention is shown in FIG. In FIG. 1, a nonaqueous electrolyte battery 1 includes a bottomed cylindrical outer can 2 having an upper opening, a sheet-like positive electrode 3 and a negative electrode 4 loaded in the outer can 2 via a separator 4. An electrode winding body 6 formed by winding, a non-aqueous electrolyte (hereinafter simply referred to as “electrolyte” except when representing a battery), and a sealing structure for sealing the upper opening of the outer can 2 The outer can 2 is made of iron or stainless steel.

  The sealing structure consists of a cover plate 8 fixed to the inner peripheral edge of the upper opening of the outer can 2 and a terminal body attached to an opening formed in the center of the cover plate 8 via a polypropylene insulating packing 9. 10 and an insulating plate 11 disposed below the lid plate 8. The insulating plate 11 is formed in a round plate shape that opens upward with an annular side wall 13 standing on the periphery of the disk-shaped base portion 12, and a gas passage 14 is opened at the center of the base portion 12. Yes. The cover plate 8 is fixed to the inner peripheral edge of the upper opening of the outer can 2 by laser welding or a crimp seal through packing while being received by the upper end of the side wall 13. The lid plate 8 or the can bottom 2a of the outer can 2 can be provided with a thin portion and provided with a vent as a countermeasure when the internal pressure rapidly increases. The positive electrode 3 and the lower surface of the terminal body 10 are connected by a positive electrode lead body 15. The negative electrode lead body 16 is welded to the upper inner surface of the outer can 2.

  FIG. 2 shows the electrode winding body 6 used in the nonaqueous electrolyte battery. As shown in FIG. 1, the electrode winding body 6 includes a positive electrode 3 and a negative electrode 4 that are connected to a separator 5. Is formed in a substantially cylindrical shape as a whole. The positive electrode 3 includes two strip-shaped positive electrode sheets 3a and 3b having the same thickness dimension, and a current collector 3c interposed between the positive electrode sheets 3a and 3b. In FIG. 3, the positive electrode sheets 3a and 3b and the current collector 3c are wound in a state where only the winding start end portion S is crimped and fixed (see (c) of FIG. 3). More specifically, as shown in FIG. 3, the current collector 3 c is overlapped with the positive electrode sheets 3 a and 3 b so that the current collector 3 c is several mm inward, and the length direction becomes the winding start end portion 3. Press 3 to 10 mm from the end of the plate. And the positive electrode 3 is wound with the negative electrode 4 and the separator 5, and the electrode winding body 6 is produced, E shows the winding end side.

  As the positive electrode active material of the positive electrode 3, for example, manganese dioxide, carbon fluoride, lithium cobalt composite oxide, spinel-type lithium manganese composite oxide, or the like can be used.

  As the electrical conductivity assistant for the positive electrode 3, for example, one or more selected from graphite, carbon black, acetylene black, ketjen black, and the like can be used. As the binder of the positive electrode 3, polytetrafluoroethylene (dispersion type or powder type), rubber binder, or the like can be used, and in particular, a dispersion type of polytetrafluoroethylene. It is preferable to use one.

  As the current collector 3c of the positive electrode 3, for example, a plain woven wire mesh made of stainless steel such as SUS316, SUS430, or SUS444, an expanded metal, a lath mesh, a punching metal, a metal foil, or the like can be used. As will be described in detail later, it is preferable to apply a paste-like conductive material to the surface of the current collector 3c.

  Even when a current collector 3c having a three-dimensional structure is used, as in the case of using an essentially flat material such as a metal foil or a punching metal, the current collecting effect is significantly increased by applying a conductive material. Improvement is observed. This is because not only the path in which the metal portion of the net-like current collector 3c is in direct contact with the positive electrode sheets 3a and 3b but also the path through the conductive material filled in the net is used effectively. It is estimated that

  As a specific example of the conductive material, for example, silver paste or carbon paste can be used. In particular, the carbon paste is suitable for reducing the manufacturing cost of the non-aqueous electrolyte battery because the material cost is lower than that of the silver paste and the contact effect is almost the same as that of the silver paste. As the binder for the conductive material, it is preferable to use a heat resistant material such as water glass or an imide binder. This is because when the moisture in the positive electrode sheets 3a and 3b is removed, a drying process is performed at a high temperature exceeding 200 ° C.

