JP2011159551A - Lead-acid storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead-acid storage battery in which an electrode plate is immersed in an electrolyte solution and the current collector of both positive and negative electrodes is made of a lead alloy containing calcium and in which corrosion of a jointing part of a current collector ear on the negative electrode side and a strap and the strap body is suppressed, while capacity recovering property after over-discharge is improved. <P>SOLUTION: At least a part of a strap of both positive and negative electrodes, a positive electrode connecting component, and a negative electrode connecting component is immersed in the electrolyte solution; the strap of the both positive and negative electrodes and the positive electrode connecting component are composed of lead or a lead alloy in which the antimony content is restricted to 0.01 mass% or less, and the negative electrode connecting component is composed of lead or a lead alloy containing antimony of 0.5 mass% or more. By this, corrosion on the negative electrode side is suppressed, and the capacity recovering property after over-discharge is remarkably improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lead-acid battery.

  In recent years, lead storage batteries for starting an engine of a vehicle have become mainstream using lead-calcium alloys as lead alloys for current collectors of both electrodes for the purpose of suppressing moisture reduction in the electrolyte. A positive electrode plate and a negative electrode plate can be obtained by filling or applying an active material corresponding to the polarity to these current collectors. The current collector is integrally provided with current collecting ears. A plurality of these positive electrode plates and negative electrode plates are laminated via a separator to constitute a cell, and current collecting ears of the same polarity are collectively welded with a strap.

  In addition, a connection body for connecting cells and / or a pole for external connection is connected to the strap. In the present specification, the connection body and the pole column are collectively referred to as connection parts.

  In a liquid lead-acid battery, a lead-antimony alloy has been used as a strap and a connecting part. The lead-antimony alloy is superior in strength and corrosion resistance to pure lead, and is excellent in castability and weldability.

  However, in some cases, calcium and antimony are mixed in the joint portion between the strap containing antimony and the current collecting ear portion containing calcium. When a strap containing a mixture of calcium and antimony is applied to the negative electrode, when the strap is exposed from the electrolyte, the joint between the strap and the current collecting ear corrodes, and the progress of this corrosion causes the strap and the It is known that there is a break between current collecting ears. It is said that calcium and antimony are mixed with each other to form a compound, which is easily corroded.

  In Patent Document 1, a lead-antimony alloy is used for a connector or pole column portion connecting cells constituting a strap, and tin is added to the negative electrode grid and the connector or pole column portion to contain 0.1% by mass or more of tin. It has been shown to weld using a lead-tin alloy. In the configuration of Patent Document 1, mixing of calcium and antimony due to mixing of molten lead alloys during welding is suppressed, and corrosion of the joint between the strap and the current collecting ear in the negative electrode as described above is suppressed.

  On the other hand, in non-liquid type, negative electrode absorption type lead-acid batteries, if antimony is present in the battery, moisture reduction in the electrolyte and self-discharge are extremely impractical, so do straps and connecting parts contain antimony? It is composed of pure lead and lead alloy limited to a very small amount.

  In recent years, for the purpose of improving the fuel efficiency of vehicles, a system for stopping idling of an engine and a system in which the amount of overcharge electricity of a lead storage battery is further suppressed as compared with a conventional vehicle are becoming widespread. In vehicles employing these systems, the state of charge (SOC) of the lead-acid battery is controlled in a lower range compared to conventional vehicles. Moreover, since the dark current continues to flow from the lead storage battery to various ECUs mounted on the vehicle while the SOC of the lead storage battery is not high, the rate at which the lead storage battery is overdischarged is also high.

  The inventor of the present invention uses antimony as used in a negative electrode absorption lead acid battery as a lead alloy used in a lead acid battery strap or a connection component in order to suppress corrosion of current collecting ears and straps in the negative electrode. When lead or lead alloys not included were used, it was confirmed that the capacity recoverability when lead-acid batteries were overdischarged was significantly reduced.

  In Patent Document 2, in order to suppress a decrease in charge acceptability of a lead storage battery when a lead alloy containing no antimony (Sb) is used for positive and negative straps and connecting parts, the surface of the negative electrode lattice or the negative electrode A configuration in which antimony is contained in the active material is shown. According to such a configuration, since the charge acceptance is improved, it is presumed that the capacity recoverability after the lead storage battery is overdischarged is also improved.

  The inventor of the present invention uses a lead alloy that does not contain antimony for the positive and negative straps and the connecting member as described above, and the lead storage battery contains antimony on the surface of the negative electrode lattice or on the negative electrode active material. As a result of confirming the capacity recoverability at the time of discharge, the capacity recoverability at the time of overdischarge is also compared with the conventional lead storage battery that contains antimony in the positive and negative straps and the connecting member even by addition of antimony to the site as described above. It was inferior. This can be presumed to be a phenomenon caused by the formation of a local battery because antimony and the negative electrode active material (sea surface lead) are present in close proximity or in contact with each other.

