JPS6229073A - Lead storage battery - Google Patents

Abstract

PURPOSE:To much lengthen the life of a lead storage battery, by adding a high-molecular organic coagulant of several thousands to scores of thousands in molecular weight to an electrolyte. CONSTITUTION:A high-molecular organic coagulant of several thousands to scores of thousands in molecular weight is added to an electrolyte. The coagulant is a cationic coagulant, a cationic and anionic coagulant or an anionic coagulant having a cation dissociation group. Hydrophilic layers around fine PbO2 grains drifting in the electrolyte are removed to assist the grains to come into contact with each other to grow larger. The grains are thus quickly removed from electrode plates to preclude the production of spongy lead to prevent an internal short circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improving the life characteristics of lead-acid batteries.

It is well known that the traditional technology of the iris and tassels is the same as that of the conventional technique. As the anode active material (PbO,) is repeatedly charged and discharged, it gradually becomes finer and its physical strength and electrical contact deteriorate. Active material pbOt (lead dioxide)
The crystal also approaches a perfect crystal from an oxygen-deficient incomplete crystal.

The problem that the invention aims to solve Lead-acid batteries generally have more O than the anode at the end of charging.

Gas and H gas are generated from the cathode. These gases are generated from the surface and inside of the electrode plate. In particular, the O gas generated from the anode discharges the above-mentioned PbO2 fine particles to the outside of the electrode plate group.

The discharged PbO and fine particles float inside the battery container and then settle. However, very small particles (within 0,100 m) take time to settle.
Particles that have been floating for a long time have more opportunities to approach the cathode, and many of them are absorbed. The adsorbed material is reduced to metallic lead at the cathode during charging. Metallic lead has a porous, spongy shape that extends toward the anode. When spongy lead reaches the anode, an internal short circuit occurs. Internal short circuits are usually
This is often observed in batteries that have been recharged, but is also often observed in relatively new batteries. When this internal short circuit occurs, the charging efficiency decreases and the output of the storage battery decreases, and when this phenomenon occurs, the battery becomes unusable at an early stage.

Preventing internal short circuits will improve the performance of storage batteries.

The present invention is concerned with improving the lifespan of storage ponds by preventing the generation of spongy lead, which is mainly caused by the above-mentioned Pb(l) particles.

Means for Solving the Problem PBO fine particles floating in the electrolyte are positively charged and form a hydrophilic layer around the particles.

This prevents fine particles from colliding with each other and gradually collapsing into larger particles. Over time, H'- in the electrolyte
The hydrophilic layer around the fine particles is removed by h (protons, cations), and the fine particles come into contact with each other and grow larger. The present invention further speeds up this phenomenon, prevents the opportunity for PBO and fine particles to be adsorbed to the cathode, and in order to promptly remove them from around the electrode plate group, organic compounds having a molecular weight of several thousand to tens of thousands are added to the electrolyte. A polymer flocculant is added.

Example An embodiment of the present invention will be described.

Figure 1 shows that 1 m of various polymer flocculants are added to a suspension of p bo, fine particles (1 μm or less) in Sp, Grl, 280 at 20°C. Sedimentation velocity (cm/min) when left to stand after adding /form and applying sufficient ultrasonic vibration
showed that.

The sedimentation rate was also calculated by measuring the time it took to move 30 an. It can be seen that the cationic polymer flocculant has the highest sedimentation rate. Single-hole anionic organic polymer flocculants are thought to be highly effective under strong acidity because they discharge due to 1(f4-) and become nonionic.

Organic polymer flocculants form large flocs! Since both of these prevent fine particles from settling in a narrow container, we investigated the molecular weight of the flocculant and the size of the flocs.

Figure 2 shows the case where a cationic organic polymer flocculant was used, and it was found that the smaller the molecular weight, the smaller the holes in the flocs. In terms of size, the smaller the better, so in terms of molecular weight, it is best to have a molecular weight of several thousand to tens of thousands at most. The molecular weight and floc size were the same for several other organic polymer flocculants.

FIG. 3 shows the results of a life test in which a flocculant was added to an actual lead-acid battery having a battery capacity of t o, th.

The conditions for one charge and discharge are as follows.

Discharge: 1 hour at 60A Charge: 3.6 hours at 20A (120℃) Battery temperature:
30±5°C The one to which 2 mFt/-e of a cationic organic polymer flocculant such as polyethyleneimine is added has an improvement of about 304 compared to the one without addition, and no decrease in capacity is observed after 100 cycles. This is because the decline in charging efficiency due to minor internal short circuits has been suppressed.

Naturally, the same effect can be produced by applying it to the inside of the body.

Effects of the Invention As described above, the present invention has great industrial value in that the life characteristics of lead-acid batteries are significantly improved.

[Brief explanation of drawings]

Figure 1 is a comparative diagram showing the influence of various flocculants on the sedimentation rate of PbO and fine particles, Figure 2 is a comparative diagram showing the relationship between the molecular weight of flocculants and the size of flocs, and Figure 3 is a diagram showing the relationship between the molecular weight of flocculants and the size of flocs. A characteristic diagram showing the life test results based on this figure is shown below.

Claims (1)

[Scope of Claims] 1. A lead-acid battery characterized in that an organic polymer flocculant having a molecular weight of several thousand to tens of thousands is added to an electrolytic solution. 2. The lead-acid battery according to claim 1, wherein a cationic type, an amphoteric type, and an anionic type containing a cation dissociative group are used as the organic polymer flocculant. 3. The lead-acid battery according to claim 2, wherein a cationic inorganic flocculant is added.