JPH0715098Y2 - Sealed lead acid battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application of the invention) The present invention relates to a sealed lead-acid battery, more specifically, the amount of electrolyte used is limited, and these electrolytes are impregnated and retained in a separator to remove gas. The present invention relates to a structure of a lead-acid battery having a closed structure having an absorption function.

(Prior Art) Speaking of lead-acid batteries, up to now, both positive electrode plates and negative electrode plates have been structured to be constantly immersed in a dilute sulfuric acid aqueous solution. By the way, as the active material of the negative electrode plate of the lead-acid battery (a substance involved in the electrochemical reaction), lead powder (P
b) is used, which is in a reduced state in a charged state and has a property of reacting well with oxygen gas. Therefore, the negative electrode plate is placed in a gas phase containing oxygen gas, the oxygen gas is easy to contact the active material of the negative electrode plate,
And a state in which sulfuric acid exists near the active material −
For example, there is a contact interface between the vapor phase and sulfuric acid on the active material of the negative electrode plate, or the active material of the negative electrode plate is covered with a thin liquid film of sulfuric acid, and oxygen gas diffuses inside this liquid film and spreads on the negative electrode surface. In a state where it can be reached, this active material easily chemically changes to lead sulfate (PbSO ₄ ) by the reaction with oxygen gas and sulfuric acid, so using this characteristic, the absorption function of the gas generated in the battery can be improved. It can be held (note that the lead sulfate produced here can be returned to the reduced state again by charging).

The sealed lead-acid battery achieves the hermetic sealing of the battery by utilizing such "gas absorption principle". Therefore,
One of the major differences between the sealed lead acid battery and the conventional lead acid battery containing liquid is the amount of electrolyte used. Then, in the sealed lead-acid battery, in order to efficiently perform the gas absorption described above, it is necessary to configure the surface of the electrode plate to be covered with a liquid film of sulfuric acid, for example, between the positive electrode plate and the negative electrode plate. A porous material having an excellent liquid retaining property such as a glass mat is arranged and used as a separator and also as a liquid holder to impregnate the porous material with a liquid. Initially, a sealed lead-acid battery with such a structure was manufactured in a very small model, but recently, a large-sized stationary model having a capacity of several hundred Ah or more has been manufactured. . However, even in the case of such a large-sized sealed lead acid battery, the basic structure of the accumulator battery has the point that it follows the liquid accumulator battery that has been used so far.

That is, as shown in FIG. 2, in a liquid storage battery, both the negative electrode plate 1 and the positive electrode plate 2 have feet F in the lower part of the electrode plate (the part facing the bottom of the battery case) and the assembly is completed as a battery. The electrode plate is supported by the foot F. Similarly, in a large-sized sealed lead-acid battery, each electrode plate 1, 2
Looking at the structure and the assembled state of the electrode plate group, the same design concept as that of the liquid-filled battery is used as it is, except that the positive electrode plate 2 is stretched. The elongation of the positive electrode plate 2 is a phenomenon that occurs when a lead alloy containing calcium is used in the grid-shaped current collector that constitutes the positive electrode plate of the sealed lead acid battery, and when the battery is used for a long period of time. The whole electrode plate expands. The measure against elongation is to prevent the battery case 6 from being destroyed by such elongation even when such elongation occurs, and a space is provided between the positive electrode plate 2 and the inner wall of the battery case 6. The method of adopting a structure in which the provided positive electrode plate 2 is not supported by the bottom of the battery case or is hung by a positive electrode column is adopted. In the figure,
3 is a separator, 4 is a terminal, and 5 is an upper lid.

