JPS597206B2 - This is the best way to get started. - Google Patents

Abstract

PURPOSE:A small copper electrode of polarization used as an element for a cell, a coulometer, a high-capacitance capacitor, etc. which use solid electrolyte.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in copper electrodes for devices such as batteries, gravimeters, and large-capacity capacitors that use solid electrolytes.

Copper has low polarization even as a smooth electrode in an acidic aqueous solution.
Since stoichiometric solution deposition is performed, a smooth electrode is used even when used as a gravimeter.

In the case of a solid electrolyte element mainly made of silver salt, the metal electrode has large polarization even if it is a porous electrode, and also has large fluctuations over time. For example, in a gravimeter element that uses gold on one electrode, silver on the other electrode, and a silver salt solid electrolyte in between, and uses the potential fluctuation as a signal when the silver deposited on the metal electrode finishes dissolving, it is possible to use an aqueous solution. Since the usable current range is narrower than in the case of using a conventional method, there are inconveniences such as having to prepare several types of elements of different sizes. Also, one electrode has Ag
Polarizable electrodes such as 2S, Ag2Se, Ag2Te,
Even in the weighing device using silver for the other electrode, consideration is given to providing a separate reference electrode and utilizing potential fluctuations of only the polarizable electrode.

Furthermore, there are attempts to use bipolar electric double layer devices with porous carbon for one electrode and silver for the other electrode to use as a weighing scale or to store energy, but the current density used must be reduced. , the disadvantage is that the error becomes large and the loss becomes large.

Previously, an electric double layer capacitor was proposed that uses a polarizable electrode such as cherry activated carbon for one electrode, copper for the other electrode, and a copper salt-based copper ion conductive solid electrolyte for the electrolyte.
Copper electrodes have greater polarization than silver electrodes, which has been a practical problem. The purpose of the present invention is to reduce the polarization of copper electrodes for devices using solid electrolytes such as this type of battery and electric double layer capacitor. A copper electrode is provided to provide a double layer capacitor.

The copper electrode of the present invention is characterized in that it is made of a molded body of a mixture of a solid electrolyte that conducts copper ions and amalgamated copper powder.

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows an example of the structure of a solid electrolyte element. In the figure,
1 is a copper electrode formed from a mixture of amalgamated copper powder and a solid electrolyte that conducts copper ions. Reference numeral 2 denotes a copper mesh serving as a current collector plate, which is placed on the temporarily formed copper electrode 1 and is crimped during the final forming.

A lead 3 is electrically connected to the current collector plate 2 by solder, silver paste, or the like.

4 is a solid electrolyte layer.

5 is a counter electrode to the copper electrode 1. When the device is a battery, it is a mixture of a positive electrode active material such as Pbl2, Pb02, MnO2, and a solid electrolyte, and in the case of a coulometer, it is a mixture of a positive electrode active material such as Pbl2, Pb02, MnO2, etc., and a solid electrolyte such as platinum or gold. In the case of an electric double layer capacitor, a molded mixture of an inert electrode material with a large surface area such as activated carbon and a solid electrolyte is used as the inert metal plate.

Reference numeral 6 denotes a current collecting container made of a metal that does not cause electrode reactions, and houses the electrode 5.

Reference numeral 7 denotes a counter electrode lead, which is electrically connected to the current collector container 6 by solder, silver paste, or the like.

Reference numeral 8 denotes an exterior case that houses the element body such as the copper electrode 1, solid electrolyte 4, and electrode 5, and the space between the element body and the element body is filled with an epoxy resin as a embedding resin.

To make this element, proceed as follows.

First, a current collector container 6 is inserted into a cylindrical pressing die, and a material constituting the electrode 5, that is, a mixed powder of a counter electrode material and a solid electrolyte, is placed in the container 6 and temporarily pressed at a pressure of 50 cm. Next, powder of a substance constituting the solid electrolyte 4 is filled and temporarily pressed.

Further, a mixed powder of amalgamated copper powder and solid electrolyte was filled on top of it and temporarily pressed, about 20 meshes of copper net was placed on top of it, and hot pressed for 3 minutes at a pressure of 4t/(177i) to form it. A lead 3,
7 is attached to form an element body, which is inserted into an exterior case 8 and embedded with embedding resin 9. Here, there are two types of copper ion conductive solid electrolytes, and the following formula 1
A double salt obtained by heating a mixture of a cuprous halide represented by the formula and an alkyl halide of a pseudo-atomatutan compound represented by the formula 2 or 3 is suitable.

In the following examples, a double salt obtained from CuBr and triethylenediamine dimethyl bromide was used.

FIG. 2 compares the polarization of copper electrodes with different degrees of amalgamation. That is, the copper electrode 1 has a solid electrolyte content of 10% by weight and an electrode weight of 1.5f! , the weight of the solid electrolyte 4 is 1.59, the electrode 5 is a mixture 49 of 10% by weight of cherry activated carbon and the solid electrolyte, and the change in polarization when anodized with a current of 1 mA is shown. Here, curve A shows the case where copper is not amalgamated, B shows the addition ratio of mercury to copper at 2.5 mol%, C shows 5 mol%, D shows 10 mol%, and E
shows the case of 20 mol%. As is clear from the figure, when the addition ratio of mercury is about 5 mol %, the polarization becomes significantly small and the change over time becomes small.

Next, Figure 3 compares the polarization when the solid electrolyte content of the copper electrode is changed, and the addition ratio of mercury to copper is 5.
The other conditions are the same as those described above.

Curve F has an electrolyte content of 0, G has an electrolyte content of 5% by weight, H has an electrolyte content of 10% by weight, I has an electrolyte content of 20% by weight, and J
indicates the case where the electrolyte content is 30% by weight, and . Polarization is minimized when approximately 10% by weight of electrolyte is added to the copper electrode. FIG. 4 shows a comparison of polarization when the electrolyte content of the copper electrode is 10% by weight and the weight is varied.

Other conditions are the same as above. Here, the curve K is only for the copper net, L is the weight of the copper electrode 1, which is 0.59, and M is the weight, which is 1.0.
9, N indicates the case where the weight is 1.59, and O indicates the case where the weight is 2.09. There is no change when the weight of the copper electrode is 1.59 or more, but a porous electrode with a larger weight is preferable in order to reduce polarization.

As mentioned above, as a copper electrode for batteries, coulometers, electric double layer capacitors, etc. that use copper ion conductive solid electrolytes,
By using a molded body made of a mixture of malgamized copper powder and a copper ion-conducting solid electrolyte, discharge polarization can be reduced, resulting in higher voltages in batteries and lower voltages in capacitors. Loss can be reduced and potential changes caused by the copper electrode can be ignored.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of a solid electrolyte element using a copper electrode in an example of the present invention, Figure 2 is a diagram comparing the discharge polarization of copper electrodes with different degrees of amalgamation, and Figure 3 is a diagram showing the solid electrolyte content. FIG. 4 is a diagram comparing the discharge polarization of copper electrodes with different weights. FIG. 4 is a diagram comparing the discharge polarization of copper electrodes with different weights.

Claims (1)

[Claims] 1. A copper electrode for a solid electrolyte element comprising a molded body of a mixture of a copper ion conductive solid electrolyte and amalgamated copper powder.