JP-A-5-275074 JP 2003-346888 A

  The present invention provides a lead-acid battery that suppresses corrosion of the negative electrode current collector ear and the junction between the negative electrode current collector ear and the nest electrode strap and has improved capacity recovery after overdischarge.

  In order to solve the above-described problem, the invention according to claim 1 of the present invention is to discharge the gas released from the positive electrode plate and / or the negative electrode plate by immersing the positive electrode plate and the negative electrode plate in an electrolytic solution. A liquid lead-acid battery having a path of a battery exterior, wherein the positive electrode plate and the negative electrode plate each include a positive electrode current collector and a negative electrode current collector made of a lead-calcium alloy, and the positive electrode current collector A positive electrode strap integrally welded to the positive electrode current collector ear, and a positive electrode connection part for inter-cell connection and / or terminal connection provided on the positive electrode strap, and integrated with the negative electrode current collector A negative electrode strap for collectively welding the provided negative electrode current collecting ear; and a negative electrode connecting part for inter-cell connection and / or terminal connection provided on the negative electrode strap. At least a part of each of the component, the negative electrode strap, and the negative electrode connection component is immersed in an electrolyte solution, and the positive electrode strap, the positive electrode connection component, and the negative electrode strap are limited to an antimony content of 0.01% by mass or less. The lead storage battery is characterized in that it is made of lead or a lead alloy, and the negative electrode connecting part is made of lead or a lead alloy containing 0.5% by mass or more of antimony.

  According to the configuration of claim 1, since the amount of antimony contained in the positive electrode strap and the positive electrode connecting part is limited to a small amount, antimony elution into the electrolytic solution and antimony precipitation on the surface of the negative electrode current collecting ear are suppressed. The Further, since the amount of antimony in the negative electrode strap is limited to a small amount, corrosion of the negative electrode current collecting ear and corrosion of the joint portion between the negative electrode current collecting ear and the negative electrode strap are suppressed.

  On the other hand, due to the antimony contained in the negative electrode connection component during charging, the overvoltage on the negative electrode side during charging is reduced, so that the charging current increases. Thereby, charging of the overdischarged positive electrode active material becomes possible. In addition, since the antimony contained in the negative electrode active material or the negative electrode current collector is limited to a small amount, the accumulation of lead sulfate due to self-discharge of the negative electrode active material is also suppressed. The capacity recovery can be remarkably improved. Such an effect is presumed to be because, although Sb is present on the negative electrode side, it is disposed at a site separated from the negative electrode active material, and thus the formation of a local battery between the negative electrode active material and Sb is suppressed.

  A lead storage battery according to claim 2 of the present invention is a lead storage battery having the configuration of claim 1, wherein the positive electrode strap, the positive electrode connecting component, and the negative electrode strap further include a lead-tin alloy. is there.

  A lead storage battery according to claim 3 of the present invention is the lead storage battery having the configuration according to claim 1 or claim 2, wherein the lead storage battery includes a plurality of cells, the cells include a series connection, and two cells connected in series The welded portion of the negative electrode connection part for connecting one cell and the positive electrode connection part for connecting the cell of the other cell is sealed in a liquid-tight manner at least with respect to the electrolyte solution of the other cell. It also has a configuration.

  According to the configuration of claim 3 of the present invention, when the present invention is applied to a lead storage battery in which a plurality of cells are connected in series, the joint including antimony between the positive electrode connecting component and the negative electrode connecting component is connected to the positive electrode. Sealed from the electrolyte of the cell containing the part. Therefore, the joint portion containing antimony is corroded by anodic oxidation, and the elution of antimony into the electrolytic solution, the precipitation of antimony on the negative electrode current collector ear, and the corrosion of the negative electrode current collector ear are further suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an outstanding effect that the corrosion of the negative electrode current collection ear and the junction part of a negative electrode current collection ear and a negative electrode strap can be suppressed, and the capacity | capacitance recoverability after an overdischarge can be improved.

The figure which shows the cross section of the lead acid battery by the 1st Embodiment of this invention. The figure which shows the other cross section of the lead acid battery by the 1st Embodiment of this invention. The figure which shows the cross section of the lead acid battery by the 2nd Embodiment of this invention. The figure which shows the principal part cross section of the lead acid battery by the 2nd Embodiment of this invention. The figure which shows the state before the connection between the cells of the lead acid battery by the 2nd Embodiment of this invention.

(First embodiment of the present invention)
The configuration of the lead storage battery according to the first embodiment of the present invention will be described below. 1 and 2 are cross-sectional views of a lead-acid battery 1 according to the first embodiment of the present invention. The positive electrode plate 2 has a configuration in which a positive electrode current collector (not shown) integrally provided with a positive electrode current collector ear 2a is filled with a positive electrode active material for a lead storage battery. The negative electrode plate 3 has a configuration in which a negative electrode current collector (not shown) integrally provided with a negative electrode current collecting ear 3a is filled with a negative electrode active material for a lead storage battery.

