JP2014164862A - Lithium battery manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithium battery manufacturing method capable of improving safety and productivity while achieving good long-term storage performance.SOLUTION: The method includes: steps (s1-s6) of housing a positive electrode mixture 3, a negative electrode lithium 4 and an electrolyte in a bottomed battery can 2 having a positive electrode terminal part 11; sealing steps (s7-s11) of fitting a sealing body 9 including the negative electrode terminal part 7 with an opening of the battery can via a gasket 10; and a preliminary discharge step (s12) after the sealing step. Among respective execution periods of plural steps included in the sealing step, and a battery can conveying period during steps before and after the plural steps, within two predetermined periods, advance discharging steps (s7b-s11b) of short-circuiting between the battery can and the sealing body are executed. In the preliminary discharge step, a predetermined load is connected between the positive electrode terminal part and the negative electrode terminal part for a predetermined time, and discharging is done so that a total discharge capacity of a gross discharge capacity in the advance discharging step becomes a predetermined ratio of capacity to the theoretical capacity.

Description

  The present invention relates to a method for manufacturing a lithium battery, and more particularly to a preliminary discharge process for a lithium battery after assembly.

  A lithium battery using a positive electrode using manganese dioxide, fluorinated graphite, copper oxide, or the like as a positive electrode active material, a negative electrode including a negative electrode active material made of lithium metal or a lithium alloy, and an organic electrolyte has a high energy density. In addition, it has excellent storability and is widely used as a power source and backup for various small portable devices.

  By the way, the outstanding preservation | save performance in a lithium battery is acquired by performing the process called preliminary discharge in the manufacturing process of a battery. The preliminary discharge is performed by discharging a predetermined ratio (for example, 1 to 3%) of capacity with respect to the theoretical capacity in advance immediately after battery assembly. Accordingly, in the lithium battery, lithium ions are electrochemically inserted into the positive electrode active material, the activity of the positive electrode active material is lowered, and deterioration of characteristics due to decomposition of the electrolyte during storage is prevented.

  Specifically, when an organic electrolyte mainly composed of propylene carbonate (PC) is used as an electrolyte in a lithium battery, and a carbon material is included as a conductive material in the positive electrode, the decomposition potential of PC is 0.8V. If the potential on the positive electrode side is less than 0.8 V with respect to metallic lithium, the PC is decomposed to generate a resistor on the surface of the carbon material, and gas is generated accordingly.

  Therefore, in the conventional method of manufacturing a lithium battery, a predetermined capacity is predischarged by flowing a small current over a long period of time while monitoring so as not to be below the decomposition potential of the PC during the predischarge process after assembly. The following Patent Document 1 discloses a technique for improving the storage performance of a lithium battery by defining predischarge conditions and the like. Non-Patent Document 1 below describes in detail the standards and performances of commercially available lithium batteries.

JP 2009-152030 A

Ina Denki Co., Ltd., “Handling Manufacturer List, Sanyo Electric, Lithium Battery”, [online], [Search on December 25, 2012], Internet <URL: http://www.inedenki.co.jp/pdf/ sanyo_lit.pdf>

  As described above, in the lithium battery, preliminary discharge after assembly is an essential process, and the preliminary discharge includes a small current including the technique described in Patent Document 1 in order to suppress decomposition of the electrolytic solution. In a so-called “constant current method”. For this reason, it has been difficult to dramatically improve the productivity of lithium batteries. Further, in the preliminary discharge by the constant current method, the discharge is performed while monitoring the current for each of the batteries, so that the equipment used for the preliminary discharge becomes complicated and the initial cost in the manufacturing equipment is increased. Furthermore, since the discharge is performed while monitoring the current, if any trouble occurs in the current monitoring system of the facility related to the preliminary discharge, an unintended large current may continue to flow and the battery may even ignite.

  Therefore, it is conceivable to perform preliminary discharge in a “short circuit method” in which a current is passed in a state where the positive and negative electrodes of the battery are short-circuited at a predetermined time, but in this short circuit method, a large current flows in the battery, Various problems accompanying it occur. Specifically, in the preliminary discharge by the short circuit method, the temperature in the battery rises due to Joule heat. And since there exists a difference in heat conductivity and heat capacity in each location in a battery, the rise characteristic of the temperature becomes non-uniform in a battery. That is, a temperature difference is generated in the battery. And the metallic lithium fine powder which comprises a negative electrode accumulates in a battery by the Seebeck effect accompanying the temperature difference. If the lithium fine powder enters the porous structure of the separator, an extremely fine short circuit (fine short circuit) occurs.

