JPH09190817A - Nickel hydroxide active material powder, nonsintered electrode, and alkaline storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the expansion of active material particles, and to improve the cycle life of a battery using a nonsintered nickel electrode, by including a specific amount of cobalt and zirconium, in the powder of a nickel hydroxide active material. SOLUTION: In the nickel hydroxide particles used in the positive electrode of an alkaline storage battery, at least cobalt; 0.2 to 5wt.%, and zirconium; 0.1 to 4wt.% are included. By using such a nickel hydroxide active material, a high capacity maintaining rate and a high temperature charging property of an alkaline storage battery is improved. Furthermore, by including zinc in the nickel hydroxide particles, while the form of the nickel hydroxide particles is made in a spherical form, it is favorable to improve the apparent density and the filling density. The paste of this active material mixture is filled to a porous base board for electric collecting and pressurized, and a nonsintered nickel electrode in which the filling density of the active material mixture is made about 2.4 to 2.9/cc is formed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a nickel hydroxide active material powder non-sintered nickel electrode used as a positive electrode of an alkaline storage battery such as a nickel-hydrogen storage battery and a nickel-cadmium storage battery, and an alkaline storage battery.

[0002]

2. Description of the Related Art In recent years, alkaline storage batteries such as nickel-hydrogen storage batteries and nickel-cadmium storage batteries have high energy density (wh / kg) per unit weight and reliability such as cycle life. It has been widely used as a power source for various portable devices due to its excellent heat resistance, and in particular, various high-capacity non-sintered nickel electrodes with a higher energy density than the sintered nickel electrodes are used as the positive electrode. Being developed. That is, the high-energy-density non-sintered nickel electrode is used as a current collecting porous substrate on a current collecting porous substrate having a porosity of 90% or more, such as a three-dimensional foamed nickel substrate or a nickel fiber porous substrate. It is obtained by filling a nickel active material powder. However, the nickel hydroxide active material powder is obtained by reacting an aqueous solution of a nickel salt with an aqueous alkali solution to cause precipitation, followed by washing with water, drying and crushing, and the surface of the particle is square. Therefore, the powder has a limit in obtaining a powder having a high packing density in the porous substrate for collecting electricity. In order to improve the charge density, a nickel hydroxide active material powder composed of a group of spherical type particles such as spherical particles and distorted spherical particles has been developed. However, there is a problem that the cycle life of the alkaline storage battery using the non-sintered nickel electrode using this as a positive electrode is shortened regardless of whether the particle shape is the above-mentioned non-spherical type or spherical type. . It is considered that the cause is that γ-NiOOH having a low density is generated in the positive electrode during charging to expand the positive electrode, absorb the electrolytic solution, and exhaust the amount of the electrolytic solution. Then, in order to suppress the expansion of this positive electrode, a nickel hydroxide active material powder in which cobalt and zinc are contained in nickel hydroxide particles has been proposed.
(JP-A-5-21064 and JP-A-2-30061)
Issue). However, we made non-sintered nickel using the nickel hydroxide active material powder consisting of the above-mentioned particle group containing cobalt and zinc, and charged and discharged the alkaline storage battery using this as a positive electrode to cycle it. When the life was examined, it was found that the swelling suppressing effect was not sufficient. Therefore, it has been found that the cycle life and high temperature charging characteristics of the alkaline storage battery using the non-sintered nickel electrode using this as a positive electrode are not sufficient and there is room for improvement. In view of the above conventional problems, further suppressing the expansion of the active material powder particles,
Development of nickel hydroxide active material powder, non-sintered nickel electrode or alkaline storage battery that can improve the cycle life of batteries using non-sintered nickel electrodes, improved capacity retention rate, improved high temperature charging characteristics, etc. Is desired.

[0003]

