JP2000182582A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of suppressing the temperature rise of a battery during charging and discharging with an extremely simple structure, the battery pack being developed for improving radiation important for a battery pack. SOLUTION: By fixing a battery 1 to a spacer 3 for holding the clearance between batteries 1, the air flows as shown in Fig. 1 in the direction orthogonal to the longitudinal direction of the battery 1 to cool the battery 1 with a cooling/ventilating clearance 4 formed around the outer circumference of the battery 1. Thereby through the cooling/ventilating clearance 4, the cooling air immediately flows around the battery 1 and efficiently cools the battery 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery in which a plurality of rechargeable cells are connected in parallel.

[0002]

2. Description of the Related Art An assembled battery in which a plurality of rechargeable cells are connected side by side in parallel is used for various purposes. The voltage and capacity of the battery pack can be greatly adjusted by adjusting the number of batteries. In general, a conventional assembled battery is configured by arranging a plurality of the unit cells in parallel and storing them in a case, or by lining up in parallel and covering the side surfaces of the unit cells with a heat-shrinkable film in close contact. In a battery pack covered with a heat-shrinkable film, attempts have been made to improve heat dissipation by opening a part of the film. However, batteries with these structures are
The battery temperature tends to rise due to heat generated during charge / discharge. In particular, the battery temperature tends to rise significantly when the charge / discharge current is increased or overdischarge occurs.

Further, in order to shorten the total length of the battery pack, the battery packs are arranged in parallel and stacked in a plurality of stages. As shown in FIG. 7, the assembled battery in which the unit cells are stacked in a plurality of stages has a cavity 2 surrounded by the unit cells 1 and having poor air ventilation. Therefore, there is a disadvantage that not all of the unit cells 1 can be cooled uniformly. In a battery pack that cannot sufficiently dissipate heat, the battery voltage is affected by the temperature, and as a result, the charging current and the discharging current are limited. In particular, nickel-hydrogen batteries and the like that are susceptible to high temperatures have a drawback that when the temperature rises during charging, the battery performance is significantly adversely affected, and thus the charging method is limited.

[0004] In addition, the heat dissipation becomes more important as the size of the cell increases. This is because when the size of the unit cell is increased in order to increase the capacity, the increase in the area of the battery surface serving as a heat radiating portion is smaller than the increase in the battery capacity.
For example, the capacity of a cylindrical rechargeable unit cell can be more than doubled by making its length constant and doubling its thickness. However, the surface area of the unit cell whose thickness is doubled can only be doubled. For this reason, a single cell having a thickness twice as large has a smaller surface area per capacity than that of the above-described one, and as a result, a heat radiation area also decreases.

[0005] To further complicate matters, a large-capacity unit cell is required to have a large charging current in order to shorten the charging time. However, when charged with a large current, the unit cell has a drawback in that heat generated inside cannot be effectively radiated from the surface, and the temperature of the cell is spurred.
In addition, the large-capacity unit cells are often discharged with a large current, and the internal heat generation increases to increase the battery temperature.
For this reason, it is extremely important how to improve the heat radiation of the assembled battery in which the large-capacity unit cells are connected.

[0006]

SUMMARY OF THE INVENTION The present invention has been developed for the purpose of improving heat dissipation important for an assembled battery. An important object of the present invention is to provide a battery having a very simple structure and a charge / discharge operation. An object of the present invention is to provide an assembled battery that can suppress a rise in battery temperature in the above.

[0007]

According to the battery pack of the present invention, a cooling ventilation gap 4 is formed on the outer periphery of the side surface of the battery 1 by maintaining the gap between the batteries 1, and as shown in FIG. It is characterized in that air flows in a direction perpendicular to the longitudinal direction and the battery 1 is cooled.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. However, the following embodiment is an example of an assembled battery for embodying the technical idea of the present invention, and the assembled battery of the present invention has the following materials, shapes, structures, and arrangements of the components. It is not specific to the structure.
Various changes can be added to the battery pack of the present invention within the scope of the claims.

Further, in this specification, in order to make it easier to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”. However,
The components set forth in the claims are by no means specific to the components of the examples.

The battery pack shown in FIGS. 1 and 2 has four rechargeable batteries 1 connected in parallel. 4 batteries 1
A spacer 3 made of tape is attached to both ends of the side surface of the battery, and a cooling ventilation space 4 is formed between the adjacent batteries 1 by the spacer 3. Spacer 3
Preferably, an insulating and heat-resistant material is used. If it is an insulating member, the outer cans can be electrically insulated and connected to each other without having to separately cover the metal battery outer can that also serves as the negative electrode terminal or the positive electrode terminal with an insulating tube or the like. it can. In addition, if the heat-resistant material is used, even when the battery generates abnormal heat, insulation between the batteries and a cooling ventilation gap can be secured. As described above, the assembled battery capable of directly cooling the metal outer can has a feature that the heat radiation effect can be particularly enhanced. Further, as the spacer 3, an insulating and heat-resistant member having an adhesive layer on one side is effective so that the spacer 3 can be easily disposed on the battery 1.

The spacing between the cooling ventilation gaps 4 between the adjacent batteries 1 can be adjusted by the thickness of the spacer 3. As shown in FIG. 1, in the assembled battery in which the spacers are arranged at both end portions of the side surfaces of all the batteries 1 and connected, the interval between the cooling ventilation gaps 4 is twice the thickness of the spacers 3. Therefore, the thickness of the spacer 3 in this case is designed to be half of the cooling ventilation gap 4.
Although not shown, in one of the adjacent batteries, the assembled battery in which spacers are arranged at both ends of the side face has one spacer interposed between the batteries. Become equal. If the space between the cooling ventilation gaps is widened, it is possible to increase the ventilation flow amount of air.However, if the cooling ventilation gap is widened, the outer shape of the battery pack becomes large. Is determined in consideration of the ventilation flow rate and the outer shape of the battery pack.

In the battery pack shown in FIGS. 1 and 2, the portion where the spacer 3 is provided can be connected by winding it with a binding wire 5 as shown by a broken line in FIG.

In the battery pack shown in FIGS. 3 and 4, prismatic rechargeable batteries 1 are connected in parallel. In this assembled battery, spacers 3 are provided at both ends of the side surface of the battery 1, and a cooling ventilation gap 4 is formed between the opposed surfaces of the battery. On the other hand, in a conventional assembled battery in which prismatic batteries are connected without using the spacer, the opposing surfaces of the batteries have a large area and are in close contact with each other. In this conventional battery pack, the facing surface of the battery that is in close contact with the battery cannot be sufficiently dissipated because ventilation is extremely poor. However, the assembled battery shown in FIGS.
Since the cooling ventilation gap 4 is provided on the facing surface, sufficient ventilation can be performed, and heat can be efficiently radiated from the entire periphery of the battery 1.

Further, the battery pack shown in FIG. 5 has eight column-shaped rechargeable batteries 1 housed in a case 6 in parallel. In this battery pack, a cavity 2 parallel to the length direction of the battery is formed between valleys of adjacent batteries 1.
Further, spacers 3 made of tape are adhered to both ends of the side surfaces of the adjacent batteries 1, and the cooling ventilation holes 4 are formed between the adjacent batteries 1 by the spacers 3. The cooling ventilation gap 4 allows the cavities 2 parallel to the length of the battery to communicate with each other, thereby forming an air flow in a direction perpendicular to the length of the battery. On the other hand, the case 6 for housing these batteries 1 has an inner shape such that the battery 1 can be housed in a close contact state at the portion where the spacer 3 is provided. The case 6 is provided with the battery 1
An air hole 7 is opened on the side surface of the case 6 and an air hole 8 is opened on the upper surface thereof so that the space between them can be sufficiently ventilated. Side air hole 7
Is opened at a position corresponding to the cavity 2 formed between the batteries 1, and an air hole 8 is formed in the upper surface of the case near the side surface of the case 6 where the air hole 7 is formed. Have been.

