JP3482970B2 - Organic electrolyte battery - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin-type (button-type) organic electrolyte battery using an aprotic organic solvent solution as an electrolyte. 2. Description of the Related Art Japanese Unexamined Patent Publication No.
JP-A-170163 discloses an organic electrolyte battery in which an organic semiconductor having a polyacene skeleton structure is used as a positive electrode and a negative electrode, and an aprotic organic solvent liquid is used as an electrolyte. [0003] In the battery, the material of the gasket which keeps the battery airtight and liquid tight and the insulation of the positive and negative electrode cans is extremely important. Conventional gasket materials include chemical resistance,
Inexpensive polypropylene, which is excellent in elasticity and creep resistance, has good moldability, and can be injection molded, has been used. The positive / negative electrode cans, separators, organic semiconductors having a polyacene skeleton structure, and electrolytes of the batteries have high melting points or boiling points and high heat resistance.
However, the polypropylene used for the gasket has a low heat-resistant temperature, so that the conventional battery has a disadvantage that the heat resistance is inferior. [0005] A coin type (button type) organic electrolyte battery is
It is mainly used as a memory backup power supply.
In such a case, after soldering a terminal for soldering to the battery, the battery is often soldered together with a memory element onto a printed circuit board. Conventionally, soldering on a printed circuit board has been performed using a soldering iron, but with the miniaturization of the equipment and the sophistication of functions, it is necessary to increase the number of electronic components mounted on the same area of the printed circuit board. Therefore, it has become difficult to secure a gap for inserting a soldering iron for soldering. Accordingly, solder is applied in advance to a portion of the printed circuit board where soldering is to be performed, and components are mounted on the portion, or after the components are mounted, small solder balls are supplied to the soldered portion, and solder is applied. A method in which the solder is melted and soldered by passing the printed board on which the components are mounted in a furnace in a high-temperature atmosphere set so that the soldered portion has a temperature equal to or higher than the melting point of the solder, for example, 200 to 230 ° C. (Hereinafter referred to as reflow soldering). A conventional coin-type (button-type) organic electrolyte battery using a gasket made of polypropylene has the problem that the polypropylene melts or deforms during reflow soldering, and the positive and negative electrodes made of stainless steel or aluminum come into contact and short-circuit. there were. In order to improve the heat resistance, it is effective to use a gasket made of a polyamide resin having excellent heat resistance. However, the polyamide resin has high hygroscopicity, and the moisture resistance of the organic electrolyte battery is reduced. There was a problem of doing. [0008] In order to solve the above-mentioned problems, the present inventors have replaced a conventional gasket made of polypropylene with a gasket made of a polyamide-based resin and replaced with a positive electrode and / or a gasket made of a polyamide resin. The negative electrode is used in a coin-type (button-type) organic electrolyte battery made of an organic semiconductor having a polyacene-based skeleton structure, and the battery is operated at a continuous operating temperature.
It has been found that by molding with a thermosetting resin in a case of a thermoplastic resin of 100 ° C. or higher, heat resistance is improved, reflow soldering becomes possible, and moisture resistance is improved. Positive electrode can, negative electrode can, positive electrode, negative electrode, positive electrode end
A negative electrode terminal, a separator, and a gasket, and the positive electrode and / or the negative electrode are made of an organic semiconductor having a polyacene skeleton structure, and the gasket is made of a polyamide resin.
A coin-type organic electrolyte battery made of
0 molded into the case at thermosetting resin ℃ or more thermoplastic resins, the positive and negative terminals is positive can, a negative electrode can Niso
Each is resistance welded or laser welded, some are heat hardened
A coin-type (button-type) organic electrolyte battery characterized by being exposed to the outside of a plasticizing resin . As shown in FIG. 1, the battery of the present invention has a sheet 2 made of a polyacene-based organic semiconductor in which conductive pastes 3 and 3 ′ are applied to the inner bottoms of a positive electrode can 1 and a negative electrode can 6.