The present invention provides a nickel hydroxide active material powder, a non-sintered nickel electrode, and an alkaline storage battery which solve the above-mentioned conventional problems and satisfy the above-mentioned needs. The nickel hydroxide active material powder of the invention has a nickel hydroxide particle having a cobalt content of at least 0.
2-5 wt. % And zirconium 0.1-4 wt. %. Furthermore, the present invention provides a nickel hydroxide active material powder which brings about a further improvement in high capacity retention rate and high temperature charging characteristics of an alkaline storage battery using a non-sintered nickel electrode. It is characterized in that zinc is further contained in the particles of the nickel active material powder. In this case, the shape of the nickel hydroxide particles is
The spherical type is preferable for improving bulk density and packing density. Further, the non-sintered nickel electrode of the present invention for achieving the above object is characterized in that the cobalt and zirconium-containing nickel hydroxide active material powder of the present invention is filled in a current collecting porous substrate. . Also, the present invention
The present invention provides a non-sintered nickel electrode that further improves the utilization rate and cycle life of the non-sintered nickel electrode of the present invention. The non-sintered nickel electrode of the present invention contains cobalt and zirconium or cobalt, zirconium and zinc. An active material mixture prepared by adding and mixing at least one cobalt-based additive of cobalt and a cobalt compound to a spherical type nickel hydroxide active material powder is filled into a porous substrate for current collection and pressed to obtain the active material. The packing density of the mixture is 2.4 to 2.9 g / c.
It is characterized in that it is c. Furthermore, the present invention provides a non-sintered nickel electrode that provides an alkaline storage battery with improved rapid discharge characteristics, in particular, an active material mixture obtained by adding nickel powder to the above-mentioned active material mixture of the present invention. Is filled in a porous substrate for current collection. Furthermore, the present invention
Provided is an alkaline storage battery having improved low-temperature discharge characteristics and high-temperature charge acceptance, which uses the non-sintered nickel electrode of the present invention as a positive electrode and LiOH as an electrolytic solution.
0-4 wt. %, KOH 20-40 wt. % Alkaline electrolyte or LiOH 0-4 wt. %, KOH + N
aOH 20-40%, NaOH 0-10 wt. % Of the alkaline electrolyte.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail. A production example of the nickel hydroxide active material powder containing cobalt and zirconium in the nickel hydroxide particles of the present invention will be described. An example thereof is nickel salt such as nickel sulfate and nickel nitrate, cobalt salt such as cobalt nitrate and cobalt sulfate, and zirconium salt such as zirconium sulfate and zirconium nitrate are dissolved in water at a predetermined ratio to obtain nickel, cobalt, After preparing a mixed aqueous solution in which the respective ions of zirconium are dissolved and reacting it with an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide in the reaction vessel for a predetermined period of time and reacting, a predetermined amount of cobalt and zirconium are respectively prepared. Nickel hydroxide particles are formed. In this case, for example, when the alkaline aqueous solution is adjusted to a strong alkaline having a pH of about 14, prismatic non-spherical nickel hydroxide particles are generated, and when adjusted to a weak alkaline having a pH of about 10 to 13, a spherical or Spherical type nickel hydroxide particles, such as elliptical or distorted spheres, are produced. In addition, it is necessary to appropriately control the heating temperature, stirring conditions, time and the like during the reaction. The nickel hydroxide particles thus produced are filtered, washed with water, and dried to obtain a non-spherical or spherical type nickel hydroxide particles containing cobalt and zirconium in the nickel hydroxide crystal in a predetermined proportion, respectively. A nickel hydroxide active material powder consisting of a mass is obtained.

The non-spherical nickel hydroxide active material has a bulk density lower than that of the spherical type nickel hydroxide active material, and has a low packing density when filled in the porous substrate for current collection. Nickel hydroxide active material is preferably used. As a method for producing a spherical type nickel hydroxide active material powder containing cobalt and zirconium in the particles, it is preferable to produce by the following easy production method. That is, a weakly basic amine is dissolved in a nickel salt aqueous solution to stabilize nickel ions as an amine complex, and a predetermined amount of cobalt salt and zirconium salt is added and dissolved therein. A predetermined amount of caustic potash, caustic soda, etc. is added to this aqueous solution and stirred to allow a uniform reaction to occur throughout. As the amines for forming the nickel amine complex, ammonia, ammonium salt and the like are used.

The nickel hydroxide active material of the present invention thus obtained is, in comparison with the conventional nickel hydroxide active material containing cobalt or zinc in spherical particles, as shown below, The result is a non-sintered nickel electrode and battery with further suppressed expansion and improved cycle life. In this case, Zr is ZrO ₂ · 2H _{2 in the} particles.
It exists as O, and it is considered that it does not participate in the oxidation reaction (charge) of the positive electrode, has the effect of increasing the oxygen overvoltage, and does not form a precharge at the negative electrode. It is thought that it will significantly contribute to the capacity increase. In particular, 0.2-5w cobalt in the particles
t. %, Zirconium 0.1 to 4 wt. It has been found that a battery having a high utilization ratio, particularly excellent cycle life and high-temperature charging characteristics, can be obtained when the content of C is 50%.

