JPS587768A - Production method of conjugated oxide for cell - Google Patents

Abstract

PURPOSE:To rapidly produce a conjugated oxide for a cell easy for refining with a simple process by dripping a mixed solution of Ag salt and Ni salt into an alkaline aqueous solution and by wet oxidizing the obtained coprecipitate with an oxidant. CONSTITUTION:A mixed solution of silver salt mainly made of silver nitrate and Ni salt selected among nickel nitrate, nickel sulfate, and nickel acetate, etc. is dripped into an alkaline aqueous solution little by little while being well stirred. Then, Ag2O and Ni(OH)2 are infinitesimally mixed together and are coprecipitated in a gel status. The gel-like coprecipitate thus obtained is wet oxidized with an oxidant as it is in the alkaline aqueous solution, thereby AgNiO2 can be easily produced. Salt persulfate, H2O2, or O3, etc. can be used for the oxidant. The AgNiO2 obtained is washed with distilled water and is dried under heat to make up refined AgNiO2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a silver/nickel composite oxide as an active material for battery anodes, such as AJFN iO! The present invention relates to a manufacturing method.

Recently, A#IO8 has been attracting attention as a positive electrode active material for batteries among silver-nickel composite oxides that have discharge voltage and voltage flatness comparable to oxidized #IK.

The reaction in alkali is to Ali +280+2e-→)di + Ni (OH
), +20H- was estimated and the amount of silver used for capacitance is half compared to ) kJ * 0, so A%il
Although O, is an active material that is inexpensive and can constitute an alkaline battery with excellent discharge characteristics, there are problems in the workability of its manufacturing method.

Conventional Al1Ni0. As for the production method, as reported by Buit Whiskey et al., KNiO, + AJFNOs → AJIN 0. + to Shu, (
1) A synthesis method using formula (1) is known. This (1)
The method for producing 4 KNIO, which is the raw material in the formula, is 2Nl (01()m + 4KOH+ Brt→2K
This was done by NjO1+ 2KBr + 4H*O(2)(2)2.

Synthesis of #N1 using the above formula (1) required holding the KNi01 mixed powder in a 2 N AJNDa@ solution at 80° C. for 10 days. In addition, to synthesize the raw material KNiO, N5(OH)l is heated at 180° in a saturated KOH aqueous solution.
Therefore, it was necessary to oxidize the material with Br snow twice at room temperature. As described above, the conventional production method consists of a three-stage reaction of formulas (1) and (2), and the production process is complicated, and moreover, it takes more than 10 days to synthesize.

Furthermore, if the reaction +1) did not progress sufficiently, there was a risk that KNi (%) would be mixed in as an unreacted substance, making it difficult to separate it.KNiO, which is such an impurity.

When #NIO, containing #NIO, is used as an anode active material for a battery, the audience voltage of the battery becomes abnormally high, causing a phenomenon in which the voltage drop at the beginning of discharge becomes significant, resulting in unfavorable results in terms of the discharge characteristics of the battery. There were drawbacks.

The present invention has been made to provide a method for producing AINtOs that eliminates the complexity of the conventional uNiOs production process and does not contain KNiO as an impurity. That is, AJNiol with excellent discharge characteristics is provided by an extremely simple production method in which a mixed solution of a silver salt and a nickel salt is dropped into an alkaline solution, and a gel-like precipitate obtained is wet-oxidized with an oxidizing agent. It is something that can be achieved.

In the production method of the present invention, the silver salt used as a raw material is mainly silver nitrate, and the double salt is selected from those having high solubility in the solvent used, such as nickel nitrate, nickel sulfate, and nickel acetate. However, it is not possible to use a solution in which the ions of one metal combine with the anions of the other metal salt to form a precipitate when a mixed solution of the two is used.

Water is mainly used as the solvent for the mixed solution of the silver salt and nickel salt, but non-aqueous solvents that are completely soluble in the alkaline aqueous solution and have a high degree of solubility of the metal salt are also used. It doesn't matter if it is.

When a mixed solution of a silver salt and a nickel salt selected from the above conditions is added dropwise into an aqueous alkaline solution while stirring well, M, 0 and N1(OH)* are microscopically heated. and co-precipitates into a gel-like state. At this time, the metal salt solution is added. Therefore, a neutralization reaction occurs, and the alkaline aqueous solution gradually becomes acidic. Therefore, the alkaline concentration must be adjusted so that it remains sufficiently alkaline even after the entire amount of the metal salt solution is added.

The gel-like coprecipitate thus obtained is wet-saponified in an alkaline aqueous solution using an oxidizing agent.
As a result, the desired ApNl can be produced in volume 1. As the oxidizing agent, persulfates are mainly used, but hydrogen peroxide, ozone, etc. can also be used. The yield of the oxidation reaction is higher and the rate is faster when the solid oxidant is mixed as an aqueous solution and stirred than when it is added as a solid to the coprecipitation slurry.

The obtained AJllNiO was thoroughly washed with distilled water, and then
- To AJNi purified by filtration and heating drying at below 200°C or heating drying at around room temperature.
is obtained.

As described above, the method for producing AJ'NiO according to the present invention has fewer species than conventional methods, the reaction is rapid, and the product can be purified very easily.