2 ′ is inserted into the positive electrode can 1 and the negative electrode can 6 so as to be in contact with the conductive pastes 3 and 3 ′, and is opposed to each other via the separator 5. The gasket 4 is compressed by the positive electrode can 1 and the negative electrode can 6 to maintain airtightness, liquid tightness, and insulation of the positive and negative electrode cans, and the electrolyte is partially made of a sheet 2, 2 ′ made of a polyacene-based organic semiconductor. It may be in the space inside and partly in the space 7. The thermosetting resin 8 completely covers the surfaces of the positive and negative electrode cans and is housed in a case 11. The positive electrode terminal 9 and the negative electrode terminal 10 are resistance-welded or laser-welded to the positive electrode can 1 and the negative electrode can 6, respectively, and a part thereof is exposed to the outside of the thermosetting resin 8. The positive electrode can and the negative electrode can are conventional, and are made of, for example, stainless steel or aluminum. The separator is commonly used in batteries or capacitors, and is, for example, a porous synthetic resin film, a material obtained by hardening inorganic fibers with a resin, paper, or the like, and is preferably made of a glass fiber nonwoven fabric. [0012] The organic electrolyte is a solution in which an aprotic organic solvent dissolves a salt that forms ions. Usually, as an electrolytic solution of this type of organic electrolyte battery, an aprotic organic solvent such as propylene carbonate or γ-butyrolactone is preferably used as a solvent, and a tetraalkylammonium salt such as, for example, (R1, R2, R3 and R4 each represent an alkyl group;
To R4 may be the same or different. X represents ClO ₄ or BF ₄ ) is preferably used. Salt is usually 0.5
It is dissolved in the above-mentioned solvent in a concentration range of up to 1.5 mol / l and used as an electrolyte. The terminals are commonly used in batteries or capacitors and are made of, for example, stainless steel nickel or the like, and are preferably made of stainless steel of the same material as the positive and negative electrode cans. Organic semiconductors having a polyacene-based skeleton structure used in the present invention are known per se.
No. 8060. The organic semiconductor is pulverized using a ball mill or the like to form a powder, a binder and a conductive material are added to the powder, mixed, and then pressed to form a polyacene sheet to form a positive electrode and / or a negative electrode. The gasket is located between the positive and negative electrode cans, and is used to keep the positive and negative electrode cans insulated and to keep the battery airtight and liquid tight. The material must have chemical resistance to aprotic organic solvent liquids, and must have excellent elasticity and creep resistance because it is placed between the positive and negative electrode cans and compressed. is there. Further, it is more preferable that the composition can be injection-molded with good moldability and suitable for mass production. In the present invention, the polyamide resin refers to an amide bond -CO in a main chain generally called a nylon resin.
It is a polymer having -NH-. Typically, a resin synthesized by polycondensation of a dicarboxylic acid and a diamine, polycondensation of an ω-aminocarboxylic acid, or ring-opening polymerization of a lactam, is not only excellent in heat resistance but also in chemical resistance. It is excellent in heat resistance, creep resistance and elasticity, has good moldability, can be injection molded and is inexpensive, and is suitable for a gasket of a battery. Among them, nylon 46 is more preferable in terms of heat resistance. The continuous use temperature in the present invention refers to a temperature at which a material retains 50% strength after 100,000 hours of continuous use, and is one of the general characteristics indicating the heat resistance of a resin. is there. The thermoplastic resin in the present invention is a resin having a property that a phenomenon of softening / melting by heating and solidifying by cooling occurs reversibly, and the battery is heated and mounted in a furnace at the time of reflow soldering. In order to receive heat radiation from peripheral components when the device is used, the outer case material of the battery needs to be particularly excellent in heat resistance, and needs to have a characteristic of 100 ° C. or more at a continuous use temperature. Examples of such a resin include polyester, polyamide, polycarbonate, polyacetal, modified polyphenylene ether and the like. Polyphenylene sulfide, polyether ketone, polyether ether ketone, polyether sulfone, polysulfone, polyetherimide, polyimide, Polyamide imide, polyarylate, wholly aromatic polyester, ethylene terephthalate / parahydroxybenzoic acid copolymer are particularly preferred. It is also possible to use a mixture of these resins with carbon-based fillers such as carbon black, glass fibers, inorganic fillers such as alumina, additives such as lubricants and coupling agents, or various metal fillers and a mixture of these fillers. it can. The case in the present invention may be any size as long as it can accommodate the entire battery except for a part of the positive and negative electrode terminals when the battery is molded with a thermosetting resin. The thermosetting resin may be partially covered or exposed. The thickness and shape of the case can be appropriately selected. The thermosetting resin in the present invention is a resin having a property of being cured by the reaction of unreacted groups remaining in the polymer by heating, the degree of polymerization being increased, the crosslinking being advanced, and the formation of a network structure. ,