[0007]

EXAMPLE An aqueous solution of nickel sulphate prepared by dissolving 1.6 mol / l of nickel sulphate in water prepared in a large number of containers was added to each of 25 wt. % Aqueous ammonia was added and stirred to prepare a nickel sulfate aqueous solution having a pH of 10.5 to 11 in which a nickel amine complex was formed. Cobalt sulphate and zirconium sulphate were added to each of the prepared liquids at various addition amounts and molar ratios and dissolved by stirring. While maintaining the pH of 10.5 to 11.0, caustic soda was gradually added and stirred. And 50 ℃
The reaction was carried out uniformly over the whole, and nickel hydroxide was deposited and formed. Thereafter, this was filtered, the nickel hydroxide precipitate was washed with water, and then dried by heating at about 50 to 70 ° C. to contain Zr and Co in the nickel hydroxide crystal as solid solutions in respective proportions. A spherical type nickel hydroxide active material as shown in 2 was obtained. On the other hand, for comparison, the conventional nickel hydroxide active material containing zinc and cobalt shown in Table 1 was prepared by the above-mentioned method except that conventionally known zinc and cobalt were added instead of cobalt sulfate and zirconium sulfate, respectively. Was manufactured. In addition, for comparison, the content of cobalt and zirconium exceeds a predetermined ratio.
And the nickel hydroxide active material powder shown in Table 2 was manufactured.
The particle size of the obtained nickel hydroxide active material powder of the present invention is
Each was about 10 μm. The tap density of the powder was about 2.1 g / cc.

[0008]

[Table 1]

[0009]

[Table 2]

Non-sintered nickel electrodes were manufactured as follows using the nickel hydroxide active material powders shown in Tables 1 and 2 above. That is, 100 parts by weight of each active material powder was mixed with 8 parts by weight of CoO as a conductive agent, and 1
% KMC aqueous solution 37 parts by weight is added and kneaded to form a paste, which is filled in a foamed nickel substrate having a porosity of 95%,
Heat drying and pressing by the usual method, each capacity 1150m
A non-sintered nickel electrode of Ah was produced.

Each of the above-mentioned non-sintered nickel electrodes and a hydrogen storage alloy electrode having a capacity of 2000 mAh manufactured as described below were laminated and wound as a negative electrode via a separator, which was housed in a cylindrical can and had a specific gravity of 1. Inject 1.95 ml of 33 alkaline electrolyte, cover with air-tightness, AA size, 11
00mAh nickel-hydrogen storage batteries were manufactured respectively. The negative electrode was prepared by mixing a mixture of 100 parts by weight of hydrogen storage alloy powder consisting of MmNi _3.3 Co _1.0 Mn _0.4 Al _0.3, 10 parts by weight of nickel powder and 2 parts by weight of PVdF with a 1% CMC aqueous solution 20.
It was kneaded together with wt% to form a paste, which had a thickness of 0.
A punching metal having a diameter of 07 mm, a porosity of 38%, and a hole diameter of 1.5 mm was applied, filled, heated and dried, and pressed.

For each sealed alkaline storage battery manufactured in this way, a charge / discharge cycle life test, a high temperature charge test,
Each was tested for utilization. The charge / discharge cycle life test was conducted at a temperature of 23 ± 2 ° C. and 1 C for each of the above batteries.
After being charged with a current of 1V, the current was increased to 1.0V with a current of 1C. Charge control was performed by -ΔV control. Then, the capacity retention rate with respect to the initial capacity measured at 20 ° C. and 0.2 C charge / discharge at the 700th cycle was measured. The high temperature charging test was carried out by charging each of the above batteries at a temperature of 50 ° C. with a current of 0.2 C at 150% and then with a current of 0.2 C at 20 ° C. for 1.0%.
The battery was discharged to V and the capacity retention ratio to the capacity measured at 20 ° C. and 0.2 C charge / discharge was measured. The utilization rate is the number of Ni (OH) ₂ g used for each of the above batteries x 28
It was calculated from the actual capacity against the theoretical capacity of 9 mAh / g. The results were as shown in Tables 1 and 2 above.

As is clear from Tables 1 and 2, Co
The battery examples 1 to 9 of the present invention using the non-sintered nickel electrode of the present invention manufactured by using the nickel hydroxide active material powder of the present invention in which the contents of Zr and Zr are within a predetermined range are
Conventional Co or Z in the particles of nickel hydroxide active material powder
Batteries using a conventional non-sintered nickel electrode produced by using a nickel hydroxide active material powder containing n alone or both Co and Zn as a positive electrode, particularly the capacity at the 700th cycle compared to Conventional Examples 1 to 3. The maintenance rate and high temperature charging characteristics are improved. However, as shown in Comparative Examples 1, 2, and 4, the Zr content is 0.1 wt. %, Or when the Co content is less than 0.2, the capacity retention rate at the 700th cycle does not become 80% or more, and the capacity retention rate of high-temperature charging characteristics is preferably 60% or more. Therefore, as shown in Examples 1 and 6, Zr is at least 0.1 wt. %, Co is at least 0.2 wt. It turns out that it is necessary to contain%. In addition, Comparative Examples 2 and 4
, The upper limits of the Zr and Co contents are 4 w each.
t. % And 5 wt. %, The above-mentioned utilization rate, cycle life, and high-temperature charging characteristics are all good, but since the respective characteristics do not increase with the increase of the addition amount of each, Zr The addition amount is 4 wt. %
Up to 5 wt. We have come to the conclusion that up to% is sufficient.