This battery pack can effectively cool the battery 1 housed in the case 6 by sucking air from the air holes 8 formed on the upper surface of the case 6. That is, when air is sucked up from the air holes 8 formed on the upper surface of the case 6, the air flows into the case 6 from the air holes 7 formed on the side surfaces of the case 6. Into the case 6 through the cavity 2 parallel to the
And is discharged from the air hole 8 to the outside of the case 6. By forming the cooling ventilation gap 4 in this manner, in addition to the air flow parallel to the length direction of the battery 1 in the assembled battery, the air flow in the direction different from the length direction of the battery 1 is created. It is possible to efficiently cool the battery from the entire side surface and prevent the battery temperature from rising.

In the above assembled battery, a cooling ventilation space 4 is provided by arranging strip-shaped spacers 3 at both ends of the side surface of the rechargeable battery 1. The band-shaped spacer 3 can be easily arranged at the end of the battery 1, and has an effect that the adjacent battery 1 can be connected by using this as a cushioning material. However, in the present invention, the type of the material of the spacer 3 is not specified, and it is sufficient that the spacer 3 can form a gap between adjacent batteries.

Next, an assembled battery according to one embodiment of the present invention;
Reference is made to the results of experiments on conventional battery packs.
[Example] A nickel-cadmium battery having a height of 109.5 mm and a diameter of 42.0 mm and a nominal capacity of 15 Ah was prepared.
At both ends of the side surface of this battery, a width of 20 mm and a thickness of 0.19
A spacer made of glass cloth tape having a thickness of 2 mm is attached by being wound twice. Four batteries to which the spacers were attached were arranged as shown in FIGS. 1 and 2 with the polarity of the electrodes exposed on the end faces of the adjacent batteries being different, and connected in series to produce an assembled battery. . This is referred to as an assembled battery of the present invention.

[Conventional Example] An assembled battery was manufactured in the same manner as in the above embodiment except that the spacer was not attached to the battery. This is a conventional battery pack.

Using the above assembled batteries, a 12 W fan is installed at a position 15 cm away from the side surfaces of these assembled batteries, and forced air is blown (in the direction of the arrow), and the assembled batteries are cooled to 0.3 C (4. After charging for 4 hours at a current of 5A), the battery was paused for 1 hour, discharged at a current of 1C (15A), and stopped when the battery voltage reached 0.8 V, and the surface temperature of the battery was measured. . Table 1 shows the results.

Note that the temperature measurement portions of the battery 1 are two portions, a surface facing the cavity 2 surrounded by the four batteries 1 and a surface not facing the cavity 2. As shown. The ambient temperature at the time of measurement is 20 ° C.

[0021]

[Table 1] As is clear from Table 1, the difference between the outer temperature and the inner temperature of the battery at the end of discharging is 1.7 ° C. in the present invention and 1.7 ° C. in the conventional battery in the conventional battery. 2.3 ° C. is lower by 0.6 ° C. in the assembled battery of the present invention. Further, when the discharge current at the time of discharge is further increased, the temperature difference at the end of discharge between the assembled battery of the present invention and the conventional assembled battery becomes more remarkable. This is because the battery pack of the present invention
This is because, despite the extremely simple configuration, the battery can efficiently radiate heat, whereas the conventional assembled battery has a local heat radiation defect in the battery.

The temperature of a battery built in a battery pack is determined by the amount of heat generated inside and the amount of heat radiated from the surface of the battery. For this reason, when a local heat radiation failure of the battery occurs as in a conventional battery pack, the amount of heat radiation of the entire battery decreases, the temperature of the battery increases, and the battery performance is adversely affected.

[0023]

According to the battery pack of the present invention, by maintaining the gap between the batteries 1, a cooling ventilation gap 4 is formed on the outer periphery of the side surface of the battery 1, and as shown in FIG. Since the air flows in the direction to cool the battery 1, the cooling air can immediately spread to the outer periphery of the battery 1 through the cooling ventilation gap 4 to efficiently cool the battery 1.

[Brief description of the drawings]

FIG. 1 is a front view of an assembled battery showing one embodiment of the present invention.

FIG. 2 is a plan view of the battery pack shown in FIG.

FIG. 3 is a front view of an assembled battery showing another embodiment of the present invention.

FIG. 4 is a plan view of the battery pack shown in FIG. 3;

FIG. 5 is a perspective view of a battery pack showing another embodiment of the present invention.

