JP2522410B2 - Solid electrolyte assembled battery - Google Patents

Description

TECHNICAL FIELD The present invention relates to a solid electrolyte assembled battery.

[Prior Art] The following have been proposed as an assembled battery.

An assembled battery (for example, a laminated dry battery or a Ni-Cd assembled battery) in which a plurality of individually made batteries are electrically connected.

An assembled battery (for example, a lead-acid battery for automobiles) manufactured by placing a plurality of sets of power generating elements in a plurality of storage chambers provided in a battery case, electrically connecting the power generating elements, and then covering the battery case.

An assembled battery in which a plurality of sets of power generating elements are connected by a bipolar plate (for example, a stacked fuel cell or a redox flow battery).

A high temperature solid oxide fuel cell using a solid electrolyte.

An assembled battery (for example, a lithium battery) in which a plurality of individual power generating elements (cells) using a polymer solid electrolyte are stacked and housed in a battery container.

SPE using an ion exchange membrane, in which anions are fixed on a polymer film, power generating elements are housed in individual cell chambers, and water is injected into the cell chambers to enhance ionic conductivity.
Fuel cell.

Among the above-mentioned assembled batteries, the assembled batteries (1) and (2) have individual power generation elements housed in independent cell chambers or containers. Therefore, since a plurality of cell chambers or containers are required, the energy density of the assembled battery is low, and the number of parts and the manufacturing process are increased. In this type of battery, when a plurality of power generating elements are placed in one cell chamber or container in order to increase the energy density and reduce the number of manufacturing processes, the electrolytic solution becomes common and a liquid short circuit occurs between the power generating elements. Occurs, and sufficient battery performance cannot be exhibited.

The above-mentioned and assembled batteries are assembled batteries using a solid electrolyte, and are the assembled batteries to be improved by the present invention.

[Problems to be Solved by the Invention] The above high temperature solid oxide fuel cell is operated at high temperature because of its low ionic conductivity at room temperature,
Equipment is expensive and uncommon. Therefore, generally, an assembled battery using the above-mentioned polymer solid electrolyte is used. Taking a known lithium battery as an example, a plurality of individual power generating elements are stacked and housed in a battery container, and high energy density has been achieved to some extent. However, there is a problem in that the work of stacking a plurality of independently-produced power generating elements and storing them in a battery container is troublesome and complicated because it is necessary to store them without breaking the stacked state.

In fact, the solid electrolyte alone has a low ionic conductivity. For that purpose, each power generating element is stored in a separate battery container,
An electrolyte (lithium chloride) and an organic solvent (propylene carbonate) are injected into the battery container to make a single cell,
In many cases, a plurality of individual cells are electrically connected. If a plurality of power generation elements stacked in one battery container are placed, and an electrolyte and an organic solvent are placed, a liquid short circuit occurs and self-discharge becomes large.

An object of the present invention is to provide a solid electrolyte assembled battery which can be easily assembled even when a plurality of power generating elements are housed in a single battery container and can reduce self-discharge.

[Means for Solving the Problem] In the solid electrolyte assembled battery of the present invention, the positive electrode agent and the negative electrode agent are alternately arranged at intervals on one surface of the ion conductive film. Further, on the other surface of the ion conductive film, a positive electrode agent or a negative electrode agent arranged on the one surface and a polar agent having different polarities face each other with the ion conductive film interposed therebetween, and a plurality of power generating elements are provided. The positive electrode agent and the negative electrode agent are alternately arranged at intervals so as to form the above. Then, the plurality of power generating elements are electrically connected in series.

[Operation of the Invention] According to the present invention, since a plurality of power generating elements are formed on one sheet of ion conductive film, each power generating element is not separated and the manufacturing and assembling are easy.

When electrically connecting a plurality of power generating elements, a conductive connector may be used, but without using a conductive connector, the connecting portions of the ion conductive film located between the plurality of power generating elements are alternately arranged. When the power generating elements are connected in series by folding back in different directions and directly contacting the adjacent anodic agent and cathodic agent located on the same surface side of the ion conductive film, the conductive connector becomes unnecessary.

