CN100550501C - The keeping method of lead accumulator and lead accumulator - Google Patents

Abstract

The present invention relates to the keeping method of lead accumulator and lead accumulator.This lead accumulator contains in accumulator housing: the barrier film that has kept the positive plate of active material and negative plate in the grid of being made by the Pb alloy, two-plate is isolated, the electrolyte that comprises sulfuric acid.This lead accumulator can be used for the engine start of vehicle etc., but carries out self discharge sometimes when the medium-term and long-term keeping of the process of circulation, and the inhibition of self discharge remains important problem.In above-mentioned grid, often use Pb-Sb class alloy or Pb-Ca class alloy, if use Pb-Ca class alloy, though the self discharge amount can be reduced to about 1/2～1/3 when having used Pb-Sb class alloy, easy self discharge when the ambient temperature when the battery keeping is high.The present invention is for the above-mentioned lead accumulator that has used Pb-Ca class alloy in the grid of positive plate and negative plate, by accumulator housing being sealed, makes the height Y of positive plate and negative plate ₀, and from the bottom of positive plate and negative plate to the distance Y of liquid level of electrolyte ₁Satisfy 15≤Y ₁/ Y ₀* 100≤60 etc., solved the problems referred to above.

Description

The keeping method of lead accumulator and lead accumulator

Technical field

The present invention relates to the keeping method of lead accumulator and lead accumulator, more particularly, the electrolyte quantitative limitation when relating to the lead accumulator keeping.

Background technology

All the time, lead accumulator is used in the various purposes such as the engine start purposes of vehicle or stand-by power supply purposes.Lead accumulator is compared with alkaline battery, and self discharge is less.But, when in its process of circulation, taking care of battery for a long time, will carry out self discharge, thereby the situation that need replenish electricity when the use of battery is arranged.So further suppressing self discharge in lead accumulator still is the important techniques problem.

In the grid of the positive plate of lead accumulator and negative plate, main Pb-Sb class alloy and the Pb-Ca class alloy of often using.The self-discharge characteristics of battery is according to different change of alloy type of grid.Though Pb-Sb class alloy is good aspect castability or intensity, yet because of the existence of Sb, the self discharge amount increases.

Therefore, Pb-Sb class alloy is being used in the lead accumulator of grid, is adopting following keeping method.The keeping method of the following battery of the first promptly, uses the battery (with reference to patent documentation 1) that assembles at the pole plate that the stage of making pole plate implements that chemical conversion is handled and dry chemical conversion has disposed.Another one is the keeping method of following battery, that is, and and fluid injection in the battery that the pole plate that uses not chemical conversion to handle assembles, the battery of after in accumulator housing, carrying out chemical conversion and handling the electrolyte in the accumulator housing being discharged.

Pb-Sb class alloy is being used in the lead accumulator of grid, is taking care of and before being about to use battery, injecting the mode of electrolyte, can prevent battery caused self discharge when long-time keeping of unused state by adopting above-described method.But, in case the problem of uncontrollable self discharge after the existence fluid injection still.

On the other hand, if in grid, use Pb-Ca class alloy, then the self discharge amount of lead accumulator can be reduced to when in grid, having used Pb-Sb class alloy about 1/2～1/3.But the easy self discharge that then becomes because the ambient temperature when the keeping battery raises even therefore used the battery of Pb-Ca class alloy, also can be carried out self discharge in keeping, need replenish when using battery sometimes.If in Japan to be example, when taking care of battery for a long time in not having the warehouse of air-conditioning equipment, the temperature in summer in the warehouse appears in regular meeting reaches the situation more than 40 ℃, thereby need replenish battery every the several months sometimes.

When replenishing electricity, battery temporarily need be unpacked, replenish the operation of packing once more behind the electricity.This kind operation has to adopt manual operations, the expense that it spent, promptly replenishes the equipment of electricity or to replenish expense and time that electric required electric energy etc. spent all very huge, and the circulation cost of battery increases.

Patent documentation 1: the spy opens clear 52-93930 communique

Summary of the invention

So, the object of the present invention is to provide a kind of can suppress for a long time to take care of the time self discharge, reduce the lead accumulator cheaply of the frequency of replenishing the electricity operation.

The present invention a kind ofly can use lead accumulator by injecting electrolyte, it is characterized in that, described lead accumulator accommodates positive plate, negative plate, barrier film and electrolyte in accumulator housing, described positive plate comprises anodal grid of being made by Pb-Ca class alloy and the positive active material that is kept by described anodal grid, described negative plate comprises negative pole grid of being made by Pb-Ca class alloy and the negative electrode active material that is kept by described negative pole grid, described barrier film is isolated described positive plate and negative plate, and described electrolyte comprises sulfuric acid; Described accumulator housing is sealed; The part of described positive plate and described negative plate is impregnated in the electrolyte; The height dimension Y of described positive plate and described negative plate ₀, and from the bottom of described positive plate and described negative plate to the distance Y of the liquid level of described electrolyte ₁Satisfy relational expression:

15≤Y ₁/Y ₀×100≤60

The height dimension Y of described positive plate and described negative plate ₀, and from the bottom of described positive plate and described negative plate to the distance Y of the liquid level of described electrolyte ₁Preferably satisfy relational expression:

30≤Y ₁/Y ₀×100≤50

The concentration of described sulfuric acid is preferably 7～27 weight %.

Described electrolyte preferably contains the sulfate of alkali metal or alkaline-earth metal.

