JPS60105168A - Manufacture of plate for alkaline storage battery - Google Patents

Abstract

PURPOSE:To supply uniform current between each counter electrode plate and a sintered substrate and increase active material impregnation efficiency by separately arranging two or more counter electrode plates in its long direction and connecting each counter electrode plate to a current collecting electrode through power sources. CONSTITUTION:Two rows of separated counter electrode plates 11-15 are arranged in their long directions at some spaces in an electrolyte bath 2. A sintered substrate is placed with tension applied in the center of two rows of counter electrode 11-15. NaOH solution is filled in the bath 2. A current collecting electrode 4 is in contact with the substrate 3 in the outside near the outlet of the bath 2. The current collecting electrode 4 is connected to the counter electrode 11-15 through power sources 5 and variable resistors 6 to supply uniform electrolytic current between counter electrodes 11-15 and the sintered substrate 3. By this process, alkaline storage battery plate having high active material impregnation efficiency is obtained.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing electrode plates for alkaline storage ponds.

Conventionally, this type of manufacturing method involves immersing a sintered substrate impregnated in a niratil nitrate or cadmium nitrate aqueous solution and heat-treated in a sodium hydroxide aqueous solution, and converting the nickel nitrate or cadmium nitrate in the sintered substrate into hydroxide. There are two known methods: a simple immersion method for converting the material into a liquid, and a method for cathodically polarizing the material by applying an electric current after the immersion. The latter is superior in terms of conversion efficiency compared to the former, and in order to facilitate the work, a sintered substrate is formed over the entire length, and is immersed in the sodium hydroxide aqueous solution while being moved through the electrolytic cell. Generally, electricity is passed between the electrode and the immersed return electrode.

However, this method has the disadvantage that the efficiency with which the active material is filled into the electrode plate is low.

An object of the present invention is to provide a method for manufacturing electrode plates for alkaline storage batteries that is free from such inconveniences.

In the latter method, when current is applied to the return electrode and the s′IL electrode that contacts the sintered substrate near the exit of the electrolytic cell, the internal resistance within the return electrode is small, so that the current flows from the entrance to the exit of the electrolytic cell. Whereas the potential drop in the sintered substrate is small, the potential drop in the same direction as the counter electrode is large because the internal resistance is large within the sintered substrate. Therefore, the electrolysis voltage and current density between the counter electrode plate and the sintered substrate near the entrance of the electrolytic cell are small, and the electrolysis 1L pressure and current density near the exit are large.

Due to the insufficient electrolytic voltage, i.e., current density, near sunrise, conversion into active material is likely to occur only on the surface of the sintered substrate, and therefore it is difficult to fill the active material deep into the pores of the sintered substrate. It is thought that the filling effect is reduced.

Based on this recognition, the present invention divides the counter electrode plate into a plurality of pieces and separates them along the length of the sintered substrate. 1 current collector 8
Il! The present invention is characterized in that each of the plurality of return electrode plates is connected to a collective electrode via a power source so that a uniform current is caused to flow between each return electrode plate and the sintered substrate.

An example of the present invention will be explained below with reference to the drawings.

FIG. 1 shows an example of a return electrode plate used in the solid line of the manufacturing method of the present invention.

Each of the five divided return electrode plates (1,) to (1,) was a nickel plate having a thickness of 1, Qxm, and a size of Nagahata 190 and width 380, and a current collector was provided on the top.

These return electrode plates (1,) to (1,) are placed in an electrolytic cell (2) (width 400 x length 1100 x height 500 liters) as shown in Figure 2.
11) were arranged at intervals of 20 ridges along the length thereof, and another row was arranged in parallel at intervals of 100 Iul. And these two rows of return electrode plates (1,) to (1,
] At the center of the sintered substrate (3
) so that it can be moved from the entrance of electrolytic cell (2) through the river mouth as shown by the arrow, and 300
An aqueous sodium hydroxide solution (3 o 9/l) of No. 1 was added. A collector electrode (4) is provided near the mouth of the electrolytic cell (2) of the sintered substrate +31 in contact with the sintered substrate (3), and the collector electrode (4) is connected to a power source (5) and a flexible resistor. Connect the device (6) (or constant current device) to the return electrodes (11) to (15), and connect them between each of the return electrodes (1,) to (1,) and the sintered substrate (3). A uniform electrolytic current of, for example, 12 A (60 A in total) was made to flow.

The solid line in Fig. 5 shows the electrolysis (1'? +21 The results of measuring the distribution of electrolytic current density (per unit length of sintered substrate) at each position from the entrance to the river mouth are shown.

The table below shows the filling value, capacity, and utilization rate when a sintered substrate is filled with cadmium hydroxide active material for 5 cycles and a chemical conversion experiment is performed for 1 cycle, as shown by the solid line.

As a conventional example, a return electrode plate E (thickness: 4mm) as shown in FIG.
A current of 6 DA was passed between the return electrode plate and the sintered substrate using a nickel plate with a length of 1,000 mm, a length of 1,000 mm, and a nickel plate with 6 current collectors on the top, and the other conditions were as follows. Experiments were conducted in the same manner as the invention. The broken line in FIG. 3 shows the measurement results when this return electrode plate was used.

Conventional example Invention 1 cycle 6975 Filling amount 2 1/109 116 3 p 154 142 (m9 / (i) 4 rt 150 1625ri16
2181 4k rrV capacity fA (mAH/cnf) 48,0
57. As shown in the table below, according to the present invention, the amount of filling was significantly larger than that of the conventional method, and the dropout during chemical formation was also small.

As is clear from the above explanation, according to the present invention,
A plurality of return electrode plates are arranged separately along the length direction of the sintered substrate, and a collector electrode is provided in contact with the sintered substrate near the outlet of the electrolytic cell, and each of the plurality of return electrode plates is connected to the sintered substrate through a power source. Since the current is uniform between each return electrode plate and the sintered substrate by connecting it to the collector electrode, it is possible to greatly improve the filling efficiency of the active material to the electrode plate, and it is possible to This has the advantage that there is no need to change the counter/electrode plate each time the value changes.

[Brief explanation of drawings]

Fig. 1 is a plan view of the return electrode plate used in the implementation of the present invention, Fig. 2
The figure is a diagram of the device used for the actual 6m of the present invention, Figure 3 is a current distribution characteristic diagram of the unit length of the sintered substrate in the electrolytic chamber of the present invention and the conventional example, and the fourth figure is the opposite electrode of the conventional example. A plan view of the plate is shown. (11)～(1u)...Return electrode plate (2)...Electrolysis! ,! ? (3)... Sintered substrate (4)... Collection ■ Pole (5)... Power supply (6)... Two people outside the variable resistor Figure 1 Figure 4 Figure 3 (A/cm ) Input/output o (mm)

Claims (1)

[Claims] A long sintered substrate impregnated with a nitrate aqueous solution and heat-treated is immersed together with a counter electrode in an alkaline solution in an electrolytic bath, and while the sintered substrate is moved, electricity is passed from the counter electrode to the sintered substrate through the alkaline solution. In the method of filling the sintered substrate with the active material, a number of bales of counter electrode plates are arranged separately along the longitudinal direction of the sintered substrate and are brought into contact with the sintered substrate near the outlet of the electrolytic cell. An alkaline storage battery characterized in that a collector electrode is provided, each of the plurality of return electrode plates is connected to the collector electrode via a power source, and a uniform current is caused to flow between each return electrode plate and a sintered substrate. Manufacturing method for electrode plates.