The storage mode in the battery container is arbitrary, and in the type that does not use the conductive connector as described above, the plurality of power generating elements can be stored in the battery container in a stacked state, so that the battery can be made compact. Even when the conductive connector is used, the insulating films can be overlapped and wound to form a wound type assembled battery. In this way, the battery can be made compact even if the conductive connector is used. When an ion conductive film that causes ionic conduction is used as the solid electrolyte, the film has a small ionic conductivity and a small cross-sectional area in the thickness direction as compared with an electrolyte solution. Even if the power generating element is configured, the liquid short circuit generated between the power generating elements due to the solid electrolyte between the power generating elements is extremely small, and the resulting self-discharge is also extremely small.

In particular, when a polymer film having an ionic dissociation group to which either an anion or a cation is fixed is used as the ion conductive film, the ionic species that can be moved to maintain the electrical neutrality of the system also move out of the ion conductive film. There is nothing to do. Further, in this way, even if the assembled battery is housed in a single battery container and a solvent capable of solvating mobile ions to increase ionic conductivity is injected into the battery container, the solvent is not injected. As in the case, the liquid short circuit between the individual power generating elements occurs only in the direction along the film surface of the ion conductive film, which is also extremely small. FIG. 4 shows the mechanism of the battery when the cation conductive film is used. In the figure, “e →” is a flow of electrons, “A →” is a flow of cations associated with a normal battery reaction, and “B →” is a flow of cations associated with a liquid short circuit through the film. Yes, "C
→ is the flow of cations that accompanies a liquid short circuit through the liquid. The flow of the regular cation “A →” is a flow in the direction perpendicular to the film surface (thickness direction). Since the film is thin, the resistance is small and the amount of cations flowing is large. Further, the flow of the cation “B →” is a flow in a direction parallel to the film surface, and since the film is thin, the resistance in this direction is large, and thus the amount of cation flow is small. The longer the distance between the power generating elements, the smaller the flow of “B →”. Also, the flow of cations “C →” due to a liquid short circuit through the liquid is caused by the flow of not only cations but also anions (in the direction opposite to the flow of cations) if there is an electrolyte solution.
Moreover, the amount of the flow becomes extremely large. However, in the case of only the solvent, the electrical neutrality cannot be maintained, so that only one ion cannot exist in the solvent. Therefore, it can be considered that there is no flow of “C →”.

In particular, when an anisotropic ion conductive film having ion conductivity only in the thickness direction of the ion conductive film is used, the above liquid short circuit does not occur at all, and as a result, self-discharge does not occur at all.

According to the present invention, for the above reason, it is easy to manufacture an assembled battery, and since a short circuit due to an electrolyte or a liquid short circuit due to a solvent does not substantially occur between the power generating elements, a plurality of power generating elements can be formed in one battery container. It becomes possible to store the battery, the ratio of the battery container to the weight and volume of the entire battery can be reduced, and the energy efficiency of the assembled battery can be dramatically improved.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a sectional view of an embodiment in which the present invention is applied to a sheet-shaped assembled battery. In the figure, 1 is an ion conductive film. In this example, as the ion conductive film 1, a polymer film having an ion dissociation group, in which one of anions or cations is fixed to the polymer in an ion dissociated state, and an ion whose substantial ion conduction is not fixed Use the one that occurs only by the seed.

