JP2014123510A - Lead storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead storage battery that has sufficient charge acceptability, durability (lifetime characteristic) and a discharge characteristic at low temperature, which can be applied to an idling stop vehicle to be used in a 'very short drive' mode.SOLUTION: In a lead storage battery, a plurality of plate groups 5 each having a plurality of positive-electrode plates 2 and negative-electrode plates 3 laminated through a separator 4 are individually housed together with an electrolyte in a plurality of cell chambers 6. The positive electrode plate 2 comprises a positive electrode grid and a positive-electrode active material filled in the positive electrode grid, and the negative electrode plate 3 comprises a negative electrode grid and a negative-electrode active material filled in the negative electrode grid. To the negative-electrode active material is added natural lignin derived from wood. When a mass of the positive-electrode active material per cell chamber 6 is denoted by Mand a mass of the negative-electrode active material is denoted by M, a mass ratio M/Mis in a range of 0.70 to 1.10.

Description

  The present invention relates to a lead storage battery used in an idling stop vehicle.

  The idling stop vehicle can improve fuel consumption by stopping the engine while the vehicle is stopped. However, since the lead storage battery supplies all electric power such as an air conditioner and a fan during idling stop, the lead storage battery tends to be insufficiently charged. Therefore, the lead storage battery is required to have a high charge acceptability that can be charged more in a short time in order to solve the shortage of charging. In addition, since idling stop vehicles frequently turn the engine on and off repeatedly, the lead discharge produced immediately after the lead sulfate generated by discharge is restored to lead dioxide and lead by charging. Life is likely to decrease. Therefore, the lead storage battery is also required to have high durability in order to eliminate the decrease in life.

  In order to improve the charge acceptability of the lead storage battery, Patent Document 1 describes a lead storage battery in which aluminum ions are contained in an electrolytic solution. Aluminum ions have the effect of suppressing the coarsening of the lead sulfate crystals produced at the positive and negative electrodes during discharge, thereby improving the charge acceptance performance of the lead storage battery.

  Further, in order to improve the durability of the lead storage battery, Patent Document 2 describes a lead storage battery in which a lead alloy layer containing antimony is provided on the surface of a negative electrode lattice not containing antimony. The lead alloy layer containing antimony has an effect of efficiently charging and recovering the negative electrode plate, and thereby the durability of the lead storage battery can be improved.

  Patent Document 3 describes a technique for suppressing shrinkage of the negative electrode active material due to repeated charge / discharge and suppressing deterioration of high rate discharge characteristics by adding lignin to the negative electrode active material.

JP 2006-4636 A JP 2006-156371 A Japanese Patent No. 11-185738

  Lead-acid batteries used in idling stop vehicles tend to be undercharged. Therefore, for the purpose of preventing overdischarge of the lead storage battery, the idling stop vehicle may be provided with a fail-safe mechanism that does not discharge the lead storage battery when the state of charge (SOC) becomes a predetermined value (for example, 60%) or less. is there.

  FIG. 1 is a graph schematically showing a state of charge (SOC) when a lead-acid battery is repeatedly discharged and charged in an idling stop vehicle. The line graph shown in FIG. 1 shows a pattern in which the lead storage battery is discharged while the vehicle is stopped, the SOC decreases, the vehicle travels again, the lead storage battery is charged, the SOC is recovered, and this is repeated. It is shown.

  If the lead-acid battery has a high charge acceptance, the lead-acid battery recovers to about 100% while the car is running. Therefore, even if the idling stop car is run for a long time as shown in the line graph A in FIG. The charge / discharge of the lead storage battery can be repeated.

  However, if the rechargeability of the lead storage battery is not high, as shown in the line graph B in FIG. 1, when the car stops in a state where the charging cannot be sufficiently performed during traveling and the SOC does not recover to 100%, Decrease in SOC due to discharge increases. When such charging / discharging is repeated, the SOC gradually decreases. In this case, when the fail-safe mechanism is provided in the idling stop vehicle, the fail-safe mechanism is activated and the discharge is stopped when the SOC becomes a predetermined value (for example, 60%) or less.

