JPH0554868A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To improve a high temperature retention characteristic by hermetically sealing a case with a sealing plate through a gasket using amorphous heat-proof thermoplastic resin as a raw material. CONSTITUTION:A power generation element 5 composed by laminating a positive electrode 2 mainly composed of graphite fluoride and a negative electrode 3 having metal lithium as an active material through a separator 4 impregnated with electrolyte is built inside a case 1 made of an BUS material. A gasket 7 consisting of thermoplastic resin having excellent heat resistance and amorphous crystal structure is fitted into an opening part 1a of the case 1 in the peripheral part of a metallic sealing plate. This resin consists of transformed polyphenylene oxide, polyether sulfone, polysulfone, polyether imide and transformed polyphenylene ether. Next, a periphery of the opening part 1a is inwardly bent by a metal mold so as to seal the opening part 1a. Then, no change occurs against thermal stress so as to maintain airtightness of the sealing part 6 thus to obtain a stable and a good high temperature retention characteristic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a light metal element such as lithium, sodium and magnesium or an alloy thereof as a negative electrode, and a metal halide, sulfide, oxide, or solid carbon fluoride as a positive electrode. , A non-aqueous electrolyte battery using a non-aqueous organic electrolyte.

[0002]

2. Description of the Related Art Conventionally, non-aqueous electrolyte batteries typified by lithium batteries have been widely used as batteries having high energy density and light weight, and recently, they have been used as a component of consumer equipment and The use as a power supply for continuous backup under high temperature is increasing. This type of battery has conventionally been insulated and sealed via a gasket made of polypropylene (PP) or polyethylene (PE) resin between a case containing a power generating element and a sealing plate.

[0003]

However, the above-mentioned gasket made of PP or PE resin is a crystalline thermoplastic resin, and has a drawback that the crystal tends to shrink in a high temperature atmosphere and in a rapid temperature change. is there. For this reason, if the battery is exposed to a high temperature atmosphere and conditions of rapid temperature changes after assembly, a slight gap is created in the battery caulking part, that is, the caulking part between the gasket, the case, and the sealing plate, from which the electrolysis inside the battery occurs. There is a problem that the liquid vaporizes and leaks. An object of the present invention is to solve these conventional problems and provide a non-aqueous electrolyte battery having excellent high temperature storage characteristics.

[0004]

The non-aqueous electrolyte battery of the present invention comprises a negative electrode, a positive electrode, an opening of a case containing a power generating element composed of a separator and a non-aqueous electrolyte, and a sealing plate which seals the opening of the case. And a heat-resistant amorphous thermoplastic resin is used as a material of the gasket.

Examples of the heat-resistant thermoplastic resin include modified polyphenylene oxide, polyether sulfone,
Examples thereof include polysulfone, polyetherimide, and modified polyphenylene ether.

[0006]

With this structure, the non-aqueous electrolyte battery of the present invention has better thermal stability than polypropylene or the like, which is a crystalline thermoplastic resin that has been conventionally used, and after the battery is assembled, it is exposed to a high temperature atmosphere and abruptly. Since the volume shrinkage due to heat stress is small even under the condition of a large temperature change, there is no dimensional change, and the sealing degree of the caulked portion of the gasket, the sealing plate, and the case is maintained for a long time.

[0007]

EXAMPLE A coin-type lithium graphite fluoride battery shown in FIG. 1 will be described below as a non-aqueous electrolyte battery showing an example of the present invention.

In FIG. 1, reference numeral 1 is a case made of SUS material, inside of which a positive electrode plate 2 whose main component is fluorinated graphite is used.
A power generation element 5 is built in which a negative electrode plate 3 having metallic lithium as an active material are laminated via a separator 4 impregnated with an electrolytic solution. The modified polyphenylene oxide, polyether sulfone, polysulfone, polysulfone, polysulfone, and polysulfone, which are thermoplastic resins excellent in heat resistance according to the present invention and having an amorphous crystal structure, are formed in the opening 1a of the case 1 and in the peripheral portion of the metallic sealing plate 6. The resin gaskets 7 made of ether imide and modified polyphenylene ether are attached and fitted.
Thereafter, the periphery of the opening 1a of the case 1 is bent inward by a mold to seal the opening 1a of the case 1, and the battery A,
It was set to B, C, D, and E.