  As shown in FIG. 1 and FIG. 3 (b), the negative electrode 4 is composed of a short metal lithium foil 4a and a long metal lithium foil 4b, which are formed on a T portion on the winding start side of the metal foil 4c serving as a current collector ( The negative electrode 4 is wound with a separator 5 interposed between the negative electrode 4 and the positive electrode 3 to form an electrode winding body 6. In this embodiment, metallic lithium is used for the negative electrode. However, in the present invention, the reactive component of the negative electrode only needs to be lithium. Therefore, in preparing the negative electrode, for example, lithium-aluminum can be used instead of the above metal lithium. You may use lithium alloys, such as.

  Examples of the material of the metal foil 4c include copper, nickel, iron, and stainless steel. Since the internal volume of the outer can 2 is reduced by the thickness of the metal foil 4c, the thickness dimension of the metal foil 4c is preferably as small as possible. In this embodiment, the thickness dimension is 0.005 mm or more and 0.00. 1 mm or less is preferable. If the thickness of the metal foil 4c is less than 0.005 mm, the metal foil 4c is likely to be torn, and if the thickness of the metal foil 4c is more than 0.1 mm, the amount of lithium and the like is reduced and the battery capacity may be reduced. There is. Furthermore, the metal foil 4c preferably has a width equal to or greater than the width of the metal lithium foils 4a and 4b, and the metal foil has an area of metal lithium arranged on both sides. It is preferably 70 to 130% of the sum. That is, by setting the area of the metal foil as described above, the width of the metal foil 4c is the same as or wider than the width of the metal lithium foils 4a and 4b, and the length becomes longer. It is possible to prevent the metallic lithium 4a and 4b from being cut and the electrical connection from being cut off. 1 and FIG. 2 conceptually show the structure of the electrode winding body 6, and the thickness dimension of the metal foil 4c is different from the actual one.

The electrolyte is prepared by dissolving LiPF ₆ , LiClO ₄ , LiCF ₃ SO _3, etc. as an electrolyte in a non-aqueous solvent such as an organic solvent, and the solvent is a cyclic ester such as ethylene carbonate or propylene carbonate. A mixture of a chain ether such as dimethoxyethane and a chain ester such as dimethyl carbonate is used, and the concentration of the electrolyte in the electrolytic solution is preferably 0.3 to 1.5 mol / l.

  As the separator 5, a nonwoven fabric such as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or a microporous film can be used.

  The electrode winding body 6 can be produced by a procedure as shown in FIG. First, as shown in FIG. 3 (a), the separator 5 is wound around the winding core 20 in half and wound once. Next, as shown in FIG. 3B, the negative electrode 4 is inserted from the single layer portion of the short metal lithium foil 4a only toward the winding core 20, and as shown in FIG. Wind one turn with the separator 5. Subsequently, as shown in FIG. 3C, the positive electrode 3 is placed on the negative electrode 4 through the separator 5 and wound around the winding core 20. Here, the positive electrode 3 is wound from the winding start end S side to which both the positive electrode sheets 3 a and 3 b and the current collector 3 c are fixed, and on the long metal lithium foil 4 b constituting the negative electrode 4. Is wound in a state of being placed via the separator 5. The metal foil 4c is disposed so as to be sandwiched between the metal lithium foils 4a and 4b, thereby forming the negative electrode 4. It is wound together with the positive electrode 3, the negative electrode 4 and the separator 5 by a winding core 20. After the winding is finished, the metal foil 4c is arranged on the outermost periphery. From the above, the electrode winding body 6 having the form as shown in FIG. 1 can be obtained.

  Also, as shown in FIG. 4 (a), after the metal foil 3c is previously wound around the winding core 20 for about one turn, the metallic lithium and separator 5 constituting the negative electrode 4 as shown in FIG. 4 (b). It is also possible to insert a folded electrode group so as to wrap up the positive electrode 3 and wind the electrode assembly to produce an electrode body. In this case, lithium is not bonded to the metal foil 4c at all.