Epoxy resins and phenol resins are more preferred. The resin has excellent heat resistance and solvent resistance, and is suitable for a coin-type (button-type) organic electrolyte battery mold. An organic semiconductor having a polyacene skeleton structure used for a positive electrode and / or a negative electrode is produced by a thermal condensation polymerization reaction and has excellent heat resistance. Stainless steel or aluminum used for the positive electrode can or the negative electrode can is a metal having excellent heat resistance. The glass fiber nonwoven fabric preferably used for the separator has a high melting point of glass and is excellent in heat resistance. As the electrolyte, an aprotic organic solvent used as a solvent for the electrolyte, for example, propylene carbonate has a high boiling point, and has much better heat resistance than the electrolyte used for the aqueous battery. Therefore, the heat resistance of the battery of the present invention was improved by using a polyamide resin having excellent heat resistance for the gasket having the lowest heat resistance. In other batteries, for example, an aqueous solution battery, the heat resistance of the electrolyte is inferior. Therefore, even if the heat resistance of the gasket is improved, the heat resistance of the battery is not improved. The above-described gasket made of a polyamide resin is replaced with a gasket made of a conventional polypropylene, instead of an organic electrolyte battery using an organic semiconductor having a polyacene skeleton structure in the positive electrode and / or the negative electrode. The heat resistance of the battery is improved by molding it with a thermosetting resin in a thermoplastic resin case with a continuous use temperature of 100 ° C or higher as described above, and the reflow soldering is possible and the moisture resistance is improved. Is done. Example 1 First, a polyacene sheet was produced as follows. JP-A-61-2180 according to the applicant of the present invention
According to the manufacturing method described in Example 1 of JP-A-60,
Insoluble and infusible polyacene films were synthesized. When the electric conductivity of the substance was measured at room temperature by a direct current four-terminal method,
It was 10 ^-4 Ω ^-1 · cm ^-1 . According to elemental analysis, the atomic ratio of hydrogen atom / carbon atom was 0.27. The specific surface area by the BET method was an extremely large value of 2100 m ² / g. Next, the polyacene film was ground using a ball mill for 3 hours to obtain a powder. After adding 5% by weight of polytetrafluoroethylene and 10% by weight of carbon black to this powder and mixing,
The polyacene sheet having a thickness of 0.2 mm was obtained by pressure molding. Next, the polyacene sheet and a separator made of a borosilicate glass fiber non-woven fabric were punched into a disk shape at 200 ° C.
And dried in a jam pot for 3 hours. Nylon which is the polyamide resin of the present invention
The gasket obtained by injection-molding No. 46 was dried by vacuum drying at 100 ° C. for 3 hours and stored in a jam pot. Next, after a conductive paste was applied to the bottom of the inside of the positive electrode can made of stainless steel, the above-mentioned polyacene sheet was placed thereon, pressed from above, and dried at 100 ° C. for 30 minutes. Similarly, a conductive paste was applied to the inner bottom surface of a stainless steel negative electrode can, a polyacene sheet was placed on the negative electrode can, and after pressing, dried at 100 ° C. for 30 minutes. To the positive electrode thus obtained, a predetermined amount of propylene carbonate containing tetraethylammonium borofluoride as an electrolyte was injected, and a separator was placed. After a predetermined amount of the electrolytic solution was similarly injected into the negative electrode, a coin-type (button-type) organic electrolyte battery having a diameter of 6.8 mm and a height of 0.96 mm as shown in FIG. 1 was assembled. still,
All the above-described assembling operations were performed in the dehumidifying room. Next, after stacking two coin-type (button-type) batteries, a stainless steel terminal was laser-welded to the positive electrode can of one battery and the negative electrode can of the other battery, so that polyphenylene sulfide (Dainippon Ink Chemical industry FZ = 3
600) case and epoxy resin (CV5032 manufactured by Matsushita Electric Works, Ltd.), bottom 8.5mm x 8.5mm, height 3.5mm
Was molded. The change in the AC internal resistance (1 kHz, 1 mA) when the organic electrolyte battery of the present invention prepared as described above was subjected to reflow soldering so that the surface of the positive and negative electrodes had the temperature transition shown in FIG. Table 1 shows the internal resistance after applying a voltage of 5.0 V for 5 days in a constant temperature and constant humidity of 60 ° C. and a relative humidity of 93% after the reflow soldering. Example 2 After stacking two coin-type (button-type) batteries manufactured in the same manner as in Example 1, a stainless steel terminal was placed on the positive electrode can of one battery and the negative electrode can of the other battery. Is welded with a laser and welded with a case of polyether ether ketone (manufactured by Sumitomo Chemical Co., Ltd.) and an epoxy resin (CV5032 manufactured by Matsushita Electric Works, Ltd.) with a bottom of 8.5 mm × 8.5 mm.
