JPS6139464A - Organic electrolyte secondary battery - Google Patents

Abstract

PURPOSE:To make water content mixed inside a battery as well as improve its service life and capacity ever so better, by inserting a desiccating agent into the inside of the battery in a state of contacting with an organic electrolyte. CONSTITUTION:A negative pole 1 consisting of lithium as a light metal and a positive pole 2 consisting of polypyrrole as a conductive macromolemolecule are each surrounded by a separator 5 wrapping a molecular sieve 3 as a dryer with polypropylene 4, and set up face-to-face. Inside a hermetrically sealed vessel 6, an organic electrolyte 9 is housed. As for this organic electrolyte, for example, such one that lithium perchlorate as an electrolyte is made to dissolve in acetonitrile as an organic solvent and dehydrated sufficiently with the molecular sieve in advance is housed inside.

Description

[Detailed description of the invention] C Industrial application field] The present invention relates to an organic electrolyte secondary battery.

[Conventional technology]

Batteries using conductive polymer materials as electrodes are conventionally known (for example, JP-A-57-118375, JP-A-57-123659, JP-A-57-1).
41879, JP-A-58-137975)
These secondary batteries (hereinafter simply referred to as batteries) have excellent advantages over lead batteries in that they have a higher open circuit voltage, are lighter in weight, and have a higher output density.

[Problem that the invention seeks to solve]

By the way, if moisture enters these batteries, it may cause problems such as gas generation during battery operation or accelerated deterioration of electrodes. For this reason, when manufacturing batteries, sufficient care is taken to prevent moisture from entering the battery.

However, no matter how careful one is, there is a problem in that it is difficult to avoid moisture in the air from entering the battery during the manufacturing process of the battery.

[Means for solving problems]

The present invention has been made to solve the above problem, and the technical problem of the present invention is to create a state in which even if moisture in the air gets into the battery during battery manufacturing, the moisture will not have an adverse effect on the battery. It's about doing.

This technical problem is solved by the organic electrolyte secondary battery of the present invention, which will be described below.

That is, the organic electrolyte secondary battery of the present invention is a secondary battery comprising a negative electrode made of a light metal, a positive electrode made of a conductive polymer, and an organic electrolyte solution in which an organic electrolyte is dissolved in a solvent. The secondary battery is characterized in that a desiccant is inserted into the secondary battery in contact with the organic electrolyte.

In the present invention, light metals such as lithium (Li), sodium (Na), and magnesium (Mg) can be used as the negative electrode.

Further, as the positive electrode, conductive polymers such as polypyrrole, polyacetylene, polyphenylene, polythiophene, etc. can be used.

An organic electrolyte is a solution of an electrolyte dissolved in an organic solvent.

As an electrolyte, lithium perchlorate (Licj!04)
, R, N(lio4 (R: alkyl group, the same applies hereinafter)
, R, NBF, , R4N P Fa, etc. can be used. In addition, as an organic solvent for dissolving these electrolytes, propylene carbonate, acetonitrile, benzonitrile, nitromethane, sulfolane, dimethyl sulfoxide, tetrahydrofuran, etc. can be used.
.

In one aspect of the present invention, a desiccant is inserted into the battery.

As the type of desiccant, molecular sheep, activated alumina, barium oxide (Bad), CaH, etc. can be used. These desiccants may be inserted into the battery as they are, or they may be wrapped in an inert copolymer film such as polypropylene or polyethylene or a bag made of paper. It is preferable to cover the positive and negative electrodes rather than simply inserting the desiccant in the desired location.When wrapping the electrodes with a desiccant agent, it is better to wrap it completely, although it is effective even if it is partially wrapped. . When wrapping an electrode in a desiccant, if the desiccant is of an amorphous shape, it is preferable to place it in the bag described above. Note that the desiccant may be formed into a predetermined shape according to the shape of the electrode. In this case, there is no need to put it in a bag.

[Effect]

According to the organic electrolyte secondary battery of the present invention, since a desiccant is inserted into the battery, even if moisture gets into the battery from the air etc. during battery manufacturing, this moisture will be absorbed into the desiccant. It will be captured and will not have any negative effect on the battery.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

(First example) A first embodiment will be described based on FIG.

