JP4236193B2 - Battery cover for cylindrical battery, cylindrical battery and method for manufacturing the same - Google Patents

Description

  The present invention relates to a battery lid for a cylindrical battery and a cylindrical battery using the battery lid.

  For cylindrical batteries such as lithium primary batteries used for camera applications, for example, the following manufacturing method is adopted. First, a positive electrode, a negative electrode, a separator, and the like are loaded into a bottomed cylindrical battery can having an opening, and a battery lid is fitted into the opening of the battery can and sealed by laser welding or the like. The battery lid is provided with an electrolyte inlet, and after injecting the electrolyte into the battery can from the inlet, a sealing member is inserted into the inlet and welded and sealed by laser welding or the like. And product (cylindrical battery).

  By the way, since it is common that a terminal body is attached to the center part of the surface which becomes the battery outer side in the battery lid of the cylindrical battery as described above, the electrolyte injection port is provided at a place other than the terminal body installation site. It has been. Therefore, when injecting electrolyte using a device that can continuously inject electrolyte into a large number of battery cans, the position of the electrolyte inlet on the device shifts for each battery can. The operation | work which matches the position of the injection | pouring nozzle of an injection apparatus with the position of an electrolyte injection hole is needed. Conventionally, for example, the position of the electrolyte injection port is monitored by a camera and the alignment between the injection port and the injection nozzle is performed, so that the operation is complicated, and the electrolyte injection device is also expensive. Therefore, it has been an impediment to reducing the manufacturing cost of cylindrical batteries.

  The present invention has been made in view of the above circumstances, and facilitates the manufacture of a cylindrical battery and achieves a reduction in manufacturing cost, and a cylindrical battery using the battery cover. And a method of manufacturing the cylindrical battery.

The present invention provides a battery cover for a cylindrical battery that is circular in plan view (hereinafter sometimes simply referred to as a “battery cover”) for constituting an exterior of a cylindrical tube battery, and an electrolyte solution inside the battery. In addition to providing an electrolyte inlet for injecting electrolyte, a recess for aligning the position of the injection nozzle of the electrolyte injector and the electrolyte inlet is provided, and the center of the battery lid is used as a reference point When the inner angle formed by the line segment passing through the center of the electrolyte inlet and the reference point and the line segment passing through the center of the recess and the reference point is set to 30 to 180 °, the above-described problem has been solved. Is.

To manufacture a cylindrical battery using the battery lid of the present invention, at least a positive electrode, a negative electrode, and a separator are loaded into a bottomed cylindrical battery can having an upper opening, and a circular battery lid is formed in a plan view. A step of fitting into the opening of the battery can and welding and sealing the opening end of the battery can and the peripheral edge of the battery lid to form a tubular battery precursor; and A method for producing a cylindrical battery, comprising: a step of injecting an electrolyte from an electrolyte inlet of the battery lid; and a step of inserting a sealing member into the electrolyte inlet and performing welding sealing. And a recess for aligning the electrolyte injection port for injecting the electrolyte into the battery can, the injection nozzle of the electrolyte injection device, and the electrolyte injection port. When the center of the battery lid is the reference point, the center of the electrolyte inlet and the reference point are And an inner angle formed by a line segment passing through the center of the recess and the reference point is 30 to 180 °, and prior to the electrolyte injection step, the electrolyte injection port, A manufacturing method for positioning a cylindrical battery precursor by inserting an alignment member into a concave portion of the battery lid of the cylindrical battery precursor in order to align the position with an injection nozzle of an electrolyte injection device. Can be adopted.

  As described above, according to the present invention, in order to align the position of the injection nozzle of the electrolytic solution injection device with the position of the electrolytic solution injection port, the injection nozzle is mechanically inserted only by fitting the alignment member into the recess of the battery lid. Can be positioned. The cylindrical battery precursor may be positioned, for example, by holding the above-mentioned alignment member in the injection nozzle of the electrolyte injection device and immediately before the injection of the electrolyte, or holding the cylindrical battery precursor. A method may be used in which the cylindrical battery precursor is positioned by an instrument having the alignment member while being held on the holding jig, and the position is fixed to the holding jig. In the latter case, the tubular battery precursor can be used for the electrolytic solution injection step and the electrolytic injection port welding sealing step with the holding jig held (position fixed).

  The battery lid preferably has two or more of the concave portions. When there are a plurality of recesses, misalignment or the like during positioning of the injection nozzle is unlikely to occur, and positioning of the electrolyte injection port and the injection nozzle can be performed more stably.