  In particular, when driving a car with a short mileage (hereinafter referred to as “choy ride”), the fail-safe mechanism is frequently used because the SOC cannot be fully charged and the SOC does not recover to 100%. Invite the situation to operate. Furthermore, when “choy ride” is performed only on weekends, the state of operation of the fail-safe mechanism becomes more conspicuous because the SOC is further lowered due to self-discharge and dark current while the vehicle is stopped.

  In addition, for example, when the idling stop vehicle is used in the “choi riding” mode in a low temperature region below 0 ° C. and a relatively deep charge / discharge is repeated, the low temperature discharge characteristic of the lead storage battery is poor. When the engine is restarted after the stop, the battery voltage decreases and the engine cannot be restarted, so that the situation where the fail-safe mechanism is activated becomes more remarkable.

  However, heretofore, there has been no lead-acid battery that has sufficient charge acceptance, durability (life characteristics), and low-temperature discharge characteristics that can be applied to an idling stop vehicle used in such a “choi ride” mode.

  The present invention has been made in view of such a problem, and its main purpose is sufficient charge acceptance, durability (lifetime characteristics), and low temperature, which can be applied to an idling stop vehicle used in the “choy ride” mode. The object is to provide a lead-acid battery having both discharge characteristics.

A lead storage battery according to the present invention is a lead storage battery in which a plurality of electrode plate groups in which a plurality of positive electrode plates and negative electrode plates are laminated via separators are respectively accommodated in a plurality of cell chambers together with an electrolytic solution. The plate includes a positive electrode lattice and a positive electrode active material filled in the positive electrode lattice. The negative electrode plate includes a negative electrode lattice and a negative electrode active material filled in the negative electrode lattice. The negative electrode active material is derived from wood. natural lignin has been added, when the mass of the positive electrode active material per cell chamber and _{M P,} the mass of the negative active material and _{M N,} by mass ratio _M N / _{M P} is 0.70 to 1.10 It is characterized by being in the range of

  In a preferred embodiment, natural lignin is added to the negative electrode active material in a range of 0.02 to 0.6% by mass with respect to the negative electrode active material.

  ADVANTAGE OF THE INVENTION According to this invention, the lead storage battery which has sufficient charge acceptance property, durability (lifetime characteristic), and low-temperature discharge characteristic which can be applied to the idling stop vehicle used by "choi riding" mode can be provided. .

It is the graph which showed typically the charge condition (SOC) when discharge and charge of a lead storage battery in an idling stop vehicle are repeated. 1 is an overview diagram schematically showing a configuration of a lead storage battery in an embodiment of the present invention. (A), (b) is the figure which showed the structure of the connection component connected by welding. It is the figure which showed the structure of the connection component integrally formed by casting.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention. Furthermore, combinations with other embodiments are possible.

  FIG. 2 is an overview diagram schematically showing the configuration of the lead storage battery 1 in one embodiment of the present invention.

  As shown in FIG. 2, in the lead storage battery 1, an electrode plate group 5 in which a plurality of positive electrode plates 2 and a negative electrode plate 3 are stacked via a separator 4 is accommodated in a cell chamber 6 together with an electrolytic solution.

  Here, the positive electrode plate 2 includes a positive electrode lattice and a positive electrode active material filled in the positive electrode lattice, and the negative electrode plate 3 includes a negative electrode lattice and a negative electrode active material filled in the negative electrode lattice.

  The plurality of positive electrode plates 2 are connected to each other in parallel with each other by the positive electrode straps (electrode plate connection plates) 7 at the ears 9 of the positive electrode lattice. They are connected in parallel by (electrode plate connection plate) 8. Further, the plurality of electrode plate groups 5 accommodated in each cell chamber 6 are connected in series via a connection body 11. Polar columns (not shown) are welded to the positive strap 7 and the negative strap 8 in the cell chambers 6 at both ends, respectively, and the respective polar columns are connected to the positive terminal 12 and the negative terminal 13 disposed on the lid 14. Each is welded.