Described barrier film is preferably made by polyethylene, and contains oil.

Described barrier film preferably contains the described oil of 10～30 weight %.

Described barrier film is preferably a bag shape, and takes in described negative plate.

The described anodal grid preferably at least a portion on the surface has and contains lead alloy layer at least a among Sb and the Sn.

The gas phase of described accumulator housing inside is preferably by inert gas replacement.

In addition, the invention provides a kind of keeping method of lead accumulator, it is characterized in that, be that lead accumulator is carried out the keeping method that the back lead accumulator that reduces electrolyte content and take care of is handled in the accumulator housing chemical conversion, described lead accumulator comprises: the barrier film that comprises positive plate that the not chemical conversion of the grid of being made by Pb-Ca class alloy handles and negative plate, described two-plate is isolated, and the electrolyte that comprises sulfuric acid; Adjust electrolyte content, make the height dimension Y of described positive plate and described negative plate ₀, and from the bottom of described positive plate and described negative plate to the distance Y of the liquid level of described electrolyte ₁Satisfy relational expression:

15≤Y ₁/Y ₀×100≤60；

And with the accumulator housing inner sealing and keeping.

According to the present invention, by being suppressed at the self discharge that long-term keeping the time is produced, can reduce the frequency of replenishing the electricity operation, and can cut down the electric weight that replenishes electricity.

In addition, the electrolyte content during owing to keeping is few, and battery weight is alleviated.In addition, because the possibility of leakage reduces, so that the carrying of battery becomes is easy.Therefore, can reduce the conveying cost of battery or the cost in the circulation such as keeping cost etc.

Description of drawings

Fig. 1 is the stereogram with a part of cutting opening of the lead accumulator of embodiments of the invention.

Fig. 2 is the longitudinal sectional drawing of monocell inside of the lead accumulator of presentation graphs 1.

Fig. 3 is the front view of the positive plate in the same lead accumulator.

Fig. 4 is the front view of the negative plate in the same lead accumulator.

Fig. 5 is the figure of the operation of the expression compound foil that obtains to be used to make grid.

Fig. 6 is the longitudinal sectional drawing of a part that the positive plate of the anodal grid that has the lead alloy layer on the surface has been used in expression.

Embodiment

Lead accumulator of the present invention uses the Pb-Ca class alloy that does not contain the many Sb of self discharge amount basically in anodal grid and negative pole grid.In addition, take care of lead accumulator in the following manner: compare the minimizing electrolyte content when using, reducing contacting of positive plate and negative plate and electrolyte, and accumulator housing is made as sealing state contacting with minimizing negative plate and oxygen.By the self discharge of battery when taking care of for a long time that suppresses unused state like this.

Below, will be elaborated to embodiments of the present invention.Fig. 1 be with a part of cutting opening of lead accumulator of the present invention stereogram.Lead accumulator of the present invention shown in Fig. 1 is an example of the formation of battery when long-term keeping of expression unused state.

Accumulator housing 29 is divided into a plurality of monocells by dividing plate 30, has respectively taken in 1 pole plate group 28 in each monocell.Pole plate group 28 is made of positive plate 21, negative plate 22 and barrier film 23, wherein, positive plate 21 comprises the anodal grid that is made of the Pb-Ca alloy and is filled in positive active material (brown lead oxide) in the described anodal grid, negative plate 22 comprises the negative pole grid that is made of the Pb-Ca alloy and is filled in negative electrode active material (lead) in the described negative pole grid, and barrier film 23 is isolated positive plate 21 and negative plate 22.Pole plate group 28 also has the shelf portion 25 that the shelf portion (strap) 24 that is connected with the ear (tab) of positive plate 21 is connected with ear with negative plate 22.

Be connected the connector 27 that is provided with the shelf portion 24 of the side of the positive electrode of pole plate group in the monocell, pass the open-work of being located on the dividing plate 30 (not shown) and be connected to the shelf portion 25 of the negative side of the pole plate group 28 of adjacent monocell and be connected on the connector 27 of setting.Like this, pole plate group 28 just with adjacent monocell in pole plate group 28 be connected in series.Shelf portion at the side of the positive electrode of accumulator housing 29 1 side ends is formed with positive pole (not shown), and the shelf portion 25 of the negative side of end side forms negative pole 26.Positive pole and negative pole 26 respectively be located at lid 32 on positive terminal 33 and negative terminal 34 be connected.

Here, Fig. 2 is the longitudinal sectional drawing of monocell inside of the lead accumulator of presentation graphs 1.The electrolyte that injects in accumulator housing 29 when chemical conversion is handled finishes the back by the method for battery counter-rotating or sucking-off is discharged ormal weight in the chemical conversion processing.Fig. 2 represents as previously mentioned electrolyte to be discharged the state when taking care of behind the ormal weight.Contain a certain amount of electrolyte in each monocell, the part (bottom) of positive plate 21 and negative plate 22 is impregnated in the electrolyte.In addition, positive plate 21 and negative plate 22 are impregnated in ratio (following table is shown impregnation rate) in the electrolyte with the height dimension Y of pole plate shown in Figure 2 (removing ear) ₀With from pole plate bottom to electrolysis liquid surface X ₁Distance Y ₁, with Y ₁/ Y ₀* 100 formula is represented.As impregnation rate (=Y ₁/ Y ₀* 100) be 15～60% o'clock, the ratio that pole plate contacts with electrolyte tails off, and can suppress self discharge.