  The present invention also includes the above cylindrical battery obtained using the battery lid of the present invention.

  According to the present invention, the positioning of the electrolyte inlet and the injection nozzle of the battery lid when injecting the electrolyte into the battery can, and the positioning of the electrolyte inlet at the time of welding and sealing are extremely important. The production speed can be increased, and the electrolyte injection device can be made simpler. Therefore, it is possible to reduce the manufacturing cost of the cylindrical battery.

  Hereinafter, the present invention will be described in detail with reference to the drawings. 1 is a schematic plan view showing an example of a battery cover for a cylindrical battery according to the present invention, FIG. 2 is a schematic plan view showing another example of the battery cover for a cylindrical battery according to the present invention, and FIG. 3 is a battery shown in FIG. FIG. 4 is a schematic cross-sectional view showing an example of a cylindrical battery of the present invention using a lid, and the cross section shown in FIG. 3 corresponds to the cross section taken along the line II in FIG. The battery lid 10 in FIG. 1 has an electrolyte inlet 11 and one recess 12, and the battery lid 10 in FIGS. 2 and 3 has an electrolyte inlet 11 and two recesses 12, 12. ing. Reference numeral 13 in FIGS. 1 to 3 denotes a terminal body, which is attached to an opening formed in the central portion of the battery lid 10 via an insulating packing made of resin such as polypropylene (15 in FIG. 3) (FIG. 3). 3).

<Battery cover>
The battery lid is a member for sealing the opening of the battery can, but as shown in FIG. 1 and FIG. 2, a terminal body is installed at the center of the battery lid. It cannot be provided at the center of the battery lid. For this reason, when injecting an electrolyte using a device capable of continuously injecting an electrolyte into a large number of battery cans, the position of the electrolyte injection port on the device is shifted for each individual battery can. The operation | work which matches the position of the injection nozzle of an electrolyte solution injection apparatus with the position of an electrolyte solution injection port is needed. In the present invention, the battery lid 10 is provided with a recess 12, for example, a rod-like alignment member is provided in an injection nozzle or an alignment tool of the electrolyte solution injection device, and the alignment member is fitted into the recess 12. Thus, the cylindrical battery precursor (with the power generation element loaded in the battery can and the battery lid welded to the battery can open end) can be positioned simply and mechanically, and the injection nozzle and the electrolyte injection port 11 has the greatest feature in that the alignment with the electrode 11 is extremely easy.

  The shape of the concave portion 12 of the battery lid 10 is not particularly limited, and may be a shape that the alignment member can be securely fitted and hardly displaced in accordance with the bottom surface shape or the horizontal sectional shape of the alignment member. For example, concave portions such as a horizontal cross-sectional shape of a circle (true circle, ellipse, etc.); a triangle (equilateral triangle, isosceles triangle, etc.), a polygon such as a quadrangle (square, rectangle, etc.); In addition, from the viewpoint of facilitating the fitting of the alignment member, a recess having a circular horizontal cross section (especially a true circle) is preferable.

The size of the recess 12 is not particularly limited, and may be a size (opening area and depth) in which the alignment member can be securely fitted and hardly displaced. The preferred size of the recess depends on the size of the battery lid and the cylindrical battery obtained by using this battery lid. For example, the opening area is preferably 3 mm ² or more, more preferably 6 mm ² or more. By setting it as such an opening area, positioning of a cylindrical battery precursor can be achieved more reliably. In addition, the upper limit of the opening area of the recess is preferably set to 30 mm ^{2 in} consideration of the fact that it can be actually installed from the size of a general cylindrical battery. For example, in the case of a concave portion having a circular shape (perfect circle), the radius is 1 mm or more (more preferably 1.5 mm or more) and 3 mm or less in order to achieve the above-described opening area. Is desirable.

  In addition, the depth of the recess 12 is desirably 0.5 mm or more, more preferably 1 mm or more. By setting the depth to such a depth, the alignment member can be firmly fitted in the recess. The positioning of the cylindrical battery precursor can be achieved more reliably. Further, the upper limit of the depth of the recess is preferably set to 3 mm, for example, considering that it can be actually installed with a general cylindrical battery.

It is preferable that the recess is formed at a certain distance from the electrolyte inlet. This is because, if the distance between the recess and the electrolyte injection port is too short, for example, when using an electrolyte injection device provided with an alignment member on the injection nozzle, it is difficult to install the alignment member on the injection nozzle. . Specifically, when the center portion of the battery lid 10 is used as a reference point, an internal angle formed by a line segment passing through the center of the electrolyte inlet 11 and the reference point and a line segment passing through the center of the recess 12 and the reference point. However, it is recommended that the angle be 30 ° or more, more preferably 60 ° or more, still more preferably 75 ° or more, and 180 ° or less, more preferably 120 ° or less, and still more preferably 90 ° or less.

