JP4092745B2 - battery - Google Patents

Description

【００２０】
表１に示す結果より、従来例電池に対して実施例電池Ａと実施例電池Ｂとでは電解液の含浸性が明らかに向上していることがわかる。
【００２１】
上記の検討を、電解液の粘度が０．１〜５００ｃＰと異なるものについて実施したところ、電池ケース１の溝部１ａの内面に凹部あるいは凸部によって電解液を誘導する間隙を備えることで電解液の含浸性を向上させることが可能であることがわかった。また、その効果は電解液の粘度が高いものほど顕著であった。
【００２２】
【発明の効果】
以上の説明から明らかなように、本発明によれば、発電要素構成群に対する電解液の含浸性が向上でき、電解液の含浸速度が速くなることにより、電解液の注液工程に必要な時間が短縮して、生産性を向上させることができる。また、電解液の含浸が不充分なことによる電池性能の低下も防止でき、安定した信頼性の高い電池を供給することができる。
【図面の簡単な説明】
【図１】 円筒形リチウムイオン二次電池の縦断面図
【図２】 本発明の実施例におけるスプライン加工を施した電池ケースの縦断面図
【図３】 同スプライン加工を施した電池ケースの横断面図
【図４】 本発明の他の実施例において電解液を誘導する間隙を溝部の内面に打痕により形成した円筒形リチウムイオン二次電池の横断面図
【図５】 従来例における絶縁板の平面図
【符号の説明】
１ 電池ケース
１ａ 溝部
２ 封口蓋
３ 発電要素構成群
４ 正極リード
５ 負極リード
６ 上部の円環状絶縁板
７ 下部の絶縁板
８ 凸部
９ 凸部 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a battery case.
[0002]
[Prior art]
Generally, a battery is manufactured by inserting a power generation element component group consisting of a positive electrode, a negative electrode, and a separator into a battery case, injecting an electrolyte, and sealing the opening of the battery case with a sealing lid or the like. It is normal. In order to extract the voltage from the battery, a current collector such as a metal ribbon is used, the positive electrode or the negative electrode is connected to the battery case, and the other electrode not connected to the battery case is connected to the sealing lid. Yes. When this type of battery is subjected to vibration or impact, there is a risk that a part of the positive or negative electrode built into the battery case will come into contact with the sealing lid or battery case connected to the other electrode, causing an internal short circuit. is there. Therefore, the internal short circuit is prevented by disposing an insulating plate on one or both of the upper part and the lower part of the power generation element configuration group. In general, the outer peripheral shape of the insulating plate is a shape along the inner peripheral shape of the battery case. For example, as a shape of a cylindrical battery, an insulating plate R formed in a ring shape as shown in FIG. 5 has been proposed. Such a structure is sufficient to prevent the internal short circuit.
[0003]
[Problems to be solved by the invention]
However, in the battery case and the insulating plate R configured as described above, the electrolyte solution impregnation path is blocked by the insulating plate R in the pouring step when the battery is manufactured. The impregnation property is poor. For this reason, the impregnation rate of the electrolytic solution is slow, and a long time is required for the step of injecting the electrolytic solution. In addition, since the power generation element component group is not sufficiently impregnated with the electrolyte solution, the battery reaction does not sufficiently occur, and the battery performance may be deteriorated.
[0004]
In order to cope with such a problem as described above, the present invention provides a battery case capable of ensuring good impregnation of the electrolytic solution in the electrolytic solution pouring process while preventing an internal short circuit. It is intended to improve the battery performance and stabilize the battery performance.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides an annular shape in which an opening of the battery case is provided with a groove that is recessed from the outer surface, and is in contact with the inner surface of the groove on the upper part of the power generation element configuration group housed in the battery case disposed insulating plates, Ru der those configured to include a gap to induce electrolyte by the annular insulating plate opposed to the concave portion or convex portion provided on the inner surface of the groove. By using the structure of the present invention, the electrolyte impregnation path from the end of the power generation element configuration group can be secured, and the air and the electrolyte at the end of the power generation element configuration group can be easily replaced. Kunar is good impregnation of the electrolytic solution. In particular, it is possible to dramatically improve the impregnation property of the electrolytic solution at the interface between the power generation element constituent group and the battery case. As a result, the impregnation rate of the electrolytic solution is increased, the time required for the electrolytic solution pouring step can be shortened, and the productivity can be improved. In addition, it is possible to prevent a decrease in battery performance due to insufficient impregnation.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
This onset Ming, which can be implemented by embodiments shown in the claims, as claimed in claim 1, provided with a groove that is recessed from the outer surface to the opening of the battery case, which is housed in the battery case An annular insulating plate that is in contact with the inner surface of the groove is disposed on the upper part of the power generation element constituent group, and a gap for guiding the electrolyte is provided by a recess or a protrusion provided on the inner surface of the groove facing the annular insulating plate. with the structure, the electrolyte pour process during cell manufacturing, the electrolyte will be injected into the battery case through the gap between the front Symbol batteries case an annular insulating plate. Accordingly, it is possible to solve the problems of the battery according to the prior art in which the annular insulating plate and the battery case inner surface are in close contact and the electrolyte solution is not easily impregnated in the battery case.
[0007]
The gap for inducing the electrolytic solution formed by the concave portion or the convex portion can be easily provided by a plurality of filaments formed in the height direction of the battery case.
[0008]
In particular, as described in claim 3, it can be efficiently carried out by subjecting the inner surface of the battery case to spline processing.
[0009]
According to the fourth aspect of the present invention, the gap for inducing the electrolyte formed by the convex portion can be easily provided by a dent in a portion facing the annular insulating plate from the outer surface of the battery case.
[0010]
【Example】
Hereinafter, examples of the present invention will be described in detail in comparison with conventional examples.
[0011]
FIG. 1 shows a longitudinal sectional view of a generally known cylindrical lithium ion secondary battery using LiCoO ₂ as a positive electrode active material and carbon as a negative electrode active material. In FIG. 1, 1 is a battery case obtained by processing a nickel-plated steel plate, 2 is a sealing lid, and 3 is a power generation element component group. In the power generation element configuration group 3, a positive electrode plate and a negative electrode plate are wound in a spiral shape a plurality of times through a separator. A positive electrode lead 4 is drawn from the positive electrode plate and connected to the sealing lid 2, and a negative electrode lead 5 is drawn from the negative electrode plate and connected to the inner bottom of the battery case 1. Reference numeral 6 denotes an annular insulating plate on the upper part of the power generation element configuration group 3, and 7 denotes an insulating plate on the lower side of the power generation element configuration group 3. Furthermore, it provided a groove 1a and Nde outer surface or et recess of the battery case 1 in the vicinity of the opening portion of the battery case 1, carrying the sealing lid 2 in the groove portion 1a, sealing the battery by caulking the opening portion of the battery case 1 is doing. The diameter of the battery case 1 is 16.4 mm, the inner diameter of the groove 1a is 13.4 mm, and when the battery case 1 is opened, the distance from the groove 1a to the battery opening end is 5.0 mm, and from the battery case bottom to the battery opening end. Is 50.0 mm, and the power generation element group 3 has an outer diameter of 15.5 mm and a length of 45.0 mm.
[0012]
Here, as the battery case of the cylindrical lithium ion secondary battery, the battery shown in FIG. 1 was prepared using the one provided with the groove 1a in the vicinity of the opening, and a conventional battery was obtained. Then, 2 to the inner surface of the battery case 1 and the splined to the inner surface of the battery case 1, as shown in FIG. 3, to induce an electrolytic solution by a plurality of protrusions 8 forming the filament in the height direction of the battery except for using the battery case 1 formed between gap will produce a battery in exactly the same structure as the conventional example batteries was as example battery a. Further, as shown in FIG. 1 with the same configuration as the conventional battery, as shown in FIG. 4 after providing the groove 1a in the opening of the battery case 1, the battery case 1 is opposed to the upper annular insulating plate 6 as shown in FIG. put two places dent to the inner surface of the groove 1a which, except formed in two places protrusions 9 on the inner surface of the groove 1a to produce a battery in exactly the same structure as the conventional example batteries was as example battery B.
[0013]
3.0 cc of non-aqueous electrolyte was injected into each of these conventional batteries, battery A and battery B, and this was decompressed to 260 mmHg for 4 seconds and then released to the atmosphere. In order to compare the impregnation of the electrolyte solution for each of the batteries thus injected, the power generation element component group was taken out from the battery immediately after being opened to the atmosphere and decomposed, and the area of the electrode plate impregnated with the electrolyte solution , Measure the amount of electrolyte remaining on the power generation element component group near the opening immediately after opening to the atmosphere, and until there is no remaining electrolyte in the battery opening from opening to the atmosphere The above three confirmations and measurements were performed. On the other hand, in order to compare the performance of the conventional battery, the battery A, and the battery B, each battery immediately after injection was sealed, its internal resistance was measured, and the following charge / discharge was performed to determine the battery capacity. It was confirmed. Charging was performed at a maximum current of 0.5 A and 4.1 V constant current constant voltage charging for 2 hours, and discharging was performed at a constant current of 720 mA up to 3.0 V.
[0014]
First, the area of the electrode plate impregnated with the electrolytic solution in the power generation element configuration group immediately after being released to the atmosphere is the largest in the example battery B, which is about 2/3 of the total electrode plate area. The area of the electrode plate impregnated with the electrolyte solution is about 3/5 of the total electrode plate area in Example Battery A, and the most electrode solution impregnated with the electrolyte solution is all electrodes in the conventional battery. It was about 1/10 of the board area.
[0015]
Next, the remaining amount of the electrolyte remaining on the power generation element configuration group in the vicinity of the battery opening immediately after opening to the atmosphere is about 2.2 cc for the conventional battery, and about 0 for the battery A of Example. It was about 0.2 cc in Example Battery B with the smallest remaining liquid amount of .3 cc.
[0016]
Next, the time from the release to the atmosphere until the remaining electrolyte remained in the battery opening is about 20 minutes at the longest for the conventional battery, then about 7 minutes for the battery A of the example, and the shortest is the time for the implementation. Example Battery B took about 5 minutes.
[0017]
On the other hand, the internal resistance of the battery was 700 mΩ, which was the highest for the conventional battery, 120 mΩ for Example battery A, and 110 mΩ for Example battery B, the lowest. The battery capacity of Example Battery B was 700 mAh, which was the largest for Example Battery B, then 690 mAh for Example Battery A, and the lowest was 250 mAh for the conventional battery. This is because the reaction area of the electrode plate in the power generation element configuration group increases or decreases because each battery has different electrolyte impregnation properties for the power generation element configuration group. That is, in Example Battery A and Example Battery B, which have good electrolyte impregnation properties, the reaction area of the electrode plate is larger than that of the conventional battery, so that the internal resistance is low and the battery capacity is increased. .
[0018]
The results are summarized in Table 1.
[0019]
[Table 1]