Thus, according to the present invention, Zr0.1
~ 4 wt. %, Co 0.2-5 wt. %, A non-sintered nickel electrode obtained by filling a porous substrate for current collection with a nickel hydroxide active material composed of a particle group containing 1% of
In comparison with the case where a conventional non-sintered nickel electrode obtained by filling a porous substrate for current collection with a nickel hydroxide active material composed of a particle group containing n is used as a positive electrode, the active material particles and the swelling of the electrode The suppression effect is improved, the utilization rate is maintained at 90% or more, the cycle life is increased, and the capacity retention rate at high temperature is improved. As a result of various studies, the content of Zr is less likely to be eluted in the alkaline electrolyte, and thus the effect of suppressing the swelling phenomenon of the nickel hydroxide particles can be maintained for a long period of time. On the other hand, the contained Co becomes CoOOH and is considered to contribute to conductivity.

As described above, since the particles of the nickel hydroxide active material powder of the present invention described above contain Zr and Co, the effect of suppressing swelling during repeated charging / discharging cycles is improved. High capacity retention rate is increased. However, on the other hand, at the same time, the adhesiveness between the particles of the filled active material powder and the porous substrate is lowered at the same time, the utilization factor is lowered, and the cycle life is shortened. Therefore, a cobalt-based additive having good conductivity, that is, at least one selected from cobalt compounds such as cobalt, CoO, Co (OH) ₂ , and CoOx is added to the active material in an amount of 8 wt. % Add and mix to make active material mixture,
It is considered that a non-sintered nickel electrode is obtained by filling a porous substrate for current collection with a mixture obtained by kneading this with a viscous liquid such as CMC, and drying and pressing. If the packing density is too low, the above properties are not improved, and if the packing density is too high, the electrolyte solution is insufficient, and conversely,
Cycle life is shortened.

As a result of various studies from this viewpoint, a paste of an active material mixture prepared by adding and mixing the above-mentioned cobalt-based additive powder to the above-mentioned nickel hydroxide active material powder of the present invention is used as a current collecting porous substrate. After being filled and dried, pressure is applied to compress the current collecting substrate so that the packing density of the active material mixture is 2.4 to 2.
By setting it to 9 g / cc, a non-sintered nickel electrode with improved utilization and cycle life could be obtained.

Next, a detailed embodiment will be described. Example Zr 1.0 wt. % And Co 0.7 wt. % Nickel-containing active material powder 10 of the present invention consisting of a population of spherical type particles containing 10% (having an average particle size of 10 μm and a tap density of about 2.1 g / cc).
37 parts by weight of a 1% CMC aqueous solution was added to an active material mixture in which 0 parts by weight and 8 parts by weight of CoO powder having an average particle size of 5 μm were mixed and kneaded to form a paste, which had a thickness of 1.1 mm and a porosity of 96. % Foamed nickel porous substrate, heated and dried, and then pressed at a pressing force of ² t / cm ² to produce a non-sintered nickel electrode. Electrodes having various packing densities of the active material mixture as shown in Table 3 below were produced by changing the degree of pressurization.
The packing density yielded the packing density of the active material mixture paste in the non-sintered nickel plate. Using each of these non-sintered nickel electrodes, the hydrogen storage electrodes produced in the above-mentioned examples were laminated and wound via separators, respectively, which were then housed in a cylindrical can and made to have a specific gravity of mainly KOH of 1 .3 alkaline electrolyte was injected to produce AA size and 1100 mAh Ni / Mh batteries, respectively. In this manufacturing process, a charging / discharging cycle test was performed on these batteries when pressing the foamed nickel porous substrate filled with the paste of the active material mixture, and the utilization rate and the capacity retention rate at the 700th cycle were evaluated as follows. I asked. The utilization rate was produced from the capacity after six times of charging at 150 ° C. with a current of 0.2 C and discharging to 1 V at a current of 0.2 C at a temperature of 20 ° C. Cycle life test is 1C at 25 ℃
1C after charging is controlled by -ΔV control
The capacity at the 700th cycle was measured by repeating the discharge up to 1 V with the current of 1., and this value was evaluated as the capacity retention rate% with the capacity charged and discharged at 0.2 ° C. as 100%. The results are shown in Table 3 below.

[0018]

[Table 3]

As is clear from Table 3, the utilization rate of 100
% Or more and the capacity retention rate at the 700th cycle of 90% or more, the packing density of the active material mixture is 2.4.
It has been found that a range of ~ 2.9 g / cc is required.

Even if powders of cobalt oxides other than Co and CoO or cobalt hydroxides alone or in a mixture thereof are used in place of the CoO used in the above-mentioned examples, the charge-discharge cycle life is similarly improved. The improvement effect was obtained.

Using the above-mentioned nickel hydroxide active material mixture of the present invention, various non-sintered nickel electrodes were tested and studied. As a result, nickel powder, preferably carbonyl nickel powder, was further added to this mixture. It was found that the rapid discharge performance can be particularly improved by adding it. An example of the implementation will be described below.

Example Zr 1.0 wt. % And Co
0.7 wt. % Of nickel-type active material powder having an average particle size of 10 μm and a tap density of about 2.1 g / cc, which is composed of a group of spherical type particles containing 10% by weight, and 8 parts by weight of an average particle size CoO powder. As shown in Table 4 below, carbonyl nickel powder INCO # 255 (Fisher size 2 μm or more)
And INCO # 210 (Fisher size 1.3μm
Each of the following) was added and mixed with 7 parts by weight of each active material mixture, and 37 parts by weight of a 1% CMC aqueous solution was added and kneaded to form a paste, each of which had a thickness of 1.1 mm and a porosity of 96% and nickel foam. Each of the porous substrates was filled, heated and dried, and then pressed with a constant pressing force to have a thickness of 0.55 mm and a packing density of 2.6.
A non-sintered nickel electrode with g / cc was produced. These two kinds of electrodes were used as a positive electrode, the same hydrogen storage alloy electrode as in the above-mentioned example was used as a negative electrode, and laminated and wound with a separator interposed therebetween, and thereafter, in the same manner as in the above-mentioned example, AA size 1100 mAh.
The respective nickel-hydrogen storage batteries were manufactured. For each battery, 150% at a temperature of 20 ° C and a current of 0.2C
Charge and perform a rapid discharge test at 0 ° C with a current of 3C to 1V, measure the capacity during the rapid discharge, and set the value to 20.
The ratio to the discharge capacity at the time of charging / discharging at 0.2 C at ° C was determined as the capacity retention rate. The results are shown in Table 4 below. For comparison, no Ni powder was added to CoO.
A battery prepared in the same manner using the non-sintered nickel electrode of Example 2 of Table 3 having the same packing density containing the active material mixture containing only 8% by weight of the active material mixture was subjected to the rapid discharge test in the same manner as above. The results obtained are shown in Table 4 as Comparative Example 1.

[0023]

[Table 4]

As is clear from Table 4, when the nickel powder was further added to the cobalt-based additive as the non-sintered nickel electrode of the present invention, compared to the case where only the cobalt-based additive was added. It can be seen that the rapid discharge characteristic at a low temperature is remarkably improved. In addition, it was found by a test that when such a conductive additive was not added, discharge at 0 ° C. and 2 C was hardly obtained.

Furthermore, the present invention uses the non-sintered nickel electrode comprising the above nickel hydroxide active material of the present invention,
In particular, the present invention provides an alkaline storage battery having improved high-temperature charge characteristics and low-temperature rapid discharge characteristics. For that purpose, LiOH 0-4 wt. %, KOH20
-40 wt. % Alkaline electrolyte or LiOH 0
~ 4 wt. %, KOH + NaOH 20-40%, NaO
H0-10 wt. %, It is preferable to use an alkaline electrolyte.

Next, a detailed embodiment will be described. Example The same Zr1wt. % And Co 0.7 wt.
% Spherical type nickel hydroxide 100 parts by weight, CoO powder 8 parts by weight, and 1% CMC aqueous solution 37 parts by weight are added and kneaded to form a paste, which is filled in a foamed nickel porous substrate, dried, and pressed. Then, a non-sintered nickel electrode was produced, and this was used as a positive electrode, and the same hydrogen storage alloy electrode as that produced in the above-mentioned examples was laminated and wound as a negative electrode via a separator, and then housed in a cylindrical can. After pouring a certain amount of various alkaline electrolytes having different compositions and concentrations of the alkaline electrolytes as shown in FIGS. 3, 4, 5 and 6 into the battery cans described above, The lid and the lid were sealed, and each nickel-hydrogen storage battery was manufactured.

