JPH1021956A - Battery containing organic additive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery of which terminal voltage decreases due to charging and discharging cycles is slight and which provides a high total dis charging capacity and is manufactured at low cost and durable for repeated charging and discharging by adding a specified organic additive to an electro lytic solution. SOLUTION: This battery contains a compound produced by binding sulfonic acid group or phosphonic acid group to a molecule comprising a plurality of benzene rings bound through conjugated double bonds as an additive in an electrolytic solution which is brought into contact with a zinc electrode. Moreover, the battery contains one or more organic additive selected from the following compounds A, B, C, D, E, and F in the electrolytic solution contacting the zinc electrode: A is anthraquinonesulfonic acid or its derivative; B is naphthalenesulfonic acid or its derivative; C is naphtholsulfonic acid or its derivative; D is anthraquinonephosphonic acid or its derivative; E is naphthalenephosphonic acid or its derivative; and F is naphtholphosphonic acid or its derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery capable of effectively preventing a decrease in capacity accompanying a charge / discharge cycle of a battery using zinc as a negative electrode.

[0002]

2. Description of the Related Art A so-called dry battery using zinc as a negative electrode, manganese dioxide as a positive electrode, and an aqueous solution of KOH, ammonium chloride or zinc chloride as an electrolyte is easy to handle and inexpensive. Widely used as a power source. Of these, the so-called alkaline manganese battery using KOH as an electrolyte is capable of discharging a large current and having a large discharge capacity, so that the self-discharge is small. Since it is located in the center and separates it from the positive electrode manganese dioxide with a separator layer, it is possible to charge dozens of times with careful charging even with currently marketed batteries, but charging is possible. With the cycle, conductive dendritic crystals are deposited from the surface of the negative electrode material toward the separator, and there is a problem that the battery life is exhausted by short-circuiting both electrodes.

[0003]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a battery having a remarkably improved charge / discharge characteristic by adding a specific organic additive to an electrolytic solution. is there.

[0004]

According to the present invention, a compound comprising a benzene nucleus bonded through a conjugated double bond and having a sulfone group or a phosphone group bonded to the molecule is used as an additive to contact the zinc electrode. A battery characterized in that it is contained in an electrolytic solution, and the following compounds A, B, C, D, E, and F
A battery comprising at least one organic additive selected from the group consisting of in an electrolytic solution in contact with a zinc electrode. A: Anthraquinonesulfonic acid or a derivative thereof B: Naphthalenesulfonic acid or a derivative thereof C: Naphtholsulfonic acid or a derivative thereof D: Anthraquinonephosphonic acid or a derivative thereof E: Naphthalenephosphonic acid or a derivative thereof F: Naphtholphosphonic acid or a derivative thereof

Furthermore, it is desirable that at least one hydrogen atom in the plurality of benzene nuclei is replaced by an oxygen atom. The number of sulfone groups or phosphone groups in each molecule can be one or more. Generally, the larger the number, the greater the effect of extending the charge / discharge cycle life. In the present invention, the mechanism by which these compounds improve the charge / discharge characteristics of the battery is not clear, but a plurality of compounds having a polar group that causes electrons to be unevenly distributed in the molecule, and bonded via a conjugated double bond. Since electrons can move freely in the benzene nucleus, the action of these polar groups becomes active, and these molecules are adsorbed on the specific surface of zinc or its compound, causing the formation of conductive dendritic crystals during charging. It is presumed to have an effect of preventing growth in a specific direction. Examples of the molecular structure of a plurality of benzene nuclei used in the present invention are shown in FIGS.

The electrolyte used in the present invention is zinc chloride, ammonium chloride, KOH,
NaOH or the like can be used.
OH and NaOH are preferred. Compound A to be used in the present invention
F can be dissolved in the electrolytic solution or added in the form of a fine powder mixed with the electrolytic solution. The amount of F added is 5 per cell when used in the mixture of the negative electrodes of the AA alkaline manganese battery. Desirably, milligrams or more, more preferably, 10 milligrams or more. In addition, by impregnating only the electrolyte solution in the separator in which a short circuit is likely to occur due to precipitation of conductive crystals with the additive, the effect can be improved with a smaller addition amount.