On one surface 1a of the ion conductive film 1, the positive electrode agent 2
0, 22, 24 and the negative electrodes 31, 33 are alternately arranged in the longitudinal direction with a predetermined interval L. Further, on the other surface of the ion conductive film 1, the negative electrode agents 30, 32, 34 and the positive electrode agents 21, 23 are alternately arranged in the longitudinal direction with a predetermined interval L. The polar agent facing through the ion conductive film 1 is
The polarities are different, and the positive electrode agent and the negative electrode agent facing each other form five unit cells, that is, power generating elements. These power generating elements are electrically connected in series by the conductive connectors 40 to 43, the positive electrode agent 20 located at one end is connected to the positive electrode terminal 5, and the negative electrode agent located at the other end.
The negative electrode terminal 6 is connected to 34. The assembled battery formed in this way is housed in an insulative battery container 7 divided into two parts. Each power generation element is pressed by the case 7 in the stacking direction.

Spaces 80 to 85 are formed between each power generation element of the assembled battery and the battery case 7, and a solvent is injected into this space. As the solvent, a solvent which does not contain ionic species and which can solvate lithium ions such as propion carbonate is injected. This solvent permeates the ion conductive film 1 and solvates lithium ions, thereby increasing the ion conductivity of the ion conductive film 1. Since the cation dissociative group is fixed to the polymer, it is not necessary for lithium ions to be present in the spaces 80 to 85 in order to maintain electrical neutrality. Therefore, the liquid short circuit path between the power generating elements is only the ion conductive film.

Examples of the ion conductive film 1 include a cation dissociative group such as a sulfonic acid group and a carboxylic acid group, and the dissociative group when the charge carrier in the electrolytic solution is a lithium ion such as a lithium battery. A polymer film having lithium ions ionically bonded to is used. When the negative electrode agent is made of hydrogen storage alloy or cadmium oxide, or when the positive electrode agent is made of nickel hydroxide, the carrier responsible for the charge transfer in the electrolyte is marine ions, so an anion group such as an ammonium group or an alkylammonium group is used. An ion conductive film made of a polymer having an ion dissociative group and a hydroxyl ion bonded to the ion dissociative group is used. Then, as the solvent to be injected into the spaces 80 to 85, in the former case, an organic solvent such as propylene carbonate or dimethyl sulfoxide that is commonly used in lithium batteries may be used, and in the latter case, water may be used. Good. The polymer used for the ion conductive film is specifically selected from polyethylene oxide-based, polystyrene-based, polydivinylbenzene-based, perfluorocarbon-based, etc. in consideration of the interaction with the solvent, and it is necessary. If appropriately crosslinked, it is used as a three-dimensional polymer.

Here, a lithium battery will be specifically described as an example.
When, for example, a polyethylene oxide-based solid electrolyte film is used as the ion conductive film, it has a high ion conductivity of 1 / 100,000 S / cm. Therefore the thickness is 1
When using an ion conductive film of 00μ, the width dimension
Assuming that the distance L between the positive electrode agent and the negative electrode agent that are 3 cm and adjacent to each other on one surface of the film is 3 mm, the resistance between the adjacent positive electrode agent and the negative electrode agent is 10 MΩ. As for the value, the amount of self-discharge electricity that flows at a voltage of 3 V in one year is 2
It is about 3 mAh. If the battery capacity is several hundred mAh, the self-discharge rate of this level is about 1% of the battery capacity in one year,
It is almost the same as the self-discharge rate of current lithium batteries.
If the distance L between the adjacent positive electrode agent and negative electrode agent is doubled, the self-discharge rate will be halved, which is almost no problem.

In the above examples, a polymer solid electrolyte membrane was used as the ion conductive film, but as the ion conductive film, an ion exchange membrane, a solid electrolyte dispersed in a matrix and formed into a film, in a porous film. It is possible to use a film obtained by impregnating and fixing an organic electrolyte monomer or oligomer, or other film having ion conductivity. In particular, an e-eye called Nafion (trademark)
When an anisotropic ion conductive film having ion conductivity only in the thickness direction of the film, such as an ion exchange membrane manufactured by DuPont, is used, a more excellent effect than the above example can be obtained.