Next, one embodiment of the present invention will be described.

Reagent special grade silver nitrate AJiFN0. 20. OJiF and reagent special grade silver nitrate '7'I At N1(NOs)m
-6)1! o 34.211 in 100ml distilled water,
The mixed metal salt aqueous solution contained was heated to 24 wt.
Drop into KOH aqueous solution lj with vigorous stirring.

As a result, oxidation 1 pigeon 0 and nickel hydroxide N1 (OH),
are microscopically mixed to form a gel-like coprecipitate IIj!
Become a JK. 1 in an alkaline solution containing a gel-like co-precipitate of kernels.
Add another 4Bg of KOH and bring to 80°C with continued stirring.
Heat to. Meanwhile, potassium persulfate, 8. O
- Dissolve 4051 in 1j of Class 11 water, heat to 80°C, mix this at once into the heated alkali coprecipitation solution, and continue stirring while heating. The oxidation reaction progresses as a result of stirring, and the color of the precipitate changes from black to black with the generation of oxygen gas. When no oxygen gas is generated, stop heating and stirring and allow to cool naturally.

After the reaction is completed, the reaction vessel is kept stationary and the supernatant liquid is quietly allowed to flow into another vessel, and 25J of distilled water is further added, stirred, and kept stationary, and the supernatant liquid is removed. Repeat this operation three times. Thereafter, the black product is vacuum-filtered while being washed with distilled water, and then dried by heating at less than 200 υ or vacuum-dried at around room temperature to obtain the desired silver-nickel composite oxide MNiO box.

-NlO synthesized according to the above embodiment of the present invention.

From X41 diffraction analysis, the interplanar spacing is d-6, 20, 3, 0?
.

246.2.12, 1.72.1.47.1.33
.

It has a main diffraction peak of 1.26AK. AJNIO, as reported by Buitwiskie et al., is said to have a hexagonal crystal structure of a-2,94, b=18.52), and each Miller index calculated from these lattice constants. The surface spacing at is d-6,17 (003)
, 3.09 (006), 246 (102).

2.10 (105), 1.71 (108), 1.4
7 (110).

1.33 (116) and 1.26 (202) A, which are all almost identical to the diffraction peaks of the examples according to the present invention. Also, uNiO obtained in the above example.

As a result of elemental analysis, it is composed of AJ-55,3, Ni mouth 27.3゜0-15.4 weight-, and the calculated value and 1 to 5z
Match.

Next, using uNiOm according to the manufacturing method of the present invention,
In addition, a comparison will be made between Battery Man and Battery B, which uses uNiOm using a conventional manufacturing method.

The anode mixture is made by pulverizing uNiO synthesized by the production method of the present invention, mixing it with 5 weight graphite scales as a conductive agent, and press-molding it, and a gel such as 3011KOH aqueous solution and sodium polyacrylate. JT8 name SR whose cathode is made of gelled zinc made by mixing a curing agent and zinc powder.
A prototype battery according to the present invention with a length of 1,130 m was manufactured at a temperature of 25°C.
Figure 1 shows the results of a constant resistance discharge test with a load resistance of 6.5KQ. As a comparative example, FIG. 1 shows Al1Ni0. The discharge curve of Battery B made using the conventional method was also shown, using the anode mixture consisting of the following, with all other configurations being the same as those of the battery.

From the comparison of discharge curves A and B shown in Fig. 1, battery B uses AJNiO, obtained by the conventional manufacturing method, as the anode mixture.
In the early release! While the voltage is high and the subsequent voltage drop is large, #N synthesized by the manufacturing method of the present invention
It is suggested that the battery A using 1 (4) as the anode mixture has a low open circuit voltage (and a small initial voltage drop), and is excellent in the flatness of the discharge voltage.

As described above, #NiO*- obtained by the production method of the present invention
Compared to the conventional method proposed by et al., which was cumbersome and difficult to produce, the production method of the present invention is extremely simple and has excellent workability, and the chemical reaction proceeds quickly. Therefore, it is possible to complete the structure in a short time.

[Brief explanation of the drawing]

FIG. 1 is a diagram comparing the discharge curves of a battery using a composite oxide according to an embodiment of the present invention and a battery B using a composite oxide according to a conventional method. Patent Applicant Name Toshiba Battery Co., Ltd. Volume 1 Diagram of Pulp Discharge Continuation Patent Publication (hr)

Claims (1)

[Claims] (1) A mixed solution of a silver salt and a nickel salt is dropped into an alkaline water container, and the resulting coprecipitate is treated with an oxidizing agent (l).
A method for producing a composite oxide for batteries as described in Patent No. 1, Kyo no Han, wherein the silver-plated composite oxide is a composite oxide having the chemical formula #Ni01. (3) The skeleton salt is silver nitrate (AlNOR), and the nickel salt is nickel borate (Ni (NO Hatake), 6 0), nickel sulfate (! (180, 6H, 0), nickel acetate). (Ni (false 000), .480) A method for producing a composite oxide for a battery according to claim 15, characterized in that the oxidizing agent is a persulfate, a persulfate, a The method for producing a composite oxide for batteries according to claim 11j11, characterized in that hydrogen oxide or ozone is used.