Impregnation rate is the smaller the better.But, in fact,, residue in the pole plate group 28 or on the inwall of accumulator housing 29 because electrolyte can not discharged in accumulator housing 29 fully, therefore be difficult in fact electrolyte is discharged to and make impregnation rate be less than 15%.On the other hand, when impregnation rate surpassed 60%, the effect of then above-mentioned inhibition self discharge will diminish.

Impregnation rate more preferably 30～50%.If impregnation rate is smaller or equal to 50%, then self discharge just can further be suppressed.The electrolyte that remains in inside battery forms liquid film at positive plate 21 and negative plate 22 surfaces.When impregnation rate less than 30% the time, the liquid film that then is formed at the surface of negative plate 22 just is interrupted, and forms the three phase boundary of oxygen/electrolyte/active material.The easy passivation of active material on this interface, thereby the situation that the charging acceptance when having battery to use reduces.

The concentration of the sulfuric acid in the electrolyte during the battery keeping is preferably 7～27 weight %.When sulfuric acid concentration during smaller or equal to 27 weight %, to compare with situation than its higher concentration, the self discharge during the battery keeping is suppressed.But when sulfuric acid concentration during less than 7 weight %, the charging acceptance when then replenishing electricity reduces.Consider that from the viewpoint of self discharge and charging acceptance the sulfuric acid concentration in the electrolyte is 12～22 weight % more preferably.

The electrolyte in when keeping preferably contains the sulfate of alkali metal such as sodium sulphate or alkaline-earth metal.Because can improve the charging acceptance when replenishing electricity, increase replenishes the discharge capacity behind the electricity.

Preferably in electrolyte, add about sodium sulphate 5～20g/L.When the concentration of sodium sulphate during, then can't clearly obtain the effect of adding less than 5g/L.On the other hand, when the concentration of sodium sulphate surpassed 20g/L, then flash-over characteristic reduced.

The peristome of accumulator housing 29 is had lid 32 coverings that are used for injecting to inside battery the liquid injection port 38 of electrolyte, and the venting plug 35 with exhaust outlet 36 is installed on liquid injection port 38.When long-term keeping, attach adhesive tape 37 to cover venting plug 35, exhaust outlet 36 is stopped up.The sealing state that when long-term keeping, just can keep like this, battery.For jointing tape 37, can use acid resistance resins such as acrylic resin or polyvinyl resin.When using jointing tape 37, not necessarily need to install venting plug 35.

In the time of just can suppressing thus for a long time to take care of air (oxygen) from outside batteries to inside battery inflow, can suppress the reaction of the lead oxide of the oxidation of negative electrode active material (spongy lead) and this generation of reason and the sulfuric acid in the electrolyte and the generation of the lead sulfate that causes.

The additive method of sealed cell is in liquid injection port 38 sealing plug that does not have exhaust outlet to be installed.

In order further to increase aforesaid sealing effectiveness, preferably with the atmosphere gas in the battery in advance with oxygen-free inert gas replacements such as nitrogen or argon gas.

Above-mentioned lead accumulator of the present invention for example can obtain by the method for operation shown below 1～4.

Operation 1: constitute lead accumulator thereby in accumulator housing 29, take in the pole plate group 28 that the positive plate 21 handled by chemical conversion not and negative plate 22 constitute, in accumulator housing 29, inject the electrolyte of ormal weight from liquid injection port 38.

The positive plate handled of chemical conversion for example is not filled the anodal paste that the raw material lead powder mixture of lead oxides (plumbous with), sulfuric acid and water etc. are mixed in anodal grid after, and it is dry and obtain to carry out slaking.In addition, the negative plate handled of chemical conversion for example is not filled the negative pole paste that the raw material lead powder mixture of lead oxides (plumbous with), sulfuric acid, water and anti-piping compounds such as lignin or barium sulfate are mixed in the negative pole grid after, and it is dry and obtain to carry out slaking.

Operation 2: after operation 1, the lead accumulator chemical conversion is handled.

Operation 3: after operation 2,, from liquid injection port 38, outside battery, discharge electrolyte so that impregnation rate reaches 15～60% by with methods such as lead accumulator counter-rotating or sucking-offs.

Operation 4: after operation 3, venting plug 35 is installed on liquid injection port 38, is attached adhesive tape 37, lead accumulator is made as sealing state to cover venting plug 35.

After electrolyte is discharged, if battery is left standstill a moment, then contained electrolyte or the electrolyte that is attached on the inwall of accumulator housing 29 just move the below in accumulator housing in the pole plate group 28, and it is that 15～60% scope impregnated in the state in the electrolyte that positive plate 21 and negative plate 22 become with impregnation rate.

For the sulfuric acid concentration in the battery electrolyte in when keeping is made as 7～27 weight %, can adjust the sulfuric acid concentration of the electrolyte that is injected, the sulfuric acid concentration of the electrolyte when above-mentioned chemical conversion processing is finished reaches 7～27 weight %.So, just do not need to adjust the operation of sulfuric acid concentration in the operation in the back.

In anodal grid and negative pole grid, use the lead accumulator of Pd-Ca class alloy owing to do not contain the Sb that promotes self discharge, therefore can suppress self discharge.Among the present invention, as mentioned above, by further electrolyte being reduced to suitable amount, the part that positive plate 21 and negative plate 22 contact with electrolyte tails off, thus the self discharge can further suppress long preservation the time.

When using battery, as long as adhesive tape 37 and venting plug 35 are taken off, replenished the electrolyte of ormal weight from liquid injection port 38 after, venting plug 35 is installed is once more got final product.