FIG. 6 is a perspective view showing a connection state of batteries stored in the battery pack of FIG. 5;

FIG. 7 is a perspective view showing a conventional assembled battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Cavity 3 Spacer 4 Cooling ventilation space 5 Binding wire 6 Case 7 Air hole 8 Air hole

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission Date] August 19, 1999 (1999.8.1)
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

Means for Solving the Problems] battery pack of the present invention, multiple
In a posture in which the longitudinal direction of several rechargeable batteries 1 is lying horizontally
A battery pack that is stacked in multiple stages in parallel and connected side by side
There are, characterized in that the cooling ventilation gap 4 is formed on the wall part of the battery 1 by holding the gaps between the battery 1, battery 1 air is flowing in the direction perpendicular to the longitudinal direction of the batteries 1 are cooled And

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

The battery pack of the present invention maintains the gap between the batteries 1 so that the cooling ventilation space 4
There is formed, because those cells 1 are cooled by air flows in a direction perpendicular to the longitudinal direction of the batteries 1 via the cooling ventilation gap 4, cooling air prevailing immediately on the outer periphery of the battery 1 Battery 1 can be efficiently cooled. Moreover,
The pond 1 is stacked in parallel in a posture with the longitudinal direction lying horizontally.
Because they are stacked and connected side by side,
As the wind flows in the cross direction, the wind touches the outer periphery of the battery
Be warmed by. Warm wind changes pressure
Rises as a result, and as a result,
In the pond, it extends to the outer periphery of the battery just above. Follow
The wind that flows inside the battery pack
As a result, the temperature of each battery can be made uniform without unevenness. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 16, 1999 (1999.11.
16)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

According to the present invention, there is provided an assembled battery in which a plurality of rechargeable batteries are stacked in parallel in a state where the longitudinal direction of a plurality of rechargeable batteries is laid horizontally and connected side by side. Is held at both ends in the longitudinal direction of the battery 1 to form cooling ventilation gaps 4 on the outer periphery of the side surface of the battery 1 so that air flows in a direction perpendicular to the longitudinal direction of the battery 1 to cool the battery 1. Features.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

In the battery pack of the present invention, the gap between the batteries 1 is charged.
By holding the pond 1 at both ends in the longitudinal direction , a cooling ventilation gap 4 is formed on the outer periphery of the side surface of the battery 1, and air flows in a direction orthogonal to the longitudinal direction of the battery 1 to cool the battery 1. Through the cooling ventilation gap 4, the cooling air can immediately spread to the outer periphery of the battery 1 and efficiently cool the battery 1. In addition, since the batteries 1 are stacked and connected in parallel in a plurality of stages with the longitudinal direction lying horizontally, the wind flows in the direction perpendicular to the longitudinal direction, and the wind touches the outer periphery of the battery. Warmed up. The warmed wind rises by the change of atmospheric pressure, and as a result,
Of the batteries stacked in multiple stages, the battery also extends to the outer periphery of the battery immediately above. Therefore, as a result of the wind flowing in the assembled battery being spread over the outer periphery of each battery, the temperature of each battery can be made uniform without unevenness. Furthermore, both ends of the battery 1 are electrode parts, etc.
Exists, and is an area that is not largely attributable to heat generation.
Utilizing this area, the gap between the batteries 1 is set in the longitudinal direction of the battery 1.
By holding at both ends in the center area excluding both ends
A wide gap can be secured, and power generation is required due to heat generation.
Can be effectively cooled in the area containing the element
You.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Furuse 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Kazuhiro Kitaoka 2--18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric F term in the company (reference) 5H020 AA01 AS05 AS06 CC22 CC41 KK13 5H031 AA03 CC01 KK08

Claims (1)

[Claims] 1. In a battery pack in which a plurality of rechargeable batteries 1 are connected side by side in parallel, by maintaining a gap between the batteries 1, a cooling ventilation gap 4 is formed on the outer periphery of the side surface of the battery 1. An assembled battery, wherein air flows in a direction perpendicular to the longitudinal direction to cool the battery 1.