Each of the above batteries was subjected to a room temperature discharge test, a low temperature rapid discharge test and a high temperature charge test. 1) In the room temperature discharge test, at 20 ° C., 150% charge was performed at a current of 0.2 C, and then discharge was performed at 0.2 C to 1.0 V. 2) The low-temperature rapid discharge test was carried out at 20 ° C after charging 150% with a current of 0.2C and then at 1 ° C with a current of 1C.
Discharged to V. 3) The high temperature charging test was conducted by charging 150% with a current of 0.2C at 50 ° C, and then at 20 ° C at 0.2C.
It was discharged to 0V. When the alkaline electrolyte composition is KOH + LiOH and KO
The test results of the above 1), 2), and 3) of H + NaOH + LiOH were as shown in FIGS. 3 and 4 and FIGS. 5 and 6, respectively.

In FIGS. 3 to 6,% means% by weight.
As is clear from these figures, KOH alone, KOH +
In alkaline electrolyte consisting of two components of LiOH, K
OH 20-40 wt. %, LiOH 0-4 wt. % Scope
In particular, the low temperature discharge characteristics and high temperature charge characteristics are particularly good
I understand that LiOH 5 wt. % Is KOH20w
t. % Was not suitable because it did not dissolve in the electrolyte. LiO
The addition of H is performed by adding Ni containing a solid Zr and Co solid solution.
(OH)_TwoLi between crystal layers⁺Ions penetrate and enter the crystal
As a result of giving distortion, activity is increased and utilization rate is improved.
You. The addition of KOH is Ni (OH)_TwoIs needed for discharge
OH^-It regulates the amount of ions, and if it is too small, OH^-Io
If the amount of electrolyte supplied is insufficient or too much, the viscosity of the electrolyte will increase.
Rise, the movement speed becomes slow, and the supply amount becomes insufficient.
Therefore, the addition amount within the above range was appropriate. In addition,
And as can be seen from FIG. 6, consisting of KOH + NaOH
In the case of alkaline electrolyte, KOH + NaOH 20-40
wt. %, And NaOH is 10 wt.
% Low temperature discharge characteristics and high temperature
It can be seen that both the charging characteristics can be maintained well.
More specifically, KOH + NaOH 20-40 wt. %of
High temperature charging with increasing amount of NaOH in the range
The characteristics are increased, but the low temperature discharge characteristics are the opposite and
It tends to decrease as the amount of addition increases, but both characteristics are good.
In order to maintain good condition, the addition amount of NaOH is 10 wt. %
It was found that it is appropriate to stop at. Na
Addition of OH is Ni (OH)_TwoIncrease oxygen overvoltage.
This is Na⁺Ions are Ni (OH) _TwoAcid on the crystal surface of
It is considered that this is because the generation of elementary substances is suppressed. Also, N
a⁺Ions are also Ni (OH)_TwoEnter the crystal of
i⁺Because the diameter is larger than that of ions, H⁺(Proton) transfer
Too much as it hinders it and reduces discharge activity.
Then, the discharge activity is lowered. As a result of the above test, N
aOH is 10 wt. Appropriate amount added up to
Was recognized. In addition, in FIG. 5 and FIG. 6, KOH + NaO
1 wt. Of Li in an alkaline electrolyte containing H. % Added
In this case, the above battery characteristics were shown, but the addition amount of Li was 0 to
4 wt. %, The same good results as above
Recognized to exhibit low temperature discharge characteristics and high temperature charge characteristics
Was.

The present invention further provides a nickel hydroxide active material powder containing Co and Zr in the particles, which is capable of further improving high temperature charging characteristics. It is characterized in that it further contains zinc. The content of zinc is 1 to 7 wt.
% Range is preferred. The method for producing the nickel hydroxide active material powder is the same as the method for producing the nickel hydroxide active material powder containing Co and Zr in the particles as described above to obtain the non-spherical or spherical type nickel hydroxide active material powder. It can be manufactured. For example, in order to produce a preferable spherical type, an appropriate amount of a predetermined amine salt is dissolved in a nickel salt aqueous solution to form a weakly alkaline aqueous solution, and a predetermined amount of cobalt salt, zirconium salt and zinc sulfate, zinc nitrate, etc. If the zinc salt is added and dissolved, and the alkali is gradually added to this with stirring, nickel hydroxide precipitates and forms, so each of the crystals contains a predetermined amount of cobalt, zirconium and zinc as a solid solution. A population of particles is obtained. Thus, thereafter, the spherical nickel hydroxide active material powder of the present invention is obtained by filtering this, washing with water, heating and drying, and pulverizing if necessary.