When battery uses, though as long as electrolyte is supplemented to positive plate 21 and negative plate 22 all are impregnated in the electrolyte, make the pole plate group 28 whole impregnated position (X among Fig. 2 that comprise shelf portion 24 and shelf portion 25 yet preferably electrolyte is supplemented to ₀).Particularly, if the shelf portion 25 of negative side exposes,, just have the situation that corrode the coupling part of the ear of shelf portion 25 or shelf portion 25 and negative plate 22 from electrolyte then because of the exposed portions serve of this shelf portion 25 contact with oxygen in the atmosphere.

Barrier film 23 is a bag shape, be that little porousness thin slice about 0.01～1 μ m make by the aperture that can see through electrolyte that is principal component with the polyvinyl resin.When the aperture surpassed 1 μ m, then active material just passed barrier film easily.

In the bag shape barrier film 23 that peristome upwards is provided with,, the ear of negative plate 22 taken in negative plate 22 so that being positioned at the mode of peristome side.Because electrolyte and barrier film 23 and electrolyte have compatibility with negative electrode active material, though therefore after accumulator housing chemical conversion processing with after the discharge of the electrolyte in the battery, still remaining in barrier film 23 inside have electrolyte.The liquid film of the electrolyte that this is remaining covers the part on negative plate 22 surfaces, and then makes barrier film 23 and negative plate 22 adhesions by electrolyte, can suppress contacting of negative plate 22 and oxygen thus.

As mentioned above, though negative plate 22 maintains electrolyte, yet because its liquid measure is the degree that forms liquid film on the surface of negative plate 22, therefore electrolyte content obviously seldom can suppress to be contacted with electrolyte and the self discharge that produces by negative electrode active material.

Barrier film 23 preferably contains the oil of 10～30 weight %.Self discharge in the time of can further suppressing keeping.Though oil is contained in the barrier film 23 in the early stage, yet the oil in the barrier film 23 little by little flows out in the electrolyte.By inference, the oil of this outflow is attached to the surface of negative plate 22, make negative plate 22 and electrolyte contact or negative plate 22 tails off with contacting of oxygen in being stranded in accumulator housing 29, can suppress the self discharge of negative plate 22 thus.

Oil mass contained in the barrier film 23 is many more, and the effect that then suppresses self discharge is just big more.But when the oil content in the barrier film 23 surpassed 30 weight %, then accumulator housing 29 inwalls just were stained with oil or grease, thereby the situation of the liquid level that is difficult to confirm electrolyte is arranged.On the other hand, when the oil content in the barrier film 23 during less than 10 weight %, the effect that then suppresses self discharge just becomes insufficient.

As oil, for example can use the mineral oil of from oil, having removed volatile ingredient, tar and pitch composition.For mineral oil, for example can use density is 0.85～0.90g/cm ³About the oil of paraffin class (straight chain saturation alkane).

Owing to when battery uses, electrolyte is supplemented to the position above electrolysis liquid surface being positioned at more lean on than pole plate, therefore the lip-deep oil that is attached to pole plate when keeping is all mobile above more leaning on than pole plate when battery uses, on electrolysis liquid surface with membranaceous expansion.So, when battery uses,, therefore can not cause harmful effect to electrode reaction owing between pole plate and electrolyte, there is not oil.

The oil that flows out to the inboard of bag shape barrier film 23 is stranded in the electrolyte in bag shape barrier film 23 easily.So, negative plate 22 is accommodated in situation in bag shape barrier film 23, compares with negative plate 22 being disposed at bag situation in the outside of shape barrier film 23, oil increases to the adhesion amount on negative plate 22 surfaces, is preferred therefore.

In order to improve the mechanical strength of anodal grid, the anodal grid of being made by Pd-Ca class alloy preferably contains the Ca of 0.05～0.1 weight %.In order to improve the corrosion resistance of anodal grid, Pd-Ca class alloy preferably also contains the Sn of 1.0～2.2 weight %.

Anodal grid preferably has at least a lead alloy layer that contains among Sb and the Sn at least a portion on surface.

When use contacts the battery of the long-term keeping of state seldom with positive plate 21 with electrolyte, form when replenishing electrolyte when positive plate all be impregnated in state in the electrolyte, on the interface between anodal grid and the positive active material, just form passivation layer easily.Passivation layer is to be formed at the lead sulfate of anodal grid surface or the insulating barrier of lead oxide, and this layer one is formed then charge acceptance and discharge capacity will be reduced sharp.Particularly in anodal grid, used in the battery of Pd-Ca class alloy, the tendency that is easy to generate passivation layer has been arranged.

Have at least a lead alloy layer that contains Sb and Sn by at least a portion at anodal grid surface, the performance that just can suppress the battery that caused by this passivation layer reduces.Sn has the effect of the conductivity that improves passivation layer, and Sb has the effect that suppresses passivation layer self generation.

The lead alloy layer that can be used for above-mentioned purpose preferably contains the Pd-Ca alloy of 1.0～10 weight %Sb.The caking property of positive active material and anodal grid is enhanced, and the part of Sb stripping in positive active material in addition improves the interparticle adhesion of positive active material, improves the charging acceptance of positive plate.Because the Sb in the lead alloy layer only partly is present in the surface of anodal grid, Sb measures very pettiness, therefore the influence to self discharge that is not caused by Sb basically.

