JPH01255156A - Sealed storage battery - Google Patents

Abstract

PURPOSE:To decrease excessive space in the upper part of an element and prevent leakage of a circulating liquid completely by furnishing a gas passage connecting the space to inside the battery between two sealing parts within the material which is made in a single piece including resilient parts. CONSTITUTION:A safety valve 6 mounted in such a way as penetrating the opening 5 of a battery and protruding to inside it seals the outside surfaces of the battery with a resilient part 7 having a greater dia. than the opening 5 and also seals the inside surfaces of the battery with another resilient part 8. The intra-battery opening of a gas passage 9 connecting inside the battery to the space between two sealing parts is located near the tip of the safety valve protruding part within the battery. In this condition, eventual tumbling of the battery does not cause the circulating liquid to leak before it reaches the opening of safety valve 6 protruding within the battery, and there is no fear of overflowing before the electrolyte reaches the top surface within the battery because the safety valve 6 is removed while the liquid is poured in. This prevents overflow of the electrolyte at the time of pouring in and leakage at the time of overcharging.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improving the leakage resistance of sealed storage batteries.

Conventional technology and its problems Conventionally, this type of battery has a structure as shown in FIG. 2, in which a positive electrode plate 1. Negative electrode plate 2. A separator 3 is housed in a battery container 4, and a cap-shaped safety valve 11 made of an elastic material is attached to a cylindrical portion 10 provided on the top surface of the container 4, so that the separator 3 can be used in the event that the pressure inside the battery rises abnormally. The safety valve opens to prevent pressure rise breakdown. This safety valve 11 is installed after injecting the electrolyte. The electrolytic solution of a sealed storage battery is made non-fluidized by one of the following methods to prevent the so-called liquid electrolytic solution from leaking out of the battery. In other words, one method is to make the electrolyte non-fluid by adding a thickener such as silica to the electrolyte, and the other is to use a material that can absorb and retain the electrolyte as a separator to remove the positive and negative electrode active materials and the separator. This method allows the pores to absorb and retain all the electrolyte in the battery.

However, no matter which method is used, if the battery is subjected to excessive charging or vibration, a portion of the fixed electrolyte may separate, become fluidized, and leak. Therefore, the cylindrical part 1
0 is often provided with a protruding portion 12 into the battery to prevent fluid from leaking even if the battery is placed in an overturned position.

The space above the element of a sealed storage battery is in principle unnecessary from the perspective of electricity going in and out, and this space above is being reduced as batteries are required to have higher energy density. However, this space is particularly important during injection before the electrolyte is absorbed into the active material or the separator, and if it is made too small, there is a risk that the electrolyte will overflow from the opening during injection.

In addition, the space above the lower opening of the protrusion 12 for leak prevention is completely useless for preventing electrolyte from spilling during injection, and as a result, the space above the element needs to be sufficiently large. It is not possible to increase the volumetric energy density of the battery.

Means for Solving the Problems The present invention penetrates an opening provided in one surface of a battery container and protrudes into the inside of the battery. It is equipped with a safety valve configured to be sealed by an elastic part having a larger diameter than the opening part, and there is a space between the two sealing parts and the inside of the battery inside the integrated material including these elastic parts. The purpose of the present invention is to provide a sealed storage battery in which the extra space above the element is reduced as much as possible by providing a gas passage connecting the elements, and at the same time, leakage of the flowing liquid can be sufficiently prevented.

Example Examples according to the present invention will be described in detail below.

FIG. 1 is a sectional view showing an embodiment of the sealed storage battery of the present invention, in which 1 is a positive electrode plate, 2 is a negative electrode plate, 3 is a separator, 4 is a battery container, and 5 is one surface of the battery container 4. This is an opening provided in the hole. Reference numeral 6 denotes a safety valve that is installed so as to penetrate through the opening 5 of the battery and protrude into the inside of the battery.The external surface of the battery is sealed by an elastic part 7 that has a larger diameter than the opening, and has a similar elasticity. It has a structure in which the inner surface of the battery is sealed by the inner surface of the battery.

Reference numeral 9 denotes a gas passage provided inside the safety valve that connects the space between the two sealing portions and the inside of the battery, and the hole inside the battery is disposed near the tip of the battery-like protrusion of the safety valve.

If such a safety valve is not installed, even if the battery is placed upside down, the flowing liquid will not leak to the outside until it reaches the opening of the safety valve that protrudes into the battery, and the safety valve will be removed when injecting liquid. The electrolyte will not overflow until it reaches the internal surfaces of the battery.

A battery A having the structure of the present invention shown in FIG. 1, a conventional battery B having a protrusion into the battery for preventing liquid leakage (not shown in FIG. 2), and a battery B having the protrusion for preventing liquid leakage removed from this conventional battery. Table 1 shows the results of testing battery C for the presence or absence of electrolyte overflow during injection, and for the presence or absence of electrolyte leakage when the safety valve was installed and then placed upside down and overcharged with a 0.1C current for 48 hours. Shown below.

As is clear from Table 1, the product of the present invention improves leakage resistance both during liquid injection and during excessive charging by effectively utilizing the space above the element compared to conventional products. be able to.

Effects of the Invention As described above, the sealed storage battery of the present invention effectively uses the space above the element to effectively prevent electrolyte overflow during injection and leakage during excessive charging. This has the advantage of providing a high energy density battery with minimal extra space in the upper part.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the sealed storage battery of the present invention, and FIG. 2 is a longitudinal sectional view showing a conventional sealed M battery.

Claims (1)

[Claims] 1. A hole protrudes into the battery through an opening provided on one surface of the battery container, and has a diameter larger than that of the opening on both the outside and inside of the battery around the periphery of the opening. A safety valve configured to be sealed by an elastic part is provided, and a gas passage is provided inside the integrated material including these elastic parts to connect the space between the two sealing parts and the inside of the battery. A sealed storage battery characterized by: