JP2923946B2 - Sealed alkaline secondary battery and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial applications   The present invention relates to the inclusion of cobalt over nickel and cobalt.
Positive electrode whose active material is mainly composed of hydroxide with a prevalence of 15 to 85 wt%
Plate, cadmium hydroxide and cadmium metal as active materials
Battery composed of negative electrode plate mainly composed of aluminum and its production
It is about the method. Conventional technology   Currently, manganese dioxide and manganese dioxide are
Silver oxide and the like are used as the positive electrode active material for secondary batteries, such as lead dioxide and hydroxyl.
Nickel chloride or the like is used. These active materials
Each is selected according to the application.   In recent years, as electronic devices have become smaller and lighter,
The emergence of high-performance primary batteries and secondary batteries is expected. Most
Recently, nickel and cobalt were used as cathode active materials.
The main component is nickel hydroxide with a
Positive electrode using active material and negative electrode composed of zinc and cadmium
An alkaline battery composed of a plate and
Ah efficiency is almost 10 times compared to batteries using nickel positive plate.
Extremely high at 0%, batteries open at open circuit voltage during discharging and charging
It has been found that the capacity of
Published Japanese Patent Application No. Sho 60-163382). Such new features
It is expected that batteries with higher performance will have higher performance. Problems to be solved by the invention   Cobalt for nickel and cobalt as positive electrode active material
Positive electrode plate mainly composed of hydroxide with a default content of 30 wt% or more
Alkaline batteries using, for example, nickel (cobalt)
The domium battery is charged by the voltage change accompanying charging and discharging.
Amount, discharge electricity amount or remaining capacity can be easily known.
It turns out that there is a selected feature that can be cut. Especially
Detects voltage rise due to large changes in charging voltage
To control charging by using the conventional nickel cadmium
Battery is easier than battery
Published Japanese Patent Application No. Sho 60-115161), charging control is easier.
Batteries are desired.   Currently, nickel-cadmium battery positive electrodes
An active material having a default content of 2 to 10% by weight is used. one
For the negative electrode plate, sintered nickel with a porosity of about 80%
Cadmium hydroxide on substrate and nickel-plated perforated steel plate
And cadmium active materials are used
I have. Charge this conventional nickel-cadmium battery
At times, charge an amount of electricity equivalent to 105-150% of the charging capacity.
Must be charged. The reason is that oxygen is released during charging.
The charging efficiency of the positive electrode plate is low because
This is because the cloning efficiency decreases. That is,
Conventional nickel-cadmium batteries overcharge when charging.
Otherwise, the capacity will not recover. this thing
Is a conventional nickel-cadmium battery a positive
Need to overcharge while generating oxygen.
Means   In nickel-cadmium batteries, from the positive electrode
The oxygen generated by the reaction shown in the formula (2)
Therefore it is absorbed.   4OH → O_Two+ 2H_TwoO + 4e^-                        (1)   O_Two+ 2H_TwoO + 4e^-→ 4OH^-                       (2)   Therefore, hydrogen is generated from the negative electrode plate even in the overcharge area.
No, oxygen generated from the positive electrode is absorbed on the negative electrode plate,
There is only heat generation. This indicates that nickel nickel
Dome battery is charged with constant current and overcharged
Thermistor measures battery temperature rise due to heat generated in the area
How to stop charging by detecting with etc., charging by gas absorption
How to stop charging by detecting a voltage drop phenomenon.
Control charging by detecting an increase in internal pressure with a pressure sensor.
Method is used. This charging method provides fast charging
To improve gas absorption performance in the overcharge area,
There must be. The rate constant of this gas absorption is
Battery case, even if the internal pressure of the battery rises.
A cylindrical battery that is less likely to deform or break
This is preferable for charging, but even in this case, 1C charging is limited.
Degrees. Also, from the viewpoint of energy density,
Prismatic batteries are preferable to batteries, but rectangular batteries
Has a lower withstand pressure than the cylindrical battery,
Withstand pressure of at most 5kg / cm even if metal such as iron is used as material^Two
It is about. Therefore, charging up to 0.3C was the limit. This
Voltage as a method of charging nickel-cadmium batteries
There is a method to detect the rise in
100-150mV, and when the temperature rises,
Since the rise is small, temperature compensation is necessary and signal
Low reliability, so-called thermal runaway when charged at low voltage
(Thermal run away) phenomenon occurs and the battery is broken
In some cases, the loss was reached.   In addition, the activities of currently used negative electrode plates for sealed
The substance does not generate hydrogen from the negative electrode plate during charging
Such measures have been taken. If hydrogen gas is charged during charging
When generated, hydrogen is very slightly absorbed by the positive plate
Only remains in the battery as it is, causing the accumulation of hydrogen.
As the oxygen partial pressure decreases, the oxygen gas absorption
The response is less likely to occur. In that case, the internal pressure will activate the safety valve
When the pressure is reached, not only hydrogen gas but also oxygen gas flows out of the valve
I will be. This means that the amount of electrolyte decreases.
This means that the capacity is eventually reduced. Further
However, this generation of hydrogen gas is not preferable from the viewpoint of safety.
No.   A specific method to prevent the generation of this hydrogen gas
In general, other than the active material corresponding to the capacity of the positive electrode plate,
Cd (OH) for saab₂Extra cadmium hydroxide called
Is taken.   The amount must compensate for at least the following main items:
It is important. B) By charging and discharging, d.
Nickel hydroxide, which is the same as the active material, when the nickel substrate is oxidized
The amount of increase in the positive electrode active material due to generation of. B) Oxygen generated during charging is
Consumed amount. C) It is equivalent to the product of the allowable internal pressure of the battery and the space volume of the battery.
Amount of oxygen.   In each case, the cadmium hydroxide present on the negative electrode plate
Is converted to metallic cadmium by that amount.
You. Cd (OH) for this reserve₂The amount of used sepa
Depends on the material of the generator, the shape of the battery, and the operating conditions
However, it usually takes 40 to 100% of the theoretical capacity of the positive electrode active material.
is there. When displayed based on the weight of the active material of the positive electrode plate,
Cd (OH) for negative electrode plate reserve₂Cadmium hydroxide containing
The content of the cathode is usually 1.77 to 2.53 times the amount of the positive electrode active material.
It is. As described above, the amount of active material of the positive electrode plate is
Extra cadmium hydroxide other than the equivalent
Needed. This is not desirable in terms of battery capacity.
But necessary to prevent the generation of hydrogen from the negative electrode plate
It was a means that did not get. This is nickel cadmium
The charging method used for the sealed lead-acid battery
It is said that charging is controlled only by detecting the rise of voltage
Means that it is virtually impossible to apply a simple method.
To taste. Therefore, the charge control is easy and the quick charge is possible.
There is a strong demand for a reliable sealed alkaline battery. Means to solve the problem   The present invention relates to the inclusion of cobalt over nickel and cobalt.
Positive electrode whose active material is mainly composed of hydroxide with a prevalence of 15 to 85 wt%
Plate and cadmium hydroxide and cadmium metal
Discharge of battery in battery consisting of negative electrode plate as main component
Cadmium hydroxide content of the negative electrode plate in the state is weight
0.95 or less of the positive electrode active material in terms of ratio, ie, Cd (OH) for reserve₂
Is not included, the conventional nickel cadmium
Battery, the charging voltage, which was considered difficult to apply
Extremely easy to detect charging and control charging
Temperature compensation of the voltage is unnecessary, and its reliability
Can be increased.   Furthermore, unlike conventional batteries, reserve Cd (OH)₂
Do not need. Therefore, it is possible to increase the capacity,
Even if it is a square battery that can only be a cylindrical battery, a conventional battery
Capable of fast charging of 1C or more, which was almost impossible
It can be. Example   Hereinafter, details of the present invention will be described based on examples.   The positive electrode active material used in the battery of the present invention is manufactured by the following method.
can do. Incidentally, the content of cobalt in the active material
Metal core to total metal nickel and metal cobalt
Indicated by Baltic content. That is, the content of cobalt =
{Co / (Ni + Co)} x 100 (wt%). (A) Nickel nitrate with cobalt content of 15-85wt%
A mixture of cobalt nitrate or a mixed solution of 110 to 350
After heating at ℃, sodium hydroxide or potassium hydroxide
Immersed in an alkaline aqueous solution such as water, washed with hot water and dried. (B) Nickel nitrate with a cobalt content of 15-85 wt%
Mixed solution of nickel and cobalt nitrate, nickel sulfate and kobal sulfate
Mixed solution of nickel or cobalt chloride and cobalt chloride
The combined solution with an alkali such as sodium hydroxide or potassium hydroxide
After the treatment with the aqueous solution, washing with hot water and drying are performed.   The negative electrode active material used in the battery of the present invention is obtained by the following method.
Can be manufactured. (C) Nitric acid is added to the active material holder such as a sintered nickel substrate.
Add cadmium, cadmium sulfate or cadmium chloride solution
After impregnation, treated with sodium hydroxide or potassium hydroxide
Then, wash with hot water and dry. Then, potassium hydroxide aqueous solution
And the amount of cadmium hydroxide in an aqueous alkaline solution such as
After charging or discharging so that it becomes
Do. (D) Predetermined amount of cadmium oxide powder and metal cadmium
Active material powder consisting of powder and polyethylene powder or polyethylene
Nickel plating with a binder such as trafluoroethylene powder
For current collectors of perforated steel plates and expanded nickel
Apply by pressing directly. (E) Predetermined amount of cadmium oxide powder and metal cadmium
Active material powder consisting of powder such as polyvinyl alcohol
After mixing with an aqueous solution of a water-soluble polymer,
Directly into perforated steel sheet or expanded nickel current collector
Apply under pressure. (F) Cadmium oxide powder or cadmium hydroxide powder
Mix with aqueous solution of water-soluble polymer such as polyvinyl alcohol
And then use nickel-plated perforated steel
It is applied to a nickel current collector, dried and pressed. Next
To a predetermined amount in an aqueous potassium hydroxide solution.
After discharging, washing with hot water and drying are performed.   Basically, as described above, the positive electrode used in the battery of the present invention is used.
The electrode plate and the negative electrode plate can be made.
Examples of the inventive battery will be described in detail. Example 1   Sintered nickel substrate with a porosity of about 80%
A mixture of cobalt nitrate and nickel nitrate with a content of 15%
After impregnation with the solution [PH = 2, specific gravity 1.50 (20 ° C)], specific gravity 1.
Immerse in 20 (20 ° C) sodium hydroxide solution, wash with hot water,
dry. This operation is repeated until the theoretical capacity is 600 mAh and 1.
An 8 x 15 x 60 mm positive electrode plate was manufactured.   Cadmium nitrate on a sintered nickel substrate with a porosity of about 80%
Solution [PH = 3, specific gravity 1.70 (20 ℃)]
1.20 (20 ° C) sodium hydroxide solution
Wash and dry. Repeat this operation to set the theoretical capacity to 500 mA.
h, a negative electrode plate of 1 × 15 × 60 mm was manufactured.   This negative electrode plate was treated with aqueous sodium hydroxide having a specific gravity of 1.20 (20 ° C).
In the solution, use a nickel plate as the counter electrode and apply a current of 500 mA for 1.5
After charging for an hour, discharge the same amount of electricity of 360mAh,
Rinse with hot water and vacuum dry at 50 ℃ for 4 hours.
Obtained.   Next, after wrapping one positive electrode plate with a polyamide nonwoven fabric,
Sandwiched between the two negative plates described above, a specific gravity of 1.25 as an electrolytic solution.
Using 1300 μl of 0 (20 ° C.) aqueous potassium hydroxide solution,
The rectangular sealed alkaline secondary battery of the present invention having a nominal capacity of 500 mAh.
(A) was produced. In addition, 2Kg / cm^TwoWorks with
Safety valve. For reserve of negative plate of this battery
Cd (OH)₂Is 0g, Cd (OH) of the negative electrode plate in the discharged state
₂Content of Ni (OH) in the positive electrode plate₂0.95 times the content of
ing. Example 2   Sintered nickel substrate with a porosity of about 80%
Mixed water of 35% cobalt nitrate and nickel nitrate
Impregnated with a solution [PH = 2, specific gravity 1.50 (20 ° C)]
Heat treatment is performed for 1 hour. Subsequently, specific gravity 1.20 (20 ℃) ℃
After being immersed in an aqueous solution of sodium chloride, it is washed with hot water and dried. This
Repeat the above operation, theoretical capacity 600 mAh, 1.8 × 15 × 60 mm
Was manufactured.   50 parts of cadmium oxide powder and 50 parts of metal cadmium powder
Part and 0.15 part of 1 mm long polypropylene single fiber
Ethylene glycol containing wt% polyvinyl alcohol
Mix with 30 ml to make a paste. Nickel paste this
Coated on a perforated steel plate,
Negative electrode plate with a theoretical capacity of domium of 360 mAh and 1.0 x 15 x 60 mm
Was made. Using this positive electrode plate and negative electrode plate,
Square sealed alkali with a nominal capacity of 500 mAh and a configuration similar to 1.
A secondary battery (B) was manufactured.   The cadmium oxide on the negative electrode plate is
The reaction shown in equation (3) occurs and consumes water.
Extra water was injected corresponding to the consumption.   CdO + H_TwoO → (OH)₂                        (3) Example 3   Cobalt nitrate and nickel nitrate with a cobalt content of 50%
Mixed solution [PH = 2, specific gravity 1.60 (20 ℃)] with 220 ℃
For 2 hours. Subsequently, specific gravity 1.20 (20 ℃)
Immerse in sodium chloride aqueous solution for 2 hours, wash with hot water, then 120 ℃
For 1 hour with hot air drying. After that, 80 ball
Crushed to below. 95 parts of this positive electrode active material powder and conductive material
5 parts of metallic cobalt powder and ethylene glycol 40
kneaded with 3 ml and a 3 mm thick nickel foam (Sumitomo Electric KK,
After filling in Celmet (product name), dry at 150 ° C for 1 hour
Was done. After that, pressurize and theoretical capacity 600mAh, 1.8 × 15
A positive electrode plate of × 60 mm was manufactured.   In addition, 100 parts of cadmium hydroxide powder and 1 mm long polypropylene
0.15 parts of single fiber of pyrene and 1.5 wt% of polyvinyl alcohol
The mixture is made into a paste by mixing with 40 ml of an aqueous solution. This page
Paste on a nickel-plated perforated steel plate and then dry.
After drying and pressurizing, the theoretical capacity of cadmium hydroxide is 500 mAh, 0.
A 9 × 15 × 60 mm negative electrode plate was manufactured. This negative electrode plate has a specific gravity of 1.2
In a 0 (20 ° C) aqueous sodium hydroxide solution,
Using a Kel plate, a current of 500 mA causes the amount of electricity to reach 140 mAh.
After charging until the battery is charged, rinse with hot water and then
Vacuum drying was performed for an hour to obtain a negative electrode plate. The positive and negative plates
Using a book with a nominal capacity of 500 mAh and a configuration similar to that of Embodiment 1.
An inventive square sealed alkaline secondary battery (C) was manufactured. Example 4   Cobalt nitrate and nickel nitrate with 85% cobalt content
Mixed solution [PH = 2, specific gravity 1.60 (20 ° C)] at 250 ° C
For 2 hours. Then water with specific gravity of 1.20 (20 ℃)
Immerse in sodium hydroxide aqueous solution for 2 hours, wash with hot water, then 120
Hot air drying was performed at 1 ° C for 1 hour. Then 80 ball mill
And crushed to below. 95 parts of this active material powder and conductive material
And 5 parts of metallic cobalt powder with 1 wt% carboxymethyl
Knead 50ml of an aqueous solution of Lulose and use a 3mm thick
Filled with Kel (Sumitomo Denko KK, trade name Celmet)
Thereafter, drying was performed at 150 ° C. for 1 hour. Then pressurize
A positive electrode plate with a theoretical capacity of 600 mAh and 1.8 × 15 × 60 mm was manufactured. Sa
In a sodium hydroxide aqueous solution with a specific gravity of 1.20 (20 ° C),
After charging at 600 mAh for 2 hours, the battery was discharged at the same current. And
The electrode plate was washed with hot water and dried to obtain a positive electrode plate.   50 parts of cadmium oxide powder and 50 parts of metal cadmium powder
Part, 0.15 part of 1 mm long polypropylene single fiber and
What mixed 3 parts of tetrafluoroethylene powder,
Press directly on both sides of 20 mesh nickel steel with rollers
The theoretical capacity of cadmium oxide is 150mAh, 0.9 × 15 × 60mm
A negative electrode plate was manufactured. Using this positive electrode plate and negative electrode plate,
The present invention square rectangular capacitor having a nominal capacity of 300 mAh and a configuration similar to that of the first embodiment.
A closed alkaline secondary battery (D) was manufactured.   In this case, the content of cadmium hydroxide depends on the positive electrode active material.
It is 0.39 times.   Note that, similarly to the case of Example 2, the cadmium oxide
Required for the electrolyte to become cadmium hydroxide by the electrolyte
Extra water was added.   Cd (OH) for reserve of the battery of the present invention₂The amount of
Is in a bad state.   Next, charge each battery with a current of 1C at 20 ° C.
Charge to a voltage of 1.75V and then discharge to 0.5V
Discharge was performed for 250 cycles.   Each cycle when the discharge capacity in the first cycle is 100
FIG. 1 shows the capacity retention ratio in the fuel cell. For comparison
A conventional positive electrode plate with a Baltic content of 8 wt% was used.
Outside, a square nickel-cadmium manufactured in the same manner as in Example 1.
The transition of the discharge capacity of the battery (E) is also shown.   FIG. 1 shows that the batteries of the present invention (A), (B), (C), and
And (D) are superior to the conventional battery (E)
Recognize. Also, the weight of the battery at the 250th cycle was measured.
However, the batteries (A), (B), (C) and (D) of the present invention
No weight loss was observed, but the conventional battery (E)
A weight loss of 0 mg was observed. This means that the battery of the present invention
Means almost no generation of oxygen gas
You.   Commonly used nickel-cadmium batteries
In the case of battery (E), the amount of cadmium hydroxide on the negative electrode plate
Not less, but more cadmium hydroxide for reserve
I have Therefore, the amount of cadmium hydroxide is
Example using a negative electrode plate 1.8 times the theoretical capacity
Build a battery similar to 1 and charge 130% of the nominal capacity with 1 CA
Charge / discharge cycle to discharge to 0.5V at 1C.
However, at the 10th cycle, the weight loss of the battery was 70 mg,
Electrolyte leaked from the safety valve. From this,
Cd (OH) for saab₂Overcharge using negative electrode plate
Then, it is understood that the effect like the battery of the present invention cannot be obtained.
You.   In the case of this battery, Cd (OH) for reserve₂Large amount of
Since there is no rise in the potential to generate hydrogen on the negative electrode plate,
Terminal voltage does not reach 1.75V during charging. Because of that
Charge / discharge is performed with a constant air volume.   The typical voltage characteristics of charging and discharging in the experiment conducted in Fig.
FIG. 2 shows only the case of the pond (C). From Figure 2
The terminal voltage rises sharply at the end of charging and its value is
It can be seen that it is extremely large, 400 mV. And discharge vessel
The amount is an amount of electricity substantially corresponding to the amount of charge. This means
Coulomb efficiency is extremely high compared to conventional batteries
means. One of the features of the battery of the present invention is that the coulomb efficiency is extremely high.
It is expensive. Therefore, according to the first embodiment,
A positive electrode plate with a different
Aqueous 1.25 kg (20 ° C) aqueous potassium hydroxide solution
After charging with a current of 500 mA for 1.5 hours using a nickel plate,
Charge and discharge to discharge to 0V (vs.Hg / HgO) with the same current
For 2 cycles. Next, the discharge capacity in the second cycle
Charges at a current of 1C based on the discharge capacity of the corresponding amount of electricity
And discharge coulomb efficiency (discharged electricity / charged electricity)
(Volume) x 100. FIG. 3 shows the results. Third
From the figure, Coulomb efficiency when the cobalt content is 10%
Is 96.0%, but when it becomes 15%, it becomes 98.0%, and it becomes 20%
It turns out that it is almost 100%. The present invention
The rise in the charging voltage of the battery is caused by the negative electrode plate as described later.
Cd (OH)₂Rise due to almost being reduced,
In other words, a sudden change in potential in the process leading to hydrogen generation and the positive electrode plate
This is due to the overlapped voltage of the potential change. And the negative electrode
Plate Cd (OH)₂Charging efficiency is approximately 10 in the range of −10 to 45 ° C.
Since it is close to 0%, the charging efficiency of the positive electrode plate is also desirably 100%.
In addition, metal cadmium (precharged
Cadmium is a metal that can be charged.
Things. ) Is already held,
The discharge capacity of the pond is determined by the Coulomb efficiency of the positive plate.
You. If the charge and discharge cycle progresses, Coulomb efficiency
If constant, discharge capacity cycle depends on Coulomb efficiency
The capacity retention rate with the passage of time is determined. Coulomb efficiency
Fig. 4 shows the theoretical capacity retention rate due to the change in the value.
If the efficiency is 95.0%, it will be the 100th cycle of charging and discharging
It turns out that the capacity will be almost gone,
Battery using conventional positive electrode plate with Coulomb efficiency close to this value
Even in the case of (E), as shown in FIG.
Even at the corner, the capacity retention rate is about 50%. this is,
Coulomb efficiency depends on charge depth
It is. In other words, when the charging depth approaches 60% of the capacity,
The reaction of oxygen is extremely low,
This is because the efficiency is almost 100%. Take this into account
Then, the capacity retention rate does not become 0 in 250 cycles from FIG.
Coulomb efficiency can be estimated to be 98.0% or more.
Cobalt content with Coulomb efficiency of 98% or more
Is 15 wt% from FIG. Therefore,
When a positive electrode plate with a content of more than 15 wt%
Guaranteed capacity retention of 60% or more even at the 0th cycle
Can be In addition, Coulomb efficiency is
Even when the ratio is as high as 90%, it shows a value of 99% or more. But
However, when the content of cobalt becomes 85wt%, the utilization rate becomes 50%
The advantage of using a positive electrode plate that exceeds 85 wt%
Practically smaller. From these facts, the cobalt content
15-85 wt% is desirable.   As described above, the battery of the present invention has a sharp
This involves a change in charging voltage, but a large potential change
Using a negative electrode plate can further enhance this effect.
You. Such a negative electrode plate is a paste similar to that used in Example 2.
Content of nickel powder in active material of
It can be obtained by eliminating it. Figure 5 shows the implementation
In Example 2, carbohydrate was added to the active material powder of the paste type negative electrode plate.
Nil nickel powder was added and the negative plate
Evolution potential and charging process at the end of charging in 0.5C charging
The potential difference from the potential of nickel is calculated as the nickel content ｛Ni / (Cd + N
i) This shows the relationship with｝ × 100. The opposite electrode
The sintered nickel positive electrode plate has a specific gravity of 1.25 (20
° C) Potassium hydroxide aqueous solution is used, and the temperature is 25 ° C.
According to FIG. 5, the potential difference of the negative electrode plate containing no nickel is 450 mV.
150m when the nickel content exceeds 10wt%
Drops sharply to V. Therefore, the nickel content should be 5 wt% or less.
No. Incidentally, in the case of the sintered nickel negative electrode plate, it was 140 mV.
Therefore, in order to enhance the effect of the present invention, the anode plate must be fired.
Non-sintered electrode plates such as paste-type negative electrode plates are
It can be said that it is excellent. This is a hydrogen generation site
This is due to the fact that   Another feature of the present invention is that the charge / discharge potential is large.
Is to change. In Example 1, the content of cobalt was
Open circuit voltage after charging at 0.5C charge / discharge of changed positive plate
The difference between the potential and the open circuit potential after the end of the discharge is determined by adding zinc oxide to the electrolyte.
Investigations using saturated 1.25 (20 ° C) aqueous KOH solution
As a result, when the cobalt content is 10 wt%, it is 150 mV.
On the other hand, when the content becomes 15 wt%, it becomes 200 mV,
Over 300mV when the cobalt content exceeds 30wt%
The potential difference increases as the cobalt content increases.
It's gone. Therefore, the potential change during charging depends on the cobalt content
Is 15% by weight or more and the potential change of the negative electrode
When combined, it produces a voltage change during charging that is not available in conventional batteries.
In other words, a charging control method for detecting a charging voltage is facilitated.   As described above, the effect of the battery of the present invention is the content of cobalt.
Contains 15-85wt% of positive electrode plate and suitable cadmium hydroxide
This is achieved only with a negative electrode plate containing a large amount. The principle
Is based on the following facts.   The product of the active material of the positive electrode plate may vary slightly depending on the manufacturing conditions.
And also depending on the formation conditions before battery assembly
However, the content weight is all Ni (Co) (OH)₂Assuming
Not practical. The discharge state of the active material on the negative electrode plate
Cd (OH)₂As a practical matter. This positive electrode active material
The quality is when the average valence changes from divalent to 3.2 when charged
Almost no oxygen gas is generated until. On the other hand, the negative electrode active material is 2
No hydrogen gas is generated until the valence changes from zero to zero. Do
The theoretical capacity of the positive electrode active material is 0.3471 Ah / g,
Since it is 0.3662 Ah / g for cadmium oxide, the negative electrode plate
The cadmium hydroxide content of the
0.95 times or less before oxygen is mainly generated from the positive electrode
This causes a sudden change in the negative electrode potential. In addition, electrolytic
When using a solution in which zinc oxide is dissolved,
It is necessary to correct the amount of zinc oxide
There is almost no problem. And this relationship is satisfied
The battery has a large charging voltage in a wide range of -30 to 45 ° C.
Change and detecting it makes charging control easy
Function is guaranteed.   As described above, according to the present invention, the negative
The amount of cadmium hydroxide on the electrode plate is 0.95 times or less that of the positive electrode active material.
Need to be For that, as explained in the embodiment
Need to control the amount of cadmium hydroxide in the negative electrode plate accurately
There is. In terms of performance, if the amount of cadmium hydroxide
It is desirable to control the amount of metal cadmium, not the scale
Therefore, the method described in the embodiment is not necessarily a simple method.
There is no.   The amount of this metal cadmium is compared to the amount of cadmium hydroxide.
It is not necessary to control strictly, so the following method
Thus, the complexity can be eliminated. The method
The cadmium hydroxide amount to 0 g,
What is necessary is just to take the method of assembling to a battery. Specifically, the negative electrode plate
After overcharging in an alkaline aqueous solution, wash with hot water and dry under vacuum.
Or cadmium oxide powder or cadmium hydroxide
Using metal cadmium powder as the active material without using powder
It is only necessary to use a boost type negative electrode plate. In that case, also fill the positive plate
It needs to be in the electrical state.
After charging with an alkaline aqueous solution, wash with hot water and dry,
Oxide, sodium hypochlorite or peroxosulfur
After oxidizing with an oxidizing agent such as potassium acid, wash with hot water and dry
Just take the law. Yet another alternative is to discharge the positive electrode
After assembling the plate and the negative plate into the battery and performing overcharge,
It may be closed. The negative electrode plate used in these methods and
The ratio of the amount of active material in the positive electrode plate may be any value, but
When the battery is discharged after being closed,
In other words, the hydroxide of the negative electrode plate in the discharged state of the battery
The content of Mn is 0.95 times or less by weight of the cathode active material.
ing.   The charging voltage of the battery of the present invention varies greatly,
In the final stage, there is 300-600mV, so the rise of the voltage
It can detect and control charging. For example, the voltage
After charging with a constant current until the rise, the rise in voltage is detected.
