Embodiment
(charging stops mechanism)
Fig. 1 is the sectional view of pith of the enclosed alkali storage battery 1 of diagram one embodiment of the invention.
In Fig. 1, by carrying out overlapping with the banded dividing plate 4 that is clipped in the middle banded positive plate 2 and banded negative plate 3 and coiling, make that the outermost overlapping layer is a negative plate 3, thereby obtain takeup type pole plate group, this takeup type pole plate group is packed in the cylindrical metal battery case 5.
The substrate edge part of positive plate is side-prominent on takeup type pole plate group, will be connected to the top edge part of substrate near the cathode collector 6 of plate-like.The negative plate that is arranged in takeup type pole plate group outermost overlapping layer is contacted with the side wall inner surfaces of battery case 5 (have the space although figure is presented between the inner surface of negative plate and battery case, but both are actually and contact with each other), thus negative plate is electrically connected to battery case 5.It is the electrolyte of the electrolyte aqueous solution of main component that importing comprises with KOH.Then, crown cap 8 is installed in the upper, open end of battery case 5 by the packing ring of being made by synthetic resin such as nylon 9, thereby battery case 5 is sealed airtightly.Also can use with KOH as main component and contain LiOH or the electrolyte of NaOH.
Lid 8 has the through hole 10 that is formed on its core, be inserted in cover 8 and cap 12 between rubber system flame arrester vent plug 11 be pressed against on the through hole 10, thereby through hole 10 is sealed airtightly.Gather in the space of gas at battery, and the air pressure in the battery is when raising, flame arrester vent plug is out of shape because of internal pressure, thereby breaks the airtight sealing state.Therefore the gas via through holes 10 in the battery emits with being formed on the through hole 13 on the cap.
Crown cap 8 inside are equipped with pressure switch.
Pressure switch comprises: metal cap 15; Metal rigidity plate 17; Sheet metal 18; Packing ring 19, this packing ring 19 are used for the space that sealing metal rigid plate airtightly 17 and sheet metal 18 are centered on, and metal rigidity plate 17 and sheet metal 18 are kept apart with cover 15; With spring 20, this spring 20 is enclosed in the space that metal rigidity plate 17 and sheet metal 18 centered on.Cover 15 peripheral part is connected to cover 8 inner surface, and formation through hole 20.
In common state (the lower state of air pressure in the battery), sheet metal 18 contacts with lid 8, is in the state that is electrically connected with it.When the air pressure in the battery raise, gas overcame the elasticity of spring 20 and depresses sheet metal 18.That is, when the air pressure in the battery surpassed particular value, sheet metal 18 separated with lid 8.Thereby cut off electrical connection.After the air pressure in the battery reduced, sheet metal 18 was upwards pushed away because of the elasticity of spring, and sheet metal 18 contacts with lid 8 once more, had therefore recovered the electrical connection between them.By giving such mechanism, just can give such function, promptly when the air pressure in the battery between charge period raises, charging is closed, when the air pressure in the battery reduces, charging is opened (hereinafter being called the pressure switch function).
Fig. 8 and Fig. 9 illustrate when charging ON/OFF translation function works, the charging current of enclosed alkali storage battery of the present invention between charge period and the behavior of battery temperature.At this, close in order to make charging, preferred as shown in Figure 8 make charging stop the operation of (charging current is 0A) fully in the charging down periods.Yet as shown in Figure 9, even in the charging down periods, the charging current that is not reduced to 0A can flow with such degree, promptly makes internal pressure or battery temperature can not be increased to above particular value.
Depend on construction of switch, also have such situation, even be exactly in the down periods, the open/close switch contact point of control circuit can not isolated fully yet, but is in the contact condition with high contact resistance.
In this case, even in the down periods, charging current can not become 0A yet, and it is mobile that low current still keeps.
Example shown in Figure 1 also is equipped with temperature switch except pressure switch.
Numbering 14 expressions among the figure are connected to the bimetallic conductive plate of cathode collector 6.In common state (state that keeps low battery temperature), conductive plate 14 contacts with metal rigidity plate 17 and keeps being electrically connected.When temperature raise, conductive plate 14 is distortion downwards in the drawings.When temperature was elevated to above particular value, conductive plate 14 separated with metal rigidity plate 17, and cut off the electrical connection between them.When the temperature step-down, conductive plate 14 recovers its original shape, therefore the electrical connection that has recovered the two.
By giving such mechanism, just can give such function, promptly between charge period, when battery temperature raises, charging is closed, when battery temperature reduces, charging is opened (temperature switch function hereinafter referred to as).
Make in its circuit of packing into as long as conductive plate is set, special restriction is not done in the position that the bimetallic conductor sheet then is set.But,,, conductive plate is connected on the current-collector so the embodiment shown in the preferred image pattern 1 is such owing to be directly connected to the internal temperature that the temperature of the current-collector on the battery lead plate has the most accurately reflected battery.
In having the battery of the present invention of temperature switch function, when battery temperature reaches the particular value that stops to charge, stop charging.But, except making as mentioned above circuit disconnects fully, keep lower charging current, thereby prevent between charge period that it also is effective method that battery temperature raises.This method comprises to be made within the scope that stops of charging in the present invention.
Particularly, in the embodiment depicted in fig. 1, cover 8 the circuit extending to, self-resetting type switch (polyswitch) (PTC element) is installed from current-collector 6, rather than the bimetallic conductive plate.This element is such element: when the temperature of this element surpassed set-point, its resistance sharply raise.Among the present invention, preferably the resistance of this element sharply raises in the time of 50 ℃~80 ℃, and the resistance value after the rising is kilo-ohm (K Ω) level or higher.
In fact the increase of circuitous resistance can be so that can not charge.
In first enclosed alkali storage battery of the present invention, be less than or equal to the opening pressure of the flame arrester vent plug of making by rubber 11 based on the particular value that stops to charge of internal gas pressure, and it is set make the deterioration that can suppress battery performance.Particularly, preferably particular value is set to 1.0MPa~3.0MPa, more preferably is arranged on 1.5MPa~2.5MPa.
Be lower than in the situation of 1.0MPa at the pressure that sets, then have such possibility, i.e. the high speed charging ratio that stops period that can cause charging is higher, makes to be difficult to finish charging at short notice.Surpass in the situation of 3.0MPa in set point, then have such possibility, promptly hydrogen bearing alloy or the cadmium as negative active core-shell material can be accumulated and corrode to oxygen in inside, causes the reduction of alkaline battery discharge capacity.
The particular value that stops to charge based on battery temperature is preferably 50 ℃~80 ℃, more preferably 60 ℃~80 ℃.
In set point was lower than 50 ℃ situation, the electric charge in the charging received and reduces at a high speed.On the other hand, set point surpasses 80 ℃ and can cause the adhesive in hydrogen bearing alloy, dividing plate and positive pole and the negative pole to change, and this can cause the discharge capacity of storage battery or the deterioration of cycle life.
Strictly speaking, employed term " battery temperature " is meant the temperature of inside battery among the present invention.Yet the side of the temperature of battery surface, particularly metal box or the surface temperature of bottom surface can be used for substituting internal temperature.Because the side or the bottom surface of battery case contact with the pole plate faciation, and metal box has high-termal conductivity, so its temperature can reflect the internal temperature of battery well.
As shown in fig. 1, alkaline battery most preferably of the present invention has pressure switch function and temperature switch function simultaneously.
Under the situation about going wrong in two kinds of functions, as long as another function does not go wrong, the battery that then has two kinds of functions just can use satisfactorily.
Yet in the present invention, battery is not always to have pressure switch function and temperature switch function simultaneously.Battery can have any one in two kinds of functions.
But, should be pointed out that the temperature switch function has following shortcoming.Specific part in battery occurs in the situation of local pyrexia, and this function is difficult to sense observantly heating.Particularly when battery is very big, have such possibility, promptly the temperature between each several part may be different in the battery, are difficult to sense observantly febrile state.
On the contrary, under the situation of working pressure switching function, can sense the state that gas produces observantly, this is that the generation of gas can cause the rising of air pressure in the battery immediately because between charge period.
Therefore, when a kind of function of preparing to dispose in pressure switch function and the temperature switch function, preferred disposition pressure switch function.
When attempting to dispose pressure switch function and temperature switch function simultaneously, battery not only can have complicated structure, and also should have the space that can guarantee to dispose two kinds of functions in the battery.
As previously mentioned, among the present invention, the surface temperature of battery can be used as battery temperature.
Therefore, can be not with temperature switch function endowing battery, but give charger, this is preferred.Temperature sensor is installed in the surface of charger and battery to be charged, preferred side or the contacted part in bottom surface, the function endowing charger that to open and charge and change between closing in charging according to measured battery temperature prevents that whereby battery temperature surpasses particular value between charge period.
(formation of positive electrode active material powder and production method)
The positive electrode powder that is applied to the positive pole of alkaline battery of the present invention preferably comprises at least a element in zinc (Zn), cobalt (Co), magnesium (Mg), copper (Cu) and the barium (Ba) of being selected from of nickel hydroxide (described nickel hydroxide is an active material) as main component and a small amount of solid solution state.The zinc (Zn) of the solid solution form in the nickel hydroxide, magnesium (Mg), copper (Cu) or barium (Ba) have the effect of the generation of inhibition γ-NiOOH when battery carries out charge/discharge, γ-NiOOH is an inertia as active material.
In addition, the solid solution of cobalt has the effect of the charged electric potential of the nickel electrode of making to the low dark decay side shifting, is suppressing the generation of oxygen on the nickel electrode between charge period thus.
Zinc and cobalt are joined in the nickel hydroxide, are effective especially thereby form solid solution in nickel hydroxide.In typical embodiment of the present invention, used in nickel hydroxide the solid solution (dusty material) of counting the cobalt of the zinc of 1 weight %~7 weight % and 1 weight %~5 weight % with amount of element.
Being applied to positive electrode active material powder of the present invention is preferably on the surface of the nickel hydroxide that comprises the zinc of a small amount of solid solution state, cobalt etc. and forms the coating that comprises cobalt compounds such as cobalt hydroxide for example and the positive electrode active material powder that obtains.
In whole positive electrode active material powder, preferably in the monomer cobalt, the ratio that will comprise the face coat of cobalt compound is adjusted to 1 weight %~7 weight %.
Be applied to positive electrode active material powder of the present invention and be preferably high-density powder, described high-density powder is by the method for known synthetic positive electrode active material powder, be that the amine complexometry is synthesized, and have the shape of almost spherical, tap density is more than or equal to 2.0.
Like this, can obtain positive pole, the density that wherein is used to the positive electrode active materials of filling is very high, and has very high active material utilization, and has high recharge efficiency in the charging at a high speed.
The average oxidation number that is applied to the transition metal (Ni and Co) that nickel hydroxide class active material powder in first enclosed alkali storage battery of the present invention is preferably wherein to be comprised is preferably 2.04~2.40, more preferably 2.07~2.30 active material powder.
The average oxidation number that is used for transition metal that active material powder is comprised is brought up to 2.04~2.40 concrete grammar and is not done special restriction.For example, active material powder being carried out chemical oxidation with oxidant in the presence of alkaline aqueous solution is to be suitable for mass-produced straightforward procedure.This is a preferred production methods.
For example, be in the NaOH aqueous solution of 10 weight % in concentration, under 90 ℃ temperature, with oxidant such as NaClO or K
2S
2O
8Come the oxidation activity material powder.
In this is handled, by regulating the ratio of active material powder and oxidant, can control in the active material at an easy rate the average oxidation number of the transition metal that is comprised.
Another kind method comprises, fill such as porous substrates such as nickel foam as the dusty material of main component in order to nickel hydroxide, the aqueous solution with potassium hydroxide or NaOH etc. carries out electrochemical oxidation as electrolyte to dusty material then, thereby produces positive electrode active material powder.
In the method, by regulating the electric weight that is applied, can control in the active material the average oxidation number of the transition metal that is comprised.
Under the situation of electrochemical oxidation, preferably with positive pole as unique electrode and be recharged, or charge in the following manner.Positive pole and negative pole are packed in the battery, with open state positive pole is charged then.After the charging, battery is carried out about 1 hour continuous air extraction, make atmosphere pressures remain on to be less than or equal to 0.01MPa, remove as the charging result and the hydrogen of occlusion in negative pole with this.By oxidation processes, the part nickel hydroxide becomes mainly by β-morphotic oxynickel hydroxide.The positive electrode active materials that is obtained comprises the cobalt compound of high-order, and this cobalt compound comprises alkaline kation, and has irregular crystallinity; This cobalt compound is formed by oxidation processes by the coating of cobalt compound, and places with the surface of nickel hydroxide as the powder of main component.This can reduce the discharge memory space that will form.
As mentioned above the average oxidation number of nickel hydroxide class active material powder is brought up to 2.04~2.40, mean and to become the high-order cobalt compound as the cobalt oxidation in the face coat of active material powder composition, wherein the oxidation number of cobalt is greater than 2, in addition, be that 2 nickel becomes oxidation number greater than 2 high-order compound with cobalt oxidation with being included in partial oxidation value in the stratum nucleare.
Oxidation not only forms high-order cobalt compound layer with gratifying conductivity improving the utilance of active material on surface of active material, and the formation of the storage that can suppress to discharge.As a result, can guarantee a large amount of charging storages.So, can suppress the generation of hydrogen on the negative pole between charge period, and suppress the rising of air pressure in the battery.
The oxidant that is used for oxidation processes is not done special restriction, can use chlorate, hypochlorite, chlorite, peracid salt or oxygen etc.
(anodal formation)
The nickel electrode of first enclosed alkali storage battery of the present invention preferably comprises such compound (its hydroxide or hydride or oxide), and this compound is included at least a element of selecting among the rare earth element of Ho, Er, Tm, Yb, Lu and Y and the Ca.
The total content of rare earth element and calcium is preferably 0.1 weight %~5 weight % in the amount of rare earth element and calcium, more preferably 0.5 weight %~4 weight %.Content at rare earth element and calcium is lower than under the situation of 0.1 weight %, suppresses the effect deficiency that oxygen produces on positive pole.
Even when content is increased to when surpassing 5 weight %, is that the effect of the generation of the inhibition oxygen compared of 5 weight % can not be improved not only, and exists anodal resistance to increase, the possibility that causes capacity to reduce with content.
The nickel electrode that is used for sealed cell of the present invention can be passed through to porous substrate, produce as filling the positive electrode powder in the nickel foam, this positive pole reactive powder is by being that the powder of the oxide of the 5 μ m~active material powder of 20 μ m and the hydroxide of rare earth element or its hydride or described element prepares with average grain diameter, and the latter's powder has and almost same size of the former powder or the size littler than the former powder.
Except such as the three-dimensional spongy objects such as nickel foam, form the three-dimensional body that projection or irregular body obtain such as two-dimentional porous body such as punched-plate or by surface at two-dimentional porous body, also can be used as porous substrate.
(formation of negative active core-shell material powder)
The negative pole of alkaline battery of the present invention is by with active material, and promptly hydrogen-bearing alloy powder or cadmium oxide or cadmium hydroxide powder are filled on the punched-plate of being made by sheet metal such as nickel or nickel-clad steel plate and the negative pole that obtains.
The average grain diameter that hydrogen-bearing alloy powder or cadmium oxide or cadmium hydroxide powder are had is preferably 15 μ m~55 μ m.In the situation of average grain diameter less than 15 μ m of powder, powder easily is corroded, and this corrosion can cause performance decrease.
On the other hand, surpass in the situation of 55 μ m, then have GAS ABSORPTION ability variation, cause the possibility that air pressure raises in the battery in its average grain diameter.
Be applied to the hydrogen bearing alloy of the negative pole of alkaline battery of the present invention, preferably comprise one or more alloys that are selected from the following group: have CaCu
5The AB of type structure
5The type alloy, has Laves' phases structure (MgCu
2Type or MgZn
2Type) AB
2The type alloy, have the AB type alloy of CsCl type structure and have Mg
2The A of Ni type structure
2The Type B alloy.
(formation of negative pole)
The negative pole of first enclosed alkali storage battery of the present invention preferably comprises the catalyst for reaction that can promote to absorb hydrogen or oxygen.The material of catalyst is not done special restriction, can use such as precious metal elements such as platinum or palladiums.
Yet, more preferably such as cheap material such as Raney nickel or Raney cobalt.Particularly, preferred average grain diameter is the powder of 1 μ m~10 μ m, and this powder is to launch to handle by known method with alkaline aqueous solution by the alloy that the alloy to the aluminium of the nickel that comprises 60 weight %~40 weight % and 40 weight %~60 weight % maybe will comprise the aluminium of the cobalt of 60 weight %~40 weight % and 40 weight %~60 weight % to prepare.
Therefore, can quicken to be created in respectively the hydrogen on negative pole and the positive pole and the absorption of oxygen between charge period, and can suppress the rising of air pressure in the battery.
The hydrogen-bearing alloy powder that is applied to the hydrogen-bearing alloy electrode of first enclosed alkali storage battery of the present invention can be immersed in such as inorganic acids such as the aqueous solution of alkali such as KOH or all example hydrochloric acids or such as in the organic acid aqueous solution (treatment fluid) such as acetic acid, the filming of oxide, hydroxide or other compound that is formed on the powder surface and comprise metal can be dissolved thus, to strengthen the activity of hydrogen-bearing alloy powder, the oxide of described metal, hydroxide or other compound are included in the hydrogen bearing alloy as component.
In addition, can in treatment fluid, add a spot of complexing agent such as ethylenediamine tetra-acetic acid (EDTA) or tartaric acid.Because it has enhancing effect of the stability of the dissolved transition metal that falls during immerse handling in treatment fluid, and have and stop the transition metal dissolve as hydroxide effect of deposition again on the hydrogen-bearing alloy powder surface, so this is more preferably.
The hydrogen-bearing alloy electrode of first enclosed alkali storage battery of the present invention preferably comprises at least a rare earth element that is selected from Ho, Er, Tm, Yb, Lu, Y and Ce.
Although these rare earth elements can exist as alloy in the hydrogen bearing alloy structure, more preferably these elements outside the hydrogen bearing alloy structure as elemental metals or as hydroxide or oxide and exist.These rare earth elements are used for strengthening the corrosion resistance of hydrogen bearing alloy in alkaline electrolyte, with this prevent hydrogen bearing alloy in charging process because the anodal oxygen that generates or owing to the rising of battery temperature is corroded.
The term here " outside the hydrogen bearing alloy structure " meaning is the inside that element is not present in hydrogen-bearing alloy powder, but is present in the outside of hydrogen-bearing alloy powder.
When hydrogen-bearing alloy powder have crackle in its surface or in described powder primary granule assembled and when forming secondary granule, the outside of the space between face crack and primary granule as the hydrogen-bearing alloy powder structure.
(formation of dividing plate)
In the situation of carrying out at a high speed charging, use to have the minimum living fluidity and low conductive dividing plate is disadvantageous, this is because exist polarization of electrode to increase, thereby has increased charging voltage and increased the possibility that gas produces.
As dividing plate of the present invention, can adopt for example non woven fabric, this non woven fabric can obtain by the following method: by non woven fabric and the gas phase sulfur trioxide reaction that will make by polyethylene, polypropylene or polyethylene/polypropylene, thereby sulfo group is incorporated on the fiber surface (sulfonation processing) or by hydrophilic radical is carried out glycerol polymerization as acrylic acid and fiber to as described in non woven fabric carry out hydrophilicity-imparting treatment.
Particularly preferably be by fibre diameter and be less than or equal to the non woven fabric that the fine fibre at 0.5 dawn constitutes.This is to have pore, uniform aperture and gratifying guarantor's fluidity because comprise the dividing plate of this non woven fabric.Dawn value representation length is its weight of fiber of 450m and the ratio of 0.5g.
Owing to have the excellent hydrophilic performance of long-term maintenance, therefore in this non woven fabric, such non woven fabric is suitable for the main composition material as dividing plate: described non woven fabric is made of fine fibre, described fine fibre is to obtain by fibrilled film fibre being divided into each composition, and described fibrilled film fibre carries out the multi-constituent fibre weaving by first composition that comprises polyolefin (as polypropylene) and second composition that comprises the ethylene/vinyl alcohol copolymer and produces.
In the situation of enclosed alkali storage battery, absorbing in negative pole at the oxygen that produces on the positive pole between charge period.
Owing to arrive negative pole at the oxygen that positive pole produced through dividing plate, so the not good dividing plate of using gases permeability can hinder the absorption of gas.
From guaranteeing to protect fluidity and the infiltrative viewpoint of gas, the basic weight of median septum of the present invention is preferably 35g/m
2~70g/m
2, 40g/m more preferably
2~60g/m
2
Basic weight at dividing plate surpasses 70g/m
2Situation in, gas permeability deficiency then, the possibility that the function that exists electrode between charge period to absorb the gas that is produced suffers damage.
At the basic weight of dividing plate less than 35g/m
2Situation in, then have very big possibility, promptly can lose the uniformity of the Fiber Distribution that constitutes non woven fabric, this can cause infringement to protect fluidity, or internal short-circuit occurs after the battery assembling.
The thickness of each dividing plate is preferably 50 μ m~120 μ m, more preferably 80 μ m~110 μ m.
Here the thickness of dividing plate is meant by measure the value that is obtained with the method A (being used for common non woven fabric) in Japanese Industrial Standards (JIS) method for measuring thickness that L1913 provided (general fibre/non woven fabric method of measurement).
(pole plate group's formation)
The pole plate group of nickle/metal hydrides storage battery of the present invention is the pole plate group who comprises positive pole (nickel electrode) and negative pole (hydrogen-bearing alloy electrode or cadmium electrode), and described positive pole and negative pole and the dividing plate that is clipped in the middle are stacked.
In first enclosed alkali storage battery of the present invention, the Capacity Ratio (N/P than) that preferably will constitute pole plate group's negative pole and positive interpolar is adjusted to 1.02~1.45, and more preferably 1.1~1.45.
This value is lower than the value 1.5~1.8 of employed alkaline battery up to now.By such adjusting N/P ratio, can prevent the reduction of high-rate discharge characteristic.In addition, combine with pressure switch function or temperature switch function, can obtain the alkaline battery that in charging at a high speed, has high recharge efficiency by adjusting with the N/P ratio.
In N/P compared less than 1.02 situation, the charge efficiency in high-rate discharge characteristic and the high speed charging will reduce.Otherwise N/P will cause the discharge capacity of battery to reduce than surpassing 1.45.
The term here " capacity of negative plates " and " positive electrode capacity " are meant determined discharge capacity when carrying out single electrode under to anodal and each temperature of comfortable 20 ℃ of negative pole tests.For example, unipolar method of testing is as follows in the single electrode test of positive pole.Positive pole is stacked on the excessive greatly negative pole of capacity through dividing plate, and presses this assembly.Preparation is 1.3g/cm with density
3The KOH aqueous solution as the test battery (opening battery) of electrolyte.For example, mercuric oxide electrode (Hg/HgO electrode) is joined in the battery as the reference electrode of measuring positive electrode potential.Based on the fill volume of positive pole, with the electric current of 0.1ItA with battery charge 16 hours.Suspend 1 hour then, next battery uses electric current identical when charging to discharge, and the electromotive force on positive pole reaches 0mV with respect to reference electrode.Carry out this charge/discharge operation repeatedly, become steady state value up to the positive discharge capacity.To work as capacity when becoming steady state value measured discharge capacity value as positive electrode capacity.
In the single electrode test of negative pole, preparation comprises test battery (the opening battery of the negative pole that combines through the excessive greatly positive pole of dividing plate and capacity; Except based on capacity of negative plates, beyond positive electrode capacity is excessive greatly, have with anodal single electrode test in identical formation).Based on the fill volume of negative pole, with the electric current of 0.1ItA with battery charge 16 hours.Suspend 1 hour then, next battery uses electric current identical when charging to discharge, and the electromotive force on negative pole reaches-600mV with respect to mercury oxide reference electrode (Hg/HgO electrode).
Carry out this charge/discharge operation repeatedly, become steady state value up to the negative discharge capacity.To work as capacity when becoming steady state value measured discharge capacity value as capacity of negative plates.
(formation of alkaline battery)
Alkaline battery of the present invention is a sealed cell, and the sealing battery comprises generating element and the electrolyte that is accommodated in the enclosure space, and described generating element comprises by positive pole, dividing plate and negative pole are carried out the stacked pole plate group who obtains.
Generating element for example is accommodated in simultaneously in the metal battery case as negative terminal, and the upper open end of battery is with simultaneously as the crown cap sealing of positive terminal.
Battery case and lid are electrically insulated from each other by the packing ring of being made by synthetic resin that inserts the two, and the space between battery case and the lid hermetic seals with packing ring.Cathode collector is connected on the positive pole, with positive conductive plate will cover and cathode collector be electrically connected to each other.
Anode collector is linked to each other with negative pole, and anode collector is connected on the battery case.
(method that alkaline battery is charged)
In the method that alkaline battery is charged of the present invention, when the air pressure in the battery between charge period and/or battery temperature surpassed particular value, charging was interrupted, and when air pressure and/or battery temperature are reduced to when being lower than particular value, charged.
In the present invention, charge repeatedly, charge and interrupt and charging again.Although charge mode of the present invention is not done special restriction, as previously mentioned, preferred constant voltage charge.
For be as short as 15 minutes~in time of 30 minutes, interrupt by charging repeatedly, charge in the present invention and again charging finish charging, preferably in constant voltage charge, the voltage that is applied is adjusted into 1.5V~1.7V.
Be lower than in the situation of 1.5V at the voltage that is applied, charging can not be finished at short notice.Surpass in the situation of 1.7V at the voltage that is applied, then the battery temperature between charge period raises, and this can cause the deterioration of battery performance.
In addition, the possibility that exists charge efficiency to reduce.
To explain the present invention in detail by reference example below.
(first enclosed alkali storage battery of the present invention; The N/P ratio is less than or equal to 1.45)
(influence of the operating pressure of pressure switch and the working temperature of temperature switch)
(embodiment 1)
(preparation of positive electrode active material powder)
The positive electrode active material powder that mainly comprises nickel hydroxide by known method preparation.
The aqueous solution that will contain nickelous sulfate, zinc sulfate and cobaltous sulfate joins gradually in the reactive tank that fills ammonium sulfate and NaOH and with them and mixes, stir this reactive tank simultaneously, the pH value of this reactive tank and temperature are set in 11.8~12.2 and 43 ℃~47 ℃ respectively.
In adition process, with the pH value of reactive tank and adjustment in above-mentioned scope.Like this, the zinc hydroxide that contains solid solution state and the nickel hydroxide powder of cobalt hydroxide have been produced.With the proportional meter of metal, the zinc that comprised in the powder and the ratio of cobalt are adjusted to 3 weight % and 2 weight % respectively.
Subsequently, nickel hydroxide powder being immersed in pH value and temperature is configured in the sodium hydrate aqueous solution with the identical value of above-mentioned value.When stirring this solution, to wherein adding cobalt sulfate solution and sodium hydrate aqueous solution gradually.During adding, with the pH in the reactive tank and adjustment to above-mentioned scope.
Like this, can obtain average grain diameter is 10 μ m and the active material powder with spherical form, and this active material powder comprises mainly by nickel hydroxide powder that constitutes and the coating that comprises cobalt hydroxide that is formed on the powder surface.
Obtained positive electrode active material powder thus.The ratio of the coated film in the nickel hydroxide class active material powder is adjusted to 4 quality %.
(oxidation processes of positive electrode active material powder being carried out with chemical oxidation)
100 gram nickel hydroxide class active material powders are joined 400cm
3Concentration is in the sodium hydrate aqueous solution of 10 weight %, and temperature is remained on 50 ℃.When agitating solution makes its dispersion, to wherein adding 45cm
3Oxidizing agent solution (NaClO; Valid density, 10%).
Then, with gained mixture continuous stirring 1 hour.Next,, wash with water by filter taking out powder, then under 80 ℃ of temperature at air drying.
(heat treated of positive electrode active material powder)
With 20 gram concentration is that the NaOH aqueous solution of 30 weight % joins and carries out thus powder being become moisture state in the nickel hydroxide class active material powder that peroxidating handles.Afterwards, under argon gas atmosphere, the temperature of mixture at 120 ℃ stirred and heating.
Subsequently, wash powder with water, under 80 ℃ temperature dry 1 hour then, to obtain positive electrode active material powder.It is 10cm that the resulting active material of 10 grams is encased in capacity
3The measurement cylinder in, its height from 10cm is freely fallen on the desk that hard rubber makes.
The operation of will falling repeats 100 times, to measure tap density.The tap density of resulting active material powder is 2.1.
(mensuration of the average oxidation number of transition metal in the positive electrode active material powder)
The average oxidation number of positive electrode active material powder is measured by ferrous sulfate method.
Particularly, take by weighing about 0.1g positive electrode active materials (sample) and about 1g iron ammonium sulfate, and it is joined concentration is that 20 volume %, temperature are arranged in 5 ℃ the acetic acid aqueous solution.With solution stir about 5 hours, so that sample and iron ammonium sulfate dissolve fully.Then, be 0.02mol/dm with concentration
3Potassium permanganate solution titration gained solution.Determine active oxygen amount (mg) in the sample with following equation.
(Su-1)
Active oxygen amount (mg/100mg sample)
In equation (1), Xsp is the weight (g) of sample, and XFe is the weight (g) of iron ammonium sulfate, and V is the amount (cm that is used for the potassium permanganate solution of titration
3), f is the coefficient of potassium permanganate solution, the 392.14th, and the molecular weight of iron ammonium sulfate.
Next, for example, measure the nickel that is included in the sample powder and the amount (mg) of cobalt by the ICP emission spectrographic analysis, the average oxidation number in the positive electrode active material powder is determined with following equation.(the term here " average oxidation number " is meant the nickel that is included in the positive electrode active material powder and the average oxidation number of cobalt.)
Resultingly be included in nickel in the active material and the average oxidation number of cobalt is 2.15.
(Su-2)
…(2)
In equation, numerical value 16000 expression (atomic weight of oxygen) * 1000, numerical value 58690 expression (atomic weight of nickel) * 1000, numerical value 58933.2 expression (atomic weight of cobalt) * 1000.
(preparation of nickel electrode)
With average grain diameter is the Yb of 1 μ m
2O
3Powder joins 100g to carry out in the active material powder of heat treated.Mix these compositions by blender, become even up to them.Obtain to be used to form anodal dusty material thus.
Adjust the Yb that is added
2O
3The ratio of powder makes in the amount of monomer ytterbium, and the ratio that is used to form the ytterbium that is comprised in the anodal dusty material is adjusted to 2 weight %.Carboxymethyl cellulose (CMC) aqueous solution that the dusty material that being used to form of 80 weight portions is anodal and 20 weight portion concentration are 0.5 weight % is to prepare paste.
To be that 1.5mm and porosity are that the banded porous substrate that 95% nickel is made applies and fills with paste by thickness.This drying substrates to remove the water in the paste, is pressurizeed with pressure roller then.Having prepared thickness thus is the banded raw sheet that is used for nickel electrode of 0.8mm.Raw sheet is cut into intended size, to obtain to be used for the nickel electrode (AA size) of cylinder battery.
The active material fill volume of the nickel electrode that is obtained is 2000mAh.
(preparation of negative pole)
As active material, can use to have by MmNi
3.6Co
0.7Mn
0.4Al
0.3The average grain diameter of the composition of (wherein Mm represents to comprise for example rare earth element alloy of the mixture of rare earth elements such as La, Ce, Pr, Nd and Sm) representative is the hydrogen-bearing alloy powder of 30 μ m.
Be that the aqueous solution of methylcellulose of 1 weight % and styrene/butadiene rubbers (SBR) powder that 1.5 weight portion concentration are 60 weight % disperse liquid-phase mixing to produce paste with 83.5 weight portion hydrogen-bearing alloy powders and 15 weight portion concentration.It is that 45 μ m, aperture opening ratio are on 45% the nickel plating punching steel plate that this paste is applied to thickness.
Then, the dry rolled sheet iron of also following.Having prepared thickness thus is the continuous raw sheet that is used for negative pole of 0.3mm.This raw sheet is cut into intended size, to obtain to be used for the negative pole (AA size) of cylinder battery.The active material fill volume of negative pole is adjusted to 2400mAh, and this is 1.2 times of anodal active material fill volume.
(preparation of cylinder type nickle/metal hydrides battery)
The positive pole and the negative pole that the centre are inserted with dividing plate are stacked, dividing plate comprises the polypropylene non woven fabric, this contains the polypropylene non woven fabric and is made of such fiber: this fiber is made with the copolymer that 1/1 ratio forms by ethene and propylene, fibre diameter was 0.2 dawn, introduced sulfo group by known method and sulfur trioxide through gas-phase reaction in this fiber, its basic weight is 50g/m
2, thickness is 100 μ m.This assembly is reeled to obtain the pole plate group, and wherein the outermost overlapping layer is a negative pole.
In this fiber, the ratio (sulfonation degree hereinafter referred to as) of the sulfo group introduced is adjusted into 1.3 weight %.
Cathode collector engages by series spot welding with takeup type pole plate group's top.This pole plate group is inserted in the cylindrical metal battery case, that part of and metal battery case of the negative pole that constitutes takeup type pole plate group outermost overlapping layer is contacted.
Nickel system positive conductive plate is connected with cathode collector as shown in Figure 1, and injects 1.7cm
3Contain 7mol/dm
3Potassium hydroxide and 0.5mol/dm
3The aqueous solution of lithium hydroxide.
Although the sulfonation degree that is used as the fiber of dividing plate in the present embodiment is adjusted to 1.3 weight %, the sulfonation degree in the battery of the present invention can not be interpreted as being confined to this.
Yet, it may be noted that sulfonation degree is preferably 0.5 weight %~2 weight %.
When ratio was lower than 0.5 weight %, the hydrophily of fiber was not good, and dividing plate has the minimum living fluidity.
When sulfonation degree surpasses 2 weight %, there is the not good shortcoming of mechanical strength of fiber.
At this, the sulfur content in the dividing plate is composed by fluorescent X-ray and is measured.Measured value is converted into every 1m
2Amount (g/m
2), and with the ratio (%) of this scaled value and dividing plate basic weight as sulfonation degree.
Next, application its installed inside as shown in Figure 1 has the lid of pressure switch, and positive conductive plate is contacted with the metal rigidity plate of pressure switch.Seal this battery case in given mode, to produce the sealed cell of AA size.
The operating pressure (the aforesaid pressure that charging circuit cuts out) of pressure switch is set at 2MPa.Do not give the temperature switch function in the present embodiment.By way of parenthesis, the operating pressure (cell internal pressure that gas inside emits by the through hole shown in Fig. 1 10 is broken, is present in to the airtight sealing state) with flame arrester vent plug is adjusted to 3.5MPa.
(embodiment 2~embodiment 5)
Adopt the formation identical with embodiment 1, difference has been to use the spring of different coefficient of elasticity, changes over 0.7MPa, 1MPa, 3MPa and 3.3Mpa respectively with the particular job pressure with pressure switch.These batteries are called the battery of embodiment 2, embodiment 3, embodiment 4 and embodiment 5.
(comparative example 1)
Adopt the formation identical with embodiment 1, difference has been to use the lid that does not have pressure switch, and cathode collector and described lid are connected to each other directly with nickel system strip-shaped conductive plate.
The battery that this battery is called comparative example 1.
(changing into)
For the battery of embodiment 1~5 and comparative example 1, prepare ten enclosed alkali storage batteries separately.These batteries were placed 3 hours under 20 ℃ temperature, under 20 ℃ temperature, changed into then.
Charging for the first time is that the electric current with 0.05ItA carried out 20 hours, and the ensuing discharge first time is the cut-ff voltage that proceeds to 1.0V with the electric current of 0.2ItA.
For the second time and in the operation of charge/discharge subsequently, charging is that the electric current with 1.0ItA carried out 16 hours, and discharge is the cut-ff voltage that proceeds to 1.0V with the electric current of 0.2ItA.The charge/discharge operation as a circulation, is repeated this charge/discharge cycle ten times, comprising operation for the first time.
(battery testing 1)
The temperature sensor that will be used to measure the battery side surface temperature is installed in each and has carried out the above-mentioned battery that changes into.Then, in temperature is 20 ℃ atmosphere, battery with the current charges of 0.1ItA 16 hours, is suspended after 1 hour, with the current discharge of 0.2ItA cut-ff voltage to 1.0V.
The discharge capacity (mean values of ten batteries) that will be obtained in this discharge is called K (mAh).Then, ten batteries of each embodiment or comparative example are divided into two groups, every group comprises five batteries.Two groups of every group of five batteries were charged 15 minutes by the constant voltage that it is applied 1.65V under the ambient temperature of 20 ℃ and 45 ℃ respectively.After suspending one hour under 20 ℃ the temperature, with battery with the current discharge of 0.2ItA cut-ff voltage to 1.0V.With the maximum temperature (mean values of five batteries) of interdischarge interval battery surface maximum temperature as battery surface.
The discharge capacity (mean values of five batteries) that will be obtained in the discharge behind the first time constant voltage charge is called L (mAh).With [L (mAh)/K (mAh)] * 100 as the charge efficiency in the constant voltage charge of 1.65V (%).
In temperature is 20 ℃ atmosphere, carry out constant voltage charge with the charging voltage of 1.65V, suspend after 1 hour, with the current discharge of 1ItA cut-ff voltage to 0.9V.
Operate as a circulation with this charge/discharge, repeat this circulation, drop to 80% of discharge capacity L (mAh) in the first time circulation of charge/discharge cycle up to discharge capacity, with the period (mean values of five batteries) so implemented as cycle life.
Test result is as shown in table 1.
(table 1)
Shown among Fig. 2 that in charging voltage be 1.65V, when ambient temperature is 20 ℃, in 15 minutes charging, the internal pressure separately of the battery of the battery of embodiment 1 and comparative example 1 is over time.Fig. 3 has shown that the battery side surface temperature over time in charging.
In addition, Fig. 4 has shown the variation of discharge capacity in the charge/discharge cycle test.
As shown in table 1, behind common constant current charge (0.1ItA, 16 hours), { K (mAh) } is basic identical for the discharge capacity of the battery of the embodiment 1~5 that is measured and the battery of comparative example 1.But for the charge efficiency of being measured in 15 minutes with the constant-potential charge of 1.65V, the performance of the battery of embodiment is significantly higher than the performance of the battery of comparative example 1.
When battery under 20 ℃ temperature with the constant-potential charge of 1.65V in the time of 15 minutes, the charge efficiency of embodiment 1, embodiment 3 and embodiment 4 compares high at least 10% with the charge efficiency of comparative example 1.
This is because as shown in Figure 3, and the temperature of the battery of comparative example 1 raises along with the carrying out of charging, and has surpassed 100 ℃ in the final stage of charging.
Therefore, the mis-behave that caused of charging and capacity reduce and cause charge efficiency to reduce.On the contrary, in embodiment 1, when the internal pressure of battery reached the particular value of 2Mpa, pressure switch played a role, and charging is closed.Then, charging is is alternately opened and closed repeatedly, and after pressure switch worked for the first time, battery can at least fill 10% electric weight (battery table of other embodiment has revealed identical charging behavior) more.
In addition, as shown in Figure 3, between charge period, battery temperature remains on and is equal to or less than 60 ℃.The capacity that does not cause causing because of mis-behave descends.
Therefore, the battery of embodiment can obtain high recharge efficiency.In the battery of embodiment, the charge efficiency of the battery of embodiment 1, embodiment 3 and embodiment 4 and cycle life are especially excellent.Therefore the particular value of preferred cell internal pressure is set to 1MPa~3MPa as can be seen.
When charging with the constant voltage of 1.65V, as shown in Figure 2, began about 10 minutes from charging after, the internal pressure of battery sharply increases.
When the battery of embodiment 1 under similarity condition during trickle charge, pressure switch plays a role, the ON/OFF conversion of charging repeatedly.As a result, the internal pressure of battery fluctuates, and has formed sawtooth curve.Because pressure switch has been brought into play such function, so the battery of embodiment 1 can suppress the rising of battery temperature, as shown in Figure 3, its maximum temperature is at most 57 ℃.
On the other hand, in the situation of the battery of comparative example 1, charging stays open state, and the internal pressure of battery continues to raise, and works up to flame arrester vent plug.At this moment, charging is closed.
In addition, as shown in Figure 3, in charging process, battery temperature continue to raise, and reaches high temperature to 115 ℃ before charging is about to stop.
The rising of battery temperature causes the reduction of charge efficiency, and causes the deterioration of battery performance subsequently.As table 1 and shown in Figure 4, the battery that has now found that comparative example 1 is compared with the battery of embodiment 1 has lower charge efficiency, and sharply reducing appears in performance (discharge capacity) in charge/discharge repeatedly.
Particularly when the ambient temperature of charging was 45 ℃, the battery of comparative example 1 had significantly lower shortcoming of charge efficiency.
(influence of the particular value of battery temperature)
(embodiment 6~embodiment 9)
Adopt and the identical formation of comparative example 1 (not having the pressure switch function), difference is only to give its temperature switch function, and (structure as shown in Figure 1, wherein omitted pressure switch, and an end of bimetallic positive conductive plate and the interior side contacts of crown cap, thereby positive electrical is connected to positive terminal), and changed bimetallic temperature characterisitic, thereby in embodiment 6~embodiment 9, the working temperature (temperature that charging circuit cuts out) of temperature switch function has been set at 50 ℃, 60 ℃, 80 ℃ and 100 ℃ respectively as positive conductive plate.The battery that these batteries is called embodiment 6, embodiment 7, embodiment 8 and embodiment 9 respectively.
(battery testing 2)
The pressure by air pressure transducer that will be used for measuring battery is installed in each test battery (ten batteries of each embodiment) of embodiment 6~9, and described battery changes into mode same as described above.
Ten batteries of each embodiment are divided into two groups, and every group comprises five batteries.With two groups of every group of five batteries respectively under the ambient temperature of 20 ℃ and 45 ℃ with the charging voltage charging of 1.65V 15 minutes.Between this charge period, with the maximum (mean values of five batteries) of the maximum pressure in the battery as air pressure in the battery.In addition, use with battery testing 1 in identical mode measure charge efficiency (mean value of five batteries, %).Then, carry out the charge/discharge test identical, to determine cycle life (mean values of five batteries) with battery testing 1.Test result is as shown in table 2.
(table 2)
The battery of embodiment 6~9 all has the charge efficiency of the battery that is higher than comparative example 1 in the constant voltage charge of 1.65V.
In the battery of embodiment, embodiment 7 and 8 battery all have high recharge efficiency charging under 20 ℃ the ambient temperature and charging under 45 ℃ ambient temperature.
As can be seen, the particular value of battery temperature is preferably 50 ℃~80 ℃, more preferably 60 ℃~80 ℃ from these results.It is believed that in charging process when battery temperature surpasses 80 ℃, strengthened anodal generation of going up oxygen, and reduced the hydrogen storage ability of negative pole, cause charge efficiency to reduce.
On the other hand, owing to following reason, it is unfavorable that the particular value of battery temperature is lower than 50 ℃.Battery temperature can reach this particular value at short notice in charging beginning back, makes charging close.Therefore, be restricted when the charging interval, for example, in the time of in 15 minutes short time, the charge efficiency step-down.
(influence of capacity of negative plates/positive electrode capacity ratio)
(embodiment 10~embodiment 13)
In embodiment 1 (having the pressure switch that operating pressure is 2MPa), except pressure switch, working temperature also be installed be 80 ℃ temperature switch.Fixedly positive electrode capacity changes capacity of negative plates, thereby make N/P than changing in 1.0~1.6 scope.
Capacity of negative plates/the positive electrode capacity of each battery is adjusted into 1.0,1.02,1.45 and 1.6 than (N/P).Other constitute with embodiment 1 in identical.
These batteries are called the battery of embodiment 10, embodiment 11, embodiment 12 and embodiment 13.
(comparative example 2 and comparative example 3)
Preparation has the battery with embodiment 10 identical formations, and difference is to have omitted pressure switch.The battery that this battery is called comparative example 2.
Preparation has the battery with embodiment 13 identical formations, and difference is to have omitted pressure switch.The battery that this battery is called comparative example 3.
(battery testing 3)
For the battery of embodiment 10~13 and comparative example 2 and 3, prepare 5 batteries separately.These batteries change into mode same as described above.Then, in temperature is 20 ℃ atmosphere, to battery charge 16 hours, suspend after 1 hour, with the current discharge of 0.2ItA cut-ff voltage to 1.0V with the electric current of 0.1ItA.The discharge capacity that is obtained in this discharge is called K (mAh).
In addition, to battery charge 16 hours, suspend after 1 hour, with the current discharge of 3ItA cut-ff voltage to 0.8V with the electric current of 0.1ItA.The discharge capacity that is obtained in this discharge is called M (mAh).With the index of the ratio between discharge capacity M and the K { [M (mAh)/K (mAh)] * 100 (%) } as the high rate discharge performance.In addition, the test battery that will carry out the embodiment 9~14 that changes into mode same as described above carries out the test identical with battery testing 1 at 20 ℃, with test charge efficiency and cycle life.Test result (mean values of five batteries) is as shown in table 3.
(table 3)
Distinguish |
The ratio (N/P) of capacity of negative plates/positive electrode capacity |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
Discharge capacity M (mAh) in the 3ItA discharge |
M/K×100(%) |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 10 |
1.0 |
1803 |
938 |
52 |
52 |
129 |
Embodiment 11 |
1.02 |
1920 |
1210 |
63 |
63 |
213 |
Embodiment 1 |
1.2 |
2033 |
1890 |
93 |
85 |
546 |
Embodiment 12 |
1.45 |
2024 |
1902 |
94 |
89 |
680 |
Embodiment 13 |
1.6 |
2013 |
1892 |
94 |
92 |
735 |
Comparative example 1 |
1.2 |
2022 |
1860 |
92 |
70 |
59 |
Comparative example 2 |
1.0 |
- |
- |
- |
46 |
50 |
Comparative example 3 |
1.6 |
- |
- |
- |
78 |
94 |
As shown in table 3, when the battery (not having the pressure switch function) of the battery (having the pressure switch function) of each embodiment and comparative example when comparing, the battery of described comparative example has the N/P ratio identical with the battery of embodiment, can find following result.Compare than the battery that is 1.0 with N/P, by giving the pressure switch function, N/P significantly improves than the charge efficiency and the cycle performance that are 1.2 battery.
Compare than the battery that is 1 embodiment 10 with N/P, the battery of embodiment 11~13 has higher M/K value (this value is the index of high rate discharge performance), and has higher charge efficiency in the constant voltage charge of 15 minutes 1.65V.
Particularly, N/P has excellent performance than the battery that is 1.2~1.6 embodiment 12 and embodiment 13.
Even also can obtain high recharge efficiency in short time charging, and can obtain the cycle performance of foregoing excellence, this is arranged on owing to the value with the N/P ratio in 1.02~1.6 the scope, and gives battery pressure switch function.
Yet should be noted that the following fact: in the situation of the battery of embodiment 13, this battery is the battery of AA size, and positive electrode capacity is up to 2000mAh, and the N/P ratio is 1.6, because the amount of the negative active core-shell material that is used to fill is bigger, so the thickness of negative plate is bigger.Therefore this formation has such shortcoming, promptly when preparation takeup type pole plate group or manufacturing battery, is easy to generate defective, causes productive rate to descend.
Therefore, in first enclosed alkali storage battery of the present invention, the N/P ratio is adjusted to 1.02~1.45.Especially, more preferably N/P is adjusted to 1.2~1.45.
(oxidation number of positive electrode active materials)
(embodiment 14~embodiment 19)
Prepare battery with the mode identical with the battery of embodiment 1, difference has been to change the oxidizing agent solution (NaClO that is used for the oxidation positive electrode active material powder and adds; Valid density, 10%) amount, thus the different positive electrode active materials of preparation oxidation number (the average oxidation number of nickel that is comprised in the positive electrode active materials and cobalt) uses these positive electrode active materials separately.
That is, adopting average oxidation number respectively is that 2.0,2.04,2.07,2.3,2.4 and 2.5 positive electrode active materials prepares battery.
These batteries are called the battery of embodiment 14, embodiment 15, embodiment 16, embodiment 17, embodiment 18 and embodiment 19.
(comparative example 4 and comparative example 5)
Preparation has the battery with the identical formation of battery of embodiment 14, and difference is to have omitted pressure switch.The battery that this battery is called comparative example 4.
Preparation has the battery with the identical formation of battery of embodiment 19, and difference is to have omitted pressure switch.The battery that this battery is called comparative example 5.
(battery testing 4)
For the battery of embodiment 14~19 and comparative example 4 and 5, prepare 5 batteries separately.These batteries change into mode same as described above.Then, in temperature is 20 ℃ atmosphere, for five batteries (battery after the discharge) of each embodiment that has carried out changing into and comparative example, with the current charges of 0.1ItA 16 hours, suspend after 1 hour, with the current discharge of 0.2ItA cut-ff voltage to 1.0V.
The discharge capacity that is obtained in this discharge is called K (mAh).The pressure sensor that will be used to measure cell internal pressure is installed in battery, when battery 20 ℃ ambient temperature, in the time of 1 hour, measure the internal pressure of each battery with the current charges of 1ItA.
Then, under 20 ℃ ambient temperature,, battery is carried out the charge/discharge cycle test with mode same as described above.By way of parenthesis, prepare the battery of five embodiment 12 separately, and use with embodiment 15~18 in identical assay method carry out cell internal pressure measuring.Its result (mean values of five batteries) is as shown in table 4.
(table 4)
Distinguish |
The average oxidation number of contained transition metal in the positive electrode active materials |
Air pressure (MPa) in 1ItA 100% charging in the battery |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 14 |
2.0 |
1.8 |
2013 |
73 |
372 |
Embodiment 15 |
2.04 |
1.5 |
2022 |
81 |
484 |
Embodiment 16 |
2.07 |
1.2 |
2030 |
83 |
530 |
Embodiment 1 |
2.15 |
1.1 |
2033 |
85 |
546 |
Embodiment 17 |
2.3 |
1.0 |
2025 |
85 |
568 |
Comparative example 18 |
2.4 |
0.8 |
1960 |
86 |
621 |
Embodiment 19 |
2.5 |
0.8 |
1857 |
83 |
646 |
Comparative example 1 |
2.15 |
1.1 |
2022 |
70 |
59 |
Comparative example 4 |
2.0 |
- |
- |
65 |
46 |
Comparative example 5 |
2.5 |
- |
- |
74 |
78 |
As shown in table 4, when the battery (not having the pressure switch function) of the battery (having the pressure switch function) of each embodiment and comparative example when comparing, the battery of described comparative example has the average oxidation number that be included in transition metal in positive electrode active materials identical with the battery of embodiment, can find following result.With average oxidation number is that 2.0 battery is compared, and average oxidation number is that 2.15 charge efficiency and the cycle performance of battery in the charging of 15 minutes 1.65V significantly improves.Compare with the battery of embodiment 14, the battery of embodiment 1 and embodiment 15~19 more can suppress the rising of cell internal pressure in the charging of 1 hour 1ItA.
Produce these results and it is believed that it is owing to following reason.Owing to before battery that positive pole is packed into, improved the oxidation number of positive electrode active materials, suppressed the formation of discharge storage in the negative pole.Owing to guaranteed the charging storage like this, so suppressed the generation of hydrogen on the negative pole between charge period.Therefore, suppress the rising of the internal pressure of battery, meanwhile, obtained the charge efficiency that improves.
Embodiment 15~19 can obtain high recharge efficiency in being as short as 15 minutes charging, and can obtain excellent cycle performance, and this is owing to being arranged on average oxidation number in 2.04~2.5 the scope, and gives battery pressure switch function.
Yet, should be noted that the following fact.Be increased in the situation of battery of 2.4 embodiment 18 at oxidation number, the amount of positive electrode active materials of participating in electric power generation reaction is less, so this battery has lower slightly discharge capacity K (mAh).The battery that oxidation number is increased to 2.5 embodiment 19 has lower discharge capacity K (mAh).In addition, in the battery of embodiment, embodiment 12 and 16~19 battery, especially embodiment 12,17 and 18 battery are suppressing excellent especially aspect effect that internal pressure raises and charge efficiency and the cycle performance.
Therefore, in the battery of packing into before, the oxidation number of positive electrode active materials is preferably 2.04~24, more preferably 2.07~2.3.
(anodal electrochemical oxidation)
(embodiment 20)
Except the chemical oxidation treatment and alkali treatment of having omitted positive electrode active material powder, use the mode identical to prepare positive pole with embodiment 1.
Anodal and with each as the nickel plate of counterelectrode and as the 7.5mol/dm of electrolyte
3The KOH aqueous solution make opening battery.Based on the capacity of positive pole, with the current charges of 1/50ItA 7.5 hours.After the charging, reclaim positive pole, wash with water and drying.Prepare ten positive poles thus.From five positive poles, reclaim active material powder, measure the nickel that comprised in this positive electrode active materials and the average oxidation number of cobalt by method same as described above.
Five electrodes that will be left with the mode identical with embodiment 1 are used for making battery, and battery is changed into.The battery that these batteries is called embodiment 20.
(embodiment 21)
Except the chemical oxidation treatment and alkali treatment of having omitted positive electrode active material powder, use the mode identical to prepare positive pole with embodiment 1.
Make ten batteries with the mode identical with embodiment 1 with these positive poles, difference is before cell sealing, based on the capacity of positive pole with the current charges of 1/50ItA 7.5 hours.After the charging, from five batteries, regain positive pole, wash with water and drying.
The nickel of measuring in the positive electrode active material powder to be comprised by the mode identical and the average oxidation number of cobalt with embodiment 1.Five remaining batteries are placed in the airtight container, to this container continuous air extraction 1 hour.
During operation, the pressure of airtight container is remained below or equal 0.01MPa.
Then, with cell sealing, and change into mode same as described above.The battery that these batteries is called embodiment 21.
(comparative example 6)
Preparation has the battery with the identical formation of battery of embodiment 20 except having omitted pressure switch.The battery that this battery is called comparative example 6.
(battery testing 5)
For embodiment 20 and 21 and the battery of comparative example 6, prepare five batteries separately.These batteries are carried out the battery testing identical with battery testing 4.Its result is as shown in table 5.
(table 5)
Distinguish |
The average oxidation number of contained transition metal in the positive electrode active materials |
Air pressure (MPa) in 1ItA 100% charging in the battery |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 20 |
2.15 |
1.1 |
2028 |
85 |
533 |
Embodiment 21 |
2.15 |
1.1 |
2035 |
85 |
547 |
Comparative example 6 |
2.15 |
- |
- |
71 |
60 |
As shown in table 5, suppressing aspect cell internal pressure raises between charge period the function and charge efficiency and cycle performance, embodiment 20 and 21 battery are better than the battery of embodiment 14, and suitable with the battery of embodiment 1.
Produce these results and it is believed that it is owing to following reason.The electrochemical oxidation that is undertaken by charging improved the oxidation number of nickel and cobalt, and taked to suppress the measure accumulated in negative pole because of the hydrogen that charging produces.Therefore, obtained to suppress the effect that the discharge storage forms.
(positive pole that comprises rare earth element and calcium)
(embodiment 22~embodiment 28)
In embodiment 1, add Ho
2O
3Powder, Er
2O
3Powder, Tm
2O
3Powder, Lu
2O
3Powder, Y
2O
3Powder, ratio are the Tm of 1:1:1
2O
3Powder, Yb
2O
3Powder and Lu
2O
3The mixture of powders of powder and Ca (OH)
2Powder replaces Yb
2O
3Powder is with as being used to form the rare-earth compound that is comprised in the anodal dusty material.
In each embodiment 22~28, like that in amount of element, adjust to 2 weight % with being used to form the rare earth element that comprised in the anodal dusty material and the content of calcium to embodiment 1.
Other constitute with embodiment 1 in identical.
These batteries are called the battery of embodiment 22, embodiment 23, embodiment 24, embodiment 25, embodiment 26, embodiment 27 and embodiment 28.For each embodiment, prepare five batteries separately, and carry out battery testing 6.
(battery testing 6)
With having carried out the battery of the embodiment 22~28 that changes into, under 20 ℃ ambient temperature, carry out the battery testing identical with battery testing 2 with mode same as described above.Its result (mean values of five batteries) is as shown in table 6.
(table 6)
Distinguish |
The kind of the rare earth element that is comprised in the positive pole |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
1.65V, the discharge capacity L (mAh) after the charging in 15 minutes |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 22 |
Ho |
2048 |
1580 |
77 |
385 |
Embodiment 23 |
Er |
2025 |
1600 |
79 |
415 |
Embodiment 24 |
Tm |
2051 |
1710 |
83 |
461 |
Embodiment 1 |
Yb |
2033 |
1728 |
85 |
546 |
Embodiment 25 |
Lu |
2019 |
1706 |
84 |
472 |
Embodiment 26 |
Y |
2028 |
1570 |
77 |
365 |
Embodiment 27 |
Tm、Yb、Lu |
2035 |
1735 |
85 |
493 |
Embodiment 28 |
Ca |
2022 |
1510 |
75 |
360 |
Comparative example 1 |
Yb |
2022 |
1415 |
70 |
59 |
As shown in table 6, the battery of embodiment 22~28 is at the battery that all is better than embodiment 29 hereinafter described aspect charge efficiency and the cycle performance two.
This may be because any rare earth element or calcium joined improved anodal oxygen overvoltage in the positive pole, and has improved charge efficiency.
Even the battery of embodiment 22~28 also can obtain high recharge efficiency in being as short as 15 minutes charging, and can obtain excellent cycle performance, this is owing to being added to positive pole with rare earth element or calcium, and gives battery pressure switch function.
(embodiment 29~embodiment 35)
In embodiment 1,, form the Yb that is comprised in the anodal dusty material in the amount of element ytterbium
2O
3The value of ratio in the scope of 0 and 0.1 weight %~8 weight % between change.
That is, its ratio is become 0,0.1 weight %, 0.5 weight %, 1 weight %, 4 weight %, 5 weight % and 8 weight %.Other constitute with embodiment 1 in identical.
These batteries are called the battery of embodiment 29, embodiment 30, embodiment 31, embodiment 32, embodiment 33, embodiment 34 and embodiment 35.
(comparative example 7 and comparative example 8)
Preparation has the battery with the identical formation of battery of embodiment 29 except having omitted pressure switch.The battery that this battery is called comparative example 7.
Preparation has the battery with the identical formation of battery of embodiment 35 except having omitted pressure switch.The battery that this battery is called comparative example 8.
(battery testing 7)
To carry out the battery of the embodiment 29~35 that changes into and the battery of comparative example 7 and 8, under 20 ℃ ambient temperature, carried out the battery testing identical with battery testing 2 with mode same as described above.Its result (mean values of five batteries) is as shown in table 7.
(table 7)
Distinguish |
Yb content (amount of element, weight %) |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
1.65V, the discharge capacity L (mAh) after the charging in 15 minutes |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 29 |
0 |
2039 |
1515 |
74 |
321 |
Embodiment 30 |
0.1 |
2037 |
1568 |
77 |
453 |
Embodiment 1 |
2 |
2033 |
1728 |
85 |
546 |
Embodiment 31 |
0.5 |
2036 |
1608 |
79 |
471 |
Embodiment 32 |
1 |
2030 |
1664 |
82 |
518 |
Embodiment 33 |
4 |
2024 |
1639 |
81 |
492 |
Embodiment 34 |
5 |
2019 |
1635 |
81 |
484 |
Embodiment 35 |
8 |
2005 |
1435 |
72 |
431 |
Comparative example 1 |
2 |
- |
- |
70 |
59 |
Comparative example 7 |
0 |
- |
- |
64 |
48 |
Comparative example 8 |
8 |
- |
- |
66 |
52 |
Table 7 has shown the following fact.When with the battery (not having the pressure switch function) of the battery (having the pressure switch function) of each embodiment and comparative example when comparing, be that the battery of 0 weight % and 2 weight % can be found following result for ytterbium content in the positive pole with identical ytterbium content.Owing to given the pressure switch function for battery, be that the battery of 0 weight % is compared with ytterbium content, ytterbium content is that charge efficiency and the cycle performance of battery in 15 minutes 1.65V charges of 2 weight % significantly improves.
Each battery in the battery of embodiment 1 and embodiment 30~35 all is better than the battery of embodiment 29 aspect cycle characteristics.
It is believed that this owing to each rare earth oxide that joins in the positive pole, and described oxide has been brought into play the effect that suppresses the generation of oxygen on the positive pole in charging process.
That is, it is believed that by corrosion and produce above-mentioned effect at improvement that suppresses side reaction, gained charge efficiency on the positive pole between charge period and the oxygen anticathode hydrogen bearing alloy that produces by reducing on the positive pole.
Embodiment 1 and 30~34 battery also can obtain high recharge efficiency in being as short as 15 minutes charging, and can obtain excellent cycle performance, this is set at 0.1 weight %~5 weight % owing to the rare earth element ytterbium being joined in the positive pole and with its content, and has given the pressure switch function for battery.
Though shown the example that adopts the battery of the positive pole that comprises rare earth oxide among the embodiment, the hydroxide that adds rare earth element also can produce identical effect.
In the embodiment of excellence, the battery of embodiment 1 and embodiment 30~34 has also shown excellent performance aspect charge efficiency.On the contrary, the battery of embodiment 35 has such shortcoming, and promptly measured its discharge capacity is lower behind the constant-potential charge with 1.65V.
This may be because a high proportion of Yb that is comprised in the positive pole
2O
3Reduced anodal conductivity, this has caused the reduction of active material utilization.
Therefore, the ratio that is added to the rare-earth compound in the positive pole is preferably counted 0.1 weight %~5 weight % with the amount of rare earth element, more preferably 0.5 weight %~4 weight %.
(amount of electrolyte)
(embodiment 36~embodiment 40)
In embodiment 1, the amount of the electrolyte of the per unit positive electrode capacity in the battery of packing into is at 0.4cm
3/ Ah~1.20cm
3Change in the scope of/Ah.
That is, the quantitative change with electrolyte is 0.4cm
3/ Ah, 0.6cm
3/ Ah, 1.05cm
3/ Ah, 1.10cm
3/ Ah and 1.20cm
3/ Ah.Other constitute with embodiment 1 in identical.
These batteries are called the battery of embodiment 36, embodiment 37, embodiment 38, embodiment 39 and embodiment 40.
(comparative example 9~comparative example 11)
Preparation has the battery with the identical formation of battery of embodiment 38 except having omitted pressure switch.The battery that this battery is called comparative example 9.
Preparation has the battery with the identical formation of battery of embodiment 36 except having omitted pressure switch.The battery that this battery is called comparative example 10.
Manufacturing has the battery with the identical formation of battery of embodiment 40 except having omitted pressure switch.The battery that this battery is called comparative example 11.
(battery testing 8)
For the battery of each embodiment 36~40 and the battery of comparative example 9~11, with five batteries that carried out changing into mode same as described above, under 20 ℃ ambient temperature, carry out the battery testing identical, to detect high rate discharge performance, charge efficiency and cycle life with battery testing 3.Test result (mean values of five batteries) is as shown in table 8.In addition, the appearance of leak of liquid in the verification test process with the naked eye.
(table 8)
Distinguish |
Amount (the cm of electrolyte
3/Ah)
|
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
Discharge capacity M (mAh) in the 3ItA discharge |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Leak of liquid |
Embodiment 36 |
0.40 |
1623 |
681 |
35 |
65 |
Do not take place |
Embodiment 37 |
0.60 |
1910 |
1491 |
73 |
185 |
Do not take place |
Embodiment |
1 |
0.85 |
2033 |
1840 |
85 |
546 |
Do not take place |
Embodiment 38 |
1.05 |
2039 |
1881 |
86 |
572 |
Do not take place |
Embodiment |
39 |
1.10 |
2035 |
1890 |
86 |
602 |
Do not take place |
Embodiment |
40 |
1.20 |
2042 |
1905 |
86 |
573 |
Take place |
Comparative example 9 |
1.05 |
- |
- |
68 |
55 |
Do not take place |
Comparative example 10 |
0.40 |
- |
- |
25 |
38 |
Do not take place |
Comparative example 11 |
1.20 |
- |
- |
74 |
52 |
Take place |
As shown in table 8, when the battery (not having the pressure switch function) of the battery (having the pressure switch function) of each embodiment and comparative example when comparing, the battery of described comparative example has the electrolyte content identical with the battery of embodiment, can find following result.Owing to given the pressure switch function for battery, with electrolyte content be 0.40cm
3The battery of/Ah is compared, and electrolyte content is respectively 1.05cm
3/ Ah and 1.20cm
3Charge efficiency and the cycle performance of the battery of/Ah in the charging of 15 minutes 1.65V significantly improves.
Compare with the battery of embodiment 36, all very excellent aspect embodiment 1 and 37~40 discharge performance, charge efficiency and the cycle performance of battery in high rate discharge { M (mAh) }.Therefore the charge efficiency step-down that it is believed that the battery of embodiment 36 is because this battery has high internal resistance, has the lower charging current and the charge capacity of minimizing in being as short as 15 minutes charging.
Embodiment 1 and 37~40 battery can obtain high recharge efficiency in being as short as 15 minutes charging, and can obtain excellent cycle performance, and this is set at 0.6cm owing to the amount with electrolyte
3/ Ah~1.2cm
3/ Ah and given the pressure switch function for battery.
Yet in the situation of the battery of embodiment 40, in the starting stage of charge/discharge cycle test (up to the 50th circulation), each in five batteries all can be observed visually the leakage of liquid.From these results as can be seen, the amount of electrolyte is preferably 0.6cm
3/ Ah~1.4cm
3/ Ah, more preferably 0.8cm
3/ Ah~1.05cm
3/ Ah.
Here omitted detailed description as the composition of the alkaline aqueous solution of electrolyte.But as the battery of routine, the electrolyte that is applied to battery of the present invention is preferably and comprises the electrolytical aqueous solution that one or more mainly are made up of KOH, and wherein the electrolytical total amount that is comprised in this electrolyte is 7.5 ± 1.5mol/dm
3
Electrolytical total amount surpasses 9.0mol/dm
3Or less than 6.0mol/dm
3Be unfavorable, this is because battery has the internal resistance of increase, and in charging process, the generation of gas such as hydrogen and oxygen is strengthened, and causes the reduction of charge efficiency and the decline of cryogenic property.
By way of parenthesis, employed electrolyte can be the electrolyte that mainly comprises KOH and comprise the LiOH that mixes with it on a small quantity, for example electrolyte of those shown in the embodiment.In addition, although do not show among the embodiment, NaOH can be mixed with KOH.
(fibre diameter and the material of the main composition material of dividing plate)
(embodiment 41)
In embodiment 38, use by basic weight is 40g/m
2, thickness is the dividing plate that the non woven fabric sulfonation of 100 μ m obtains, this non woven fabric is made of the fiber of the copolymer of 1/1 ratio of ethene and propylene, and fibre diameter was 0.7 dawn.
Other formation is identical with embodiment 38.(, the ratio of the sulfo group introduced is adjusted to 0.3 weight % as embodiment 12.)
The battery that this battery is called embodiment 41.
(embodiment 42)
In embodiment 38, use by basic weight is 40g/m
2, thickness is the dividing plate that the non woven fabric sulfonation of 100 μ m obtains, this non woven fabric is made of the fiber of the copolymer of 1/1 ratio of ethene and propylene, and fibre diameter was 0.5 dawn.
Other formation is identical with embodiment 38.
The battery that this battery is called embodiment 42.
(embodiment 43)
In embodiment 38, use by basic weight is 40g/m
2, thickness is the dividing plate that the non woven fabric sulfonation of 100 μ m obtains, this non woven fabric is made of the fiber of the copolymer of 1/1 ratio of ethene and propylene, and fibre diameter was 0.3 dawn.Other formation is identical with embodiment 38.
The battery that this battery is called embodiment 43.
(embodiment 44)
In embodiment 38, the dividing plate that use is made by non woven fabric, the fibre diameter of this non woven fabric after riving was 0.2 dawn, and thickness is 100 μ m, this non woven fabric is that the fibre diameter that splits film composite fibre and 40 weight portions at 3 dawn is that the core/sheath type composite fibre at 2 dawn carries out wet papermaking and handles by the fibre diameter to 60 weight portions, is 40g/m to form basic weight
2Sheet material, then to these sheet material inject high pressure current, come interlacing fiber and rive fibrilled film fibre simultaneously and obtain with this, the wherein said film composite fibre that splits is by carrying out the bicomponent fibre spinning to polypropylene and ethylene/vinyl alcohol copolymer with the part by weight of 1:1, make it alternately arrange in the fibre section and obtain, wherein said core/sheath type composite fibre comprises as the polypropylene of core composition with as the polyethylene of sheath composition.
Other formation is identical with embodiment 38.
The battery that this battery is called embodiment 44.
(comparative example 12 and comparative example 13)
Preparation has the battery with the identical formation of battery of embodiment 44 except having omitted pressure switch.The battery that this battery is called comparative example 12.
Preparation has the battery with the identical formation of battery of embodiment 41 except having omitted pressure switch.The battery that this battery is called comparative example 13.
(battery testing 9)
For the battery of embodiment 41~44 and the battery of comparative example 12 and 13, prepare five batteries that carried out changing into separately with mode same as described above, carry out the battery testing identical 20 ℃ ambient temperatures, to measure cell internal pressure and cycle performance in the charging process with battery testing 4.Test result (mean values of five batteries) is as shown in table 9.
(table 9)
Distinguish |
The fibre diameter of dividing plate (dawn) |
The main composition material of dividing plate |
Air pressure (MPa) in 1ItA 100% charging in the battery |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 38 |
0.2 |
The E/P copolymer of sulfonation |
1.1 |
86 |
572 |
Embodiment 41 |
0.7 |
The same |
1.9 |
80 |
193 |
Embodiment 42 |
0.5 |
The same |
1.4 |
82 |
267 |
Embodiment 43 |
0.3 |
The same |
1.3 |
84 |
435 |
Embodiment 44 |
0.2 |
E/VA copolymer fibrilled film fibre |
0.9 |
86 |
594 |
Comparative example 12 |
0.2 |
The same |
- |
68 |
56 |
Comparative example 13 |
0.7 |
The same |
- |
66 |
55 |
As shown in table 9, when each embodiment battery (having the pressure switch function) and comparative example battery (not having the pressure switch function) when comparing, described comparative example battery has the dividing plate fibre diameter identical with the embodiment battery, can find following result.Owing to given the pressure switch function for battery, be that the battery at 0.7 dawn is compared with the dividing plate fibre diameter, fibre diameter is that charge efficiency and the cycle performance of battery in 15 minutes the charging at 1.65V at 0.2 dawn significantly improves.
It is believed that this use owing to the fiber with fubril diameter, it makes the dividing plate densification to have uniform pore size distribution, and has excellent electrolyte retentivity and gas permeability.
Embodiment 38 and 42~44 battery can obtain high recharge efficiency in being as short as 15 minutes charging, and can obtain excellent cycle performance, this has the diameter that was less than or equal to for 0.5 dawn and has given the pressure switch function for battery owing to the fiber that constitutes dividing plate.Compare with the battery of embodiment 41, it is all more excellent aspect function aspects that cell internal pressure raises and the cycle performance that the battery of embodiment 42~44 suppresses between charge period.Embodiment 38,43 and 44 battery are especially excellent.
Therefore, the fibre diameter that constitutes the non woven fabric of dividing plate preferably was less than or equal to for 0.5 dawn, was more preferably less than or equaled for 0.3 dawn.
In addition, comparison shows that between embodiment 38 that the dividing plate fibre diameter is identical and 44 the battery, on the function and cycle performance that suppress the cell internal pressure rising, the battery of embodiment 44 all is better than the battery of embodiment 38.Therefore, the fiber material of formation dividing plate especially preferably comprises ethylene/vinyl alcohol copolymer and polyacrylic fibrilled film fibre.
This is because in the fiber of being rived, it is believed that those fibers of being made by the ethylene/vinyl alcohol copolymer have high long-term hydrophily.A kind of in two kinds of composition fibers is in the fibrilled film fibre of non-hydrophilic fibers (in an embodiment, it is corresponding to polypropylene fibre), hydrophilic radical such as sulfo group can be incorporated in the non-hydrophilic fibers, though do not adopt this technology in the present embodiment.
In each embodiment 41~44, do not observe described assembly failure hereinafter.
(basic weight of dividing plate and thickness)
(embodiment 45~embodiment 51)
In embodiment 44, the basic weight of dividing plate and thickness are respectively at 25g/m
2~80g/m
2With change in the scope of 40 μ m~110 μ m.
That is, the basic weight of each dividing plate in embodiment 45~50 and thickness are as follows: be 25g/m in embodiment 45
2With 40 μ m; In embodiment 46 35g/m
2With 70 μ m; In embodiment 47 40g/m
2With 80 μ m; In embodiment 48 40g/m
2With 110 μ m; In embodiment 49 60g/m
2With 100 μ m; In embodiment 50 70g/m
2With 100 μ m; Be 80g/m in embodiment 51
2With 100 μ m.Other formation is identical with embodiment 44.
In the battery of embodiment 45~embodiment 51, each self assembly 50 batteries, and assembly failure (occurring internal short-circuit in assembling process) detected.
(comparative example 14 and comparative example 15)
Preparation has the battery with the identical formation of battery of embodiment 45 except having omitted pressure switch.
Select five batteries that do not have assembly failure.
The battery that these batteries is called comparative example 14.Manufacturing has the battery with the identical formation of battery of embodiment 51 except having omitted pressure switch.
Prepare five batteries that do not have assembly failure.The battery that these batteries is called comparative example 15.
(battery testing 10)
For embodiment 45~51, select five batteries that do not have assembly failure separately.Change into mode same as described above battery these batteries and comparative example 14 and 15.Then, by the method identical, under 20 ℃ ambient temperature, detect the function that the inhibition cell internal pressure of these batteries raises with battery testing 8.
Test result (mean values of five batteries) is as shown in table 10.
(table 10)
Distinguish |
Dividing plate basic weight (g/m
2)
|
Block board thickness (μ m) |
Air pressure (MPa) in 1ItA 100% charging in the battery |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Assembly failure rate (%) |
Embodiment 45 |
25 |
40 |
0.5 |
83 |
24 |
Embodiment 46 |
35 |
70 |
0.7 |
85 |
0 |
Embodiment 47 |
40 |
80 |
0.9 |
87 |
0 |
Embodiment 44 |
40 |
100 |
0.8 |
86 |
0 |
Embodiment 48 |
40 |
110 |
0.8 |
86 |
0 |
Embodiment 49 |
60 |
100 |
1.1 |
85 |
0 |
Embodiment 50 |
70 |
100 |
1.2 |
82 |
0 |
Embodiment 51 |
80 |
100 |
1.7 |
79 |
0 |
Comparative example 12 |
40 |
100 |
- |
68 |
- |
Comparative example 14 |
25 |
40 |
- |
69 |
- |
Comparative example 15 |
80 |
100 |
- |
68 |
- |
As shown in table 10, when each embodiment battery (having the pressure switch function) and comparative example battery (not having the pressure switch function) when comparing, described comparative example battery has the dividing plate basic weight identical with the embodiment battery, can find following result.When having given the pressure switch function for battery, with basic weight be 80g/m
2Battery compare, basic weight is less than or equal to 70g/m
2The charge efficiency of battery in the charging at 1.65V in 15 minutes significantly improve.It is believed that the dividing plate basic weight is 80g/m because the gas permeability of dividing plate is not good
2Battery have the charge efficiency of reduction, so the absorption to the gas that produced is suppressed in the charging process, the internal pressure of battery raises easily.
The battery of embodiment 45~50 can obtain high recharge efficiency in being as short as 15 minutes charging, this is 25g/m owing to basic weight
2~70g/m
2Dividing plate and the pressure switch function of being given.
But in the situation of the battery of embodiment 45, the ratio that assembly failure occurs is very high.This is to connect short circuit because because of the dividing plate basic weight is little dividing plate takes place in preparation takeup type pole plate group's step.
In addition, the battery of embodiment 51 suppresses aspect the effect that cell internal pressure raises the battery not as other embodiment between charge period.
This may be because as mentioned above, has suppressed the oxygen that produced between charge period and move and absorbed by negative pole to negative side through dividing plate on positive pole.
As shown in table 10, the battery of embodiment 46~50 has excellent performance, the particularly battery of embodiment 46~49 and has excellent performance.
As long as the dividing plate basic weight is more than or equal to 40g/m
2, just do not have the possibility that assembly failure occurs.
Therefore, the basic weight of dividing plate is preferably 35g/m
2~70g/m
2, more preferably 40g/m
2~60g/m
2
The thickness of each dividing plate is preferably 70 μ m~110 μ m.
(hydrogen-bearing alloy electrode that comprises the catalyst that is used for the hydrogen/oxygen absorption reaction)
(embodiment 52)
Except the hydrogen-bearing alloy powder of the Raney nickel powder that will comprise 2 weight % as the negative active core-shell material, adopt the formation identical with embodiment 45.