In FIG. 1, 1 is a negative electrode made of lithium as a light metal, and 2 is an anode made of polypyrrole as a conductive polymer. The negative electrode 1 and the positive electrode 2 are each surrounded by a separator 5 in which a molecular sieve 3 as a desiccant is wrapped in polypropylene 4. The negative electrode 1 and the positive electrode 2 surrounded by the separator 5 are arranged facing each other in the closed container 6.

Further, lead wires 7 are connected from the negative electrode 1 and the positive electrode 2, respectively.
, the lead wire 8 is taken out of the closed container 6.

An organic electrolyte 9 is placed in the sealed container 6. The organic electrolyte 9 contains lithium perchlorate as an electrolyte mixed with 0.5 Mf4 in acetonitrile as an organic solvent, and sufficiently dehydrated using a molecular sieve in advance.

(Second example) A second embodiment will be described based on FIG.

In FIG. 2, 1 is a negative electrode made of lithium as a light metal, and 2 is an anode made of polypyrrole as a conductive polymer. A separator 11 in which a glass mat 10 is wrapped in polypropylene 4 is provided between the negative electrode 1 and the positive electrode 2. With the separator 5 sandwiched between them, the negative electrode 1 and the positive electrode 2 are disposed facing each other in the closed container 6. In addition, this negative electrode 1 and positive electrode 2
The lead wires 7 and 8 are connected to the airtight container 6, respectively.
being taken outside. A molecular sieve 3 as a desiccant is placed at the bottom of this airtight container 6.

An organic electrolyte 9 is placed in the sealed container 6. The organic electrolyte 9 contains lithium perchlorate as an electrolyte dissolved in 0.5M acetonitrile as an organic solvent and sufficiently dehydrated using a molecular sieve in advance.

Next, performance tests were conducted on these batteries.

In this performance test, the charging and discharging conditions are as follows: After charging at a constant current of 1mA/CIA for 1 hour, discharging at 1mA/c+d, and repeating charging and discharging until the discharge end voltage reaches 2.2■. I went there. For comparison, a similar test was also conducted on a conventional battery that did not contain a desiccant agent. The results are shown in FIG. In FIG. 3, a is a battery in which the desiccant according to the first embodiment is inserted between the electrodes;
b is a battery in which the desiccant according to the second embodiment is placed in the bottom of the battery;
C shows the case of a conventional battery without a desiccant.

As is clear from FIG. 3, it can be seen that the life of the battery of this example is significantly longer than that of the conventional battery. Furthermore, it can be seen that the battery life is extended more when the desiccant is inserted so as to wrap around the electrodes than when it is simply inserted into the battery.

Although specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, but includes various embodiments within the scope of the claims. .

〔Effect of the invention〕

As described above, the organic electrolyte secondary battery of the present invention has the following effects.

(a) Since moisture mixed into the battery is rendered harmless, gas generation due to moisture is eliminated, and deterioration of the electrodes is also suppressed. Therefore, the durability (life span) and performance of the battery are improved.

(b) Since there is no problem with the incorporation of some moisture, it becomes easier to manufacture batteries.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an organic electrolyte secondary battery according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view showing an organic electrolyte secondary battery according to a second embodiment of the present invention, and FIG. The figure is a graph showing the charge/discharge efficiency of an organic electrolyte secondary battery according to an example of the present invention. l・-・・−Negative electrode 2・・・−Positive electrode 3−・−・−・Molecular sieve (desiccant) 4・−−
- Polypropylene 5.11 - Separator 6 - Sealed container 7.8 - Lead wire 9 - Organic electrolyte 10 - Glass mat

Claims (2)

[Claims] (1) A secondary battery comprising a negative electrode made of a light metal, a positive electrode made of a conductive polymer, and an organic electrolyte solution in which an organic electrolyte is dissolved in a solvent. An organic electrolyte secondary battery characterized in that a desiccant is inserted in contact with the organic electrolyte secondary battery. (2) The organic electrolyte secondary battery according to claim 1, wherein the desiccant is provided to completely or partially surround the positive electrode and the negative electrode.