JPS5923260A - Solid-state electrochemical element - Google Patents

Abstract

PURPOSE:To obtain an element of a small size and light weight having an actuator effect, by laminating successively a layer which donates and accepts ions by charging and discharging, a solid-state electrolyte layer which conducts ions and a metallic layer corresponding to ions and providing terminals to the ion donating and accepting layer and the metallic layer. CONSTITUTION:An ion donating and accepting layer 1 consisting essentially of chalcogenides of transition metals of IVa or Va group of periodic table and chalcogen compds. of Cn<++>, Ag<+> which are beforehand donated and accepted, a solid state electrolyte layer which conduct Cu<++>, Ag<+>, for example, a layer 3 consisting of 10-30mol% RbCl 10-60mol% CuI, 30-70mol% CuCl, and a layer 2 consisting essentially of the metal corresponding to the ions to be donated and accepted such as Cu, Ag or the like and contg. the above-described solid state electrolyte are thermally molded to one body under pressure to munufacture a structural body 10. Electrical terminals 4, 5 are respectively provided to the layers 1, 3, and the body is supported on a stator 11, whereby an electrochemical element is manufactured. If electric current is supplied from the terminal 5 to 4, ions enter the layer 1. Then the layer expands and the part 12 of the body 10 displaces. Said part maintains that state even when the current supply is stopped and when the current is run conversely, said part restores the original state. The actuator of a small size and light weight is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid-state electrochemical device that is movable by energization.

In recent years, with the development of mechatronics, the importance of so-called actuators that convert electrical energy into mechanical work has increased. Conventionally, such actuators have been used in the order of electromagnets and lenoids based on electromagnetic force. However, as mechanisms are required to be smaller and lighter, smaller and lighter electromagnetic actuators are required. In addition to electromagnetic methods, methods using piezoelectric phenomena, shape memory alloys and bimetals that perform mechanical work by converting electrical energy to thermal energy have been devised.

An object of the present invention is to provide an actuator based on a completely different principle from the above-mentioned actuators.

In other words, it is based on the principle of an electrochemical reaction that converts electrical energy into mechanical work by moving the constituent atoms from one layer of a three-layer structure to the other layer through the middle layer by applying electricity. The present invention provides a solid electrochemical device having an actuator function using the present invention.

Next, the structure of the element of the present invention will be explained using the drawings.

Some electronically conductive inorganic compounds have the ability to electrochemically accept external ions and use them as constituent atoms, or conversely donate constituent atoms to the outside as ions. We will call such a substance an ion acceptor. The details of this ion acceptor will be described later. FIG. 1(a) is a sectional view of the basic structure of the solid electrochemical device of the present invention, and FIG. 1(b) is a perspective view. In FIG. 1, 10 is a layer 1 basically consisting of an ion exchanger, a layer 2 basically consisting of a metal corresponding to the ions, and a layer 10 sandwiched between these which conducts the ions. This is a structure in which the solid electrolyte layer 3 is entirely integrated, and a circumferential member 1 is provided on a part of the structure 1o to mechanically fix the structure 1o and at the same time to attach the element to a mechanical device or the like.
1 and the remaining surface is mechanically opened R812
Furthermore, a pair of electrical terminals 4.6 for conducting current between the ion exchanger layer and the metal layer are provided. Note that in the present invention, the stator 11 is not necessarily required.

In the following explanation of the operation, in order to make it easier to understand, it is more convenient to provide a stator.

Next, the operation of this solid electrochemical device will be explained. In the device shown in FIG. 1, when a current is passed in the direction from the electric terminals 5 to 4, the metal atoms constituting the metal layer 2 are ionized, pass through the solid electrolyte layer 3, and reach the ion exchanger layer 1.
It is reduced and accepted. Due to this energization, the number of atoms constituting the ion exchanger layer 1 increases, so that the volume of the layer increases, and therefore the structure 10 is elongated in the longitudinal direction. As a result, the structure 1o curves downward. Therefore, by installing an object to be moved linearly on the movable part of the structure, the object can be moved. In the case where a stator is not provided, for example, in a mechanical object that has parallel gap planes, moves perpendicular to the gap plane, and is loaded by a spring or gravity in the direction that narrows the gap, one end and the center By inserting the elements of the present invention each having an electric terminal in each part and energizing the three elements, the mechanical object can be moved by the curvature of the structure. When the energization to the element is stopped, the movement of ions is stopped, so the curvature of the movable part of the present invention is maintained. Next, when the direction of the current is reversed, the flow of ions is reversed, the curvature disappears, and the shape returns to its original shape.

Next, materials used in the solid-state electrochemical device of the present invention will be described. The following compounds can be used as the ion transferor. One type is known as an intercalation compound, which has a crystal structure in which a two-dimensional network structure is weakly bonded in layers, and various ions are inserted by breaking the bonds between the layers, increasing the interlayer distance. Volume increases by enlarging. As a material that can be applied to the ion transfer body in the device of the present invention, group lVb or
Examples include chalcogenides of group b transition metals (chalcogen elements are a general term for S, Se, and Te). These exhibit the necessary electronic conductivity as a characteristic of the ion transfer body in the device of the present invention.