This Raney nickel powder is the Raney nickel powder that average grain diameter is about 3 μ m, and it is that the alloy of 1/1 al and ni launches to obtain with mass ratio by utilize known method in the caustic-alkali aqueous solution of temperature.
The battery that this battery is called embodiment 52.
(embodiment 53)
Except the hydrogen-bearing alloy powder of the Raney cobalt powder that will comprise 0.2 weight % as the negative active core-shell material, adopt the formation identical with embodiment 51.
This Raney cobalt powder is the Raney cobalt powder that average grain diameter is about 3 μ m, and it is that the alloy of 1/1 aluminium and cobalt launches to obtain by utilize known method in the caustic-alkali aqueous solution of temperature with mass ratio.
The battery that this battery is called embodiment 53.
(embodiment 54)
Except the hydrogen-bearing alloy powder of the Raney cobalt powder that will comprise 1 weight % as the negative active core-shell material, adopt the formation identical with embodiment 51.
The battery that this battery is called embodiment 54.
(embodiment 55)
Except the hydrogen-bearing alloy powder of Raney cobalt powder that will comprise the Raney nickel powder of 0.5 weight % and 0.5 weight % simultaneously as the negative active core-shell material, adopt the formation identical with embodiment 51.
The battery that this battery is called embodiment 55.
(comparative example 16)
Preparation has the battery with the identical formation of battery of embodiment 54 except having omitted pressure switch.
The battery that this battery is called comparative example 16.
(battery testing 11)
For the battery of embodiment 52~55, prepare five batteries separately, and change into mode same as described above.Then, by the method identical with battery testing 4, that detects these batteries suppresses function, charge efficiency and the cycle life that cell internal pressure raises between charge period.
Test result (mean values of five batteries) is as shown in table 11.
(table 11)
Distinguish |
The kind of the catalyst that is comprised in the negative pole |
The ratio of catalyst (quality %) in the negative pole |
Air pressure (MPa) in 1ItA 100% charging in the battery |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 52 |
Raney nickel |
2 |
0.8 |
86 |
630 |
Embodiment 53 |
Raney cobalt |
0.2 |
0.6 |
87 |
638 |
Embodiment 54 |
Raney cobalt |
0.5 |
0.5 |
88 |
651 |
Embodiment 55 |
The Raney nickel Raney cobalt |
0.50.5 |
0.5 |
88 |
662 |
Embodiment 44 |
- |
0 |
0.9 |
86 |
594 |
Comparative example 12 |
- |
0 |
- |
68 |
56 |
Comparative example 16 |
Raney cobalt |
0.5 |
- |
70 |
60 |
As shown in table 11, by the comparison between embodiment battery that does not all contain Raney cobalt in the negative pole (having the pressure switch function) and comparative example battery (not having the pressure switch function), and, can find following result by the embodiment battery (having the pressure switch function) of the Raney cobalt that all contains 0.5 weight % in the negative pole and the comparison between comparative example battery (not having the pressure switch function).When having given the pressure switch function for battery, the cycle performance of battery that contains the Raney cobalt of 0.5 weight % significantly improves.
Even be as short as 15 minutes short time charging repeatedly, the also almost undiminished reason of performance that comprises the battery of Raney cobalt in the negative pole may be because quickened the absorption of negative pole to gas.
Even be as short as 15 minutes short time charging repeatedly, the battery of embodiment 52~55 also can obtain excellent cycle performance, and this has given the pressure switch function owing to the adding of Raney nickel in the negative pole or Raney cobalt with for battery.Compare with the battery of embodiment 44, it all is excellent that the battery of embodiment 52~55 suppresses aspect function that cell internal pressure raises and the cycle performance between charge period.
N/P is being easy to generate hydrogen at negative pole in the charging at a high speed than the battery less than prior art.
It is believed that because Raney nickel has the catalytic activity that the reaction that causes negative pole to absorb hydrogen is quickened, therefore as N/P than being in the battery of 1.25 embodiment 52, demonstrated the effect of inhibition internal pressure rising in than the battery of N/P that is lower than the battery that uses up to now at N/P than (the N/P ratio is above 1.6).
When alkaline battery charges with high speed, between charge period, be easy to produce oxygen at positive pole.In the battery of embodiment 53 and 54, Raney cobalt plays the effect of the catalyst that the reaction that causes negative pole to absorb oxygen is quickened.It is believed that in the battery that can charge with high speed, in negative pole, add Raney cobalt and strengthened the effect that between charge period, suppresses the cell internal pressure rising as being intended among the present invention.
In the battery of described embodiment, the battery that adds the embodiment 55 that Raney nickel and Raney cobalt are arranged in the negative pole has simultaneously demonstrated excellent especially performance.
The Raney nickel that will add in the negative pole and the ratio of Raney cobalt are not done special restriction.But, when the additional proportion of Raney nickel and Raney cobalt is respectively 0.2 weight %~2 weight % or 0.2 weight %~1 weight %, can obtain significant effect.
(activation processing of hydrogen bearing alloy)
(embodiment 56)
In embodiment 44, use hydrogen-bearing alloy powder: under 100 ℃ temperature, it is immersed in 7mol/dm through following processing
3The KOH aqueous solution in 1 hour, by removing by filter the KOH aqueous solution, washing and dry this powder then.
Other constitute with embodiment 44 in identical.The battery that this battery is called embodiment 56.
(comparative example 17)
Preparation has the battery with the identical formation of battery of embodiment 56 except having omitted pressure switch.The battery that this battery is called comparative example 17.
(battery testing 12)
With the mode identical the battery that has carried out changing into is tested with battery testing 4.Test result is as shown in table 12.
(table 12)
Distinguish |
The alkali treatment of hydrogen bearing alloy |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
Air pressure (MPa) in 1ItA 100% charging in the battery |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 56 |
Handle |
2041 |
0.6 |
87 |
617 |
Embodiment 44 |
Be untreated |
2029 |
0.9 |
86 |
594 |
Comparative example 12 |
Be untreated |
- |
- |
68 |
56 |
Comparative example 17 |
Handle |
- |
- |
70 |
61 |
As shown in table 12, in embodiment battery (having the pressure switch function) and comparative example battery (not having the pressure switch function), by wherein hydrogen bearing alloy do not carry out the battery of alkali treatment and wherein this alloy carried out comparison between the battery of alkali treatment, can find following result.Alloy has wherein carried out the battery of alkali treatment, even be as short as 15 minutes charging repeatedly, still has superior cycle performance, but also has the superior effect that suppresses the cell internal pressure rising between charge period.The improvement that it is believed that these performances is because hydrogen bearing alloy is immersed the activity that has improved in the alkaline aqueous solution as the hydrogen bearing alloy of negative active core-shell material.
The acquisition of these excellent properties has been given the pressure switch function owing to the alkali treatment of hydrogen bearing alloy with for battery.
Though what use in the present embodiment is alkaline aqueous solution, handle with inorganic acid such as all example hydrochloric acids or such as organic acid aqueous solution such as acetic acid, through determining that be effective in raising aspect active.
(hydrogen-bearing alloy electrode that comprises rare earth element)
(kind of rare earth element)
(embodiment 57~embodiment 63)
Adopt the formation identical with embodiment 44, difference is to use such negative pole, wherein comprises amount in rare earth element respectively as the hydrogen-bearing alloy powder of negative active core-shell material, respectively the do for oneself Ho of 1 weight % of content
2O
3, Er
2O
3, Yb
2O
3, Tm
2O
3, Lu
2O
3, Y
2O
3And Ce
2O
3
These batteries are called the battery of embodiment 57, embodiment 58, embodiment 59, embodiment 60, embodiment 61, embodiment 62 and embodiment 63.
(embodiment 64)
Only in embodiment 64, use by the resulting negative pole of following method, by using the mode identical to handle hydrogen bearing alloy, in the gained hydrogen-bearing alloy powder, add the Yb that counts 1 weight % with the amount of monomer ytterbium then in the method with alkaline aqueous solution with embodiment 56
2O
3Other formation is identical with embodiment 56.
The battery that this battery is called embodiment 64.
(comparative example 18 and comparative example 19)
Preparation has the battery with the identical formation of battery of embodiment 60 except having omitted pressure switch.The battery that this battery is called comparative example 18.
Preparation has the battery with the identical formation of battery of embodiment 64 except having omitted pressure switch.
The battery that this battery is called comparative example 19.
(battery testing 13)
For the battery of each embodiment and the battery of comparative example, prepare five batteries that carried out changing into separately with mode same as described above.By the test identical, under 20 ℃ ambient temperature, detect the charge efficiency and the cycle performance of the battery of embodiment 57~64 and comparative example 18 and 19 with battery testing 4.Test result (mean values of five batteries) is as shown in table 13.
(table 13)
Distinguish |
The kind of the rare earth element that is comprised in the hydrogen bearing alloy |
The content of rare earth element (quality %) |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 57 |
Ho |
1 |
2031 |
85 |
617 |
Embodiment 58 |
Er |
1 |
2020 |
85 |
625 |
Embodiment 59 |
Tm |
1 |
2023 |
85 |
626 |
Embodiment 60 |
Yb |
1 |
2033 |
85 |
634 |
Embodiment 61 |
Lu |
1 |
2015 |
85 |
610 |
Embodiment 62 |
Y |
1 |
2026 |
85 |
604 |
Embodiment 63 |
Ce |
1 |
2028 |
85 |
611 |
Embodiment 64 |
Yb |
1 |
2030 |
86 |
652 |
Comparative example 18 |
Yb |
1 |
- |
69 |
52 |
Comparative example 19 |
Yb |
1 |
- |
70 |
55 |
Annotate: in embodiment 64 and comparative example 19, hydrogen-bearing alloy powder is handled by immersing in the alkaline aqueous solution.
As shown in table 13, even in being as short as 15 minutes charging repeatedly, the cycle performance of the battery of embodiment 57~64 also is better than the battery of embodiment as shown in table 9 44.
In addition, the cycle performance of the battery of embodiment 64 is better than the battery (hydrogen bearing alloy has carried out alkali treatment as embodiment 64) of embodiment as shown in table 12 56.
The generation that it is believed that this effect is because the adding of any rare earth element has improved the corrosion resistance of hydrogen bearing alloy from Ho to Yb and in the scope of Ce, thereby the oxygen that has suppressed to produce at positive pole during alloy is recharged corrodes.
In addition,, it is believed that with alkaline aqueous solution hydrogen-bearing alloy powder is handled the generation that has suppressed anodal last oxygen between charge period, therefore can obtain better cycle ability for the battery of embodiment 64.
As shown in table 13, even in being as short as 15 minutes charging repeatedly, the battery of embodiment 57~64 also can obtain excellent cycle performance, and this has given the pressure switch function owing to the adding of any above-mentioned rare earth element in the negative pole with for battery.
(the comparison between charge mode: battery testing 14)
(embodiment 65)
The battery of five embodiment 64 of preparation.To carry out the battery charge that the changes into final charging voltage to 1.65V with the electric current of 4ItA, making the maximum charge time is 15 minutes (relatively charge mode).Then, with the electric current of 0.2ItA battery discharge is arrived the cut-ff voltage of 1.0V.
To be the charge efficiency among the embodiment 65 by this discharge discharge capacity that obtains and the likening to of discharge capacity that obtains with operation same as described above, described operation comprises with 0.1ItA current charges 16 hours, subsequently with the current discharge of the 0.2ItA cut-ff voltage to 1.0V.
With the electric current of 4ItA with battery charge 15 minutes, and with the current discharge of 1ItA cut-ff voltage to 0.9V.Repeat charge/discharge as a circulation.In this circulation, discharge capacity is reduced to 80% required period of discharge capacity in the circulation for the first time as the cycle life among the embodiment 65.
Test result is as shown in table 14.
(table 14)
Distinguish |
Charge mode |
Charge efficiency (%) |
Cycle life (circulation) |
Embodiment 65 |
With the constant current charge of 4ItA 15 minutes |
76 |
446 |
Embodiment 64 |
With the constant-potential charge of 1.65V 15 minutes |
86 |
652 |
As shown in table 14, carrying out the charging interval identical with embodiment 65, in the time of promptly 15 minutes, in the constant voltage charge pattern shown in the embodiment 64, charging has obtained the charge efficiency higher than the constant current charge of embodiment 65.
This is the effect of being brought by following: for enclosed alkali storage battery is given pressure switch function and/or temperature switch function, and this function combined with the constant voltage charge pattern.As implied above, in various charge modes, preferred constant voltage charge.
(the charging voltage in the constant voltage charge: battery testing 15)
(embodiment 66~embodiment 69)
In embodiment 64, charging voltage changes in the scope of 1.45V~1.8V.
That is, charging voltage is become 1.45V, 1.5V, 1.7V and 1.8V.Other condition is identical with embodiment 64.
These charging methods are called the charging method of embodiment 66, embodiment 67, embodiment 68 and embodiment 69.
In addition, at the side surface mounting temperature sensor of each battery, to measure battery temperature.
(comparative example 20 and comparative example 21)
In the charging method of embodiment 66 and 69, use the battery that does not have pressure switch as the battery that is recharged.
These charging operations are called comparative example 20 and comparative example 21.Test result (mean values of five batteries) is as shown in Table 15.
In the charging process, the battery temperature in first circulation as shown in Figure 5.
(table 15)
Distinguish |
Charging voltage (V) |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
Constant voltage, the discharge capacity L (mAh) after the charging in 15 minutes |
Charge efficiency in the constant voltage charge (%) |
Embodiment 66 |
1.45 |
2035 |
1282 |
63 |
Embodiment 67 |
1.5 |
2031 |
1563 |
77 |
Embodiment 64 |
1.65 |
2033 |
1769 |
87 |
Embodiment 68 |
1.7 |
2030 |
1644 |
81 |
Embodiment 69 |
1.8 |
2032 |
1524 |
75 |
Comparative example 20 |
1.45 |
- |
- |
63 |
Comparative example 19 |
1.65 |
- |
- |
70 |
Comparative example 21 |
1.8 |
- |
- |
67 |
As shown in Table 15, embodiment 67, embodiment 64 and embodiment 68 have obtained high recharge efficiency.
Therefore, charging voltage is preferably 1.5V~1.7V.In the situation of embodiment 69, the internal pressure of battery has just reached particular value in the charging beginning back short time, causes charging to suspend and prolongs.It is believed that this is in being as short as 15 minutes charging, causes the reason that charge efficiency reduces among the embodiment 69.
In addition, between charge period, the battery temperature among the embodiment 69 has surpassed 90 ℃.This is unfavorable, because the material that constitutes battery is along with carrying out and deterioration repeatedly of charging, and this may damage cycle performance.
(second enclosed alkali storage battery of the present invention: N/P is than the battery that surpasses 1.45)
(embodiment 70)
(production of positive electrode active materials)
Preparing with the nickel hydroxide with the mode identical with embodiment 1 is the positive electrode active materials of main component.
But, omitted the oxidation processes and the heat treated of the positive electrode active materials that is synthesized.
The average oxidation number of the transition metal that is comprised in the active material (Ni and Co) by with embodiment 1 in identical method measure.As a result, its average oxidation number is 2.0.
(preparation of nickel electrode)
Except not adding Yb
2O
3In addition, using the mode identical with embodiment 1 is that to be used for the discharge capacity that preparation is used for cylinder battery (AA size) be the nickel electrode of 1600mAh for 2.0 positive electrode active materials with the average oxidation number of transition metal (Ni and Co).
(preparation of negative pole)
With the mode identical with embodiment 1 will be with embodiment 1 identical hydrogen-bearing alloy powder to be used for the discharge capacity that preparation is used for cylinder battery (AA size) be the hydrogen-bearing alloy electrode of 2400mAh.