  In the present invention, the ratio of the negative electrode capacity to the positive electrode capacity (negative electrode capacity / positive electrode capacity) is set to 0.93 to 1.03. When the negative electrode capacity / positive electrode capacity is smaller than 0.93, This is because when the voltage drops rapidly during discharge and the negative electrode capacity / positive electrode capacity is larger than 1.03, the capacity is hindered. That is, when the negative electrode capacity / positive electrode capacity is smaller than 0.93, the positive electrode capacity is excessively filled as compared with the negative electrode capacity, so that the negative electrode is completely consumed while the positive electrode capacity remains. As a result, the voltage suddenly drops during the discharge. Thus, if the voltage drops rapidly during discharge, it becomes difficult to predict the battery life. On the other hand, when the negative electrode capacity / positive electrode capacity is larger than 1.03, the negative electrode is excessively filled, which hinders the increase in capacity. In the present invention, the ratio of the negative electrode capacity to the positive electrode capacity (negative electrode capacity / positive electrode capacity) is preferably 0.96 to 1.03.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In this embodiment, a cylindrical lithium battery having an outer diameter of 17 mm and a height of 45 mm will be described as an example of a nonaqueous electrolyte battery. Moreover, in the following examples etc.,% which shows a density | concentration, a water content, etc. is the mass% unless it mentions the reference | standard especially.

Example 1
The nonaqueous electrolyte battery of Example 1 was manufactured in the order of [Preparation of positive electrode], [Preparation of negative electrode], [Preparation of electrode winding body], [Assembly of battery], [Post-treatment, Pre-discharge, Aging]. explain.
[Production of positive electrode]
The production of this positive electrode will be described in the order of “formulation”, “sheeting”, and “current collector” to be used.
Formula:
After mixing for 5 minutes in a dry manner using a planetary mixer at a ratio of 3% carbon black and 92% manganese dioxide (Tosoh Corp.), 5% water is added to give a solid content of 20%. Mixed for minutes. To the obtained mixture, polytetrafluoroethylene dispersion (D-1, manufactured by Daikin Industries, Ltd.) was added as a solid content in a state where 5% was diluted in the remaining water and mixed for 5 minutes. The water content in the formulation was adjusted to 30 with respect to the solid content of 100.

Sheeting:
The compounding agent prepared by mixing as described above, using two rolls with a diameter of 250 mm, adjusting the roll temperature to 130 ± 5 ° C., pressing pressure 7 ton / cm, roll interval 0.4 mm, rotation speed 10 rpm Rolling with a roll and sheeting were performed. The compounding agent (preliminary sheet) that passed through the roll was dried at 105 ° C. ± 5 ° C. until the residual moisture became 2% or less. Next, the dried preliminary sheet was pulverized using a pulverizer. Here, the pressed preliminary sheet was pulverized until it became twice or more the original apparent volume. Most of the pulverized particle diameter was 1 mm or less, and the polytetrafluoroethylene fiber added as a binder was cut to a length of 1 mm or less.

The pulverized material was formed into a sheet by a roll again. The interval between the rolls is adjusted to 0.6 ± 0.05 mm, the roll temperature is 120 ± 10 ° C., the press pressure is 7 ton / cm, the sheet is formed at a rotation speed of 10 rpm, a positive electrode sheet is obtained, and is cut into a predetermined dimension. did. This positive electrode sheet had a thickness of 1.0 mm and a density of 2.5 g / cm ³ .

  In this way, two positive electrode sheets 3a and 3b [see FIG. 1 and FIG. 3 (c)] for the inner periphery and the outer periphery were produced. The inner periphery positive electrode sheet 3a was 37 mm wide and 51 mm long, and the outer periphery positive electrode sheet 3b was 37 mm wide and 62 mm long.

Current collector:
An expanded metal made of stainless steel (SUS316) was used as the current collector 3c. This expanded metal was cut into a width of 34 mm and a length of 56 mm, and a stainless steel ribbon having a thickness of 0.1 mm and a width of 3 mm was attached to the central portion in the length direction as a positive electrode lead body 15 by resistance welding. A carbon paste (manufactured by Nippon Graphite Co., Ltd.) was applied to the current collector 3c so as not to crush the mesh, and then dried at a heating temperature of 105 ° C. ± 5 ° C. for 2 hours or more. Here, the carbon paste was applied so as to be 5 mg / cm ² .

  Next, as shown in FIG. 3 (c), the two positive electrode sheets 3a and 3b are fixed to only one end in the length direction with the current collector 3c interposed therebetween. Integrated. Specifically, the two positive and negative electrode sheets 3a and 3b for inner and outer periphery are set so that one end in the length direction is aligned and the end of the current collector 3c does not protrude from the positive electrode sheets 3a and 3b. In this state, the three members were integrated by press-bonding 5 mm (the S portion in FIG. 1) from the end in the length direction with a press. Subsequently, the positive electrode sheets 3a and 3b and the current collector 3c were dried with hot air at 250 ° C. ± 10 ° C. for 6 hours to obtain the positive electrode 3. Here, the positive electrode sheets 3a and 3b and the current collector 3c are integrated for convenience of work, and the independent positive electrode sheets 3a and 3b and the current collector 3c are integrated at the time of winding. There is no problem in characteristics.