Other preferred lead alloy layer is the Pd-Sn alloy that contains 3～7 weight %Sn.Because when Sn content surpassed 7 weight %, the effect that is caused by Sn was identical with the situation that contains 7 weight %, therefore in order to limit the use amount of expensive Sn, the Sn content in the lead alloy layer preferably is made as smaller or equal to 7 weight %.On the other hand, when Sn content during less than 3 weight %, then the effect that is caused by Sn diminishes.

The anodal grid that the surface has the lead alloy layer can obtain as followsly.For example, in calendering procedure, to contain at least a lead alloy-foil among Sb and the Sn, with supply with between a pair of stack by the mother metal thin slice made from the identical Pd-Ca class alloy material of described grid, by lead alloy-foil being pressed together on obtain on the mother metal thin slice compound foil that constitutes by mother metal layer and lead alloy layer.Then, this compound foil that passes through processing (expandingprocess) of foaming obtains anodal grid.The preferred thickness of the mother metal layer of compound foil is 0.7～1.3mm, and the preferred thickness of lead alloy layer is 0.01～20 μ m.

The negative pole grid of being made by Pd-Ca class alloy preferably contains the Ca of 0.05～0.1 weight %.Can not reduce the hydrogen overvoltage of negative pole grid and improve the mechanical strength of negative pole grid.In order further to improve the mechanical strength of negative pole grid, Pd-Ca class alloy preferably also contains the Sn about 0.5 weight %.

As implied above, lead accumulator of the present invention can be suppressed at the self discharge that long-term when keeping produces, and can reduce the frequency of the additional electricity that carries out when long-term keeping, reduces the expense of replenishing in the electricity.

In addition, because electrolyte content is few, so battery is by lightweight.Because the state that lead accumulator of the present invention is sealed is so can suppress leakage.Therefore can more easily carry lead accumulator.

Though the above-mentioned structure that has adopted bag shape barrier film to take in negative plate in addition, also can adopt laminar barrier film is rolled over the structure that twice (U font) also sandwiches negative plate betwixt.

Below, will be elaborated to embodiments of the invention.

Embodiment 1

(1) making of positive plate

Made positive plate shown in Figure 3 21 as followsly.

The Pd-0.06wt%Ca-1.30wt%Sn alloy sheet that utilizes casting to obtain is calendered to thickness is 1.1mm, by the processing of foaming, the anodal grid 41 that has obtained having ear 42 is (vertical: 115mm, horizontal stroke: 137.5mm).

On the other hand, by raw material lead powder (mixture of lead and lead oxides) and water, sulfuric acid are added and mixing with 100: 15: 5 ratio of weight ratio, obtained anodal paste 43.

After this, after in anodal grid 41, having filled the anodal paste 43 of 100g, carry out the slaking drying, obtained the not positive plate 21 of chemical conversion processing.

(2) making of negative plate

Made negative plate shown in Figure 4 22 as followsly.

The Pd-0.06wt%Ca-0.30wt%Sn alloy sheet that utilizes casting to obtain is calendered to thickness is 0.7mm, by the processing of foaming, the negative pole grid 51 that has obtained having ear 52 is (vertical: 115mm, horizontal stroke: 137.5mm).

On the other hand, by with raw material lead powder, water, sulfuric acid and as the lignin of additive and barium sulfate with weight ratio 100: 15: 3.5: 2.5: 2.5 ratio is added and mixing, has obtained negative pole paste 53.After this, after in negative pole grid 51, having filled 75g negative pole paste 53, carry out the slaking drying, obtained the not negative plate 22 of chemical conversion processing.

(3) making of lead accumulator

Utilize following method, made the lead accumulator of structure shown in Figure 1.Fig. 1 be with a part of cutting opening of lead accumulator stereogram.

6 negative plates 22 that will obtain in aforesaid operations are accommodated in respectively in bag shape barrier film 23, and they and above-mentioned 5 positive plates 21 that obtain are alternatively stacked, carry out stacked across bag shape barrier film 23 positive plate 21 and negative plate 22 thus., the ear 42 and 52 of the pole plate of same polarity respectively carried out joint welding, form shelf portion 24 and 25, thereby obtained pole plate group 28 thereafter.At this moment, in bag shape barrier film 23, used the material of aperture smaller or equal to little porous polyethylene system of 1 μ m.Pole plate group 28 is accommodated in respectively seriatim in 6 monocells 31 that mark off by dividing plate 30 of accumulator housing 29, is connected in series with adjacent pole plate group 28 by be connected the connector 27 that is provided with shelf portion 24.In the present embodiment, the connection between the pole plate group is to be undertaken by the open-work of being located on the dividing plate 30 (not shown).

Formed positive pole (not shown) 28, one of the pole plate groups that is arranged in the two ends that are connected in series, another has formed negative pole 26.After this, lid 32 is installed on the peristome of accumulator housing 29, and will be located at positive terminal 33 and negative terminal 34 and positive pole and negative pole 26 welding on the lid 32.Thereafter, the liquid injection port 38 on being located at lid 32, injection is the sulfuric acid of 34 weight % as the concentration of the 700ml of electrolyte in each monocell, carries out the accumulator housing chemical conversion and handles.After chemical conversion is handled, venting plug 35 with exhaust outlet 36 that the gas that is used for producing at inside battery discharges outside battery is installed on liquid injection port 38, thereby has been made the starting lead battery (following note work " battery ") of the 55D23 type (12V-48Ah) of defined among the JIS D5301.