To stop charging, or set the voltage to a constant voltage
There is a way.   Also, a quasi-constant voltage method can be applied. Conversely, the present invention uses a constant current
The overcharging method involves the generation of hydrogen gas from the negative electrode plate.
Liquid, resulting in reduced capacity
Absent.   In the embodiment, 1C quick charging of a rectangular battery, which was conventionally difficult, is performed.
However, even if this charging rate was set to 2C, the safety valve
There was no liquid leakage or weight loss.   This function is based on the fact that the battery of the present invention
It is almost unnecessary to generate gas from the positive electrode.
Features that rarely occur and electricity that leads to hydrogen gas generation
Charge control is easy by detecting a sudden rise in position
First created by the rational combination of
It is a thing. In this case, the voltage rise at the end of charging
Because it is three to four times larger than batteries,
There is virtually no need for voltage compensation due to the rise. The invention's effect   As described above, the alkaline battery of the present invention is
3 to 6 times increase in voltage at the end of charging of cadmium batteries
Increase and charge by detecting its voltage rise
Control can be performed with high accuracy, and the charge / discharge cycle
And the decrease in capacity associated therewith is extremely small. Use this feature
With the 1C charging and 2C charging of square batteries
Such quick charging can also be realized with high reliability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram comparing the capacity retention ratio of a battery according to the present invention and a conventional battery with charge / discharge cycles, and FIG. 2 is a diagram showing 1CA charge / discharge characteristics of the battery of the present invention. FIG. 3 shows the relationship between the Coulomb efficiency of the positive electrode plate and the cobalt content, and FIG.
The figure shows the theoretical change curve of the capacity retention with the charge / discharge cycle of the positive electrode plate with different Coulomb efficiencies. FIG. 5 shows the difference between the hydrogen generation potential of the negative electrode plate and the potential in the charging process, and the nickel content. FIG.

Claims (1)

(57) [Claims] 15 cobalt content relative to nickel and cobalt
Cadmium hydroxide of a negative electrode plate in a discharged state of a battery in a battery comprising a positive electrode plate mainly composed of an active material mainly composed of hydroxide of about 85 wt% and a negative electrode plate mainly composed of cadmium hydroxide and metal cadmium. Is a sealed alkaline secondary battery, characterized in that the content by weight of the positive electrode active material is 0.95 or less by weight. 2. 2. The sealed alkaline secondary battery according to claim 1, wherein the negative electrode plate is a paste type negative electrode plate. 3. 3. The sealed alkaline secondary battery according to claim 2, wherein the negative electrode plate contains nickel, and its content is 5 wt% or less in terms of {Ni / (Cd + Ni)} × 100. . 4. 4. The sealed alkaline secondary battery according to claim 1, wherein the shape of the battery is rectangular. 5. 15 cobalt content relative to nickel and cobalt
A battery composed of a positive electrode plate mainly containing up to 85 wt% hydroxide of an active material and a negative electrode plate mainly containing cadmium hydroxide and metal cadmium as an active material. A method for manufacturing a sealed alkaline battery in which the content of cadmium oxide is 0.95 or less of the amount of the positive electrode active material by weight, wherein the positive electrode plate and the negative electrode plate are assembled in a fully charged state. Production method. 6. 15 cobalt content relative to nickel and cobalt
A battery composed of a positive electrode plate mainly containing up to 85 wt% hydroxide of an active material and a negative electrode plate mainly containing cadmium hydroxide and metal cadmium as an active material. In a method for manufacturing a sealed alkaline battery in which the content of cadmium oxide is 0.95 or less of the amount of the positive electrode active material by weight, the positive electrode plate and the negative electrode plate in a discharged state are assembled into a battery, then overcharged and then sealed. Of manufacturing a sealed alkaline battery.