(Production of negative electrode)
For the negative electrode 4, metallic lithium having a width of 37 mm and a thickness of 0.28 mm was cut into a metallic lithium foil 4 a having a length of 46 mm and a metallic lithium foil 4 b having a length of 82 mm, and these were used for producing a negative electrode. The metal foil 4c is a copper foil having a width of 37 mm, a length of 135 mm, and a thickness of 0.010 mm. The nickel negative electrode lead body 16 having a width of 3 mm, a length of 20 mm, and a thickness of 0.1 mm is used for the metal lithium foil 4b. Then, these metal lithium foils 4a and 4b were pressure-bonded to the copper foil as the metal foil 4c with a roll only at the T portion (10 mm each) on the winding start side as shown in FIG. At this time, the area of the copper foil was 105% of the sum of the areas of the metal lithium foils disposed on both surfaces thereof.

[Production of wound electrode body]
A microporous polyethylene film (Hypore (trade name) manufactured by Asahi Kasei Co., Ltd.) having a width of 44 mm and a thickness of 0.025 mm is cut into 140 mm and used as the separator 5, and divided into two as shown in FIG. Was wound around the winding core 20 having a diameter of 4 mm. Next, as shown in FIGS. 3B and 3C, the negative electrode 4 is wound once around the separator 5 at the same time, and then the fixed side of the positive electrode sheets 3 a and 3 b is placed on the winding core 20 side. I wound it. After winding, the metal foil 4c covered the outermost periphery. From the above, an electrode winding body 6 as shown in FIG. 1 was obtained.

[Battery assembly]
A polypropylene insulating plate 7 having a thickness of 0.2 mm is inserted into the bottom of the outer can 2 made of nickel-plated iron can, and the electrode winding body 6 is inserted thereon with the positive electrode lead body 15 facing upward. did. The negative electrode lead body 16 was resistance welded to the inner surface of the outer can 2, and the positive electrode lead body 15 was resistance welded to the lower surface of the terminal plate 10 after inserting the insulating plate 11. At this point, the insulation resistance was measured and it was confirmed that there was no short circuit.

As the electrolytic solution, 3.3 ml of 0.5 M LiClO ₄ / (PC + DME = 1: 2) was injected into the outer can 2. The injection was divided into three times, and the whole amount was injected under reduced pressure in the final step. After injecting the electrolytic solution, the lid 8 is fitted into the opening of the outer can 2 and the inner peripheral portion of the opening end of the outer can 2 and the outer peripheral portion of the lid 8 are welded by laser welding. The opening of was sealed. The electrolyte solution will be described in detail. The electrolyte solution is prepared by dissolving 0.5 mol / l of LiClO _{4 in} a mixed solvent of propylene carbonate (PC) and dimethoxyethane (DME) in a volume ratio of 1: 2. This is a non-aqueous electrolyte solution.

[Post-processing: Pre-charging, aging]
The sealed battery was predischarged with a resistance of 1Ω for 30 seconds, stored at 45 ° C. for 24 hours, and then subjected to secondary predischarge with a constant current of 1 A for 1 minute. The battery after the preliminary discharge was aged at room temperature for 7 days, and the open circuit voltage was measured. Thus, a nonaqueous electrolyte battery of Example 1 having an outer diameter of 17.0 mm and a total height of 45.0 mm was obtained. The ratio of the negative electrode capacity to the positive electrode capacity of the battery of Example 1 (hereinafter referred to as “negative electrode capacity / positive electrode capacity”) was 1.00.

Example 2
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the thickness of metallic lithium was changed to 0.27 mm and the thickness of the positive electrode sheet was changed to 1.01 mm. The battery of Example 2 had a negative electrode capacity / positive electrode capacity of 0.96, and the area of the copper foil was 105% of the sum of the areas of the metal lithium foils disposed on both sides thereof.

Example 3
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the thickness of metallic lithium was changed to 0.27 mm. The battery of Example 3 had a negative electrode capacity / positive electrode capacity of 0.97, and the area of the copper foil was 105% of the sum of the areas of lithium disposed on both surfaces thereof.

Example 4
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the thickness of the positive electrode sheet was changed to 0.98 mm. The battery of Example 4 had a negative electrode capacity / positive electrode capacity of 1.03, and the area of the copper foil was 105% of the sum of the lithium areas arranged on both sides thereof.