Typical examples of these include TiS2 and TaS2. In order to be used as an ion acceptor, ions to be transferred may be received in advance.

For example, by making TiS7 accept copper ions, Cu)(
TIS7 (may be set as 0 (1 < 1)
□Other ion acceptors include, for example, copper or silver chalcogen compounds. Konera also has the necessary electronic conductivity as a characteristic of the ion transfer body in the solid electrochemical device of the present invention. Representative examples of these include copper sulfide and silver chloride.

As a solid electrolyte that conducts ions, for copper ions, there is a compound consisting of three components, for example, RbC1, Cu(J), and CuI.The preferred composition for ion conduction is 1o4R.
bct243o, 1o-;CuI/;6o, 3
It is composed of a compound in the region of o<-CuO4<A (numbers represent all mol%). Indeed, RbAg4I5 is known as an electrolyte that conducts silver ions.

The three-layer integrated structure of the ion transfer layer, the solid electrolyte layer, and the metal layer is obtained by integrally molding and pressing each phase material powder. Hot pressing is performed in order to bond the structure more tightly, but it is preferable to perform heat treatment after pressing. In addition, in order to smoothly carry out the electrochemical reaction of ion exchange when electricity is applied, the ion exchanger layer and metal layer are
It is preferable to mix a small amount of the same solid electrolyte powder as used for the solid electrolyte.

Next, examples will be described. Cu1.
Copper sulfide with a composition of 59S is used, and Rb2C is used as the solid electrolyte.
A copper ion solid electrolyte with a composition of uBI3C17 was used. Mixture f 8 of 50% copper sulfide and 50% solid electrolyte
0 mg was weighed and filled into a metal with a cross section of 4 mm in width and 20 mm in 1% width, molded once at a pressure of 100 kg/ca, and then filled with a solid electrolyte of SO MY to form a similar material. Temporarily formed, and finally weighed and filled 120 mg of a mixture of 80% copper powder and 20% of the above solid electrolyte.
It was molded at a pressure of ton/ca4. In addition, the molding is 160
A stator and an electric terminal were set apart over a length of 4 mm from one end of the three-layer integral structure produced by molding, as shown in FIG.

The stator was made of plastic, and the electrical terminals were made of gold, an inert metal.

FIG. 2 shows the operating state of the solid electrochemical device of the present invention. (EL) in FIG. 2 shows the state before the start of energization. When a current of 10 mA is passed in the direction from the electrical terminals 6 to 4 for 1 minute, the structure curves downward as shown in FIG. 2(b), and exhibits a displacement of 0.4 mm at the open end. When the current supply is stopped, the displacement is maintained in that state. When the direction of the current is reversed, the original state is restored as shown in FIG. 2(a). Similar results can be obtained by repeating the same energization state.

As mentioned above, the solid electrochemical device of the present invention has an extremely simple structure and can be made small and lightweight. The solid electrochemical device of the present invention has extremely high utility value as a small and lightweight actuator.

[Brief explanation of drawings]

FIG. 1 shows the structure of an integrated electrochemical device according to an embodiment of the present invention, in which (a) is a sectional view, (b) is a perspective view,
FIG. 2 shows the operating state of the solid electrochemical device of the present invention, in which (a) is a side view showing the initial state, and (b) is a side view showing the state after energization. 1... Ion exchanger layer, 2... Metal layer, 3...
...solid electrolyte layer, 4. +5... Electrical terminal, 10... Structure, 11... Stator. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure ((1) l? Figure 1

Claims (5)

[Claims] (1) A first layer basically consisting of an ion donor/receiver that donates its constituent atoms to the outside as ions or conversely receives external ions as constituent atoms into its interior through charging and discharging, and the above-mentioned A structure integrally comprising a second layer basically made of a metal corresponding to ions, and a solid electrolyte provided between the first layer and the second layer to conduct the ions, and the first layer. and a pair of electrical terminals each electrically connected to the second layer. (2) A solid electrochemical device according to claim 1, characterized in that a stator is provided in a part of the structure. (3) The metal layer is basically made of copper or silver, the solid electrolyte layer is made of a solid electrolyte that conducts copper ions or silver ions corresponding to the above metal, and the ion transfer layer is group +Vb of the periodic table. or 4?, characterized in that it consists of a chalcogenide of a Group Vb transition metal. , i'F The solid electrochemical device according to claim 1. (4) The metal layer is basically made of copper or silver, the solid electrolyte layer is made of a solid electrolyte that conducts copper or silver ions corresponding to the metal, and the ion exchanger layer is composed of the metal layer. The solid electrochemical device according to claim 1, characterized in that it is made of chalcogenated steel or silver chalcogenide, depending on the metal. (5) The metal layer is made of copper, the ion exchange layer is made of copper sulfide, and the solid electrolyte has RbG1 of 10 to 30-E/
l/%, CuI 10 to 60 mo/I/%. The solid electrochemical device according to claim 3, characterized in that it is composed of a chemical compound in which Cu (J is 30 to 70 mol%).