  The micro short circuit caused by the fine lithium powder causes a loss of a small amount of capacity equivalent to several percent below the decimal point at a 10-year rate when the battery is stored for a long period of time. Certainly, the absolute value of the capacity lost due to the fine short circuit is very small. However, a bobbin-type lithium battery is required to have a performance that can retain 95% of the initial capacity for 10 years, and even if the capacity that is lost due to a fine short circuit is small, it is required for the lithium battery. Performance may not be maintained.

  Accordingly, an object of the present invention is to provide a method for producing a lithium battery that can improve safety and productivity while achieving good long-term storage performance.

In order to achieve the above object, the present invention provides a bottomed metal battery can having a positive electrode terminal portion, as a power generation element, a positive electrode made of a positive electrode mixture and a negative electrode active material made of lithium metal or a lithium alloy. Containing a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte are accommodated, and the opening of the battery can is upwardly connected to the negative electrode. A method for producing a lithium battery that is sealed with a metal seal in a state of
Inserting the power generation element into the battery can and injecting the organic electrolyte into the power generation element filling step;
A sealing step of fitting the sealing body including the negative electrode terminal portion into the opening of the battery can via a gasket;
For the lithium battery assembled by the sealing step, a preliminary discharge step for discharging a predetermined electric capacity,
Including
The sealing step further includes a plurality of steps, and each of the execution periods of the plurality of steps and a predetermined two or more periods among the periods in which the battery can is transported between the steps preceding and following the plurality of steps. In performing a pre-discharge step of short-circuiting between the battery can and the sealing body,
In the preliminary discharge step, a predetermined load is connected between the positive electrode terminal portion and the negative electrode terminal portion for a predetermined time, and the total discharge with the total discharge capacity in the preliminary discharge step executed in the two or more periods Discharging so that the capacity becomes a predetermined ratio of capacity with respect to the theoretical capacity,
This is a method for manufacturing a lithium battery.

  Further, in the sealing step, as the plurality of steps, a sealing plate arranging step of arranging a sealing plate in an electrically connected state with the negative electrode in the battery opening via a gasket, and a top of the sealing plate Negative electrode terminal plate laminating step of laminating the negative electrode terminal plate to be the negative electrode terminal portion, curling step of bending the edge of the opening of the battery can inward, and caulking the opening of the battery can inward And a caulking step of fitting the sealing body composed of the sealing plate and the negative electrode terminal plate in a laminated state into the opening of the battery can, and in an execution period of any two or more of the plurality of steps It can also be set as the manufacturing method of a lithium battery which performs the said preliminary discharge process. The load is more preferably 30Ω or more.

  According to the method for manufacturing a lithium battery according to the present invention, productivity can be improved and safety during manufacturing can be ensured. In addition, a lithium battery having good long-term storage performance can be provided. Other effects will be clarified in the following description.

It is a structural diagram of a bobbin type lithium battery. It is a figure which shows an example of the assembly procedure of a bobbin type lithium battery. It is a figure which shows the manufacturing method of the lithium battery which concerns on the Example of this invention.

=== Technical idea of the present invention ===
As described above, in the conventional method for manufacturing a lithium battery in which preliminary discharge is performed by the “constant current method”, improvement in productivity is not expected. However, if 1 to 3% of the capacity is discharged by the short-circuit method, deterioration of long-term storage characteristics due to heat generation becomes a problem. There is also a problem that the PC constituting the electrolytic solution is decomposed to generate gas.

  However, since it is clear that the productivity is improved by adopting the preliminary discharge by the short-circuit method, the present inventor avoided various problems related to this method while using the preliminary discharge by the short-circuit method as a basis. I searched for a possible method. Specifically, the time from the current flowing to the generation of heat by actually performing preliminary discharge by the short circuit method and measuring each part of the outer surface of the battery can with a thermocouple while discharging at room temperature Etc. were examined. And about 10 minutes after the discharge start, it discovered that a temperature difference generate | occur | produces in a battery, and a temperature difference will become still larger if external temperature is low. On the other hand, the time from when the current flows until it generates heat, or the time until the PC in the electrolyte decomposes is not instantaneous, and if it is several seconds to several tens of seconds, preliminary discharge by short circuit is possible. I also found that there was.

  Of course, the required 1 to 3% capacity cannot be discharged by preliminary discharge of several seconds to several tens of seconds. Although it is conceivable to divide the short-time preliminary discharge by the short-circuit method into a large number of times, it is necessary to discharge 1 to 3% of the capacity after assembly, so even if the time required for one preliminary discharge is short As long as the preliminary discharge cannot be performed continuously, considering the time interval of the preliminary discharge before and after and the number of preliminary discharges, the overall time required for the preliminary discharge cannot be drastically reduced. It cannot be improved.

  Therefore, the present inventor decided to discard the conventional common sense that the preliminary discharge is performed after the lithium battery is assembled. As long as the power generation element composed of the positive electrode, the negative electrode, the separator, and the electrolytic solution is filled in the battery can, the discharge itself is possible, and the current lithium battery assembly process is in a dischargeable state. From the point in time until assembly is completed, a process that allows the positive electrode and the negative electrode to be in contact with each other simultaneously, such as simultaneously holding a part of the battery can also serving as the positive electrode terminal and the metal part connected to the negative electrode Focused on the fact that there are several.

  Conventionally, jigs and manufacturing apparatuses used in the process of simultaneously touching a positive electrode and a negative electrode are configured so as not to cause a short circuit. For example, at least a part that touches a battery is made of an insulator, or is positive or negative. The terminal did not short-circuit. And the execution period of the process which touches both these positive electrodes and negative electrodes is about 5 to 10 seconds, and if it is in this time, the micro short circuit resulting from the heat_generation | fever by a short circuit or decomposition | disassembly of PC in electrolyte solution will be carried out. And so on. The present invention has been conceived as a result of intensive investigations starting from the above-mentioned destruction of common sense and the point of interest obtained by the destruction.

=== Structure of lithium battery ===
FIG. 1 shows a schematic configuration of a lithium battery which is an object of the present invention. The lithium battery 1 shown here is called a cylindrical bobbin type (or inside-out type), and in this figure, a longitudinal sectional view when the extending direction of the cylindrical shaft 100 is the vertical (vertical) direction. Is shown. The lithium battery 1 includes a bottomed cylindrical battery can 2 also serving as a positive electrode terminal, a positive electrode mixture 3 formed into a hollow cylindrical shape, a negative electrode 4, a cylindrical cup-shaped separator 5, a negative electrode terminal plate 7, and the like. Has been.

  The battery can 2 is made of metal, and a convex positive terminal portion 11 is formed on the outer bottom surface thereof by pressing. The positive electrode mixture 3 is obtained by molding and solidifying a mixture of manganese dioxide (EMD) serving as a positive electrode active material, a carbon material serving as a conductive material, and a fluorine-based binder (PTFE) into a hollow cylindrical core. It is used. The separator 5 has a cylindrical bag shape and is made of a composite material made of polypropylene, polyethylene, and glass fiber.

  The negative electrode 4 is formed by rolling a metallic lithium plate as a negative electrode active material into a hollow cylindrical shape, and one end portion 6a of the negative electrode lead 6 is attached in advance to a part thereof. The negative electrode lead 6 is a strip-shaped metal thin plate, and its one end 6a is connected to the negative electrode 4 in a state of being fixed in a planar shape, thereby forming a negative electrode current collector. There is also a lithium battery that uses a lithium alloy (for example, lithium-aluminum alloy) for the negative electrode 4.

  Further, with the opening end 13 side of the battery can 2 facing upward, the upper opening of the battery can 2 is sealed by the sealing body 9 via the gasket 10. The sealing body 9 is formed by laminating a disc-shaped sealing plate 8 below the flat plate-shaped metal negative electrode terminal plate 7, and the other end 6 b of the negative electrode lead 6 is spot welded to the lower surface of the sealing plate 8. Has been. Thereby, the negative electrode terminal plate 7 and the negative electrode 4 are in an electrically connected state.