In above-mentioned battery was made, the sulfuric acid concentration that electrolyte is adjusted into the electrolyte in each monocell that makes after chemical conversion is handled reached 37 weight %, and the electrolyte content in each monocell reaches 700ml.The electrolysis liquid surface of this moment is X among Fig. 2 ₀The position, be that positive plate 21, negative plate 22, shelf portion 24 and 25 all are impregnated in the state in the electrolyte.With this battery as battery A (comparative example).

After chemical conversion is finished dealing with, the sulfuric acid concentration or the electrolyte content of electrolyte is adjusted into the various values shown in the table 1.After chemical conversion is handled, sulfuric acid concentration is adjusted in the scope of 5～37 weight %, thereafter again by the part of electrolyte being discharged outside battery and electrolyte content being adjusted into the various values shown in the table 1.The discharge of electrolyte outside battery undertaken by battery is reversed, and the time that changes the counter-rotating battery is adjusted the discharge rate of electrolyte.

Electrolyte content 350ml, 280ml, 245ml, 140ml and 70ml in the table 1 is the amount of 50 weight %, the 40 weight %, 35 weight %, 20 weight % and the 10 weight % that are equivalent to regulation electrolyte content (700ml) respectively, and the impregnation rate of this moment is respectively 75%, 60%, 50%, 30% and 15%.

Impregnation rate be by from pole plate bottom to electrolysis liquid surface X ₁Distance Y ₁With pole plate height Y ₀Ratio (=Y ₁/ Y ₀* 100) try to achieve.

With respect to impregnation rate 75%, 60%, 50%, 30% and 15%, the time of battery counter-rotating was respectively 15,20,30,80 and 180 seconds.Liquid level X ₁The position be after electrolyte is discharged, Visual Confirmation when having passed through 30 minutes.

[table 1]

Sulfuric acid concentration or electrolyte content different battery B1～B4, C1～C4, D1～D6, E1～E4, F1～F4 have been made as described above.

In addition, in the electrolyte of battery A and battery D1～D6, add the sodium sulphate of 10g/l again, made battery A ' and battery D1 '～D6 '.

The adhesive tape 37 that venting plug 35 usefulness of all batteries made in the aforesaid operations are made by acrylic resin covers, and seals exhaust outlet 36, with cell sealing.And described venting plug 35 has used the stopper with splash-back, thereby makes electrolyte can easily not overflow outside battery because of the swing of electrolysis liquid surface.Battery A, A ' and battery B1～B4 are comparative examples, and battery C1～C4, D1～D6, D1 '～D6 ', E1～E4 and F1～F4 are embodiment.

[evaluation of battery]

Each above-mentioned battery was placed 3 months in 40 ℃ thermostatic chamber.After the placement, adhesive tape is peeled off, venting plug is taken off, replenish electrolyte from liquid injection port, make that the sulfuric acid concentration in the electrolyte reaches 37 weight %, the electrolyte content of each monocell reaches 700ml, and (liquid level is the X among Fig. 2 ₀The position).

Then, under 25 ℃ of environment, each battery is carried out 20 hour rates (current value is 2.88A) discharge with the final voltage of 10.5V, measured the residual discharge period.Thereafter, each battery has been carried out recovering charging (the constant voltage charging: setting voltage is 14.8V, and maximum current is 25A, and the charging interval is 12 hours) under 25 ℃ of environment, and then carry out the discharge of 20 hour rates with the final voltage of 10.5V, measured the recovery discharge period.Its measurement result is shown in the table 1.

According to table 1 as can be known, for impregnation rate battery C1～C4, D1～D6, D1 '～D6 ', E1～E4 and the F1～F4 of 15～60% scope, long 40 ℃ of residual discharge periods after placing 3 months down.This is considered to because by the limit electrolysis liquid measure, the contact area of electrolyte and active material tails off, and self discharge is suppressed.Be battery D1～D6, D1 '～D6 ', the E1～E4 of 30～50% scope for impregnation rate, the flash-over characteristic after the placement further improves.

Sulfuric acid concentration in electrolyte is under the situation of 5 weight %, because self discharge is few, so the residual discharge period is elongated, yet recovers the discharge period minimizing.Thus, the sulfuric acid concentration in the electrolyte is preferably greater than and equals 7 weight %.

According to the result of battery D1～D6 and D1 '～D6 ' as can be known, though the interpolation of the sodium sulphate in the electrolyte the residual discharge period is not impacted basically, yet can cause recovering the increase of discharge period.Particularly, if the sulfuric acid concentration of the electrolyte of time is more than or equal to 7 weight % certainly, then sulfuric acid concentration is low more, and the effect of recovering the discharge period increase is just big more.

When suppressing self discharge,, so the charging acceptance of battery, recover the tendency that there is reduction the discharge period because the sulfate ion amount is limited by the sulfuric acid concentration in limit electrolysis liquid measure and the electrolyte.When interpolation sodium sulphate under the few state of such electrolyte content, because sulfate ion is replenished, the reduction of the acceptance that therefore charges is suppressed, and the recovery discharge period is elongated.

In addition, when sulfuric acid concentration surpasses 27 weight %, then because the sulfuric acid quantitative change is many, generate lead sulfate easily, therefore the residual discharge period shortens.From this result as can be known, preferred 7～27 weight % of sulfuric acid concentration.For sulfuric acid concentration is battery D3, D4, D3 ' and the D4 ' of the scope of 12～22 weight %, and the flash-over characteristic after the placement further improves.