Example 5
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the length of the copper foil was 92 mm and the negative electrode shown in FIG. 6 was used. The negative electrode shown in FIG. 6 has a copper foil length of 92 mm as the metal foil 4c, and only the T portion (length 10 mm) on the winding start side of the metal lithium foil 4a having a length of 46 mm is rolled on this copper foil. In addition, only the T portion (10 mm in length) on the winding start side of the 82 mm-long metallic lithium foil 4b is pressure-bonded to the copper foil with a roll, and the negative electrode lead body 16 is on the side in contact with the metallic lithium foil 4b. It is attached to the metal foil 4c. The battery of Example 5 had a negative electrode capacity / positive electrode capacity of 1.00, and the area of the copper foil was 70% of the sum of the areas of metallic lithium disposed on both surfaces thereof.

Example 6
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the length of the copper foil was 166 mm and the negative electrode shown in FIG. 7 was used. Here, the negative electrode shown in FIG. 7 will be described. The copper foil as the metal foil 4c has a length of 166 mm, the metal lithium foil 4a has a length of 46 mm, and the T portion on the winding start side (length 10 mm). Only the copper foil is pressure-bonded with a roll, the metal lithium foil 4b is 92 mm in length, and only the T portion (length 10 mm) on the winding start side is pressure-bonded to the copper foil with a roll. It is attached to the metal foil 4c on the side in contact with the foil 4b. The battery of Example 6 had a negative electrode capacity / positive electrode capacity of 1.00, and the area of the copper foil was 130% of the sum of the areas of metallic lithium disposed on both surfaces thereof.

Example 7
A copper foil having a length of 160 mm and a thickness of 0.010 mm is used as the metal foil 4c, and the copper foil as the metal foil 4c is wound around the winding core 20 as shown in FIG. Negative electrode 4 made of a lithium metal foil having a width of 37 mm, a thickness of 0.28 mm, and a length of 128 mm, and a microporous polyethylene film having a width of 44 mm, a thickness of 0.025 mm, and a length of 160 mm [Hypore (trade name) manufactured by Asahi Kasei Corporation] A non-aqueous electrolyte battery was manufactured using an electrode winding body in which an electrode body folded and wrapped around the positive electrode 3 as shown in FIG. The battery of Example 7 had a negative electrode capacity / positive electrode capacity of 1.00, and the area of the copper foil was 125% of the sum of the areas of metallic lithium disposed on both sides.

Comparative Example 1
As shown in FIG. 8, a non-aqueous electrolyte battery was produced by winding with the same configuration as in Example 1 except that a negative electrode not using a metal foil was used. Here, the negative electrode shown in FIG. 8 will be described. The metal lithium foil 4a has a length of 46 mm, the metal lithium foil 4b has a length of 92 mm, and does not use a copper foil as a current collector. The body 16 is attached on the winding end side of the metal lithium foil 4a so that the tip thereof is inserted between the metal lithium foil 4a and the metal lithium foil 4b. The battery of Comparative Example 1 had a negative electrode capacity / positive electrode capacity of 1.00.

Comparative Example 2
As in the case shown in FIG. 8, a non-aqueous electrolyte battery was produced by winding with the same configuration as in Example 2 except that a negative electrode not using a metal foil was used. The battery of Comparative Example 2 had a negative electrode capacity / positive electrode capacity of 0.96.

Comparative Example 3
As in the case shown in FIG. 8, a nonaqueous electrolyte battery was produced by winding with the same configuration as in Example 3 except that a negative electrode not using a metal foil was used. The battery of Comparative Example 3 had a negative electrode capacity / positive electrode capacity of 0.97.

Comparative Example 4
As in the case shown in FIG. 8, a non-aqueous electrolyte battery was produced by winding in the same configuration as in Example 4 except that a negative electrode not using a metal foil was used. The battery of Comparative Example 4 had a negative electrode capacity / positive electrode capacity of 1.03.

Comparative Example 5
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the thickness of the positive electrode sheet was 1.0 mm and the thickness of the metal lithium was 0.25. The battery of Comparative Example 5 had a negative electrode capacity / positive electrode capacity of 0.90, and the area of the copper foil was 105% of the sum of the areas of metallic lithium disposed on both surfaces thereof.