  The number of recesses 12 may be one as shown in FIG. 1, two as shown in FIG. 2, or three or more (for example, three, four, five, etc.). Absent. However, it is preferable that the number of the recesses is 2 or more from the viewpoint of improving the stability at the time of alignment between the electrolyte solution injection port and the injection nozzle. When the number of recesses is two or more, the number of contacts with an instrument having an alignment member or an injection nozzle can be increased during alignment, so that there is a displacement in positioning the cylindrical battery precursor. It becomes harder to occur and positioning can be performed more stably than when there is only one recess. On the other hand, if the number of recesses is excessively large, it becomes difficult to design the injection nozzle when processing the battery lid or the injection nozzle of the electrolyte injection device has an alignment member. Is realistic.

  For example, when the battery lid has two recesses as shown in FIG. 2, the internal angle formed by the line segment passing through the center of the electrolyte inlet and the reference point and the line segment passing through the center of each recess and the reference point These may be the same angle or different angles, but are preferably the same angle from the viewpoint of improving the stability during positioning.

  There is no restriction | limiting in particular in the size and shape of the electrolyte injection hole 11, What is necessary is just to make it the same size and shape as employ | adopted with the conventionally well-known cylindrical battery. For example, it is common to use a circular shape with a diameter of 0.5 to 3 mm.

As a material of the battery lid 10, for example, iron or stainless steel is generally used. In the case of iron, it is preferable that the surface is plated with Ni or the like. The size of the battery lid 10 depends on the size of the cylindrical battery using the battery lid 10. For example, in the case of a cylindrical cylindrical battery, the diameter of the battery lid 10 is generally 9 to 35 mm. It is. The cylindrical battery of the present invention to which the battery lid of the present invention is applied has a cylindrical shape. Moreover, the thickness of the metal plate which forms the battery cover 10 is 0.1-1 mm normally.

  As shown in FIGS. 1 and 2, the battery lid 10 may be provided with a thin vent 14 as a countermeasure when the internal pressure suddenly increases. For example, in the case of a circular battery lid 10 as shown in FIGS. 1 and 2, the vent 14 is generally provided along the outer periphery of the battery lid 10 so that the inner angle between both ends is about 90 to 150 °. Is. In the battery lid 10 having the vent 14, the electrolyte solution inlet 11 and the recess 12 are formed at a place other than the place where the vent 14 is formed.

<Cylindrical battery>
The cylindrical battery of the present invention will be described with reference to FIG. Note that the cylindrical battery shown in FIG. 3 is merely an example of the cylindrical battery of the present invention, and the internal structure of the cylindrical battery of the present invention is not limited to the structure of FIG. Further, in the case of a cylindrical shape, the present invention is particularly effective for positioning at the time of electrolyte injection because the side wall of the battery can does not have a flat portion that can serve as a reference for alignment.

  3 has a battery lid 10 and a bottomed cylindrical battery can 21 having an upper opening. An insulating plate 29 made of resin (such as polypropylene) is inserted into the inner bottom surface of the battery can 21. In addition, an insulating plate 25 made of resin (such as polypropylene) is installed at the bottom of the battery lid 10. The insulating plate 25 is formed in a round plate shape with an annular side wall 27 standing on the periphery of a disc-shaped base portion 26 and opened upward. A gas passage 28 is opened at the center of the base portion 26. Yes. In a state where the battery lid 10 is received by the upper end of the side wall 27, the peripheral edge thereof is welded and sealed to the open end of the battery can 21 by, for example, laser welding.

  An electrode body 22 composed of a positive electrode, a negative electrode, and a separator is loaded between the insulator 25 and the insulator 29. The electrode body 22 has at least a positive electrode, a negative electrode, and a separator (not shown), and the positive electrode and the lower surface of the terminal body 13 are connected by a positive electrode lead body 23. The negative electrode of the electrode body 22 and the inner surface of the battery can 21 are connected by a negative electrode lead body 24. An electrolytic solution is injected into the cylindrical battery 20.

  In the cylindrical battery 20, an electrolyte solution inlet (not shown) provided in the battery lid 10 is welded and sealed, for example, by laser welding after inserting a sealing member.

  Examples of the electrode body 22 include a wound electrode body such as a spiral electrode body wound in a spiral shape with a separator interposed between a sheet-shaped positive electrode and a sheet-shaped negative electrode.