  The positive electrode current collector used in the lead storage battery 1 of the present invention and the positive electrode current collector ear 2a provided integrally therewith are both lead alloys containing calcium. The content of antimony in the portion not covered with the active material of the positive electrode current collector ear 2a and the positive electrode current collector is limited to 0.005% by mass or less. This is because when calcium is added to the molten lead, calcium and antimony in the molten lead are combined to reduce the content of antimony in the molten lead as a raised soot.

  Therefore, by containing calcium, the amount of antimony contained in the bulk of the positive electrode current collector and the positive electrode current collector ear 2a is limited to 0.005 mass% or less, but for the purpose of improving the life in deep discharge, A layer containing about 0.5 parts by mass of antimony with respect to 100 parts by mass of the positive electrode active material may be formed only on the surface of the positive electrode current collector that is in contact with the positive electrode active material. The content of calcium is determined in consideration of the mechanical properties (tensile strength, elongation) and corrosion resistance of the positive electrode current collector ear 2a and the positive electrode current collector, and in many cases 0.05 mass% to 0 mass%. Although it is set in the range of 0.09 mass%, it is not limited to this.

  Further, the potentials of the positive electrode current collector and the positive electrode current collector ear 2a shift more preciously by charging in the electrolyte (dilute sulfuric acid), and the positive electrode current collector and the positive electrode current collector ear 2a are subjected to oxidative corrosion. In consideration of corrosion resistance, Sn may be further included in an amount of about 0.5% to 2.0% by mass. In addition, the range of this content is an illustration, Comprising: You may be outside this range.

  The negative electrode current collector used in the lead storage battery 1 of the present invention and the negative electrode current collecting ear 3a provided integrally therewith are both lead alloys containing calcium, and the content of antimony is limited to 0.005% by mass or less. The The calcium content can be set in the same range as that of the positive electrode current collector and the positive electrode current collector ear 2a, and may further contain Sn. Sn in the negative electrode current collector and the negative electrode current collection ear 3a is, as is well known, about 0.1% by mass to 0.5% by mass in consideration of mechanical strength and productivity (castability, expandability). Selected by quantity. In addition, the range of this content is an illustration, Comprising: You may be outside this range.

  In the lead storage battery 1, separators 8 are disposed between the plurality of positive plates 2 and negative plates 3, respectively. The plurality of positive electrode current collecting ears 2a are electrically connected to each other by a positive electrode strap 2b. The plurality of negative electrode current collecting ears 3a are electrically connected to each other by a negative electrode strap 3b.

A cell 9 composed of the positive electrode plate 2, the negative electrode plate 3, and the separator 8 is accommodated together with the electrolytic solution 5 in the battery exterior 4. As is well known, the electrolytic solution 5 is dilute sulfuric acid, and, for example, one having a density at 20 ° C. of 1.200 g / cm ^{3 to} 1.400 g / cm ³ is used. In addition to the sulfuric acid, the electrolytic solution 5 may include salts such as sodium sulfate, sodium tetraborate, and aluminum sulfate for the purpose of improving charge acceptability or improving cycle life.

  The positive strap 2b and the terminal 7 are electrically connected by a positive connection component 2c, which is also called a positive pole. The negative electrode strap 3b and the terminal 7 'are electrically connected by a negative electrode connecting component 3c, also called a negative electrode column.

  The lead storage battery 1 of the present invention is a liquid type and has an exhaust path for communicating between the internal space 4b of the battery exterior 4 and the external space of the battery exterior 4, that is, the atmosphere. As a configuration example of the exhaust path, as is well known, a configuration in which a liquid port 4a is provided in the battery exterior 4 and a liquid port plug 6 including the exhaust path is attached to the liquid port 4a can be used. Inside the liquid spout 6, a splash-proof body 6 a for suppressing leakage of liquid electrolyte 5 to the outside of the battery, or a filter 6 b that functions as a frame arrester may be arranged. Further, it is not always necessary to include the exhaust path inside the liquid spout 6, and an exhaust path having a labyrinth structure may be arranged inside the battery exterior 4.

  In the lead storage battery 1 of the present invention, the liquid surface 5a in the initial state of the electrolyte 5 is immersed in the positive electrode plate 2, the negative electrode plate 3, the positive electrode strap 2b, and the negative electrode strap 3b, as shown in FIGS. The positive electrode connecting component 2c and the negative electrode connecting component 3c are set at a position to immerse at least a part thereof.

  In the lead storage battery 1 of the present invention, lead or a lead alloy whose antimony content is limited to 0.01% by mass or less is used for the positive electrode connecting component 2c, the positive electrode strap 2b, and the negative electrode strap 3b. On the other hand, a lead alloy containing 0.5% by mass or more of antimony is used for the negative electrode connection part 3c.

  In the configuration of the present invention, since the antimony content contained in the positive electrode connecting component 2c and the positive electrode strap 2b is limited to a small amount of 0.01% by mass or less, the electrolytic solution 5 from the positive electrode connecting component 2c and the positive electrode strap 2b. Antimony elution into the water is suppressed. Therefore, precipitation of antimony on the surface of the negative electrode current collector ear 3a and corrosion of the negative electrode current collector ear 3a due to this are suppressed.

