JPS6247173Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a measuring electrode body for the purpose of measuring the discharge state of a lead-acid battery whose positive electrode plate constituting an electrode plate group contains antimony.

Conventionally, when measuring the specific gravity of lead-acid batteries using electrodes, measurements were carried out using an electrode body consisting of a detection electrode made of lead dioxide and a standard electrode made of lead dioxide immersed in a reference solution, which were integrated into a container body. A device has been proposed. However, the biggest drawback of such a measuring device is the difficulty in keeping the concentration of the reference solution in the standard electrode in the electrode body constant over a long period of time.

In other words, there is no problem when used for short periods at normal temperatures, but when used for many years or at high temperatures, the evaporation rate depends on the charging current and temperature to keep the electrode potential constant. etc. cannot be ignored. Therefore, it is necessary to adjust the reference solution of the standard electrode at regular intervals.

In addition, a lead dioxide positive electrode and a lead negative electrode, which are placed in the electrolyte and are always maintained at a constant potential or higher during charging, are placed at the bottom of the container body to prevent changes in the electrolyte concentration of the lead-acid battery to be measured due to charging and discharging. A device has been proposed that measures the potential difference between two electrodes using an electrode body that is integrally provided. However, in such devices, when the lead negative electrode that constitutes the electrode body together with the lead dioxide positive electrode performs the above-mentioned charging in the lead acid battery, antimony eluted from the positive electrode plate of the lead acid battery electrode group is deposited on the lead negative electrode of the electrode body. Therefore, the potential of the lead negative electrode has the disadvantage that it becomes progressively more noble as the years of use pass.

The present invention eliminates the above-mentioned drawbacks by adsorbing antimony eluted from the positive electrode plate of the electrode group of the lead-acid battery to be measured on an adsorbent provided on the surface of the electrolyte side of the lead negative electrode of the electrode body. By keeping the potential of the lead negative electrode of the electrode body constant even during use for a period of time, the electrolyte concentration of the lead acid battery can be accurately measured.

1 is a container body made of a synthetic resin such as polyethylene, polyvinyl chloride, acrylic butadiene styrene, etc., which has a negative electrode 2 made of activated lead and a positive electrode 3 made of lead dioxide in the lower periphery; 4 is a synthetic resin such as polyethylene, polystyrene, etc.; Lid made of vinyl chloride, acrylic, butadiene, styrene, etc.
Reference numerals 5 and 5' denote pole terminals made of lead or platinum for electrically connecting the negative electrode 2 and the positive electrode 3 to lead wires 6 and 6' made of copper or the like, respectively. 7 is a filler made of acid-resistant, oxidation-resistant, insulating synthetic resin, such as epoxy resin or polyester resin, to prevent sulfuric acid from entering into the lead wires 6, 6'; 8 is a conventional electrode body to be described later; Positive electrode 3 and electrolyte 1 inside 9
4, an electrolyte flow port 10 for contacting the positive electrode 3, and 10 an ion-permeable protector for the positive electrode 3 made of, for example, glass, synthetic resin woven fabric or non-woven fabric;
11 is a conventional electrode body composed of members 1 to 8 and 5', 6', and 10, and 11 is a carbon-containing micropore that adsorbs antimony eluted from the positive electrode plate of the electrode plate group 13 of the lead-acid battery to be measured. The adsorbent is made of a synthetic resin film and is attached to the container body 1 by heat welding so as to cover the surface of the negative electrode 2 on the electrolyte side. This adsorbent 11 is made by adding about 5 to 10% by weight of carbon powder to polyethylene resin powder, further adding mineral oil, mixing it, heating and melting it, forming it into a film, and then adding mineral oil to the polyethylene resin powder using a trichlorethylene aqueous solution. By eluting the oil, an adsorbent 11 having a large number of ion-permeable micropores is obtained. Reference numeral 9A designates an electrode body of the present invention comprising members 1 to 8, 5', 6', and 10, 11, 12 a battery case, and 15 a meter for measuring potential.

An example of actual measurement of the discharge state of a lead-acid battery using the electrode body 9A of the present invention will be explained with reference to FIG. 4. FIG. 4 shows the state of change in the battery voltage A and the electrode body voltage B in the present invention as the discharge progresses when a commercially available 12V30Ah lead-acid battery is discharged at a current of 5A. In general, the potential of the positive electrode active material lead dioxide shows a linear change in response to a change in sulfuric acid concentration, while the negative electrode active material lead also changes approximately linearly in response to a change in sulfuric acid concentration, but the change is minute. The purpose is to measure the linear potential change depending on the sulfuric acid concentration of these positive and negative electrodes. The actual measurement results, as shown by straight line B, vary linearly as the amount of discharge increases.
Therefore, by reading the potential difference between the measuring electrodes, it is possible to know the discharge state of the lead-acid battery. On the other hand, the electrode body 9A must always maintain an electrode potential above a certain voltage, and is charged with a current that is about 1/1000 of the electrode capacity. Therefore, some of the dissolved antimony in the electrolyte of the storage battery to be measured, that is, the antimony eluted from the positive electrode plate of the electrode plate group 13, moves toward the two negative electrodes of the electrode assembly 9A, and the electrode assembly of the present invention shown in FIG. 9A, and the negative electrode potential does not change, but the conventional electrode body 9 shown in FIG. 1 tends to deposit on the negative electrode 2 and make the potential of the negative electrode 2 nobler. Therefore, the voltage of the electrode body 9A shown in FIG. 2 in the present invention at a constant concentration does not change during the life of the storage battery to be measured, whereas the voltage of the electrode body 9A shown in FIG. Changes during the period. The trend is shown in Figure 5. In FIG. 5, A is a product of the present invention and B is a conventional product. The life test in Fig. 5 was conducted in accordance with the JIS standard test method.

When actually measuring using the electrode body 9A of the present invention, appropriate modifications can be made to the detection circuit and the meter 15 portion to facilitate visual inspection.
For example, by inserting an approximately 2V reverse battery into the detection circuit and setting the operating range of the meter 15 to 0 to 200mV, it is possible to read the capacitance change with higher accuracy.

As mentioned above, the present invention is a simple means for stably detecting changes in the electrolyte concentration of a storage battery to be measured over a long period of time, and has a simple structure, so it has great practical value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional electrode body, FIG. 2 is a sectional view showing an embodiment of the electrode body in the present invention,
Figure 3 is a cross-sectional view showing the electrode body shown in Figure 2 attached to the lead-acid battery to be measured, and Figure 4 is the relationship between the discharge time and voltage change of the lead-acid battery to be measured, and the voltage change of the electrode body in the present invention. FIG. 5 is an explanatory diagram showing the tendency of the voltage values of the present invention and the conventional electrode body in a fully charged state as the cycle of the lead-acid battery to be measured progresses. 1 is a container body, 2 is a negative electrode, 3 is a positive electrode, 4 is a lid, 9
A is an electrode body, 11 is an adsorbent, and 13 is a group of electrode plates.

Claims (1)

[Scope of utility model registration request] A lead acid battery containing antimony as the positive electrode plate constituting the electrode plate group has a lead dioxide positive electrode and a lead negative electrode, which are always maintained at a potential above a certain level during charging, placed in a storage battery electrolyte at the bottom of the container that hangs down from the lid into the battery. This is an electrode body that is placed so as to be immersed in the electrolyte to measure the concentration of the electrolyte as the potential difference between the two electrodes, and an antimony adsorbent made of a microporous synthetic resin containing carbon is provided on the surface of the lead negative electrode that is in contact with the electrolyte. Electrode body for measuring the concentration of lead-acid battery electrolyte.