(preparation of cylinder type nickle/metal hydrides battery)
Nickel electrode (positive pole) and the discharge capacity that with discharge capacity is 1600mAh is that the hydrogen-bearing alloy electrode (negative pole) of 2400mAh combines, and is used for preparing N/P than the cylinder type nickle/metal hydrides battery (AA size) that is 1.5 in the mode identical with embodiment 1.
Yet, change the amount of the electrolyte of being packed into into 2.0cm
3As embodiment 1, for the nickle/metal hydrides battery is given the pressure switch function.
But, the operating pressure of pressure switch is adjusted to 0.5MPa.The battery that this battery is called embodiment 70.
(embodiment 71~embodiment 73)
In embodiment 70, the operating pressure of pressure switch is adjusted to 0.3MPa.
Other constitute with embodiment 70 in identical.The battery that this embodiment is called embodiment 71.
In embodiment 70, the operating pressure of pressure switch is adjusted to 1.0MPa.Other constitute with embodiment 70 in identical.The battery that this embodiment is called embodiment 72.
In embodiment 70, the operating pressure of pressure switch is adjusted to 2.0MPa.Other constitute with embodiment 70 in identical.
The battery that this embodiment is called embodiment 73.
(comparative example 22)
In embodiment 70, the enclosed alkali storage battery that preparation does not have the pressure switch function.
Other constitute with embodiment 70 in identical.The battery that this battery is called comparative example 22.
(embodiment 74)
In embodiment 70, change the discharge capacity of negative pole into 2720mAh.Other constitute with embodiment 70 in identical.(N/P is 1.7).
The battery that this battery is called embodiment 74.
(embodiment 75~embodiment 77)
In embodiment 74, the operating pressure of pressure switch is adjusted to 0.3MPa.Other constitute with embodiment 74 in identical.The battery that this embodiment is called embodiment 75.
In embodiment 74, the operating pressure of pressure switch is adjusted to 1.0MPa.Other constitute with embodiment 74 in identical.The battery that this embodiment is called embodiment 76.
In embodiment 74, the operating pressure of pressure switch is adjusted to 2.0MPa.Other constitute with embodiment 74 in identical.The battery that this battery is called embodiment 77.
(comparative example 23)
In embodiment 74, the sealed cell that preparation does not have the pressure switch function.
The battery that this battery is called comparative example 23.
(changing into)
For the nickle/metal hydrides battery of embodiment 70~77 and comparative example 22 and 23, prepare five batteries separately.
With the condition identical these batteries are changed into embodiment 1.
(battery testing 16)
To the nickle/metal hydrides battery that has carried out changing into, under 20 ℃ temperature, carry out the test identical with battery testing 1.In 15 minutes constant voltage charges at 1.65V, the cell internal pressure of embodiment 72 and comparative example 22 and battery temperature (battery side surface temperature) are respectively as shown in Figure 6 and Figure 7.
The test result of the battery of embodiment 70~77 and comparative example 22 and 23 is shown in table 16.
(table 16)
Distinguish |
The ratio (N/P) of capacity of negative plates/positive electrode capacity |
The particular value of air pressure (MPa) in the battery |
20 ℃, the discharge capacity K (mAh) in the 0.2ItA discharge |
1.65V, the maximum temperature in the charging in 15 minutes (℃) |
1.65V, the charge efficiency (%) in the charging in 15 minutes |
Cycle life (circulation) |
Embodiment 70 |
1.5 |
0.5 |
1615 |
43 |
87 |
543 |
Embodiment 71 |
1.5 |
0.3 |
1616 |
35 |
80 |
656 |
Embodiment 72 |
1.5 |
1.0 |
1609 |
51 |
90 |
528 |
Embodiment 73 |
1.5 |
2.0 |
1618 |
77 |
85 |
448 |
Embodiment 74 |
1.7 |
0.5 |
1616 |
41 |
89 |
611 |
Embodiment 75 |
1.7 |
0.3 |
1611 |
35 |
82 |
693 |
Embodiment 76 |
1.7 |
1.0 |
1614 |
54 |
90 |
623 |
Embodiment 77 |
1.7 |
2.0 |
1619 |
79 |
85 |
575 |
Comparative example 22 |
1.5 |
No pressure switch |
- |
97 |
65 |
48 |
Comparative example 23 |
1.7 |
The same |
- |
95 |
67 |
52 |
As shown in Figure 6, in the situation of the battery of embodiment 72, be installed to pressure switch on the battery and play the regulating cell internal pressure and make its not function of super 1MPa.As shown in Figure 7, the temperature of battery surface is lower than 60 ℃ between charge period.
On the contrary, as shown in Figure 7, owing to do not have a pressure switch function, in the situation of the storage battery of comparative example 22, the battery temperature between charge period is elevated to considerably beyond preferred temperature upper limit, i.e. 80 ℃ temperature.
As the battery of comparative example 1, the battery of comparative example 22 is all poor aspect charge efficiency and cycle performance.
Shown in table 16, the battery temperature between the charge period of the nickle/metal hydrides battery of embodiment 70~72 and 74~76 is regulated, make it be less than or equal to 60 ℃ as particularly preferred temperature upper limit.
The acquisition that it is believed that this effect is the ON/OFF conversion of charging repeatedly therefore to have suppressed the rising of battery temperature because pressure switch makes.
On the contrary, though the battery temperature of the battery of embodiment 73 and 77 between charge period is lower than 80 ℃ as the preferred temperature upper limit of alkaline battery, 60 ℃ have been surpassed as particularly preferred temperature upper limit.
It is believed that the reason that produces these results is as follows.Because N/P is better than N/P than the battery that is less than or equal to 1.45 than the battery that surpasses 1.45 in the function aspects that absorbs the gas that is produced between charge period, so suppressed the rising of cell internal pressure between charge period.In addition, the GAS ABSORPTION reaction has produced a large amount of heats, and this has quickened the rising of battery temperature between charge period.Therefore, before pressure switch worked, battery temperature raise and has surpassed 60 ℃.
It is believed that these are the battery of embodiment 73 and 77 reasons not as the battery of other embodiment aspect cycle performance.
It is unfavorable that the particular value of cell internal pressure surpasses 2.0MPa, and this is that promptly 80 ℃ possibility is very high because the battery temperature between charge period may surpass preferred temperature upper limit, although omitted detailed explanation about this point at this.In addition, embodiment 71 and 75 battery have low discharge capacity and low charge efficiency.
Its reason may be to be set at lower value because of the operating pressure with pressure switch, so pressure switch just working in early days after the charging beginning, and the ratio that causes charging the period of closing increases.
Can find from the result shown in the table 16, surpass in 1.45 the enclosed alkali storage battery at the N/P ratio, the particular value (set point of the operating pressure of pressure switch) of the cell internal pressure that making charges closes is preferably 0.5MPa~2.0MPa, more preferably 0.5MPa~1.0MPa.
Comparative example 22 and 23 battery aspect charge efficiency and cycle performance all not as the battery of embodiment 70~77.
This may be because the battery temperature of battery between charge period of each comparative example all considerably beyond as 80 ℃ of preferred temperature upper limit.
In second enclosed alkali storage battery of the present invention, also can be as in first enclosed alkali storage battery of the present invention, chemistry or the electrochemical oxidation that carries out positive electrode active materials handled, added rare earth element or calcium, adds rare earth element, adds Raney cobalt or Raney nickel, carries out the activation processing of hydrogen-bearing alloy powder, the fibre diameter of regulating dividing plate and basic weight etc., though these formations do not show in the embodiment of second enclosed alkali storage battery of the present invention to negative pole to negative pole to positive pole.
Given above-mentioned explanation is that example is made with the nickle/metal hydrides battery, and this battery comprises the negative pole of employing hydrogen bearing alloy as active material.But the present invention should not be interpreted as being confined to the nickle/metal hydrides battery, and the present invention can also be applicable to the nickel-cadmium cell that uses cadmium in negative pole.
(embodiment 1 of electrode assembly)
Preferred embodiment to electrode assembly of the present invention is introduced below with reference to the accompanying drawings.
Figure 10 is the front view of the electrode assembly 21 of the present embodiment; This view has shown the state before the screw winding.
Figure 11 is the part vertical cross-section diagram of storage battery 100 that has adopted the electrode assembly 21 of the present embodiment.
Figure 12 be as the employing of the present embodiment the sectional view of major part of storage battery 200 of another embodiment of electrode assembly 21.
At first, will introduce roughly the formation of the storage battery 100 of the electrode assembly 21 that adopts the present embodiment.
As shown in figure 11, storage battery 100 comprises: with the positive pole 21 and the negative pole 24 of stacked state screw winding; Be inserted between positive pole 21 and the negative pole 24 and be used to make electrode dividing plate insulated from each other 30; These elements are accommodated in wherein case 40; Battery cover 50 with the closure of openings of case 40; With being used for and the outside cap 60 that is connected of being connected with battery cover 50.
Numbering 65 expressions among Figure 11 have the opening insulation board, and cathode-chip wiring 3 hereinafter described extends through this opening.That is, cathode-chip wiring 3 links to each other with battery cover 50 when the opening through insulation board 65 extends.Numbering 70 expressions are used for the packing ring in the space between the inner peripheral surface of the periphery of sealed cell lid 50 and case 40.
As the negative active core-shell material that is used to fill negative pole 24, can use, for example hydrogen bearing alloy.As the electrolyte that is encased in the case 40, can use, for example with the aqueous solution of potassium hydroxide as one or more alkali of main component.In addition, as dividing plate 30, can preferably use the dividing plate that has for example carried out hydrophilicity-imparting treatment.
The battery that comprises electrode assembly shown in Figure 12 is the battery that disposes the battery embodiment of pressure switch function.This battery connect anodal 21 and the circuit that is used for the outside cap 60 that is connected have according to stress level and make circuit from reaching the pass or opening the function that changes from closing to.
That is, anodal 21 and the cap 60 that is used for being connected with the outside be connected to each other by cathode-chip wiring 23, metal connecting elements 220, metal connecting ring 230 with the continuous battery cover 50 of the cap that is used for being connected 60 with the outside.
Comprise containment member 210, the case 40 of synthetic resin mouldings and pass connecting elements 220 that the through hole that is formed on the containment member central part extends and seal each other and contact, thus the inside battery space is hermetic sealed.
Reduce to be formed on the thickness of peripheral part of the through hole of containment member 210 central parts, give flexible for containment member 210 thus.Like this, on being embedded in that connecting elements 220 in the containment member 210 can be in the drawings/below moves up.
Under common state (battery keeps the state of low internal pressure), connecting elements 220 is in the state that the elastomer 240 that is placed in the inboard that is used for the cap that is connected with the outside is pressed to the below of figure.That is, the connecting ring 230 that links to each other with connecting elements 220 contacts with crown cap 50, and circuit is in connected state.When the internal pressure of battery raises and is higher than the pressure of elastomer 240, then connecting elements 220 and the connecting ring 230 that links to each other with connecting elements 220 are pushed to the top among the figure.Connecting ring 230 separates with crown cap 50 as a result, and circuit becomes disconnection by connection.
When the internal pressure of battery reduced, then connecting elements 220 and the connecting ring 230 that links to each other with connecting elements 220 were pressed towards the below among the figure.Connecting ring 230 contacts with crown cap 50 as a result, and circuit becomes connection from disconnection.
In the present invention, for example, by changing elastomeric coefficient of elasticity, can be in the pressure switch function circuit being regulated from the cell internal pressure (pressure when pressure switch plays a role) that connection becomes when disconnecting.
Pressure when in the present invention, pressure switch being played a role is not done special restriction.Yet, be preferably 0.5 MPa~3 MPas (MPa), more preferably 1MPa~2.5MPa.When the pressure when pressure switch plays a role is lower than 0.5Mpa, then there is the possibility of the large percentage of circuit off period in the charging interval, causes charge efficiency to reduce.
When the pressure when pressure switch plays a role surpassed 3MPa, the battery temperature rising produced dysgenic possibility to battery performance between charge period thereby then exist.
As mentioned below, battery according to the present invention is the battery that obtains by the battery that electrode assembly 21 is applied to have the pressure switch function, so this battery has the charge efficiency of further raising in quick charge.
Next introduce the electrode assembly 21 of the present embodiment.As shown in figure 10, electrode assembly 21 comprises electrode base board 22 and the single lug plate 23 that links to each other with electrode base board.
As shown in figure 10, it is that a, minor face width are the rectangular shape of α that electrode base board 22 has long hem width degree, and can make wherein a minor face towards the center and screw winding.More specifically, electrode base board 22 comprises the active material of porous substrate and this porous substrate of filling.
Porous substrate can be, for example, and the punch metal plate of metallic fiber sintered body, metallic particles sintered body, punch metal plate or surface imperfections such as foam metal, for example nickel fiber sintering body such as nickel foam for example.
The basic weight of porous substrate can be 250g/m
2~600g/m
2, preferred 350g/m
2~500g/m
2, more preferably 400g/m
2~450g/m
2
Its basic weight is less than 250g/m
2Be unfavorable, because such substrate has low conductibility, charge efficiency reduction in causing charging at a high speed and the discharging efficiency in the high rate discharge reduce.
In addition, such substrate has low mechanical strength, and this can cause the appearance of battery assembly failure.When its basic weight surpasses 600g/m
2The time, then the nickel electrode porosity descends, and has suppressed the ion motion of electrode interior, causes existing the possibility to the applicability decline of quick charge.
In addition, because the increase of the hardness of this electrode, so there be the possibility of electrode roll around the difficulty that becomes.
As active material,, then can use various materials as long as can bring into play the effect of the electric power generation reaction that helps battery electrode.For example, in the nickel electrode of alkaline battery, it is main component and the active material that is equipped with cobalt compound in its surface that active material can be preferably with the nickel hydroxide.
Lug plate 23 can have Any shape.In the present embodiment, consider that from being easy to prepare it is that c, long hem width degree are the rectangular shape of γ that lug plate 23 has the minor face width with the viewpoint that is suitable for being connected with battery cover.
The material of lug plate is not done special restriction, for example can use the nickel plate.
Lug plate 23 is joined on the electrode base board 22 with such state: the short side direction of lug plate 23 is consistent with the long side direction of electrode base board 22, and the long side direction of lug plate 23 is consistent with the short side direction of electrode base board 22.
In addition, lug plate 23 is bonded on such position, makes the distance b between the minor face 22a of the center line X (passing the imaginary bisector of half position of lug plate minor face width c) of its broadside and electrode base board 22 and the long hem width degree a of electrode base board satisfy relation of plane: 0.3a≤b≤0.6a down.This can produce following effect.
That is, when b<0.3a, then the specific part of cell substrates 22 is extremely away from lug plate 23.
For example, when b<0.3a, then among Figure 10 the bottom right district of electrode base board extremely away from lug plate 23.
In this case, damage the charge efficiency of this specific part, caused having damaged charge etc.
In addition, when b<0.3a, be in lug plate 23 in the electrode base board 22 of screw winding state and be positioned at position near " spiral " center.
Shown among Figure 13 that positive pole 21, negative pole 24 and dividing plate 30 are in the oblique view of screw winding state.As shown in figure 13, along with shortening of the distance at distance center, the radius of curvature of " spiral " diminishes.
Therefore, when lug plate 23 was positioned at near excessively position, " spiral " center, this can cause rigidity because of lug plate 23 to make the problem that spiral is difficult to form.
Similarly, as b〉during 0.6a, exist specific region in the electrode base board 22 extremely away from the problem of lug plate 23.