Next, the amorphous heat-resistant thermoplastic resin used in the batteries A, B, C, D and E of this embodiment will be described. The modified polyphenylene oxide (PPO) resin is an aromatic polyether resin. Is a plastic obtained by modifying polyphenylene oxide, which is a styrene resin, with polyphenylene oxide being a polymer having an ether bond obtained by oxidative polymerization of 2,6-dimethylphenol, which is a phenolic monomer, in the presence of a catalyst. ..

Polyethersulfone (PESF) resin is a plastic containing a repeating unit represented by the following (formula 1) in the molecule.

[0011]

[Chemical 1]

The polysulfone (PSF) resin is a plastic containing a repeating unit represented by the following chemical formula 2 in the molecule.

[0013]

[Chemical 2]

The polyetherimide (PEI) resin is a plastic containing an aromatic imide represented by the chemical formula (3) and an ether bond as a repeating unit.

[0015]

[Chemical 3]

The modified polyphenylene ether (PPE) resin is a plastic whose polymer main chain contains a benzene ring and an ether bond as a repeating unit in the molecule as shown in (Chemical Formula 4), and is 2,6 dimethyl-1,4-phenylene ether. It is a plastic modified with styrene resin.

[0017]

[Chemical 4]

The resin used in the examples of the present invention described above is an amorphous heat-resistant thermoplastic resin having a high heat distortion temperature of 120 to 210 ° C., and also for organic electrolytes. An engineering plastic with strong resistance.

Next, in order to compare the dimensional stability of the gasket of the present invention and the conventional gasket made of polypropylene, which is a crystalline thermoplastic resin, these gaskets were left in an atmosphere of 100 ° C. for 120 hours, and thereafter, It was left at room temperature for 24 hours to be subjected to heat stress. As a result,
The gasket used in the non-aqueous electrolyte battery of this example has a dimensional change rate (shrinkage rate) of 0.01% before and after applying thermal stress.
In contrast to the following, the conventional one is as large as 0.52%, which shows that the gasket of the present invention has extremely high dimensional stability under high temperature storage.

Next, in order to confirm the effectiveness of the gasket of this embodiment, batteries A to E using these gaskets and coin-type lithium battery BR3032 using a gasket made of polypropylene as a conventional battery are respectively used.
I made 0. 4 these lithium batteries at 100 ℃
After being stored for a week, they were taken out and evaluated as the battery characteristics such as an open circuit voltage, an internal resistance, a weight reduction amount of the battery due to scattering of an electrolytic solution, and a capacity ratio at the time of discharging with a load resistance of 20 kΩ. The results are shown in Table 1. No significant difference in open circuit voltage is observed,
In the transition of the internal resistance, the initial value of 12Ω was increased to 160Ω in the battery F having the conventional configuration. Regarding the discharge characteristics, the battery F having the conventional configuration was deteriorated to 29 when the initial discharge capacity was 100. On the other hand, in the batteries A to E according to the present invention, the open circuit voltage was almost unchanged from the initial value. As is clear from this result, it can be seen that the structure of this example has an excellent effect in terms of high temperature storage.

[0021]

[Table 1]

[0022]

As is apparent from the above description of the embodiments,
Since the one using the gasket material of the present invention has an amorphous crystal structure, it does not cause a dimensional change for a long time due to thermal stress and has a strong resistance to an organic solvent. The airtightness of the sealing part can be maintained for a long time,
A battery with stable battery characteristics can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a non-aqueous electrolyte battery according to an embodiment of the present invention.

[Explanation of symbols]

 1 case 1a case opening 2 positive electrode 3 negative electrode 4 separator 5 power generating element 6 sealing plate 7 gasket

Claims (6)

[Claims] 1. A battery in which an opening of a case containing a negative electrode, a positive electrode, a separator and a power generating element composed of a non-aqueous electrolyte is sealed with a sealing plate via a gasket, and the non-material is used as a material of the gasket. A non-aqueous electrolyte battery comprising a crystalline heat-resistant thermoplastic resin. 2. The non-aqueous electrolyte battery according to claim 1, wherein the heat resistant thermoplastic resin is a modified polyphenylene oxide. 3. The non-aqueous electrolyte battery according to claim 1, wherein the heat-resistant thermoplastic resin is polyether sulfone. 4. The non-aqueous electrolyte battery according to claim 1, wherein the heat-resistant thermoplastic resin is polysulfone. 5. The non-aqueous electrolyte battery according to claim 1, wherein the heat-resistant thermoplastic resin is polyetherimide. 6. The non-aqueous electrolyte battery according to claim 1, wherein the heat resistant thermoplastic resin is a modified polyphenylene ether.