  In addition, since the antimony content of the negative electrode strap 3b in contact with the negative electrode current collector ear 3a containing calcium is limited to a small amount of 0.01% by mass or less, the calcium at the junction between the negative electrode current collector ear 3a and the negative electrode strap 3b is reduced. And the formation of antimony compounds are suppressed, and corrosion of the joints is suppressed. Further, corrosion of the negative strap 3b is also suppressed.

  On the other hand, since the negative electrode connecting part 3c contains 0.5% by mass or more of antimony and a part thereof is in contact with the electrolytic solution 5, the overvoltage of the cell at the time of charging is lowered, and the capacity recoverability after overdischarge is reduced. Is improved. Although the antimony contained in the negative electrode connecting part 3c is electrically connected to the negative electrode active material, the negative electrode active material differs from the case where the negative electrode active material or the negative electrode current collector contains antimony depending on the resistance component between them. It is presumed that the discharge of the local battery formed by the antimony and the antimony can be suppressed, and the accumulation of lead sulfate as the negative electrode active material can be suppressed.

  Therefore, according to the present invention, in a liquid type lead storage battery in which the positive and negative electrode current collectors contain calcium, corrosion of the negative electrode current collector ear, the junction between the negative electrode current collector ear and the negative electrode strap, and the negative electrode strap is suppressed. In addition, the capacity recovery after overdischarge can be remarkably improved.

  When the antimony content of the positive electrode connection component 2c, the positive electrode strap 2b, and the negative electrode strap 3b exceeds 0.01% by mass, the corrosion of the negative electrode current collecting ear 3a, and the junction between the negative electrode current collecting ear 3a and the negative electrode strap 3b easily proceeds. Therefore, it should be avoided. In addition, although these members may be pure lead, when mechanical strength is requested | required, such as for vehicles, you may contain about 0.2 mass%-5.0 mass% tin. .

  The lead alloy containing tin as described above has good weldability and suppresses welding defects in the strap. Moreover, you may contain about 0.03 mass%-about 0.1 mass% calcium. Note that when a lead alloy containing calcium is melted, welding defects may occur due to oxidation of calcium. Therefore, the welding atmosphere is preferably an inert gas atmosphere such as argon.

  On the other hand, if the antimony content of the negative electrode connecting part 3c is less than 0.5% by mass, the capacity recoverability after the overdischarge of the lead storage battery 1 is deteriorated, so the antimony content should be 0.5% by mass or more. It is. In addition, although this invention does not prescribe | regulate the upper limit of this antimony content, 5.0 mass% can be made into the standard of an upper limit as an example. In addition, for the purpose of ensuring the strength of the alloy when a lead-antimony alloy is used, it contains about 0.05 mass% to 0.35 mass% of arsenic and about 0.001 mass% to 0.01 mass% of selenium. It may be. Further, it may contain about 0.01% by mass to 0.5% by mass of tin in consideration of weldability, and is contained as an impurity in the lead-antimony-arsenic alloy, sulfur, copper, bismuth, iron , Nickel and zinc. However, these impurities should be limited to a content that does not impair the self-discharge characteristics and liquid reducing characteristics of the lead-acid battery.

(Second embodiment of the present invention)
The lead storage battery 10 according to the second embodiment of the present invention has a configuration described below in addition to the lead storage battery 1 of the first embodiment described above. FIG. 3 is a view showing a cross section of the lead-acid battery 10 according to the second embodiment of the present invention. In the lead storage battery 10, the interior of the battery exterior 11 is partitioned into a plurality of internal spaces 4 b by partition walls 11 a, and the cells 9 having the same configuration as described in the first embodiment are provided in the internal space 4 b with the electrolyte 5. It is stored with. The initial position of the liquid surface 5a is the same as in the first embodiment.

  In the first embodiment described above, only the positive and negative pole columns that connect between the terminals 7 and 7 'and the positive strap 2b or the negative strap 3b are used as the positive connection component 2c and the negative connection component 3c. On the other hand, in the lead storage battery 10 according to the second embodiment, since a plurality of cells are connected in series inside the battery casing 11, in the cells at both ends of the series connection, either one of the positive and negative connection parts is a pole column. The other connection component is also a component called a connection body used to connect the cell 9 and the cell 9.

  When the number of cells 9 is three or more, the intermediate cell 9 excluding the cells 9 at both ends of the series connection is a connection body for inter-cell connection, both of the positive electrode connection component 2c and the negative electrode connection component 3c. is there. In the present specification, the positive electrode connection component 2c is a generic name for the positive electrode column and the positive electrode connection body, and similarly, the negative electrode connection component 3c is a generic name for the negative electrode column and the negative electrode connection body.

  In the lead storage battery 10 according to the second embodiment of the present invention, in a pair of cells 9 connected in series, a negative electrode connection part 3c for connection between one cell and a positive electrode connection part for connection between cells of the other cell 9 The welded portion with 2c has a configuration that is sealed in a liquid-tight manner with respect to the electrolyte solution 5 of the cell 9 to which the positive electrode connection component 2c belongs.