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

  As the conductive assistant for the positive electrode, for example, one or two or more kinds of conductive substances selected from graphite, carbon black, acetylene black, ketjen black and the like can be used. As the binder of the positive electrode, polytetrafluoroethylene (PTFE) (dispersion type or powder type), rubber binder, etc. can be used, but a PTFE dispersion type can be used. Particularly preferred.

  Moreover, it is also preferable that a positive electrode is a laminated body containing the two positive electrode sheets which have the same thickness dimension, and the electrical power collector interposed between these positive electrode sheets. In the production of the wound electrode body, it is preferable that the positive electrode sheet and the current collector are fixed by crimping only the winding start end. Specifically, after overlapping the three so that the current collector is several mm inward from the two positive electrode sheets, 3-10 mm from the end in the longitudinal direction that is the winding start end It is preferable to press.

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

  Even when a current collector having a three-dimensional structure is used, by applying a conductive material, the current collector is collected in the same manner as when a material consisting essentially of a flat plate such as metal foil or punching metal is used. Significant improvement in electrical effect is observed. This is presumed to be due to the fact that not only the path in which the metal portion of the net-like current collector is in direct contact with the positive electrode sheet but also the path through the mesh-filled conductive material is effectively used. The

  As a specific example of the conductive material, for example, a silver paste, a carbon paste, or the like can be used. In particular, the carbon paste is suitable for reducing the manufacturing cost of the cylindrical 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. For the binder of the conductive material, it is preferable to use a heat resistant material such as water glass or an imide binder. This is because in the manufacturing process of the positive electrode, a drying process may be performed at a high temperature exceeding 200 ° C. in order to remove moisture in the positive electrode sheet.

  Examples of the negative electrode include a metal lithium foil, a foil-like lithium alloy (for example, a lithium-aluminum alloy) and the like.

  In addition, the negative electrode is preferably a laminate including a short metal lithium foil, a long metal lithium foil, and a current collector interposed between these metal lithium foils. In this case, the current collector and the long metal lithium foil are overlapped and crimped by about 10 mm from the end portion on the winding start side. Further, the short metal lithium foil is an ultra-long metal lithium foil. It is preferable to overlap the current collector on the inner side of the end of the crimping portion between the electrode and the current collector (the inner end of the current collector) and to crimp about 10 mm from the end of the short metal lithium foil. In the case of a negative electrode including two metal lithium foils and a current collector, a foil-like lithium alloy (such as a lithium-aluminum alloy) may be used instead of the metal lithium foil.

  The current collector used for the negative electrode is composed of a metal foil. Examples of the metal foil material include copper, nickel, iron, and stainless steel. In addition, since the internal volume of the battery can 21 is reduced by the thickness of the metal foil, the thickness dimension of the metal foil is preferably as small as possible, for example, 0.005 mm or more and 0.1 mm or less is recommended. The If the thickness of the metal foil is too large, the thickness of the metal lithium foil or the like must be reduced in order to suppress a decrease in the internal volume of the battery can 21, which may cause a reduction in battery capacity. The width of the metal foil is preferably the same as or longer than that of the short and long metal lithium foils. Moreover, it is preferable that the area of metal foil is 70 to 130% of the sum of the areas of the metal lithium foil arranged on both surfaces thereof. By making the area of the metal foil as described above, the width of the metal foil is the same as or wider than the width of the metal lithium foil disposed on both sides, and the length becomes longer. Even if a phenomenon such as breakage of the metal lithium foil occurs, the electrical connection in the negative electrode can be maintained.

  As the separator, a nonwoven fabric made of polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polyphenylene sulfide, etc., a microporous film, etc. can be used.

The electrolyte solution may be selected according to the configuration of the positive electrode and the negative electrode to be used. For example, in the case of the above wound electrode body, the electrolyte solution is prepared by dissolving the electrolyte in a non-aqueous solvent such as an organic solvent. Is preferred. Specifically, the solvent is preferably a mixture of a cyclic ester (ethylene carbonate, propylene carbonate, etc.) and a chain ether (dimethoxyethane, etc.) and / or a chain ester (dimethyl carbonate, etc.). , LiPF ₆ , LiClO ₄ , LiCF ₃ SO _{3 and the} like are suitable, and the concentration of the electrolyte in the electrolytic solution is recommended to be 0.3 to 1.5 mol / l.

