JP2946127B2 - Battery and battery manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery using an electrode plate processed into a state of being combined with a battery, such as a pellet, a tube, or a sheet, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the use of highly integrated semiconductors has increased in recent years, and the cost has been low.
Cordless use is progressing. Against the background of the growing market needs for such high-performance electronic devices, the power supplies used are also being directed to using small batteries as much as possible. In particular, batteries having a high energy density, a wide operating temperature range, and excellent liquid leakage resistance, such as organic electrolyte batteries, are rapidly expanding their use range.

A flat battery as an example of the organic electrolyte battery will be described below with reference to the drawings.

[0004] In FIG. 2, reference numeral 1 denotes a positive electrode plate formed by pressing a positive electrode active material mainly composed of manganese dioxide into a pellet shape, which is press-fitted into a positive electrode can 2. Reference numeral 3 denotes a negative electrode can having a negative electrode plate 4 made of a negative electrode active material mainly composed of lithium, 5 is a separator impregnated with an organic electrolyte and interposed between the positive and negative electrodes, and 6 is a positive electrode between the positive electrode can 2 and the negative electrode can 3. This is an insulating packing that intervenes and liquid-tightly seals both so as not to leak to the outside.

In the production of the battery having the above-described structure, the electrolyte in the battery must be sufficiently absorbed by the electrode plate, particularly the positive electrode plate 1, and after the electrolyte is well absorbed by the electrode plate, the positive electrode can 2 There is a so-called sealing step of fitting the battery pack and the negative electrode can 3 with the insulating packing 6 interposed therebetween. However, the electrolytic solution is hardly absorbed by the molded electrode plate, and in the sealing step, if the electrolytic solution is not sufficiently absorbed by the electrode plate, the electrolytic solution overflows from the inside of the battery, and the discharge duration of the battery is reduced. There were problems such as being short and the appearance of the battery being dirty. For this reason, conventionally, after the electrolyte is injected into the battery, the battery is stored in the production line without being sealed, and the electrolyte in the battery is sufficiently absorbed by the electrode plate, and then the process shifts to the sealing step. Was. Therefore, the batteries must be stored in the production line before the sealing step in order to allow the electrode plate to sufficiently absorb the electrolyte, and there is a problem that the productivity of the batteries cannot be increased due to the storage time.

[0006]

As described above, conventionally, since the absorption of the electrolyte solution of the electrode plate is not good, the productivity of the battery cannot be increased, and the cost has been increased.

That is, it is necessary to form the electrode plate so as to absorb the electrolyte well. The problem we are trying to solve is
It is a point to clarify a measure for obtaining an electrode plate having good electrolyte solution absorbability which can enhance battery productivity.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides an electrode plate formed into a form used in a battery by 50% of the apparent surface area.
Is brought into contact with 1,2-dimethoxyethane (hereinafter referred to as DME), and an electrode plate having an absorption capacity of a lower limit of 40 milligrams per gram of the electrode plate after 1 minute from the contact is used as a battery. It has been used to establish a highly productive manufacturing method.

[0009]

In the battery using the electrode plate according to the present invention, since the electrolyte is sufficiently absorbed in the electrode plate in a short time, even if the production line is speeded up, the electrolyte does not overflow from the battery in the closing step. Things.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

The structure of the battery is exactly the same as that shown in FIG. FIG. 1 is a block diagram illustrating the steps of the battery manufacturing method of the present invention.

In FIG. 1, the first step is a step of forming a pellet-shaped positive electrode plate, in which a powder obtained by mixing manganese dioxide and a binder is formed into a pellet. And the above-mentioned pellet-shaped positive electrode plate is placed in a container in which
When immersed for 1 minute and pulled up, 40 g
Milligrams of DME had been absorbed. The immersion area of the positive electrode plate immersed in the container containing DME by the clamping body was 50% of the whole. The second step is a step of pressing the pellet-shaped positive electrode plate into a positive electrode can, the third step is a step of injecting an electrolytic solution into the positive electrode can, and the fourth step is a step of accommodating the negative electrode through the insulating packing of the positive electrode can. This is a sealing step in which the thus-formed negative electrode cans are fitted and both are sealed in a liquid-tight manner. As described above, according to the production method of the present invention, since the electrode plate has a good ability to absorb the electrolytic solution, the electrolyte solution is poured into the positive electrode can containing the positive electrode plate as in the related art, and the positive electrode can is left unsealed. Since there is no need for a pooling step for storing, it is possible to shift to the sealing step next to the electrolyte injection step, and the productivity is high.