  In the embodiment shown in FIG. 2, a through hole 11b is formed in the partition 11a at a position corresponding to the positive electrode connecting component 2c and the negative electrode connecting component 3c, and the positive electrode connecting component 2c and the negative electrode connecting component 3c are joined through the through hole 11b. Joined at part 12. A resistance welding method and a plasma welding method can be applied as a joining method of both.

  The positive electrode connection part 2c in which the amount of antimony is limited and the negative electrode connection part 3c containing antimony are melted and solidified to form the joint portion 12. Therefore, the joining part 12 contains antimony at a higher concentration than at least the positive electrode connecting component 2c. When such a joint 12 containing a large amount of antimony is in contact with the electrolytic solution 5 as a part of the positive electrode connecting portion 2c, antimony is eluted into the electrolytic solution 5 and causes corrosion on the negative electrode side. As shown in FIG. 4, at least the positive electrode connection component 2c is disposed at a position hermetically sealed with respect to the electrolyte solution 5 so as not to contact the electrolyte solution 5 of the cell 9 to which the positive electrode connection component 2c belongs.

  For example, in the resistance welding method, such a configuration can be realized by defining the welding heat amount (which has a positive correlation with the energization power during welding) and the heat capacities of the positive electrode connecting component 2c and the negative electrode connecting component 3c. . That is, by increasing the ratio (C / Q) of the heat capacity C of the positive electrode connecting component 2c and the negative electrode connecting component 3c to the welding heat quantity Q, the volume of the connecting portion 12 is reduced, and the positive electrode connecting component 3c after welding is reduced. Antimony exposure on the surface can be suppressed. Further, by increasing the pressure during resistance welding, the close contact between the positive electrode connecting component 2c and the partition wall 11a is maintained, and the contact between the joint 12 and the electrolyte due to the penetration of the electrolyte 5 into the joint 12 is achieved. Can be prevented. In addition, it is permissible for the joint portion 12 to be exposed on the surface of the negative electrode connection component 3c.

  Further, in the plasma welding method, as shown in FIG. 5, the positive electrode connecting member 2c is provided with a convex portion 2d in advance, and the negative electrode connecting component 3c is provided with a through hole 3d that fits the convex portion 2d. If the boundary between the convex portion 2d and the through hole 3d is heated and melted by plasma arc in the state where the convex portion 2d penetrates 3d, the content of antimony on the surface of the positive electrode connecting component 2c after inter-cell connection is The antimony content contained in the positive electrode connection component 2c before the inter-connection is not increased, and the second embodiment of the present invention can be obtained. In such a case, the convex portion 2d having a limited amount of antimony is exposed on the surface of the negative electrode connection part 3c after inter-cell connection, but this does not impair the effect of the present invention and is acceptable.

  According to the second embodiment of the present invention, even in a lead storage battery in which a plurality of cells are connected in series, the effect of the present invention can be obtained as in the first embodiment.

  The lead acid battery (12V48Ah) for starting by the example of this invention and a comparative example was created, and the liquid reduction performance, the presence or absence of corrosion of the negative electrode ear part, and charge acceptance were evaluated by the roller which performs an overcharge test and an overdischarge test. .

  The configurations of the lead storage batteries (hereinafter referred to as batteries) of the present invention and comparative examples will be described below. The current collector used in the batteries of the present invention and the comparative example is a lead-calcium-tin alloy for both positive and negative electrodes. In both the inventive examples and the comparative examples, the calcium content in the positive electrode current collector is 0.07% by mass, the tin content is 1.3% by mass, the calcium content in the negative electrode current collector is 0.07% by mass, The tin content is 0.25% by mass. The antimony content of both the positive electrode current collector and the negative electrode current collector was less than 0.001% by mass.

  Both the positive electrode current collector and the negative electrode current collector are obtained by the expanding method. In this example, after melting a lead alloy containing the above components to cast a strip-shaped slab, the slab is hot-rolled into a long lead alloy sheet, and a staggered slit is formed in the lead alloy sheet. And developed to form a lath network by the expanding method. The lath mesh is filled with a lead-acid battery active material paste according to the polarity, then the lead alloy sheet is cut into a predetermined size and shape, and then aged and dried to obtain an unformed positive electrode plate and negative electrode plate. It was.

  After combining the positive electrode plate, the negative electrode plate and the microporous polyethylene separator obtained above, the positive electrode current collector ear and the negative electrode current collector ear were placed on a comb-shaped mold, and then placed on the current collector ear of each polarity. The lead lead having the composition to be placed was placed, and the positive electrode connecting component and the negative electrode connecting component having the composition to be described later were disposed in a predetermined position of each comb-like mold.

  The additional lead is melted by the burner flame, and molten lead is poured by gravity into the gap between the current collecting ears and the gap between the current collecting ears and the connecting parts. After the molten lead is cooled and solidified, the comb-shaped mold is collected into the current collecting ears. Removed from. In this embodiment, the lead lead melted and solidified corresponds to the positive strap and the negative strap.