  When the electrode body 22 is the above-described wound electrode body, the winding is performed so that the separator is interposed between all the positive and negative electrodes, and the negative electrode is disposed on the outermost periphery. Moreover, when using said laminated body for a negative electrode, the length of metal lithium foil and metal foil is adjusted so that the collector (metal foil) of a negative electrode may be arrange | positioned in the outermost periphery. There is no restriction | limiting in particular in winding frequency, What is necessary is just to set suitably from the relationship with the volume of the battery can 21. FIG.

  In addition, when making the electrode body 22 into the said winding electrode body, it is preferable that ratio (negative electrode capacity / positive electrode capacity) of negative electrode capacity | capacitance and positive electrode capacity shall be 0.93 or more and 1.03 or less. This is because if the value of the negative electrode capacity / positive electrode capacity is too small, the voltage may drop rapidly during discharge, and if it is too large, the increase in capacity may be hindered. That is, when the negative electrode capacity / positive electrode capacity value is smaller than 0.93, the positive electrode is excessively filled as compared with the negative electrode, so that the negative electrode is completely consumed while the positive electrode capacity remains. In the middle of discharge, the voltage drops rapidly. 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 value is larger than 1.03, the negative electrode is excessively filled, which hinders the increase in capacity.

<Method for producing cylindrical battery>
Next, the manufacturing method of the cylindrical battery of this invention is demonstrated based on FIG. An electrode body 22 is loaded into a battery can 21 having an insulating plate 29 on the inner bottom surface, and the negative electrode in the electrode body 22 and the inner surface of the battery can 21 are connected by a negative electrode lead body 24. Thereafter, the insulating plate 25 is attached. After the lower surface of the terminal plate 13 of the battery lid 10 and the positive electrode of the electrode body 22 are connected by the positive electrode lead body 23, the battery lid 10 is fitted into the opening of the battery can 21, and the opening end of the battery can 21 and the battery The peripheral part of the lid 10 is welded and sealed by laser welding or the like to obtain a cylindrical battery precursor.

  Next, an electrolytic solution is injected into the battery from an electrolytic solution injection port (not shown) of the battery lid 10. In order to align the electrolytic solution injection port and the injection nozzle prior to this electrolytic solution injection step. Next, the cylindrical battery precursor is positioned. The cylindrical battery precursor can be positioned by, for example, the following two methods.

  As a first method, an electrolytic solution injection device having an injection nozzle provided with an alignment member is used, and the alignment member is fitted into a recess (not shown) of the battery lid 10 so that the injection nozzle and the electrolyte injection port are The cylindrical battery precursor is positioned so that the positions match. The alignment member is not particularly limited as long as it can be positioned by fitting in a recess, for example, a rod shape.

  In the second method, as shown in FIG. 4, the cylindrical battery precursor 20 a is held by a holding jig 30. The holding jig 30 has a mechanism for holding the side wall of the cylindrical battery precursor 20a (side wall of the battery can) and a mechanism for fixing the position after the positioning of the cylindrical battery precursor 20a. Therefore, using an appliance having an alignment member, the alignment member of the appliance is fitted into the recess 12 of the battery lid of the cylindrical battery precursor 20a to position the cylindrical battery precursor 20a, and the holding jig 30 is used. Fix the position. The cylindrical battery precursor 20 a fixed in position by the holding jig 30 is subjected to an electrolyte injection process while being held by the holding jig 30. As the electrolyte injection device, a device provided with a fixing jig for fixing the holding jig 30 is used, and if the holding jig 30 is fixed to the fixing jig, the injection nozzle of the electrolyte injection device By setting the position of the cylindrical battery precursor 20a so as to be aligned with the electrolytic solution injection port 11, the alignment between the electrolytic solution injection port 11 and the injection nozzle can be performed very easily. The alignment member related to the instrument having the alignment member used in the second method is not particularly limited as long as it can be positioned by being fitted in a recess, for example, a rod shape. Although not shown in FIG. 4, the holding jig 30 may be provided with various means (holes, notches, etc.) for fixing to the electrolyte solution injection device or the like on the side wall or the bottom surface thereof. .

  In any of the above methods (1) and (2), there are no particular restrictions on the operation of the cylindrical battery precursor and the alignment member during positioning, but for example, a cylindrical tube In the case of a battery, the cylindrical battery precursor is held by a jig having a mechanism for holding the side wall of the cylindrical battery precursor (side wall of the battery can), and the alignment member is a battery lid of the cylindrical battery precursor. When fitting into the recess, positioning is performed by changing the phase by a rotation operation with the axis passing through the longitudinal center of the cylindrical battery precursor (the axis taking the center of the battery lid and the center of the bottom of the battery can) as the rotation axis. It is preferable to carry out. In the case of the method (1), the jig for holding the cylindrical battery precursor when the electrolyte injection apparatus injects the electrolyte, and the jig having the mechanism for holding the side wall of the cylindrical battery precursor. And it is sufficient. In the case of the method (2), the holding jig corresponds to a jig having a mechanism for holding the side wall of the cylindrical battery precursor.