In addition, the electrolyte content the during keeping of the battery D3 of embodiments of the invention is that each monocell is 245ml.In the time of 25 ℃, be about 1.184g/ml because sulfuric acid concentration is the density of electrolyte of 27 weight %, so the electrolyte weight of each battery is about 1740g.

On the other hand, the electrolyte content the during keeping of the battery A of comparative example is that each monocell is 700ml, be about 1.273g/ml because sulfuric acid concentration is the density of electrolyte of 37 weight % in the time of 25 ℃, so the electrolyte weight of each battery is about 5350g.

Therefore, the battery weight when lead accumulator of the present invention can reduce keeping significantly can be cut down the circulation cost of carrying cost or keeping cost and so on.

Embodiment 2

The oil that in the bag shape barrier film identical, contains the various amounts shown in the table 2 with embodiment 1.Oil content in the table 2 is represented the ratio with respect to the weight of the bag shape barrier film that contains oil.For oil, used mineral oil (the Daphne oil CP of Idemitsu Kosen Co., Ltd.'s system).Except having used the bag shape barrier film that contains oil, use the method identical to make battery G2～G6 with the battery A of embodiment 1.As a comparative example, made the battery G1 (is identical formation with battery A) that has used the bag shape barrier film that does not contain oil.

In addition, except taking in positive plate with above-mentioned barrier film rather than taking in the negative plate, utilize the method identical to make battery H1～H6 with the battery A of embodiment 1.

In addition, be that the battery of 245ml (impregnation rate 50%) is as battery I1～I6 with having discharged the electrolyte of battery G1～G6 and having made the electrolyte content of each monocell.With having discharged the electrolyte of battery H1～H6 and having made the electrolyte content of each monocell is that the battery of 245ml (impregnation rate 50%) is as battery J1～J6.Battery G1～G6 and H1～H6 are comparative example, and battery I1～I6 and J1～J6 are embodiment.

[evaluation of battery]

For each above-mentioned battery, utilize the method identical with embodiment 1, measured the residual discharge period of placing after 6 months.Its measurement result is shown in the table 2.

[table 2]

For when placing, having reduced the electrolyte in the battery and in barrier film, having contained the battery I2～I6 and the J2～J6 of oil, to compare with battery I1 and J1, self discharge is suppressed, and the residual discharge period is elongated.Particularly in battery I3～I6 and J3～J6, the flash-over characteristic after the placement further improves.On the other hand, for the battery G2～G6 and the H2～H6 that do not discharge electrolyte, though according to the difference of the oil content in the barrier film, the residual discharge period slightly changes, yet can't obtain the effect as the battery of having discharged electrolyte.

Though it is also uncertain for its mechanism, but be presumed as follows, by discharging electrolyte, the oil in the electrolyte forms coverlay on the negative plate surface of having exposed, make negative plate and electrolyte and be present in the minimizing that contacts of oxygen in the battery thus, thereby self discharge is suppressed.

In addition, bag shape barrier film taken in negative plate battery, compare with the battery that bag shape barrier film has been taken in positive plate, can obtain more good self-discharge characteristics.

Can think because following reason for this point: the oil that flows out from the outside of bag shape barrier film spreads in accumulator housing, and the oil that flows out from the inboard of bag shape barrier film is stranded in the barrier film inboard.Therefore, when bag shape barrier film has been taken in negative plate, form oily coverlay easily on the negative plate surface.

Though among the described embodiment 2 impregnation rate is made as 50%, in impregnation rate is 15～60% scope, can obtains the effect identical with embodiment 2.

Embodiment 3

In calendering procedure, as shown in Figure 5, lead alloy-foil 41b is supplied with between a pair of stack 45 with mother metal thin slice 41a, utilize stack 45 that mother metal thin slice 41a and lead alloy-foil 41b are rolled simultaneously.Thus, lead alloy-foil 41b just is pressed together on the mother metal thin slice 41a, thereby has obtained having the compound foil that thickness is the lead alloy layer of 20 μ m on thickness is the single face of mother metal layer of 1.1mm.Lead alloy-foil 41b has used the Pb-5.0wt%Sb alloy.Mother metal thin slice 41a has used the anodal grid identical materials with embodiment 1.

By this compound foil being implemented foaming processing, obtained anodal grid.After this, use this positive pole grid, utilize the method identical to obtain positive plate with embodiment 1.This positive pole grid has the Pb-5wt%Sb alloy-layer in the one side of the grid of rhombus as shown in Figure 6.

Electrolyte content after using the anodal grid that obtains and chemical conversion handled in aforesaid operations is made as each monocell as the 200ml (impregnation rate is 40%) (amount of 28.6 weight % that is equivalent to the electrolyte content of battery A), utilize the method identical, made battery K1 with the battery A of embodiment 1.

Embodiment 4

Whole bag shape barrier films in the pole plate group are not to take in negative plate but take in the positive plate, utilize the method identical with embodiment 3 to make battery K2.

Embodiment 5

Except used the anodal grid of embodiment 1 without the anodal grid of embodiment 3, utilize the method identical to make battery K3 with embodiment 3.

Embodiment 6

Except with venting plug and adhesive tape with cell sealing before with the gas phase of inside battery with nitrogen replacement, utilize the method identical to make battery K4 with embodiment 3.

Comparative example 1

Except not attaching adhesive tape, venting plug being taken off to form the open system, utilize the method identical to make battery K5 with embodiment 3.