  The cells in which the formation of the positive strap and the negative strap are completed are stored in a cell chamber partitioned by a partition inside the battery exterior, and adjacent to each other through a through hole provided in the partition as shown in FIG. The positive electrode connecting component and the negative electrode connecting component were electrically connected by resistance welding. In this example, six cells were connected in series inside the battery exterior. In addition, the connection part melted at the time of resistance welding and cooled and solidified was brought into close contact with the positive electrode connection part and the partition so as not to contact the electrolyte solution on the positive electrode connection part side.

  After that, the battery exterior is closed with a lid, and the terminal formed on the lid is connected to the positive electrode connection component (positive column) and the negative electrode connection component (negative column) provided in the cells at both ends of the series-connected cell rows by welding. The battery was not poured.

Next, an electrolytic solution (dilute sulfuric acid) is injected into the battery from the liquid port provided in the lid corresponding to the cell, and the battery is formed between the terminals. The sulfuric acid concentration was adjusted so as to be 1.280 g / cm ³ (20 ° C.). In addition, as shown in FIGS. 1 to 3, the liquid surface position of the electrolytic solution is immersed in all of the positive electrode plate surface and the positive and negative electrode straps, and all of the positive electrode connecting component and the negative electrode connecting component. The part was in contact with the electrolyte.

  Here, as lead added to be melted and solidified to become a positive electrode strap or a negative electrode strap, a lead-tin alloy (hereinafter referred to as alloy A) having an antimony content of 0.005 mass% and containing 2.5 mass% of tin One of lead-antimony alloys (hereinafter referred to as Alloy B) having an antimony content of 2.5% by mass and further containing 0.2% by mass of arsenic was used.

  In addition, the positive electrode connecting component and the negative electrode connecting component were also two types of alloys A and B similar to the above-described lead.

  Table 1 shows combinations of alloys used for the positive electrode strap, the negative electrode strap, the positive electrode connecting component, and the negative electrode connecting component of the batteries of the present invention and the comparative example.

  Each battery shown in Table 1 was subjected to an overcharge test under the following conditions.

(Overcharge test)
The overcharge test in this example is intended for comparative evaluation of the liquid reduction characteristics of each battery and the negative electrode current collector ear, the negative electrode current collector ear and the negative electrode strap joint and the negative electrode strap corrosion, This test pattern assumes how the overcharge tendency is used.

  In the overcharge test, each battery shown in Table 1 was continuously performed in a gas phase atmosphere at 75 ° C. for 120 hours, with the charge voltage controlled to a constant voltage of 13.8 V, and after this charge. By repeating the cycle consisting of a 48-hour rest in a 75 ° C. gas phase atmosphere 12 times.

  In addition, in order to assume a state in which liquid reduction progresses due to charging, and thus the upper part of the electrode plate is exposed from the electrolyte solution, the electrolyte solution is set to the lower limit level (the lower half of the positive electrode connector and the negative electrode connector is immersed in the electrolyte solution). In the state where each upper half is exposed from the electrolyte solution), when one cycle is completed, if the electrolyte surface level drops from the bottom of the negative strap to 10 mm, the next cycle charge is Immediately before the start, ion exchange water was replenished to adjust the liquid surface position to the lower limit level described above.

  This rehydration was also done after the last 12th charge. Moreover, the mass of ion-exchanged water supplemented was recorded for each battery, and the cumulative mass of ion-exchanged water supplemented up to the time when the overcharge test was completed was calculated. The accumulated mass of supplemented ion-exchanged water in each battery corresponds to the accumulated liquid reduction amount of each battery. Then, the percentage of the liquid reduction amount of each battery with respect to the liquid reduction amount of the battery P was determined as the liquid reduction amount (%).

  Disassembling each battery that has been overcharged, disconnecting the connection between the cells, and cutting the negative electrode current collector ear and the negative electrode plate at the base of the negative electrode current collector ear, the negative electrode strap and the negative electrode current collector ear Was sampled. The negative electrode strap and the negative electrode current collector ear were washed with water and dried, and then the state of the negative electrode strap, the joint state between the negative electrode strap and the negative electrode current collector ear were visually confirmed, and the thickness of the negative electrode current collector ear was measured.

  Regarding the thickness measurement of the negative electrode current collector ear, after removing the corrosion products generated on the surface of the negative electrode current collector ear, the thickness of the thinnest portion of the negative electrode current collector ear is measured, and this measured thickness is tested. The previous percentage of the thickness of the negative electrode current collector ear in the initial state was determined, and the value of this percentage was defined as the negative electrode current collector ear remaining rate. When there is no corrosion, the negative electrode current collecting ear remaining rate is 100 (%), and when the corrosion causes a portion of the negative electrode current collecting ear thickness to be 0, the negative electrode current collecting ear remaining rate is 0 (%). It becomes.

  Table 2 shows the liquid reduction amount, the measurement result of the negative electrode current collecting ear remaining rate, and the state observation result of the negative electrode strap obtained above.