=== Assembly of lithium battery ===
FIG. 2 shows an example of an assembly process of the lithium battery 1 having the above structure. First, a cylindrical insulator (insulating cylinder) is detachably mounted on the battery can 2 in which the positive electrode mixture 3 is inserted in advance (s1), and then the separator 5 is disposed inside the positive electrode mixture 3. (S2). Then, the negative electrode 4 with the one end 6a of the negative electrode lead 6 fixed thereto is inserted into the ring-shaped positive electrode mixture 3 through the separator 5 (s3).

  Next, the beading portion 12 is formed around the upper end side of the battery can 2 and the other end portion 6b of the negative electrode lead 6 is welded to the sealing plate 8 placed via the gasket 10 (s4, s5). Next, an organic electrolyte containing PC as a solvent is injected into the battery can 2 (s6). After the injection, the sealing plate 8 is inserted into the battery can 2 (s7). At this time, the sealing plate 8 is placed with the previous beading portion 12 as a seat through the gasket 10. Further, the negative electrode terminal plate 7 is inserted into the battery can 2 while being laminated above the sealing plate 8 (s7). Then, after the insulating cylinder mounted on the battery can 2 is removed, the opening end 13 of the battery can 2 is subjected to curling (bending) processing (s8, s9). Further, the area from the beading 12 to the opening end 13 of the battery can 2 is caulked inward to seal and seal the battery can 2 (s10). The assembly of the lithium battery 1 is completed through the above steps. Each member such as the battery can 2, the separator 5 and the gasket 10 into which the positive electrode mixture is inserted is subjected to a drying process in advance, and the above-described battery assembly is assembled in a dry atmosphere.

=== Embodiment of the Invention ===
The lithium battery manufactured by the manufacturing method according to the embodiment of the present invention has the same structure as the bobbin type lithium battery 1 shown in FIG. However, the method has a feature in the manner of preliminary discharge, and thereby has succeeded in improving the productivity of the lithium battery and the long-term storage characteristics of the lithium battery after manufacture. Schematically, during the assembly process of the lithium battery 1 described above, a part of the battery can 2 such as the positive electrode terminal part 11 and a part electrically connected to the negative electrode 4 (negative electrode terminal plate 7, sealing plate). 8) etc., there are several steps to contact at the same time. Therefore, in the method for manufacturing a lithium battery according to an embodiment of the present invention, preliminary discharge is performed by a short-circuit method during the execution period of the step of simultaneously contacting the positive electrode and the negative electrode included in the assembly step of the lithium battery 1 described above. A characteristic is that a part of the capacity for preliminary discharge is discharged before the assembly of the lithium battery 1 is completed.

  In the assembly process shown in FIG. 2, the jig and the manufacturing machine are, for example, a sealing plate insertion step (s 7), a negative electrode terminal plate insertion step (s 8), an insulating tube removal step (s 9), a curling step (s 10), In the caulking process (s11) or the like, the positive electrode terminal portion 11 and the negative electrode terminal plate 7 are simultaneously contacted. Therefore, after all the power generation elements (the positive electrode mixture 3, the negative electrode 4, and the electrolytic solution) are accommodated in the battery can 2, and the step of simultaneously contacting the positive electrode terminal portion 11 and the negative electrode terminal (hereinafter, the terminal portion contact step) If the jig or the manufacturing machine used in (1) is configured with a conductor, or the portion in contact with the positive electrode terminal portion 11 and the negative electrode terminal plate 7 is electrically connected, these terminal portion contacts During the process, the positive electrode and the negative electrode are short-circuited, and a part of the capacity is discharged. FIG. 3 shows a method for manufacturing a lithium battery according to an embodiment of the present invention. In all the steps (s7a to s11a) corresponding to the terminal portion contact step (s7 to s11) in the assembly process shown in FIG. 2, preliminary discharge (hereinafter referred to as predischarge: s7b to s11b) by the short circuit method is performed. . Then, after the assembly is completed, of the discharge capacity that is finally required, the capacity that has not been discharged by the pre-discharge is preliminarily discharged (hereinafter, main discharge) (s12).