(Problems to be solved by the invention) As described above, the large-sized sealed lead-acid battery to date has the same electrode plate structure as the conventional liquid-filled battery, and as a result, the installation direction is upright like the liquid-filled battery. Has been adopted.
However, sealed lead-acid batteries have one of the characteristics that they can be used even if they are laid sideways because there is no excess liquid that flows, and in the future, it will be possible to reduce the battery installation space. Or, in order to realize the flexible installation of batteries in various power supply facilities, it is considered that even in the case of large-sized stationary lead-acid batteries for stationary installation, the form of horizontal installation is strongly required. However, as described above, the conventional sealed lead-acid battery for stationary use is not designed at all in consideration of usage forms other than the upright installation. Therefore, if the plates are installed horizontally in the direction perpendicular to the installation surface without changing the structure of the plates, the sides of the plates (strictly speaking, the parts that become the sides when upright) will not be supported. Since there is nothing at all, the plate group is pulled downward by gravity. The electrode plate group is connected to the battery case only by the part where the pole pillar penetrates to the outside of the battery, and when it is placed horizontally, it will be supported by this part, so if gravity occurs as described above, it will result in The stress concentrates on the pole column penetration. In this way, in the case of a large model, when it is used horizontally, there is a possibility that a force will be applied to the pole column penetration part by the electrode plate group and an obstacle such as a crack will occur in this part, resulting in poor airtightness. In the installed form, long-term use was impossible. Sealed lead acid batteries have a completely airtight structure that separates the atmosphere from the inside of the battery.If airtightness occurs and the atmosphere communicates with the inside of the battery, oxygen in the atmosphere is absorbed by the negative electrode and the discharge performance of the battery is significantly reduced. It becomes impossible. Therefore, it can be said that the occurrence of airtightness in the pole portion is directly related to the deterioration of the battery. (Basically, it can be said that there is no such fear if the electrode plate is placed in parallel with the installation surface.) Thus, the large-scale sealed lead-acid batteries that have been manufactured so far are Due to the restriction from the surface, there was a serious drawback that horizontal installation such that the electrode plate and the installation surface are vertical is impossible. In other words, the sealed lead-acid battery has a completely sealed structure, does not leak liquid, does not require water supply, and can be installed in any direction. However, at least large sealed lead-acid batteries for stationary use cannot be said to have a completely unlimited installation direction.

An object of the present invention is to improve the structure of the electrode plate, and to provide a large-sized sealed lead-acid battery for stationary use that does not hinder the battery even if it is horizontally installed in any orientation and used for a long period of time even if it is upright. It is in.

(Means for Solving the Problems) In order to solve the above problems, in the sealed lead acid battery according to the present invention, a positive electrode plate, a negative electrode plate, and a porous substance that insulates these electrodes and holds an electrolyte solution are alternately combined. In a sealed lead-acid battery in which the electrode group configured as described above is housed in a battery case, the size of the portion of each electrode plate in which the substance involved in the battery reaction is retained is larger than the inner size of the battery case. Although it is small, there is a protrusion in the periphery of the electrode plate, and at least the protrusions of the positive electrode plate among the protrusions are provided at the four corners of the positive electrode plate, and when the electrode plate group is housed in the battery case. It is characterized in that these projections are configured to come into contact with the inner wall and bottom of the battery case.

The most important feature of the present invention is that even if the sealed lead-acid battery is placed for a long time in a direction in which the electrode plate is perpendicular to the installation surface, the positive and negative electrodes do not generate excessive force on the pole post. For each of the plates, protrusions that serve as supports around the electrode plate are provided at least at the four corners of the positive electrode plate. Since such an electrode plate is used, all electrode plates in the electrode plate group are in contact with the inner wall of the battery case in the assembled state, and even if the sealed lead acid battery is used sideways, the electrode plate will not Each piece is supported by a battery case, and unlike the conventional sealed lead-acid battery, no force is applied to the poles.

(Embodiment) FIG. 1 is a view showing an embodiment of the present invention. In the figure, 1 is a negative electrode plate, 2 is a positive electrode plate, 3 is a glass mat used as a separator, 4 is a terminal, 5 is an upper lid, and 6 is a battery case.

As shown in FIG. 1, the sealed lead-acid battery has a negative electrode plate 1 and a positive electrode plate 2 in a space sealed by an upper lid 5 in a battery case 6.
Are stored in a state of being superposed on each other via the separator 3.