  From the results shown in Table 2, in particular, the batteries E to P of the comparative example contained less in the initial stage of liquid reduction, but contained in the positive electrode side connection parts (positive electrode connection body and positive electrode column) as the cycle progressed. It is thought that this is because antimony is eluted and deposited on the negative electrode, the hydrogen overvoltage is lowered, and hydrogen gas is easily generated.

  The batteries E to H of the comparative example have a relatively small amount of liquid reduction than the batteries IL to the comparative example, and the batteries I to L of the comparative example have a relatively small amount of liquid reduction than the batteries M to P of the comparative example. . In the battery of this example, such a difference in the amount of liquid reduction is that the surface area of the strap part is larger than that of the connection body part, and therefore, in the positive electrode, the surface area of the portion containing antimony increases toward the negative electrode side. This is considered to be caused by the increased amount of antimony deposited.

  Further, the negative electrode side was not as large as the positive electrode side described above, but there was a tendency that the amount of liquid reduction increased as the surface area of the portion containing a large amount of antimony increased.

  On the other hand, the batteries A, C and D of the comparative examples and the battery B of the example of the present invention increase the liquid reduction with the progress of the cycle by limiting the amount of antimony in the positive electrode strap and the connecting part of the positive electrode to a small amount. The effect which eliminates is seen and the final liquid reduction amount can be suppressed to 40 to 53% of the battery P of a comparative example.

  Further, the corrosion of the negative electrode current collecting ear in this test was remarkable and particularly remarkable in the batteries E to P of the comparative examples. In the comparative battery B and the battery A of the present invention, corrosion of the negative electrode current collector ear, the negative electrode strap, and the junction between the negative electrode current collector ear and the negative electrode strap was suppressed. This is because, in the batteries E to P of the comparative examples, antimony contained in a large amount in the positive electrode strap and / or the connecting component is deposited on the negative electrode current collector ear during the overcharge test. Is considered to have corroded. In this respect, regarding the batteries A, C, and D of the comparative examples and the battery B of the example of the present invention, it was considered that the antimony deposition on the negative electrode current collector ear was suppressed and the corrosion of the negative electrode current collector ear was significantly suppressed. It is done.

  Further, in the batteries C and D of the comparative example, as described above, although the corrosion of the negative electrode current collector ear portion was suppressed, the progress of corrosion at the joint portion between the negative electrode current collector ear and the strap was recognized. This is because if the lead contains a lot of antimony, when the lead is melted to form a strap, the antimony contained in the lead and the calcium contained in the negative current collector ear react easily. This is thought to be due to the formation of corrosive calcium and antimony compounds.

  On the other hand, the battery A of the comparative example and the battery B of the example of the present invention are limited to 0.005% by mass of antimony in the positive electrode connecting part and the positive and negative electrode straps. There is no cause of the above-described corrosion reaction at the joint between the negative electrode strap and the negative electrode strap, and it is considered that the negative electrode current collector ear and the negative electrode current collector ear and the negative electrode strap had good corrosion resistance.

(Overdischarge test)
Next, an overdischarge test was performed on each battery shown in Table 1 assuming that it was left overdischarged. In the overdischarge test, each battery whose temperature was adjusted to 25 ° C. was continuously discharged at a constant current of 9.6 A until the battery voltage reached 10.5 V to obtain a complete discharge state in 5-hour rate discharge ( After the first discharge), a 10 W lamp is connected between the terminals of each battery, and the battery with the 10 W lamp connected is left in a gas phase atmosphere at 40 ° C. for 14 days. The battery which was removed from between the terminals and opened was left to stand (overdischarge left) for 14 days under the same atmosphere.

  The battery after being left overdischarged was further left in a gas phase atmosphere at 25 ° C. for 24 hours to adjust the temperature of the battery to 25 ° C. The battery was recovered and charged in a gas phase atmosphere at 25 ° C. The conditions for recovery charging are constant voltage charging with a maximum charging current of 25 A and a maximum charging voltage controlled to 15.0V. This recovery charge was carried out continuously for 4 hours. After the completion of the recovery charge, each battery was continuously discharged at a constant current of 9.6 A until the battery voltage reached 10.5 V, and the discharge duration was measured. The product of the discharge duration and the discharge current (9.6 A) is the recovery capacity after overdischarge of the battery. Table 3 shows the measurement results of the recovery capacity. The recovery capacity shown in Table 3 is expressed as a percentage of the recovery capacity of the battery P.

  From the results shown in Table 3, the recovery capacity of only the battery A of the comparative example was significantly inferior to the battery B of the present invention example and the batteries CP of other comparative examples. This difference is considered to be caused by antimony present in the battery. In particular, the negative electrode side connection component and / or the negative electrode strap containing a large amount of antimony has shifted the charging potential of the negative electrode plate during charging in a more noble direction and improved the charging efficiency of the positive electrode plate. It is thought to have occurred. The positive electrode side connection component and / or the positive electrode strap containing antimony shows a better recovery capacity than the battery A. This is because the antimony contained in the positive electrode side connection component and / or the positive electrode strap is an electrolyte. This is thought to be due to elution into the negative electrode and re-deposited on the negative electrode side.