Then, a cobalt-based additive is added to a predetermined amount of the nickel hydroxide active material powder thus obtained, or nickel powder is further added thereto to prepare an active material mixture. A non-sintered nickel electrode of the present invention can be obtained by adding a viscous liquid such as a 1% CMC aqueous solution to and kneading it into a paste, filling the foamed nickel porous substrate with heat, drying and pressing. . Thus, by using this electrode as a positive electrode and the hydrogen storage alloy electrode as a negative electrode, an alkaline storage battery such as a nickel-hydrogen storage battery can be manufactured in the same manner as in the above embodiment. Needless to say, the negative electrode is not limited to the hydrogen storage electrode.

In the case of using the active material powder of the present invention containing Zr, Co and Zn, next, as compared with the case of using the active material powder of the present invention containing only Zr and Co, high temperature charging characteristics It will be clarified by the examples that

Example: For each nickel sulfate aqueous solution prepared by dissolving 1.6 mol / l nickel sulfate in water prepared in a large number of containers, 25 w
t. % Aqueous ammonia was added and stirred to prepare 3 l of a nickel sulfate aqueous solution having a pH of 10.5 to 11 in which a nickel amine complex was formed. Cobalt sulphate, zirconium sulphate and zinc sulphate were added to the respective preparations at various addition amounts and molar ratios and dissolved by stirring to obtain a pH of 10.5 to 1
While maintaining 1.0, caustic soda was gradually added and stirred, and a uniform reaction was allowed to proceed at 50 ° C. to precipitate nickel hydroxide. Then, this is filtered, the nickel hydroxide precipitate is washed with water, and then dried by heating at about 50 to 70 ° C. to form Zr, Co and Zn in the nickel hydroxide crystal.
To obtain a nickel hydroxide active material containing each as a solid solution. On the other hand, for comparison, a nickel hydroxide active material powder containing only cobalt and zinc in the particles was manufactured by the same manufacturing method as above except that zirconium sulfate was not added as a starting material. Further, a nickel hydroxide active material powder corresponding to Example 2 in Table 1 containing only cobalt and zirconium in the particles was produced by the same production method as described above except that zinc was not added as a starting material.

Non-sintered nickel electrodes and alkaline storage batteries using the same were prepared under the same conditions as described below for each of the nickel hydroxide active material powders made of the spherical type particle group thus manufactured. That is, 8 parts by weight of CoO was added to 100 parts by weight of each active material powder, and 1 w was added to the active material mixture.
t. % CMC aqueous solution was added and kneaded to form a paste, which was filled in a foamed nickel porous substrate, heated and dried, and pressed to obtain a nickel electrode. The nickel electrode and the hydrogen-absorbing alloy electrode were laminated and wound with a separator interposed therebetween, which was housed in a cylindrical can, and a predetermined amount of alkaline electrolyte was injected, and the lid was sealed. Alkaline electrolyte is KOH22
wt. %, NaOH 7 wt. %, LiOH 1 wt. % Was dissolved in water and used with a specific gravity of 1.33. Thus, an AA size, 1100 mAh nickel-hydrogen storage battery was manufactured.

A high temperature charging test was conducted on each of the batteries produced as described above, that is, at 50 ° C.
After charging 150% with 0.2C current, 0.2C at 20 ℃
Was discharged up to 1.0 V. The discharge capacity at that time was measured. At 20 ° C, 150% charge at 0.2C current, and then at 20 ° C discharge to 1.0V at 0.2C current, the discharge capacity is taken as 100%, and the capacity retention rate% in the above high temperature charge test I asked.

[0035]

[Table 5]

As is clear from Table 5, Zr,
The nickel hydroxide active material powder containing three components of Co and Zn has significantly higher high-temperature charging characteristics than those containing two components of Co and Zn that do not contain Zr in the particles (conventional example). And Z corresponding to the previous embodiment of
It can be seen that the high-temperature charging characteristics are further improved as compared with those containing two components of r (Comparative Example). In this case, the Zr content in the particles is 0.1 to 4 wt. %, Co 0.2-3w
t. % And Zn 1 to 7 wt. When contained in the range of%,
The above-mentioned excellent high temperature charging characteristics were retained.

The nickel hydroxide active material powder composed of the above-mentioned nickel hydroxide particle group containing Co, Zr and Zn was not burned in the same manner as in the above-mentioned Examples, like the above-mentioned powder containing Co and Zn. An alkaline nickel battery can be manufactured by producing a bonded nickel electrode and using this as a positive electrode.