[0007]

EXAMPLE A zinc powder, a KOH aqueous solution, a gelling agent, and a negative electrode of an AA alkaline manganese dry battery having the structure shown in FIG.
A test battery was prepared by using a mixture of 15 mg of the compound powder shown in Table 1, using a mixture of manganese dioxide, graphite and an aqueous KOH solution for the positive electrode, and assembling both electrodes via a separator paper. In Table 1, K2, Na2, Na12
Etc. mean K ₂ , Na ₂ and Na ₁₂ respectively. Each battery was discharged at 150 mA for 5 hours and then charged at 50 mA for 15 hours. The upper limit of the terminal voltage of the battery was 1.7 V. After the completion of charging, the battery was suspended for one hour, and discharging and charging were repeated under the same conditions. When the terminal voltage during discharge is 1.
The test was terminated when the voltage reached 0 V, and the total discharge amount (AH) up to that point was determined. Table 2 shows the results. The ratio of the total discharge amount of the battery containing no organic additive, 5.93 AH, to the total discharge amount of the battery containing various additives is determined by the following equation.
This was used as an evaluation value. Evaluation value = total discharge amount of each battery (A
H) / Total discharge amount (AH) of the battery not containing the additive, that is, the larger the evaluation value, the more effective the secondary battery.

Table 2 shows the evaluation values and the number of charge / discharge cycles performed so far. As a result, anthraquinone 2,
The addition of 7-disulfonic acid is extremely effective in increasing the total discharge amount, and isomers (N
o. 34, 35, 36) were also effective, and various naphthalenesulfonic acids (Nos. 11, 18) and phenol red having similar electron distributions in the molecule were also effective. Similar effects were observed when the sulfone group of each of the above compounds was replaced with a phosphone group.

[0009]

[Table 1]

[0010]

[Table 2]

The numbers in Table 2 correspond to the numbers in Table 1, and the number 0 indicates the case where there is no additive.

[0012]

As is apparent from the above description, in the battery containing zinc as the negative electrode and containing the organic additive of the present invention in the electrolytic solution, the terminal voltage is not significantly reduced by the charge / discharge cycle, and a large total discharge amount is obtained. Thus, a low-cost battery that can withstand repeated charging and discharging can be obtained, which is extremely useful in industry. In the battery of the present invention, a difference in the magnitude of the effect is naturally recognized depending on the structure of the electrode and the like, and this can be appropriately selected by a technique known to those skilled in the art. Further, in order to increase the solubility of the additive used in the present invention, a solvent such as alcohol may be used in combination with water to form an electrolyte.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of a battery of the present invention.

FIG. 2 is a specific example of a molecular structure of a plurality of benzene nuclei of the present invention.

[Explanation of symbols]

1: Negative electrode 2: Current collector 3: Positive electrode 4: Case 5: Mixture of zinc powder, KOH aqueous solution, gelling agent and organic additive 6: Separator paper 7: Mixture of manganese dioxide, graphite and KOH aqueous solution

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuko Takei 796-20 Wakasato, Nagano City, Nagano Prefecture (72) Inventor Masamichi Yamashita 1-3, Tatara Toya, Tanabe-cho, Tetsuki-gun, Kyoto (72) Inventor Atsushi Sato Nagoya 4-313 Gokuraku, Meito-ku

Claims (6)

[Claims] 1. A compound comprising a molecule comprising a plurality of benzene nuclei bonded through a conjugated double bond and having a sulfone group or a phosphone group bonded thereto is contained as an additive in an electrolytic solution in contact with a zinc electrode. And batteries. 2. The battery according to claim 1, wherein a compound in which at least one hydrogen atom of the plurality of benzene nuclei is substituted with an oxygen atom is used as an additive. 3. The battery according to claim 1, comprising an alkaline manganese battery. 4. A battery comprising at least one of the following compounds A, B, C, D, E and F in an electrolyte in contact with a zinc electrode. A: Anthraquinonesulfonic acid or a derivative thereof B: Naphthalenesulfonic acid or a derivative thereof C: Naphtholsulfonic acid or a derivative thereof D: Anthraquinonephosphonic acid or a derivative thereof E: Naphthalenephosphonic acid or a derivative thereof F: Naphtholphosphonic acid or a derivative thereof 5. The battery according to claim 4, comprising an alkaline manganese battery. 6. The compound A according to claim 4 or 5,
Using an anthraquinone 2,7 disulfonate as a battery.