  As described above, the battery A according to the present invention has the effect of inhibiting the corrosion of the negative electrode current collector and / or the junction between the negative electrode current collector and the negative electrode strap in the lead-acid battery using the positive and negative current collectors, and the overdischarge caused by antimony. The effect of improving the subsequent capacity recovery can be obtained at the same time. Moreover, the amount of liquid reduction is also suppressed as compared with the conventional lead storage battery using a lead alloy containing antimony in the positive and negative straps.

  Next, for the battery B shown in Table 1, the resistance welding current was increased to such an extent that no molten lead was scattered, and a battery (battery Q of the example of the present invention) in which resistance welding was performed between cells was created. . In this battery Q, a part of the antimony contained in the negative electrode connection body of the adjacent cells at the time of welding between the cells is exposed to a part of the positive electrode connection body, and this part is in contact with the electrolytic solution.

  When the above-described overcharge test and overdischarge test were performed on this battery Q, the liquid reduction amount was 41% with respect to the battery P, the negative electrode current collecting ear remaining rate was 96%, and the state of the negative electrode strap was good. The recovery capacity after being left overdischarged was 99%. The characteristics of the battery Q are the characteristics excluding the recovery capacity after being left overdischarged, and are slightly inferior to the battery B of the present invention example, but the amount of liquid reduction and the negative electrode current collection compared with each battery of the comparative example The ear remaining rate, the state of the negative electrode strap, and the recovery capacity after being left overdischarged were compatible at the same time.

  The reason why the battery Q is slightly inferior to the battery B is presumed that a part of the junction between the negative electrode connector and the positive electrode connector is in contact with the electrolyte solution of the cell on the positive electrode connector, and a small amount of antimony is eluted from the junction. . Such a small amount of antimony does not greatly impair the effect of the present invention. However, in order to obtain the effect of the present invention most remarkably, a part of the joint is an electrolyte solution with respect to the electrolyte solution on the positive electrode current collector side. Most preferably, it is in a liquid-tight state.

  In this example, 0.005% by mass of antimony contained in the positive electrode strap, the positive electrode column, the positive electrode connector, and the negative electrode strap of the battery B and the battery Q of the present invention example, and the antimony included in the negative electrode connector and the negative electrode column was Although the content is 2.5% by mass, the same characteristics as those of the battery B and the battery Q of the present invention example can be obtained by setting the former to 0.01% by mass or less and the latter to 0.5% by mass or more. The effect of the present invention was obtained.

  The present invention can be applied to liquid lead acid batteries for various uses, including lead acid batteries for starting.

DESCRIPTION OF SYMBOLS 1 Lead acid battery 2 Positive electrode plate 2a Positive electrode current collection ear 2b Positive electrode strap 2c Positive electrode connection component 2d Convex part 3 Negative electrode plate 3a Negative electrode current collection ear 3b Negative electrode strap 3c Negative electrode connection component 3d Through-hole 4 Battery exterior 4a Liquid port 4b Internal space 5 Electrolysis Liquid 5a Liquid surface 6 Liquid stopper 6a Splash-proof body 6b Filter 7, 7 'Terminal 8 Separator 9 Cell 10 Lead storage battery 11 Battery exterior 11a Partition 11b Through-hole 12 Joint part

Claims (3)

The positive electrode plate and the negative electrode plate are immersed in the electrolytic solution,
A liquid lead-acid battery having a path for discharging gas released from the positive electrode plate and / or the negative electrode plate in a battery exterior,
The positive electrode plate and the negative electrode plate each include a positive electrode current collector and a negative electrode current collector made of a lead-calcium alloy,
A positive electrode strap that collectively welds positive electrode current collecting ears provided integrally with the positive electrode current collector;
Provided with a positive electrode connection part for inter-cell connection and / or terminal connection provided on the positive electrode strap,
A negative electrode strap that collectively welds negative electrode current collector ears provided integrally with the negative electrode current collector;
Provided with a negative electrode connection part for inter-cell connection and / or terminal connection provided in the negative electrode strap,
The positive electrode strap, the positive electrode connecting component, the negative electrode strap and the negative electrode connecting component are all at least partially immersed in an electrolyte solution,
The positive electrode strap, the positive electrode connection component and the negative electrode strap are made of lead or a lead alloy whose antimony content is limited to 0.01% by mass or less,
The lead-acid battery, wherein the negative electrode connecting component is made of lead or a lead alloy containing 0.5% by mass or more of antimony. The lead acid battery according to claim 1, wherein the positive electrode strap, the positive electrode connecting component, and the negative electrode strap are made of a lead-tin alloy. Have multiple cells,
The cell comprises a series connection;
The negative electrode connection part for inter-cell connection of one of two cells connected in series;
The lead-acid battery according to claim 1 or 2, wherein a welded portion between the other cell and the positive electrode connection part for inter-cell connection is sealed in a liquid-tight manner at least with respect to the electrolyte of the other cell.

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