Comparative example 2

Except do not discharge electrolyte after chemical conversion is handled, the electrolyte content that makes each monocell is beyond the 700ml, utilizes the method identical with embodiment 3 to make battery K6.

Comparative example 3

Whole bag shape barrier films in the pole plate group are not to take in negative plate but taken in the positive plate, utilize the method identical with comparative example 2 to make battery K7.

[evaluation of battery]

For the battery K1～K7 that obtains in the aforesaid operations, utilize the method identical with embodiment 1, measured the residual discharge period of placing after 3 months.In addition, for the situation of having placed 6 months, measured the residual discharge period similarly.Its measurement result is shown in the table 3.In addition, give the measurement result of battery A as a comparative example.

[table 3]

Place after 3 months, the battery K1～K5 for the few state of electrolyte content is placed down because self discharge is suppressed, therefore compares with the battery K6 and the K7 that place with common electrolyte content, and the residual discharge period is elongated.But, placing after 6 months, battery K3 and K5 compare with battery K6 and K7, and the residual discharge period slightly shortens.So, under 6 months situation of placement, preferably adopt the formation of battery K1, K2 and K4.

According to the result of battery A and K6 as can be known, when battery is placed, do not reduce under the situation of electrolyte, the lead alloy layer of anodal grid surface have or not the influence that can not cause basically to the residual discharge period.According to the result of battery K1 and K3 as can be known, particularly being under 6 months the situation between resting period, set the lead alloy layer by the surface at anodal grid, flash-over characteristic can improve.

Because it is more good that battery K1 and battery K2 compare residual flash-over characteristic, therefore as can be known, in the battery that has reduced electrolyte content,, the residual discharge period can be prolonged more by further negative plate being accommodated in bag shape barrier film.In addition, according to the result of battery K6 and K7 as can be known, this effect can't obtain in battery in the past.

In the above embodiments 3,4 and 6, though in the lead alloy layer on the surface that is formed at anodal grid, used the Pb-Sb alloy, but under the situation of having used Pb-Sn-Sb alloys such as Pb-Sn alloys such as Pb-5.0wt%Sn or Pb-5.0wt%Sn-5.0wt%Sb, also can obtain the effect identical with embodiment 3,4 and 6.In addition, though in the foregoing description 3～6, impregnation rate is made as 40%, in impregnation rate is 15～60% scope, also can obtain the effect identical with embodiment 3～6.

Lead accumulator of the present invention is owing to can suppress self discharge during long-term keeping, and the flash-over characteristic after the therefore long-term keeping is good, the engine start that is suitable for use as vehicle with or the battery used of stand-by power supply.

Claims (10)

1. One kind by injecting electrolyte operable lead accumulator is characterized in that,

   Described lead accumulator accommodates positive plate, negative plate, barrier film and electrolyte in accumulator housing, described positive plate comprises the positive active material that keeps in the anodal grid made by the Pb-Ca alloy and the described anodal grid, described negative plate comprises the negative electrode active material that keeps in the negative pole grid made by the Pb-Ca alloy and the described negative pole grid, described barrier film is isolated described positive plate and negative plate, and described electrolyte comprises sulfuric acid;

   Described accumulator housing is sealed;

   The part of described positive plate and described negative plate is impregnated in the electrolyte;

   The height dimension Y of described positive plate and described negative plate ₀, and from the bottom of described positive plate and described negative plate to the distance Y of the liquid level of described electrolyte ₁Satisfy relational expression:

   30≤Y ₁/Y ₀×100≤60；

   The concentration of described sulfuric acid is 7～27 weight %.
2. 2. lead accumulator according to claim 1 is characterized in that,

   The height dimension Y of described positive plate and described negative plate ₀, and from the bottom of described positive plate and described negative plate to the distance Y of the liquid level of described electrolyte ₁Satisfy relational expression:

   30≤Y ₁/Y ₀×100≤50。
3. 3. lead accumulator according to claim 1, wherein, described electrolyte contains the sulfate of alkali metal or alkaline-earth metal.
4. 4. lead accumulator according to claim 1, wherein, described barrier film is made by polyethylene.
5. 5. lead accumulator according to claim 4, wherein, described barrier film contains oil.
6. 6. lead accumulator according to claim 5, wherein, described barrier film contains the described oil of 10～30 weight %.
7. 7. lead accumulator according to claim 4, wherein, described barrier film is the bag shape, and takes in described negative plate.
8. 8. lead accumulator according to claim 1, wherein, described anodal grid at least a portion on the surface has at least a lead alloy layer that contains among Sb and the Sn.
9. 9. lead accumulator according to claim 1, wherein, the gas phase of described accumulator housing inside is by inert gas replacement.
10. 10. the keeping method of a lead accumulator is characterized in that,

    Be the keeping method that carries out the lead accumulator of keeping lead accumulator being carried out electrolyte content is reduced, described lead accumulator comprises: comprise positive plate that the not chemical conversion of the grid of being made by the Pb-Ca alloy handles and negative plate, the barrier film that described positive plate and negative plate are isolated and the electrolyte that comprises sulfuric acid;

    Described method comprises: adjust electrolyte content, make the height dimension Y of described positive plate and described negative plate ₀, and from the bottom of described positive plate and described negative plate to the distance Y of the liquid level of described electrolyte ₁Satisfy relational expression:

    30≤Y ₁/Y ₀×100≤60；

    The concentration of described sulfuric acid is 7～27 weight %;

    And the accumulator housing sealing is taken care of.

Images