  The cylindrical battery precursor after injection of the electrolytic solution is subjected to a welding sealing process of the electrolytic solution injection port, a sealing member is inserted into the electrolytic solution injection port, and the product is sealed by laser welding or the like (cylindrical battery) ). When the positioning method (2) is adopted, the welding apparatus also has a fixing jig for fixing the holding jig, and the holding jig is fixed to the fixing jig. It is preferable to set the welding means of the welding apparatus so that the positions of the electrolytic solution injection port of the cylindrical battery precursor are matched. In this case, if it is subjected to the welding sealing process with the cylindrical battery precursor held in the holding jig, the welding means and the planned welding position (electrolyte inlet) of the cylindrical battery precursor Therefore, the productivity of the cylindrical battery can be further improved.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention. The “%” used in this example is based on mass unless otherwise specified.

Example 1
A cylindrical battery was produced using the battery lid having the structure shown in FIG. The material for the battery lid and battery can was iron plated with Ni. The thicknesses of the metal plates used for the battery lid and the battery can are 0.6 mm and 0.25 mm, respectively.

  The battery lid was a circle having a diameter of 16.1 mm, and the electrolyte inlet was a circle having a diameter of 1 mm centered at a point 5.95 mm from the center of the battery lid. Further, the concave portion was formed into a circular shape having a diameter of 2 mm centered at a position of 5.35 mm from the center of the battery lid at 75 ° from the center of the electrolyte solution inlet, and the depth thereof was set to 1 mm. The vent is a line segment passing through the center of the battery lid and the center of the electrolyte inlet, with the central portion in the battery lid circumferential direction at 60 ° angle positions on both sides, and with the center as the center of the battery lid. A circle passing through the center of the inlet was provided so as to pass through the center of the bottom of the vent (the center in the diameter direction of the battery lid). The width of the bottom of the vent (the width in the battery lid diameter direction) was 1.2 mm. Furthermore, the terminal body is installed in the battery cover through the insulation packing made from a polypropylene similarly to what is shown in FIG.

  A polypropylene insulating plate having a thickness of 0.2 mm was inserted into the inner bottom surface of the battery can, and the wound electrode body to which the positive electrode lead body and the negative electrode lead body were attached was inserted with the positive electrode lead body facing upward. Subsequently, the negative electrode lead body was resistance welded to the inner surface of the battery can, and the positive electrode lead body was resistance welded to the lower surface of the terminal body of the battery lid after inserting an insulating plate (similar to that shown in FIG. 3). At this point, the insulation resistance was measured and it was confirmed that there was no short circuit. Thereafter, the battery lid was fitted to the opening end of the battery can, and the outer peripheral portion of the battery lid and the inner peripheral surface of the opening end portion of the battery can were welded and sealed by laser welding.

In addition, the following were used for the said wound electrode body.
[Positive electrode]
Carbon black: 3% and manganese dioxide (manufactured by Tosoh Corporation): 92% are mixed by a dry method using a planetary mixer for 5 minutes, and then water is added so that the solid content is 20% by mass ratio. For another 5 minutes. To the resulting mixture, PTFE dispersion (“D-1” manufactured by Daikin Industries, Ltd.) as a solid content was added in a state of 5% diluted in the remaining water and mixed for 5 minutes to prepare a compounding agent. The water content in the final compounding agent was 30 with respect to the solid content of 100 by mass ratio.

  Using the above-mentioned compounding agent, two rolls having a diameter of 250 mm, adjusting the roll temperature to 130 ± 5 ° C., and rolling under the conditions of press pressure: 7 ton / cm, roll interval: 0.4 mm, rotation speed: 10 rpm Rolling and sheeting was 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 PTFE 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 gap between the rolls was adjusted to 0.6 ± 0.05 mm, the roll temperature was 120 ± 10 ° C., the press pressure was 7 ton / cm, and the rotation speed was 10 rpm. Cut to dimensions. This positive electrode sheet had a thickness of 1.0 mm and a density of 2.5 g / cm ³ .

  As described above, two positive electrode sheets for inner circumference and outer circumference were produced. The positive electrode sheet for the inner periphery was 37 mm in width and 51 mm in length, and the positive electrode sheet for the outer periphery was 37 mm in width and 62 mm in length.