[0038]

As described above, according to the present invention, 0.2 to 5 w of cobalt is contained in the particles of the nickel hydroxide active material powder.
t. % And zirconium 0.1-4 wt. %, The non-sintered nickel electrode produced using this contains
When used as the positive electrode of an alkaline storage battery, the effect of suppressing the swelling of the particles due to its charge / discharge cycle, therefore, the effect of suppressing the swelling of the electrode is improved as compared with the conventional one containing cobalt or zinc, and the cycle life is improved. A battery having an increased capacity retention rate can be obtained.

The active material powder is filled with an active material mixture prepared by mixing cobalt-based additive powder in a current collecting porous substrate and pressurized to have a packing density of the active material mixture of 2.4 to 2. .9 g
When it is set to be / cc, the utilization factor of the active material is improved, and the charging / discharging cycle life is further extended.

Furthermore, an active material mixture obtained by adding nickel powder to the active material mixture is used as the active material mixture, and the packing density of 2.4 to 2.
When it is 9 g / cc, the utilization factor of the active material is improved, the charge / discharge cycle life is extended, and further the rapid discharge property is improved.

Further, the non-sintered nickel electrode manufactured by using the above-mentioned active material powder of the present invention is used as a positive electrode, and LiOH 0 to 4 wt. %, KOH 20-40w
t. % Alkaline electrolyte or LiOH 0-4w
t. %, KOH + NaOH 20-40%, NaOH 0-
10 wt. % Alkaline storage batteries provide improved low temperature discharge characteristics and high temperature charge characteristics.

When a non-sintered nickel electrode is prepared by using a nickel hydroxide active material powder further containing Zn in the above particles, an alkaline storage battery using this as a positive electrode is a high temperature battery. The charging characteristics are particularly improved.

[Brief description of the drawings]

FIG. 1 is a drawing-substitute electron micrograph showing a spherical type particle shape of the nickel hydroxide active material powder of the present invention.

FIG. 2 is a drawing-substitute electron micrograph showing a spherical type particle shape of the nickel hydroxide active material powder of the present invention.

FIG. 3 is a diagram showing a relationship between an alkaline electrolyte in which LiOH is added to KOH and discharge characteristics of an alkaline storage battery at 20 ° C. and −10 ° C.

FIG. 4 is a diagram showing the relationship between the alkaline electrolyte in which the amount of LiOH added is changed to KOH and the discharge characteristics at 50 ° C. of the alkaline storage battery.

FIG. 5: 20 ° C. of alkaline electrolyte and alkaline storage battery in which the amount of added LiOH was fixed and the amount of added NaOH was changed.
It is a figure which shows the relationship with the discharge characteristic in -10 degreeC.

FIG. 6: 50 ° C. of alkaline electrolyte and alkaline storage battery in which the amount of added LiOH was fixed and the amount of added NaOH was changed.
FIG. 6 is a diagram showing the relationship with the discharge characteristics in FIG.

Claims (8)

[Claims] 1. Nickel hydroxide particles contain at least 0.2 to 5 wt. % And zirconium 0.1 to 4
wt. % Of nickel hydroxide active material powder. 2. The nickel hydroxide active material powder according to claim 1, wherein the nickel hydroxide particles further contain zinc. 3. The nickel hydroxide active material powder according to claim 1, wherein the shape of the nickel hydroxide particles is a spherical type. 4. A non-sintered nickel electrode, wherein the nickel hydroxide active material powder according to claim 1, 2, or 3 is filled in a porous substrate for current collection. 5. A paste of an active material mixture obtained by adding at least one of cobalt and a cobalt-based additive powder of a cobalt compound to the spherical nickel hydroxide active material powder according to claim 3 or 4. , The porous substrate for current collection is filled and pressurized, and the packing density of the active material mixture is set to 2.4 to 2.
A non-sintered nickel electrode characterized by having 9 g / cc. 6. The porous substrate for current collection is filled with a paste of an active material mixture obtained by further adding nickel powder to the active material mixture according to claim 5. Non-sintered nickel electrode. 7. The non-sintered nickel electrode according to claim 3, 4, 5 or 6 is provided as a positive electrode, and LiOH 0-4 wt. %, KOH 20-40 wt. %, And an alkaline storage battery characterized by being provided with an alkaline electrolyte. 8. The non-sintered nickel electrode according to claim 3, 4, 5 or 6 is provided as a positive electrode, and LiOH 0-4 wt. %, KOH + NaOH 20-40
%, NaOH 0-10 wt. %, And an alkaline storage battery characterized by being provided with an alkaline electrolyte.