=== Effectiveness of Manufacturing Method According to Examples ===
In the manufacturing method shown in FIG. 3, in the main discharge step (s12) after the assembly is completed, even if the discharge is performed by the constant current method similar to the conventional method, since a part of the capacity is discharged by the preliminary discharge, it is ensured. The discharge time can be shortened. However, since the preliminary discharge by the constant current method itself takes a long time and it is necessary to consider the risk due to the trouble of the current monitoring system, the manufacturing method according to the embodiment of the present invention uses the main discharge. In the step (s12), the preliminary discharge is performed by a method of connecting a predetermined load (fixed resistance) between the positive and negative electrodes (hereinafter referred to as a constant resistance method), so that the time required for the preliminary discharge is reduced while ensuring safety. To make it shorter. Of course, even if the preliminary discharge time can be shortened, if the open circuit voltage (OV) after aging falls below a specified value or the long-term storage characteristics deteriorate, the incidence of defective products increases. In other words, productivity is reduced.

  Therefore, a CR2 / 38L type lithium battery was prepared as a sample, and the effectiveness of the manufacturing method according to the example of the present invention was evaluated based on the presence or absence of preliminary discharge in the manufacturing process of the sample and the conditions of the main discharge. . Specifically, 150 individuals were prepared for each of the four types of samples with different manufacturing conditions, and an initial characteristic test for measuring the open circuit voltage (OV) after aging was performed on all individuals. The appearance rate (%) of individuals that became defective was determined. In this initial property test, a long-term storage property test was performed on individuals whose OV exceeded the standard value. The long-term storage characteristic test was performed by obtaining the defective individual appearance rate (%) at which the OV was below the standard value after the accelerated deterioration test (stored at 70 ° C. for 114 days) corresponding to about 10 years.

  Table 1 below shows the preliminary discharge conditions and test results of each sample.

  In Table 1, Sample 1 is one in which preliminary discharge is performed in a short-circuit manner after assembly without performing preliminary discharge. Samples 2 to 4 were discharged by a pre-discharge process in the process of assembling the samples according to the manufacturing method shown in FIG. 3, and after assembly, resistors of 40Ω, 30Ω, and 20Ω were respectively inserted between the positive and negative electrodes. This discharge was performed. In addition, the total amount of discharge capacity in each of the five preliminary discharge steps (s7b to s11b) shown in FIG. 3 is 0.3% of the theoretical capacity. And in this discharge process (s12), it was made to discharge so that a total discharge capacity might be set to about 2% irrespective of the presence or absence of a prior discharge process (s7b-s11b). Table 1 also shows the discharge capacity (%) during the main discharge.

  From Table 1, Sample 1 which performed the main discharge by the short circuit method without performing the pre-discharge could not satisfy the initial characteristics required by 2.0% of the individuals. In the long-term storage characteristic test, 2.7% of defective individuals were generated. In the preliminary discharge in the short-circuit method, since the battery immediately after assembly is discharged at the maximum current that can be output, a temperature difference occurs in the battery until 2% of the capacity is discharged (about 10 minutes). This temperature difference causes the above-mentioned fine short circuit, which seems to have deteriorated the long-term storage characteristics. In addition, in the short-circuit type preliminary discharge, the closed-circuit voltage during discharge continues to be almost 0 (V), so there is a possibility that a small amount of PC in the electrolyte is decomposed, reduction of manganese in the positive electrode mixture, etc. Conceivable. In any case, it was confirmed that the productivity was lowered in the preliminary discharge by the short circuit method.

  On the other hand, in the samples 2 to 4 subjected to the preliminary discharge, no failure in the initial characteristic test occurred in all the individuals. Further, in the long-term storage characteristic test, in Sample 4 subjected to the main discharge through the 30Ω resistance, 0.6% of defective individuals were generated, but the sample 2 was subjected to the main discharge through the larger 45Ω and 40Ω resistors. In No. 4, no defect occurred in the long-term storage characteristic test. In any case, in samples 2 to 4 in which pre-discharge was performed, both the initial characteristic failure rate and the long-term storage failure rate were drastically reduced compared to sample 1.

  And according to the manufacturing method of a present Example, by performing a preliminary discharge first, the time concerning a preliminary discharge can be shortened reliably and productivity can be improved. Further, since the main discharge is performed by the constant resistance method, there has been a problem in the preliminary discharge by the constant current method. Complex equipment becomes unnecessary, and the initial cost in the production equipment can be reduced. Furthermore, since there is no need to monitor the current, it is not necessary to consider troubles in the facility itself related to preliminary discharge (ignition due to overdischarge, etc.), and safety is high.

  Note that the time required for the main discharge and the connected load are almost inversely proportional. The smaller the load, the shorter the time required for the main discharge. However, if the load is too small, it will be in a state close to a short circuit. More preferably, it is 30Ω or more.