An expanded metal made of stainless steel (SUS316) was used as a current collector for the positive electrode. This expanded metal is cut to 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 is attached to the central portion in the length direction by resistance welding as a positive electrode lead body. It was. A carbon paste (manufactured by Nippon Graphite Co., Ltd.) was applied to the current collector to such an extent that it was not crushed by the mesh, and then dried at a heating temperature of 105 ± 5 ° C. for 2 hours or more. Here, the carbon paste was applied so as to be 5 mg / cm ² .

  Next, three positive electrodes were integrated by fixing only one end in the length direction with a current collector interposed therebetween. Specifically, the two positive and negative electrode sheets for the inner and outer circumferences are set so that one end in the length direction is aligned and the end of the current collector does not protrude from the positive electrode sheet. The three parties were integrated by press-bonding 5 mm from the end of each. Subsequently, the positive electrode sheet and the current collector were dried with hot air at 250 ± 10 ° C. for 6 hours to obtain a positive electrode. Note that the two positive electrode sheets and the current collector are integrated here for the convenience of work. Even if the independent positive electrode sheet and the current collector are integrated at the time of winding, there is no problem in characteristics. Absent.

[Production of negative electrode]
Metal lithium having a width of 37 mm and a thickness of 0.28 mm was cut into a short metal lithium foil having a length of 46 mm and a long metal lithium foil having a length of 82 mm, and these were used for producing a negative electrode. And as metal foil used as a collector, the copper foil of width: 37mm, length: 135mm, thickness: 0.010mm is used, width: 3mm, length: 20mm, thickness to long metal lithium foil; After crimping a 0.1 mm nickel negative electrode lead body, a copper foil and a long metal lithium foil are overlapped and crimped about 10 mm from the end on the winding start side, and further a short metal The lithium foil is overlapped on the copper foil inside the end of the crimped portion between the ultra-thin metal lithium foil and the copper foil (the inner end of the copper foil), and is crimped by about 10 mm from the end of the short metal lithium foil. A negative electrode was produced. 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.] with a width of 44 mm and a thickness of 0.025 mm is cut into 140 mm and used as a separator, and sandwiched between two winding cores with a diameter of 4 mm: 4 mm I rolled one lap. After winding the negative electrode one turn at the same time as the separator, the fixed side of the positive electrode sheet was placed on the winding core side and wound three times. After winding, the copper foil covered the outermost periphery. Thus, a wound electrode body was obtained.

After the battery lid and battery can were sealed by welding, an electrolyte solution was injected into the battery. As the electrolytic solution, a non-aqueous electrolytic solution prepared by dissolving LiClO ₄ in a molar ratio of 1: 2 in a mixed solvent of propylene carbonate (PC) and dimethoxyethane (DME) at 0.5 mol / l was used. When injecting the electrolyte, a jig having a mechanism for holding the side wall of the battery can of the battery precursor provided in the apparatus using an electrolyte injection apparatus having an injection nozzle provided with a rod-shaped alignment member The alignment member is configured to hold the battery precursor and to change the phase by a rotation operation that rotates the axis passing through the longitudinal center of the battery precursor (the axis passing through the center of the battery lid and the center of the bottom of the battery can). Was placed in the recess provided on the battery lid to position the battery precursor. After positioning the battery precursor, the electrolyte solution was injected in three portions, and the entire amount was injected under reduced pressure in the final step. Subsequently, a rivet-shaped sealing member was loaded into the electrolyte inlet, and was welded and sealed by laser welding to obtain a cylindrical battery having an outer diameter of 17 mm and a height of 45 mm.

Example 2
The battery precursor before injection of the electrolytic solution produced in the same manner as in Example 1 was held with a holding jig as shown in FIG. This holding jig has a mechanism for holding the side wall of the battery can of the battery precursor, and a mechanism for fixing the position after the positioning of the battery precursor. For the battery precursor held by the holding jig, an instrument having a rod-shaped alignment member is used to pass the axis passing through the center in the longitudinal direction of the battery precursor (the center of the battery lid and the center of the battery can bottom). The battery precursor was positioned by fitting the alignment member into the recess provided in the battery lid while the phase was changed by a rotation operation that rotates the shaft), and the position was fixed by a holding jig.