In the present invention, as shown in FIG. 1 (b), the side and bottom of the negative electrode plate 1 are provided with ear-shaped projections 7 that support the electrode plate. Further, as shown in FIG. 1 (c), the positive electrode plate 2 described above is also provided with the same protrusions 7 as the negative electrode plate 1. However, the negative electrode plate 1 and the positive electrode plate 2 have different electrochemical states during use (discharge is rare in a battery used as an emergency standby power source, and they are almost in a charged state), and the negative electrode plate 1 and the positive electrode plate 2 are different from each other. Is always placed in the reduced state, whereas the positive electrode is in the oxidized state. Therefore, the grid-shaped current collector of the positive electrode expands, and the entire electrode plate is significantly deformed.
Therefore, the protrusions 7 provided on the positive electrode plate 2 should be of a degree sufficient to support the weight of the electrode plate, and it is necessary to pay particular attention to the size and the number of installations so as not to hinder the extension 7 from occurring. is there. When the grid-shaped current collector extends, the positive electrode plate 2
Is bulged and rounded so that it is extruded from the central part of the electrode plate toward the outer peripheral part, so the four corners of the electrode plate are set as the installation positions so that this extension is not obstructed as much as possible. . On the other hand, with respect to the negative electrode, since the dimensions at the time of initial manufacturing are maintained as they are even after the battery has reached the end of its life, it is not necessary to consider the mounting position or the like when installing the protrusion. If a sealed lead-acid battery is constructed by using the electrode plates with protrusions on the periphery in this way, one electrode of each electrode plate is used.
Since the projections 7 support the sheet on the inner wall of the battery case, even if the sheet is installed sideways, the electrode plate group is not lowered downward. That is, since an unreasonable force is not generated in the pole column penetrating portion, it is possible to set upside down as well as sideways with an arbitrary surface facing down. In this embodiment, when casting the grid-shaped current collector, the projections are formed on the side portions of the current collector. It is also possible to separately prepare a plastic part having a role and to attach it to an arbitrary position on the outer edge of the current collector. Since the object of the present invention can be achieved by any of these methods, any method may be adopted depending on manufacturing conditions.

(Effect of the Invention) As described above, in the sealed lead-acid battery of the present invention, the projections are provided on the electrode plates of each electrode. Therefore, even if it is used in a horizontal orientation, the projections support the electrode plate on the inner wall of the battery case, so that the concentration of force on the pole column penetration portion does not occur. That is, the sealed lead acid battery of the present invention can be installed even if any surface faces downward, so that even in a large-sized stationary sealed lead acid battery, the degree of freedom in the installation direction is guaranteed for the first time. The effect of the present invention is particularly great for a large sealed lead-acid battery in which the weight of the electrode plate group becomes large, and the industrial advantage is also great.

[Brief description of drawings]

FIG. 1 is an example of the electrode plate structure of a sealed lead acid battery according to the present invention, and FIG. 2 is an example of the electrode plate structure of a conventional sealed lead acid battery. 1 ... Negative electrode plate, 2 ... Positive electrode plate, 3 ... Separator, 4 ...
… Terminals, 5… Top lid, 6… Battery case, 7… Projection.

Claims (1)

[Scope of utility model registration request] 1. A seal formed by accommodating a positive electrode plate, a negative electrode plate, and an electrode plate group configured by alternately combining porous materials that insulate the positive electrode plate and the negative electrode plate and impregnate and hold an electrolytic solution in a battery case. In the lead acid battery, the size of the portion of each electrode plate in which the substance involved in the battery reaction is held is smaller than the inner size of the battery case, but there is a protrusion on the periphery of the electrode plate, At least the protrusions of the positive electrode plate are provided at the four corners of the positive electrode plate, and when the electrode plate group is housed in the battery case, these protrusions are configured to contact the inner wall and bottom of the battery container. Sealed lead acid battery characterized by.