FIG. 2 shows a sectional view of a different embodiment of the assembled battery of the present invention. In this embodiment, the power generating elements are stacked to form a stacked type assembled battery. Ion conductive film 10
Positive electrode agents 120 to 124 and negative electrode agents 130 to 134 are arranged on both surfaces of 1 so as to form five power generating elements as in the embodiment of FIG. In this example, an ion conductive film
The connecting portions 101A to 101D connecting the respective power generating elements of 101 are alternately folded back in different directions, and the adjacent anodic agent (for example, 121,123) and cathodic agent (for example, 130,132) located on the same surface side of the ion conductive film 101 are connected to each other. Adjacent power generating elements are connected in series by making direct contact.

The stacked body thus stacked is housed in the battery container 107 in a compressed state in the stacking direction to complete the assembled battery.
The bottom wall portion of the battery container 107 is in contact with the negative electrode agent 134, and the battery container 107 constitutes a cathode terminal. Further, a conductive lid plate 110 is provided in the opening of the battery container 107 via an insulating packing 109.
Are fitted, and the lid plate 110 contacts the positive electrode agent 120 to form a positive electrode terminal. Although the solvent is injected into the space 108 formed between the battery container 107 and the laminated body, the problem of self-discharge due to the liquid short circuit does not occur as in the case of the description of the embodiment shown in FIG.

In the embodiment shown in FIG. 2, the power generating elements are stacked to reduce the size of the battery. However, similar to the existing cylindrical type battery, a wound type battery can be used to reduce the size of the battery. You can also For example, similarly to the embodiment shown in FIG. 1, an anodic agent, a cathodic agent, and a conductive connector which are arranged on one surface of the ionic conductive film to form a power generating element with a predetermined interval in the ionic conductive film. The insulating film may be placed on the above to make a polymer, and the polymer may be wound, and the winding method is arbitrary.

FIG. 3 shows an example for explaining the winding method. In this example, the positive electrode agent 220, the negative electrode agent 230, and the positive electrode agent 221 are alternately arranged on one surface of the ion conductive film 201, and the positive electrode agent 220 and the negative electrode agent 230 are electrically conductive connectors 20.
Although not shown, a positive electrode terminal is connected to the positive electrode agent 221. Further, the negative electrode agent 231, the positive electrode agent 222, and the negative electrode agent 232 are alternately arranged on the insulating film 111, and the negative electrode agent 231 and the positive electrode agent 222 are connected by a conductive connector (not shown). Not the negative terminal is connected. In this manner, the ion conductive film 201 and the insulating film 111 in which the positive electrode agent and the negative electrode agent are arranged
Are wound by a known winding type so that the positive electrode agent and the negative electrode agent face each other with the ion conductive film 201 interposed therebetween to form a power generation element. Then, the wound one is housed in a cylindrical battery container. Even if the solvent is injected into the battery container, there is almost no influence of the liquid short circuit as in the embodiment shown in FIG. When a winding type assembled battery is constructed as in the example shown in FIG.
Prepare a continuous body in which a positive electrode agent and a negative electrode agent are sequentially arranged on an elongated ribbon-shaped insulating film and an ion conductive film, respectively, and wind these in a known winding type to generate the required power generation. By cutting the continuous body according to the number of elements (cells), it becomes possible to continuously produce an assembled battery having a desired number of cells. As a result, it becomes easy to control the manufacturing conditions of the battery parts.

EFFECTS OF THE INVENTION According to the present invention, an assembled battery can be easily manufactured, and a short circuit due to an electrolyte or a liquid short circuit due to a solvent does not substantially occur between the power generating elements. It is possible to store the battery in the battery container, and it is possible to reduce the ratio of the battery container to the weight and volume of the entire battery.
It is possible to dramatically improve the energy efficiency of the assembled battery.

In particular, when electrically connecting a plurality of power generating elements, a conductive connector can be used, but the connecting portions of the ion conductive films located between the plurality of cells are alternately different without using a conductive connector. If the electric power generating elements are connected in series by folding back in a direction and directly contacting the adjacent anodic agent and cathodic agent located on the same surface side of the ion conductive film, there is an advantage that a conductive connector is not required.