It was molded to a height of 3.5 mm. The organic electrolyte battery of the present invention prepared as described above, the positive and negative electrode
Table 1 shows the change in the AC internal resistance (1 kHz, 1 mA) when the reflow soldering was performed so that the temperature changes as shown in Table 1. After the reflow soldering, the temperature was measured in a constant temperature and humidity room at 60 ° C and 93% relative humidity. Table 2 shows the internal resistance after applying a voltage of 5.0 v for 5 days. [Table 1] [Table 2] Comparative Example 1 A coin-type organic electrolyte battery was assembled using a gasket injection-molded with polypropylene in the same manner as in Example 1, and the change in AC internal resistance when resin molding was performed and reflow soldering was performed. It is shown in Table 1. Comparative Example 2 A coin-type organic electrolyte battery similar to that of the embodiment was assembled using a gasket obtained by injection-molding nylon 46, and the AC internal resistance when reflow soldering was performed without performing resin molding. The change is shown in Table 1 and the internal resistance is shown in Table 2 after applying a 5.0 V voltage for 5 days in a constant temperature and humidity condition of 60 ° C. and a relative humidity of 93% after the reflow soldering. COMPARATIVE EXAMPLE 3 A coin-type organic electrolyte battery was molded using a polystyrene case in the same manner as in the example, and reflow soldering was performed. As a result, abnormalities such as melting and deformation of the case were observed. In Tables 1 and 2, the product of the present invention and the conventional product are compared. The product of the present invention does not cause a short circuit in the reflow soldering, shows no change in AC internal resistance, has improved heat resistance, enables reflow soldering, and has improved moisture resistance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a coin type (button type) according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a battery. FIG. 2 shows a change in the surface temperature of the positive and negative electrode terminals during reflow soldering. [Description of Signs] 1: Positive electrode can 2, 2 ': Sheet 3, 3' made of polyacene organic semiconductor: Conductive paste 4: Gasket made of polyamide resin 5: Separator 6: Negative electrode can 7: Electrolyte 8: Mold resin 9: Positive terminal 10: Negative terminal 11: Case

Continuation of front page    (72) Inventor Hisashi Satake               Osaka, Miyakojima-ku 1-chome 2-6-1303               issue (72) Inventor Shizukuni Yada               2-6-13 Miyanishi, Harima-cho, Kako-gun, Hyogo Prefecture (72) Inventor Toyorou Harada               5-30-1, Nishitaga, Taihaku-ku, Sendai-shi (72) Inventor Isamu Shinoda               5-30-1, Nishitaga, Taihaku-ku, Sendai-shi                (56) References JP-A-4-73861 (JP, A)                 JP-A-5-13058 (JP, A)                 JP-A-4-264354 (JP, A)                 JP-A-60-170163 (JP, A)                 JP-A-57-96456 (JP, A)                 58-83760 (JP, U)

Claims (1)

(57) [Claims] [Claim 1] A positive electrode can, a negative electrode can, a positive electrode, a negative electrode, a positive electrode terminal ,
A negative electrode terminal, a separator, and a gasket are provided.
Or, together with the negative electrode comprises an organic semiconductor having a polyacene skeleton structure, the gasket is a polyamide resin
A coin-type organic electrolyte battery is operated at a continuous use temperature of 100 ° C.
Molded with a thermosetting resin in the above thermoplastic resin case, the positive terminal and negative terminal are positive and negative terminals respectively.
Resistance welded or laser welded, partially thermosetting
An organic electrolyte battery which is exposed to the outside of a resin .