[0020]
From the results shown in Table 1, it can be seen that in Example Battery A and Example Battery B, the impregnation performance of the electrolyte is clearly improved as compared with the conventional battery.
[0021]
Additional studies, where the viscosity of the electrolytic solution was carried out for those different from the 0.1～500CP, Ru provided between gap to induce electrolyte I by the concave or convex portion on the inner surface of the groove 1a of the battery case 1 Thus, it was found that the impregnation property of the electrolytic solution can be improved. The effect was more remarkable as the viscosity of the electrolytic solution was higher.
[0022]
【The invention's effect】
As is clear from the above description, according to the present invention, the time required for the step of injecting the electrolytic solution can be improved by improving the impregnation property of the electrolytic solution into the power generation element component group and increasing the impregnation rate of the electrolytic solution. Can be shortened and productivity can be improved. In addition, it is possible to prevent the battery performance from being deteriorated due to insufficient impregnation of the electrolytic solution, and to supply a stable and highly reliable battery.
[Brief description of the drawings]
1 is a longitudinal sectional view of a cylindrical lithium ion secondary battery. FIG. 2 is a longitudinal sectional view of a battery case subjected to spline processing in an embodiment of the present invention. FIG. 3 is a cross-sectional view of the battery case subjected to the spline processing. FIG. 4 is a cross-sectional view of a cylindrical lithium ion secondary battery in which a gap for inducing an electrolytic solution is formed on the inner surface of the groove portion by a dent in another embodiment of the present invention. FIG. Plan view [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery case 1a Groove part 2 Sealing lid 3 Power generation element group 4 Positive electrode lead 5 Negative electrode lead 6 Upper annular insulating plate 7 Lower insulating plate 8 Convex part 9 Convex part

Claims (4)

A groove portion that is recessed from the outer surface is provided in the opening of the battery case, and an annular insulating plate that is in contact with the inner surface of the groove portion is disposed on the upper part of the power generation element component group housed in the battery case, and the annular insulation cell characterized by having a gap that induces the plate opposite to said conductive by the concave or convex portion provided on the inner surface of the groove solution liquid. The battery according to claim 1, wherein the concave portion or the convex portion is a plurality of filaments formed in a height direction of the battery case. The battery according to claim 1 , wherein the concave portion or the convex portion is formed by spline processing. Cell according to claim 1, characterized in that the convex portion was formed by denting from the outer surface of the batteries case.

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