=== Other Embodiments ===
In the above embodiment, as shown in FIG. 3, the preliminary discharge is executed five times during the assembly process, but this number can be increased or decreased. For example, in the step after the liquid injection step, if there is a further opportunity to short-circuit between the positive and negative electrodes, the number is more than five. If the capacity required for pre-discharge can be secured, the number can be less than five. Also, depending on the arrangement relationship of the manufacturing machines and jigs that make up the production line, the battery can may be transported while being gripped by the pick-up of the transfer device between the previous and subsequent processes, and pre-discharge is performed during the transport. Is also possible.

  Further, depending on the production equipment or the type and structure of the battery, the assembly process may be slightly different from that shown in FIG. For example, when assembling a battery can without attaching an insulating cylinder, there is no step of removing the insulating cylinder. Some lithium batteries have a structure in which there is no sealing plate and a negative electrode lead is welded to the lower surface of the negative electrode terminal plate. However, regardless of the type of process and the type and structure of the lithium battery, pre-discharge may be performed in any two or more periods of the appropriate process and transport period.

  Of course, even if there is a process that can short-circuit between the positive and negative electrode terminals and a period of conveyance, if the time that can be short-circuited at that time (hereinafter, short-circuitable time) is too long, a temperature difference may occur in the battery. is there. Therefore, whether or not the pre-discharge is necessary may be determined by the short-circuit possible time at the time of executing the process or at the time of transport. In any case, if a necessary capacity can be discharged without causing a temperature difference, pre-discharge due to a short circuit can be performed during an appropriate process or during conveyance.

  In the above embodiment, the method for manufacturing the bobbin type lithium battery has been described. However, the present invention can also be applied to a method for manufacturing a coin type lithium battery or a cylindrical spiral type lithium battery.

1 bobbin-type lithium battery, 2 battery can, 11 positive terminal, 3 positive electrode mixture,
5 Separator, 4 Lithium negative electrode, 9 Sealing body, 7 Negative electrode terminal plate, 8 Sealing plate,
6 Negative electrode lead, 10 Gasket

Claims (3)

In a bottomed metal battery can having a positive electrode terminal portion, as a power generation element, a positive electrode made of a positive electrode mixture, a negative electrode containing a negative electrode active material made of lithium metal or a lithium alloy, and between the positive electrode and the negative electrode The separator and the non-aqueous electrolyte are contained in the battery can, and the opening of the battery can is turned upward, and the opening is sealed with a metal sealing body in a state of being electrically connected to the negative electrode. A method for producing a lithium battery comprising:
Inserting the power generation element into the battery can and injecting the organic electrolyte into the power generation element filling step;
A sealing step of fitting the sealing body including the negative electrode terminal portion into the opening of the battery can via a gasket;
For the lithium battery assembled by the sealing step, a preliminary discharge step for discharging a predetermined electric capacity,
Including
The sealing step further includes a plurality of steps, and each of the execution periods of the plurality of steps and a predetermined two or more periods among the periods in which the battery can is transported between the steps preceding and following the plurality of steps. In performing a pre-discharge step of short-circuiting between the battery can and the sealing body,
In the preliminary discharge step, a predetermined load is connected between the positive electrode terminal portion and the negative electrode terminal portion for a predetermined time, and the total discharge with the total discharge capacity in the preliminary discharge step executed in the two or more periods Discharging so that the capacity becomes a predetermined ratio of capacity with respect to the theoretical capacity,
A method for producing a lithium battery. In claim 1,
In the sealing step, as the plurality of steps, a sealing plate arrangement step of arranging a sealing plate in an electrically connected state with the negative electrode in the battery opening via a gasket, and the sealing plate on the sealing plate, Negative electrode terminal plate laminating step of laminating a negative electrode terminal plate to be a negative electrode terminal portion, curling step of bending the edge of the opening of the battery can inward, and the laminated state by caulking the opening of the battery can inward A caulking step of fitting the sealing body made of the sealing plate and the negative electrode terminal plate into the opening of the battery can, and the above-mentioned thing in the execution period of any two or more of the plurality of steps A method for producing a lithium battery, comprising performing a pre-discharge step.   3. The method of manufacturing a lithium battery according to claim 1, wherein the load is 30Ω or more.

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