In addition, work as b〉0.6a, and should positive pole 21 during with negative pole 24 and dividing plate 30 screw windings, lug plate 23 is positioned at the near excessively position of outer peripheral edges with " spiral ", cause the contacted possibility of inwall of lug plate 23 and for example case 40, thereby cause short circuit (referring to Figure 11).In addition, because the essential length that increases lug plate is disadvantageous so lug plate 23 is in this position.
From these viewpoints, 0.3a≤b≤0.6a should be satisfied in the position of lug plate 23 in the present embodiment.Like this, active material utilization and charge characteristic can be improved, the short circuit that lug plate 23 causes can be prevented effectively simultaneously.
More preferably, electrode assembly can constitute like this, makes that when lug plate 23 was expressed with β with the length of electrode base board 22 overlapping areas, a, c, α, β and γ satisfied relation of plane down:
0.02≤c/a≤0.07
0.065≤β/α≤0.45
0.1≤β/γ≤0.75。
That is, when c/a<0.02, the resistance of electrode base board 22 increases.On the other hand, as c/a〉0.07 the time, the area that can fill the part of active material on the electrode base board 22 reduces, and is difficult to fully improve capacity.
When beta/alpha<0.065, lug plate 23 reduces with the area of electrode base board 22 overlapping areas.The result not only resistance between two parts increases, and is difficult to guarantee bond strength enough between these parts, causes assembly failure may take place more continually.
On the other hand, when beta/alpha〉0.45 the time, although can obtain the raising of bond strength and the decline of resistance, the area that can fill the part of active material on the electrode base board 22 reduces, and is difficult to fully improve capacity.
In addition, when β/γ<0.1, lug plate 23 reduces with the area of electrode base board 22 overlapping areas.The result not only resistance between two parts increases, and is difficult to guarantee bond strength enough between these parts, causes assembly failure may take place more continually.
On the other hand, as β/γ〉0.75 the time, although can obtain the raising of bond strength and the decline of resistance, the area that can fill the part of active material on the electrode base board 22 reduces, and is difficult to fully improve capacity.In addition, also there is the problem that is difficult to engage between battery cover 50 and the lug plate 23.
By way of parenthesis, lug plate 23 can be formed by the various electric conducting materials that can join on the electrode base board 22.For example, the thickness of lug plate is 0.05mm~0.3mm, preferred 0.1mm~0.2mm.
From the viewpoint of intensity and resistance, engaging between lug plate and electrode base board is preferably welding.From intensity and machinability viewpoint, welding is preferably the spot welding shown in Figure 14 A.
More preferably, as shown in Figure 14B, can carry out spot welding at following solder joint, described solder joint radioactively be arranged in the electrode base board 22 that the center line X of lug plate 23 is connected with lug plate 23 long limit 22c intersection point around.
By adopting this formation, can improve the charge efficiency of entire electrode substrate 22.
(embodiment 2)
Below will be by introducing another embodiment preferred of electrode assembly of the present invention with reference to the accompanying drawings.Figure 15 be the present embodiment electrode assembly 21 ' front view; This view has shown the state before the screw winding.
Carry out mark with identical or corresponding member in the above-mentioned embodiment 1 with same numbering or symbol, and omitted introduction them.
As shown in figure 15, the electrode assembly 21 of the present embodiment ' have lug plate 23 ', replace the lug plate 23 in the electrode assembly of embodiment 1.
Constitute like this lug plate 23 ', make lug plate 23 ' basic identical with the profile of the shape of electrode base board 22 overlapping areas and electrode base board 22.
Particularly, similar to the lug plate 23 in the embodiment 1, lug plate 23 ' have minor face width c and grow the limit width gamma.But, have minor face width c ' with electrode base board 22 overlapping areas.
More specifically, constitute like this lug plate 23 ', make it have minor face width c from electrode base board 22 outward extending parts, itself and electrode base board 22 overlapping parts have minor face width c ', and c ' satisfies c '/β=(0.8~1.2) * (a/ α).
The electrode assembly 21 with this formation ' in, can make entire electrode substrate 22 apart from lug plate 23 ' distance become even.
Therefore, this embodiment also has the effect that can further improve the charge characteristic of electrode base board 22 except having the effect in the above-mentioned embodiment 1.
(embodiment)
The embodiment that below introduction is related to storage battery, each storage battery all adopt the electrode assembly of above-mentioned embodiment 1 as positive pole.
(embodiment 78~embodiment 81)
(anodal formation)
Use basic weight to be 400g/m
2, long hem width degree a is that 100mm, minor face width α are that the foamed nickel substrate of 43mm is used as porous substrate.Fill this foamed nickel substrate with nickel hydroxide class active material, with preparation electrode base board 22.Then, by 5 means of spot welds nickel lug plate 23 is engaged on it.
Use γ=25mm, c=4mm and thickness to be used as nickel lug plate 23 as the nickel lug plate of 0.1mm.The welding position b of nickel lug plate 23 (distance in the electrode assembly shown in Figure 10 between the center line X of minor face 22a and lug plate 23) is: b=0.3a (embodiment 78), b=0.4a (embodiment 79), b=0.5a (embodiment 80) and b=0.6a (embodiment 81).
Be constructed as follows in detail.Promptly, employed nickel hydroxide class active material is such nickel hydroxide class active material: comprise nickel hydroxide and be included in wherein 3 weight portion zinc and 2 weight portion cobalts as main component and in metal ratio with solid solution state, its surface applies with β-cobalt hydroxide.The amount of coated β-cobalt hydroxide is counted 4 weight % with amount of metal.
This nickel hydroxide class active material of 80 weight portions is mixed the paste that is used to fill with preparation with 20 weight portions, 0.5% carboxymethyl cellulose aqueous solution.
Paste is applied to foamed nickel substrate and dry equably.Then, substrate is pressed into the size that is used for the AA size cell, and the size of cut growth hem width degree a=100mm, minor face width α=43mm.Cut and make that lug plate position b is aforesaid 0.3a (embodiment 78), 0.4a (embodiment 79), 0.5a (embodiment 80), 0.6a (embodiment 81).The capacity of the electrode of Xing Chenging is 1800mAh thus.
(formation of negative pole)
For negative pole, used to consist of MmNi
3.6Co
0.7Mn
0.4Al
0.3Hydrogen bearing alloy (wherein Mm represents to comprise for example rare earth element alloy of the mixture of rare earth elements such as La, Ce, Pr, Nd and Sm).Respectively with the amount of 15 weight % and 1.5 weight % to the water-based SBR latex that wherein adds 1% methylcellulose and 60% as adhesive.These compositions are mixed with the preparation paste.Then, paste is applied on the punching steel plate and drying.After the drying, the steel plate of compacting through applying is with the preparation hydrogen-bearing alloy electrode.Then, electrode cutting is become to be used for the size of AA size cell.The adjustment capacity of negative plates is 1.4 times of positive electrode capacity.
(formation of nickle/metal hydrides battery)
With positive plate 21 and negative plate 24 and be clipped between them dividing plate 30 screw windings together, dividing plate 30 all comprises glycerol polymerization, and acrylic acid thickness is arranged is the acrylic resin non woven fabric of 100 μ m.This winding unit is put into the cylinder case.To comprise concentration is 7mol/dm
3Potassium hydroxide and concentration be 0.5mol/dm
3The electrolyte of the aqueous solution of lithium hydroxide inject case with the amount of 1.8mL/ battery.Like this, having prepared capacity is the enclosed alkali storage battery (nickle/metal hydrides battery) of the cylindric AA size of 1800mAh.Obtain the battery of embodiment 78~81 with above-mentioned mode.
(comparative example 24 and comparative example 25)
Adopt the formation identical with the embodiment that provides above, difference is that the bonding station b of nickel lug plate becomes b=0.1a (comparative example 24) and b=0.8a (comparative example 25).
(resistance test)
For embodiment 78~81 and comparative example 24 and 25, prepare 100 storage batterys separately and measure resistance.Particularly, in temperature is 20 ℃ atmosphere, to the nickle/metal hydrides battery charge of embodiment 78~81 and comparative example 24 and 25 16 hours, suspend after 1 hour with the charging current of 0.1ItA, with the current discharge of 0.2ItA to 1.0V; Should operate and repeat 10 times.After final discharge, cause in the charging direction electric current of 10A to stop this electric current after 10 milliseconds (msec).Measured cell voltage and electric current stopped the measured cell voltage of back 0.1msec before electric current was about to stop poor (V) divided by electric current (10A), with the merchant of gained as resistance value.Test result (mean value) is as table 17 and shown in Figure 16.
(table 17)
Distinguish |
Lug plate bonding station (b/a) |
Internal resistance (m Ω) |
Charge efficiency (%) |
Assembly failure rate (%) |
Comparative example 24 |
0.1 |
34.2 |
73 |
4 |
Embodiment 78 |
0.3 |
19.7 |
84.0 |
0 |
Embodiment 79 |
0.4 |
15.5 |
90.7 |
0 |
Embodiment 80 |
0.5 |
13.6 |
91.6 |
0 |
Embodiment 81 |
0.6 |
17.4 |
89 |
0 |
Comparative example 25 |
0.8 |
31.1 |
68 |
43 |
From table 17 and Figure 16 obviously as can be seen, embodiment 78~81 is through confirming to have comparative example of being lower than 24 and 25 resistance.In addition, comparative example 25 has high assembly failure rate.Causing these bad reasons is the short circuits that contact and produce owing to the lug plate and the inner peripheral surface of case.
(charge efficiency test)
As resistance test, embodiment 78~81 and comparative example 24 and 25 100 storage batterys are separately carried out the charge efficiency test.
Particularly, battery is carried out 16 hours initial charge, suspends after 1 hour with the electric current of 0.1ItA, with the current discharge of 0.2ItA to 1.0V, to measure discharge capacity A.In addition, to battery charge 15 minutes, suspend after 1 hour with the electric current of 4ItA, with the current discharge of 0.2ItA to 1.0V, to measure discharge capacity B.With the value of B/A * 100 as charge efficiency.
Test result (mean value) is same as table 17 and shown in Figure 16.
From table 17 and Figure 16 obviously as can be seen, the battery of embodiment 78~81 is through confirming to have the battery charge efficient that is higher than comparative example 24 and 25.
The reason of charge efficiency that the battery that it is believed that embodiment 78~81 has the battery that is higher than comparative example 24 and 25 is as follows.Nickel electrode as positive pole is charged in all parts of electrode, therefore, has improved active material utilization.In addition, compare with the battery of comparative example, the battery of embodiment has the density of charging current of reduction, and (for example, the decomposition reaction of electrolyte) generation, this has brought the improvement of charge efficiency in quick charge to have suppressed side reaction between charge period.
By way of parenthesis, as table 17 and shown in Figure 16, in embodiment 78~81, embodiment 78 has the charge efficiency more lower slightly than other embodiment.In embodiment 79~81, the value of charge efficiency is up to 89% or higher.
From these results as can be seen, in the storage battery that does not have the pressure switch function as shown in figure 11, the bonding station of lug plate (b/a) is preferably 0.3~0.6, and more preferably 0.4~0.6, this can bring higher charge efficiency.
(embodiment 82~embodiment 85)
Adopt the battery that is equipped with the pressure switch function as shown in figure 12 to constitute.In Figure 12, as elastomer, the pressure when pressure switch is worked is adjusted to 2 MPas (MPa) with the synthetic rubber mouldings.To be applied to the battery of this formation with identical electrode assembly among the embodiment 78~81.Like this, just prepared except having pressure switch, had battery with embodiment 78~81 identical formations.The battery that these batteries is called embodiment 82~85.
(comparative example 26 and comparative example 27)
Will the electrode assembly identical be applied to have in the battery of the pressure switch function identical with embodiment 82~85 with comparative example 24 and 25.Other formation is identical with comparative example 24 and 25.The battery that these batteries is called comparative example 26 and 27.
(charge efficiency test)
As described above, to battery charge 16 hours, suspend after 1 hour with the electric current of 0.1ItA, with the current discharge of 0.2ItA to 1.0V, to measure discharge capacity A.
In addition, to battery charge 15 minutes, suspend after 1 hour with the electric current of 4ItA, with the current discharge of 0.2ItA to 1.0V, to measure discharge capacity B.With the value of B/A * 100 as charge efficiency.Test result is shown in table 18.
(table 18)
Distinguish |
Lug plate bonding station (b/a) |
Internal resistance (m Ω) |
Charge efficiency (%) |
Comparative example 26 |
0.1 |
34.0 |
74 |
Embodiment 82 |
0.3 |
19.3 |
91.8 |
Embodiment 83 |
0.4 |
15.0 |
93.6 |
Embodiment 84 |
0.5 |
13.2 |
95.3 |
Embodiment 85 |
0.6 |
17.0 |
93 |
Comparative example 27 |
0.8 |
30.9 |
70 |
Shown in table 18, the battery of embodiments of the invention 82~85 is compared with 27 battery with comparative example 26 has higher charge efficiency.
The reason that the battery that it is believed that embodiment 82~85 has higher charge efficiency is as follows.Compare with 27 battery with comparative example 26, the battery of embodiment 82~85 has the density of charging current of reduction, has suppressed the generation of side reaction between charge period (for example, the decomposition reaction of electrolyte).Therefore, the battery of embodiment has suppressed the rising of internal pressure, so the period that the pressure switch function works and charging circuit cuts out, the ratio in the charging interval was less.
When attempt to fully or the battery of almost completely discharge be as short as 15 minutes~when carrying out quick charge in time of 30 minutes, then battery temperature raises, thereby has quickened side reaction, and the possibility that causes charge efficiency to descend.From the given result's of the given result of table 17 and table 18 comparison, can find out the battery of embodiments of the invention 82~85 even have the charge efficiency higher significantly than the battery of embodiment 78~81.
In addition, though the battery of embodiment 78 has lower slightly charge efficiency, the battery that has the embodiment 85 of identical lug plate bonding station (b/a) with embodiment 78 has up to the charge efficiency more than 90%.
It is believed that its reason is as follows.Because the battery of embodiment 82~85 has been endowed the pressure switch function, so charging circuit ON/OFF translation function plays a role between charge period.Therefore these batteries raise than the part that the battery of embodiment 78~81 more can suppress internal temperature, have suppressed the generation of side reaction between charge period thus.
It is believed that by electrode assembly of the present invention being applied to foregoing battery, can significantly improve the charge efficiency in the quick charge with pressure switch function.
Shown in table 18, when in the scope of bonding station (b/a) 0.3~0.6 of lug plate, the battery with pressure switch function has demonstrated up to the charge efficiency more than 90%.Particularly, when in the scope of bonding station (b/a) 0.4~0.6 of lug plate, charge efficiency is more than or equal to 93%.Therefore the latter's scope is particularly preferred as can be seen.
By way of parenthesis, the material (composition) of the active material of battery of the present invention and other composition should not be construed as those that restriction describes in an embodiment.For example, thus can be to carry out oxidation by chemistry or electrochemical method the oxidation number of the transition metal that comprised in the active material such as nickel and cobalt to be adjusted to the active material that surpasses 2 value as the active material of anodal nickel electrode.
In addition, the compound (oxide or hydroxide) that comprises rare earth element such as erbium, thulium, ytterbium, lutetium or yttrium can be joined in the nickel electrode, thereby suppress the generation of oxygen on the nickel electrode between charge period, and and then raising charge efficiency.
Though as embodiment the nickle/metal hydrides battery is illustrated above, the present invention should not be construed as restriction in these embodiments, and the present invention can be applied to other battery.
In addition, among the embodiment that provides in the above, shown with the electric current constant current charge of 4ItA 15 minutes as the example of quick charge.But, be applicable to that the charge mode of battery of the present invention and charging interval should not be construed as to be confined to this.For charge mode, for example, it also is effective using constant voltage charge.