  By fixing the battery precursor positioned on the holding jig together with the holding jig to the fixing jig of the electrolytic solution injection device, the electrolytic solution injection port of the battery precursor and the injection nozzle of the electrolytic solution injection device The position of was adjusted. Subsequently, an electrolytic solution was injected into the battery precursor in the same manner as in Example 1. A rivet-shaped sealing member is loaded into the electrolyte inlet of the battery precursor after the electrolyte is injected, and the holding jig is fixed to the fixing jig of the laser welding apparatus together with the holding jig, so that the planned welding position (electrolyte) The inlet) was aligned with the laser. And it sealed by welding on the same conditions as Example 1, and obtained the cylindrical battery.

  Thus, in the cylindrical batteries of Example 1 and Example 2 using the battery lid provided with the above-described recess, the injection nozzle and the electrolyte injection port were aligned while being checked with the camera when the electrolyte was injected. Compared with the conventional method of manufacturing a cylindrical battery, it was confirmed that the time required for the electrolyte injection step can be remarkably shortened and the production rate can be greatly improved. In addition, it was confirmed that the electrolyte injection device does not require a precision device such as a camera for position confirmation, and the cost and maintenance of the device can be omitted.

It is a plane schematic diagram showing an example of a battery lid for cylindrical batteries of the present invention. It is the plane schematic which shows the other example of the battery cover for cylindrical batteries of this invention. It is a section schematic diagram showing an example of a cylindrical battery of the present invention. It is a perspective view which shows a mode that the cylindrical battery precursor was hold | maintained with the jig | tool for holding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Battery cover for cylindrical batteries 11 Electrolyte injection port 12 Recess 13 Terminal body 14 Vent 15 Insulation packing 20 Cylindrical battery 20a Cylindrical battery precursor 21 Battery can 22 Electrode body 23 Positive electrode lead body 24 Negative electrode lead body 25 Insulating plate 26 Base part 27 Side wall 28 Gas inlet 29 Insulating plate 30 Holding jig

Claims (6)

A battery lid that is circular in plan view for constituting the outer casing of a cylindrical cylindrical battery,
The battery lid has a terminal body at the center, and has an electrolyte inlet for injecting an electrolyte into the battery, and positions of an injection nozzle of the electrolyte injector and the electrolyte inlet If you are have a recess for matching,
When the center of the battery lid is used as a reference point, the internal angle formed by the line segment passing through the center of the electrolyte solution inlet and the reference point and the line segment passing through the center of the recess and the reference point is 30 to 180 °. cylindrical battery battery lid, characterized in der Rukoto.   The battery lid according to claim 1, wherein the battery lid has two or more concave portions. A positive electrode, a negative electrode, a power generating element comprising a separator and an electrolyte is loaded, the battery can of a bottomed circular cylindrical having an upper opening, a battery lid according to claim 1 or 2,
The opening end of the battery can and the peripheral edge of the battery lid are welded and sealed,
A cylindrical battery characterized in that the electrolyte inlet of the battery lid is sealed with a sealing member inserted and welded. A bottomed circular cylindrical batteries the can having an upper opening, at least the positive electrode was charged with the negative electrode and the separator, a circular battery cover in a plan view, fitted into the opening of the battery can, of the battery cans A step of welding and sealing the open end and the peripheral portion of the battery lid to form a cylindrical battery precursor; and a step of injecting an electrolyte from the electrolyte inlet of the battery lid of the cylindrical battery precursor; , A method of manufacturing a cylindrical battery having a step of inserting a sealing member into the electrolyte solution inlet and performing welding sealing,
The battery lid has a terminal body at the center, and the electrolyte inlet for injecting the electrolyte into the battery can, the injection nozzle of the electrolyte injector, and the electrolyte inlet are aligned. And a line passing through the center of the electrolyte inlet and the reference point, and a line passing through the center of the recess and the reference point. Use a battery lid with an internal angle of 30-180 °,
Prior to the electrolyte injection step, an alignment member is inserted into the concave portion of the battery lid of the cylindrical battery precursor in order to align the electrolyte injection port and the injection nozzle of the electrolyte injection device. Thus, the cylindrical battery precursor is positioned, thereby manufacturing a cylindrical battery.   The manufacturing method of Claim 4 which positions the said cylindrical battery precursor using the electrolyte solution injection apparatus which has the injection | pouring nozzle provided with the said alignment member. Holding the cylindrical battery precursor with a holding jig, positioning the cylindrical battery precursor with an instrument having the alignment member, and fixing the position to the holding jig;
Subjecting the tubular battery precursor to the electrolyte injection step while being held in the holding jig,
Furthermore, the manufacturing method of Claim 4 which uses for the welding sealing process of an electrolyte injection port in the state which hold | maintained the said cylindrical battery precursor after electrolyte injection with the said holding jig.

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