Further, the storage mode in the battery container is arbitrary, and there is an advantage that the size of the battery can be made compact if it is a laminated type or a wound type.

When a polymer film having an ionic dissociation group to which either an anion or a cation is fixed is used as the ion conductive film, the ionic species that can be moved to maintain the electrical neutrality of the system also move out of the ion conductive film. Even if the assembled battery is housed in a single battery container and a solvent capable of solvating mobile ions to increase ionic conductivity is injected into the battery container, a liquid short circuit occurs between individual power generating elements. Occurs only in the direction along the film surface of the ion conductive film, and since it is also extremely small, the liquid short circuit does not pose a problem.

When an anisotropic ion conductive film having ion conductivity only in the thickness direction of the ion conductive film is used, liquid short circuit does not occur at all, and as a result, self-discharge can be completely prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sheet-shaped embodiment of the assembled battery of the present invention, FIG. 2 is a cross-sectional view of an embodiment of the assembled battery of the present invention in a stack type, and FIG. 3 is a winding-type assembled battery. FIG. 4 is a conceptual diagram for manufacturing the battery, and FIG. 4 is an explanatory view for explaining the mechanism of the battery of the present invention. 1,101,201 …… Ion conductive film, 7,107 …… Battery case, 20〜24,120〜124,220〜222 …… Cathode, 30 ・ ・ ・ 34,1
30〜134,230〜232 …… Anode agent, 111 …… Insulating film.

Claims (9)

(57) [Claims] 1. A positive electrode agent and a negative electrode agent are alternately arranged at intervals on one surface of an ion conductive film, and the positive electrode agent or the positive electrode agent is arranged on the other surface on the other surface. The positive electrode agent and the negative electrode agent are alternately arranged at intervals so that the negative electrode agent and the electrode agents of different polarities face each other through the ion conductive film to form a plurality of power generating elements, A solid electrolyte assembled battery in which individual power generating elements are electrically connected in series. 2. The solid electrolyte assembled battery according to claim 1, wherein the plurality of power generating elements are electrically connected in series by a roadway connector. 3. The solid electrolyte assembled battery according to claim 2, wherein the assembled battery in which the plurality of power generating elements are connected in series is wrapped with insulating films and wound and housed in a battery container. 4. The connecting parts of the ion conductive films located between the plurality of power generating elements are alternately folded back in different directions, and the adjacent anodic agent located on the same side of the ion conductive film and the adjacent anodic agent. The solid electrolyte assembled battery according to claim 1, wherein the plurality of power generating elements are electrically connected in series by being brought into direct contact with a cathodic agent. 5. An ion in which the ionic conductive film is a polymer film having an ionic dissociative group, and one of an anion and a cation is fixed to the polymer in an ion dissociated state, and substantial ionic conduction is not fixed. The solid electrolyte assembled battery according to claim 1, 2, 3 or 4, which is caused only by seeds. 6. The solid electrolyte assembled battery according to claim 1, 2, 3, or 4, wherein the ion conductive film is an anisotropic in-on conductive film having ion conductivity only in the thickness direction. 7. The anodic agent and the cathodic agent, which are laminated with the ion conductive film interposed therebetween, are housed in a battery container so as to be pressed in the stacking direction, and the ionic species is contained in the battery container. The solid electrolyte assembled battery according to claim 5, wherein a solvent not containing is injected. 8. The ion conductive film is a cation conductor, the unfixed ionic species is lithium ions, and the negative electrode agent contains lithium.
5. The solid electrolyte assembled battery described in 5, 6, or 7. 9. The ion conductive film is an anion conductor, the unfixed ionic species is a hydroxide ion, and the negative electrode agent is mainly composed of a hydrogen storage alloy, or cadmium oxide. 8. The solid electrolyte assembled battery according to claim 5, 6 or 7, wherein the positive electrode agent is nickel hydroxide.