Comparative Example 6
A nonaqueous electrolyte battery was produced in the same manner as in Example 1 except that the thickness of the positive electrode sheet was 0.99 mm and the thickness of the metal lithium was 0.29 mm. The battery of Comparative Example 6 had a negative electrode capacity / positive electrode capacity of 1.05, and the area of the copper foil was 105% of the sum of the areas of metallic lithium disposed on both surfaces thereof.

Comparative Example 7
A non-aqueous electrolyte battery of Comparative Example 7 was produced by winding in the same configuration as Comparative Example 6 except that a negative electrode not using a metal foil as shown in FIG. 8 was used. The negative electrode capacity / positive electrode capacity of the battery of Comparative Example 7 was 1.05.

  The discharge capacity when the batteries of Examples 1 to 7 and Comparative Examples 1 to 7 were discharged to a final voltage of 2 V at a constant current of 23 ° C. and 5 mA was measured. The number of samples of each battery is 5, and the average value is obtained. The results are shown in Table 1 together with the negative electrode capacity / positive electrode capacity as light load characteristics. Moreover, the discharge capacity when the batteries of Examples 1 to 7 and Comparative Examples 1 to 7 were discharged to a final voltage of 2 V at a constant current of 23 ° C. and 300 mA was measured. The number of samples of each battery is five, the average value is obtained, and the results are shown in Table 1 as medium load characteristics.

  As shown in Table 1, in Examples 1-7, compared with Comparative Examples 1-7, both the discharge capacity at 5 mA constant current discharge and the discharge capacity at 300 mA constant current discharge are large, especially at 300 mA constant current discharge. The discharge characteristics were large, and the discharge characteristics at light to medium loads with a discharge current of about 1 to 500 mA were excellent.

It is a longitudinal cross-sectional view which shows one Embodiment of the nonaqueous electrolyte battery of this invention. It is a cross-sectional view which shows one Embodiment of the nonaqueous electrolyte battery of this invention. The process which produces the electrode winding body in the nonaqueous electrolyte battery of this invention in Example 1 is shown, (a) is a figure which shows the state which wound only the separator around the winding core, (b) The state arrange | positioned so that it may be suitable for winding a negative electrode is shown, (c) shows the state arrange | positioned so that it may be suitable for winding a part of negative electrode and winding a positive electrode. The process which produces the electrode winding body in the nonaqueous electrolyte battery of this invention is shown, (a) shows the state arrange | positioned so that the metal foil of a negative electrode might be suitable for winding to a winding core, (b) A state where a part of the metal foil of the negative electrode is wound around the winding core and the positive electrode and the negative electrode are arranged so as to be suitable for winding is shown. It is a figure which shows the state before winding of the negative electrode used in Example 1. FIG. It is a figure which shows the state before winding of the negative electrode used in Example 5. FIG. It is a figure which shows the state before winding of the negative electrode used in Example 6. FIG. It is a figure which shows the state before winding of the negative electrode used in the comparative example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nonaqueous electrolyte battery 2 Exterior can 3 Positive electrode 3a Positive electrode sheet 3b Positive electrode sheet 3c Current collector 4 Negative electrode 4a Metal lithium foil 4b Metal lithium foil 4c Metal foil 5 Separator 6 Electrode winding body 15 Positive electrode lead body 16 Negative electrode lead body 20 Winding heart

Claims (4)

A cylindrical shape containing a non-aqueous electrolyte and an electrode winding body obtained by winding a sheet-like positive electrode and a sheet-like negative electrode through a separator in a bottomed cylindrical outer can having an upper opening. The negative electrode uses a metal foil as a current collector, the metal lithium or lithium alloy is disposed on both sides or one side of the metal foil, and the metal lithium or lithium alloy is partially crimped to the metal foil. A non-aqueous electrolyte battery characterized in that the ratio of negative electrode capacity to positive electrode capacity is negative electrode capacity / positive electrode capacity = 0.93 to 1.03. Metal lithium or lithium alloy is disposed on both sides of the metal foil, the width of the metal foil is equal to or greater than the width of the metal lithium or lithium alloy, and the area of the metal foil is 70 to 70% of the total area of the metal lithium or lithium alloy. The nonaqueous electrolyte battery according to claim 1, wherein the battery is 130%. The nonaqueous electrolyte battery according to claim 1 or 2, wherein the thickness of the metal foil is 0.005 mm or more and 0.1 mm or less. The non-aqueous electrolyte battery according to claim 1, wherein the metal foil is made of any one of copper, nickel, iron, and stainless steel.

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