Next, a flat type battery was prepared with a diameter of 20 mm and a thickness of 3.2 mm.
The flat battery was manufactured using positive electrode plates A, B, C, D, and E having different DME absorption amounts, and combined with other battery elements to produce 100 flat batteries. After contacting 50% of the apparent surface area of each positive electrode plate with DME, the amount of DME absorbed per gram of the positive electrode plate after 1 minute, the amount of electrolyte overflowing from the inside of the battery in the battery sealing step, and the Table 1 shows the discharge capacity.

[0014]

[Table 1]

As is clear from Table 1, the positive plates D, E
Indicates that when 50% of the apparent surface area was brought into contact with DME, the amount of DME absorbed one minute after the contact exceeded 40 mg per gram of the positive electrode plate.
Batteries using B, A, and C, which have less DME absorption than the positive plates D and E, have a larger discharge capacity,
In addition, the difference is that there is no amount of electrolyte overflowing out of the battery in the closing step at the time of the high-speed production line, and it can be seen that the positive electrodes D and E are excellent in both productivity and discharge performance. Then, the positive electrode plate D is a 1000 mg positive electrode.
The active material is pressurized with a pressure of 10 tons, and the thickness is 1.75 to
1.77 mm, so that the electrode plate density was 3.77 mm.
03 to 3.00 g / cm ³ . Also positive
The electrode plate E pressurizes 950 mg of the positive electrode active material at a pressure of 8 tons.
And the thickness is 1.75 to 1.77 mm,
Therefore, the electrode plate density was 2.88 to 2.85 g / cm ³ .
Things. The amount of DME absorbed by the positive electrode
Positive electrodes A, which are less than D and E and different from the present invention.
B and C are as follows. That is, the positive electrode plate B is 115
0 mg of the positive electrode active material is pressurized at a pressure of 16 tons to reduce the thickness.
1.75 to 1.77 mm
Density is 3.59~3.46g / cm ^3. Also positive
The electrode plate A is obtained by applying 1100 mg of the positive electrode active material at a pressure of 14 tons.
Pressurized to a thickness of 1.75 to 1.77 mm
Therefore, the electrode density is 3.59-3.46 g / cm ³ .
is there. The positive electrode plate C contained 1050 mg of the positive electrode active material in one.
Pressurized with a pressure of 2 tons, thickness 1.75-1.77mm
Therefore, the electrode plate density was 3.27 to 3.1.
5 g / cm ³ . The positive electrode active material of the positive electrode plate is
All manganese dioxide, Ketjen black as a conductive agent
And polyfluoroethylene as a binder in a weight ratio of 9
It was mixed at a ratio of 0: 5: 5.

[0016]

[0017]

Further, the same results as in Table 1 were obtained when the form of the electrode plate was not limited to a pellet, but was a cylinder, rod or sheet.

[0019]

The battery using the electrode plate according to the present invention does not require an inefficient production line in which the electrode plate stores the electrolyte before absorbing the electrolyte, and the storage time for the above-mentioned purpose is not required. Thus, even in a closing step of a high-speed operation production line in which the number of cells is reduced, there is no overflow of the electrolyte and a battery having good discharge performance can be manufactured with high productivity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing steps of a battery manufacturing method according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a flat battery according to the present invention and a conventional example.

[Explanation of symbols]

 Reference Signs List 1 positive electrode plate 2 positive electrode can 3 negative electrode can 4 negative electrode plate 5 separator 6 insulating packing

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-145435 (JP, A) JP-A-1-248471 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01M 4/02-4/04

Claims (2)

(57) [Claims] (1) When 50% of an apparent surface area of an electrode plate formed into a form in a battery is brought into contact with 1,2-dimethoxyethane, the absorption amount of 1,2-dimethoxyethane after one minute from the contact is measured. A battery using an electrode plate having an absorption performance of a lower limit of 40 milligrams per gram of the electrode plate. 2. A predetermined electrolyte is injected into an unsealed battery containing the electrode plate according to claim 1, and the battery is unsealed so that the electrode plate absorbs the electrolyte. A battery manufacturing method that directly shifts to the closing step of a production line in which the storage time is not set.