  In the present embodiment, wood-derived natural lignin is added to the negative electrode active material. Natural lignin derived from wood has the effect of suppressing the shrinkage of the negative electrode active material due to repeated charge and discharge, and suppressing the decrease in low-temperature discharge characteristics, thereby suppressing the decrease in voltage at engine restart. it can.

Further, in the present embodiment, when the mass of the positive electrode active material per cell chamber 6 and _{M P,} the mass of the negative electrode active material and _{M N,} the mass ratio _M N / _{M P} therebetween, from 0.70 to 1. It is set to a range of 10, preferably 0.80 to 1.00. When the mass ratio M _{N /} M _P of the negative electrode active material for the positive electrode active material is in this range, while maintaining the life characteristics, improved charge acceptance of the lead storage battery 1, the idling stop vehicle, "Choi low temperature region Even when used in the “riding” mode, the operation of the fail-safe mechanism can be suppressed.

  Here, “natural lignin derived from wood” in the present invention refers to lignin produced by chemical treatment using natural lignin extracted as a by-product in the process of producing pulp from wood. Synthetic lignin produced in this way (for example, synthetic lignin containing a bisphenolsulfonic acid-based condensate) is not included.

  In the present embodiment, the wood-derived natural lignin (hereinafter simply referred to as “natural lignin”) is in the range of 0.02 to 0.6% by mass relative to the negative electrode active material, more preferably, relative to the negative electrode active material. Thus, it is added to the negative electrode active material in the range of 0.05 to 0.5% by mass. As a result, even if the idling stop vehicle is used in the “choy ride” mode in a low temperature region below 0 ° C., it is possible to suppress the voltage drop at the time of engine restart and to suppress the operation of the fail safe mechanism. it can.

  In the present invention, it is preferable that a synthetic lignin containing a bisphenolsulfonic acid-based condensate is further added to the negative electrode active material. Thereby, the charge acceptance property of a lead storage battery can further be improved. Here, the synthetic lignin is preferably added to the negative electrode active material in a range of 0.05 to 0.3% by mass with respect to the negative electrode active material.

  Moreover, in this invention, it is preferable that the aluminum ion is added to the electrolyte solution in 0.01-0.3 mol / L. Thereby, the charge acceptance property of a lead storage battery can further be improved.

  In the present embodiment, the positive electrode plate 2 and the negative electrode plate 3 of the electrode plate group 5 are connected in parallel by straps (electrode plate connection plates) 7 and 8 extending in the stacking direction of the electrode plates, respectively. The electrode plate connection plates 7 and 8 of the plate group 5 are connected in series via the connection body 11, and the connection body 11 is connected to the electrode plate connection plates 7 and 8 on the line on which the electrode plate connection plates 7 and 8 extend. It is preferable that they are integrally formed. Thereby, the internal resistance of the lead storage battery is reduced, and the charge acceptance of the lead storage battery can be further improved.

  Here, the electrode plate connection plates 7 and 8 are respectively connected to the ear portions 9 and 10 of the positive electrode plate 2 and the negative electrode plate 3, and the electrode plate connection plates 7 and 8 and the connection body 11 are the ear portions 9 and 10. In addition, it is preferable that they are integrally formed by casting (COS: Cast on Strap).

Hereinafter, the structure and effect of the present invention will be further described with reference to examples of the present invention. The present invention is not limited to these examples.
(1) Production of lead acid battery The lead acid battery 1 produced in the present example is a liquid lead acid battery having a D23L type size defined in JIS D5301. Each cell chamber 6 accommodates seven positive electrode plates 2 and eight negative electrode plates 3, and the negative electrode plate 3 is accommodated in a bag-like polyethylene separator 4.

  The positive electrode plate 2 was prepared by kneading lead oxide powder with sulfuric acid and purified water to prepare a paste, and filling this into an expanded lattice made of a calcium-based lead alloy composition.

  The negative electrode plate 3 is prepared by adding 0.3% by mass of wood-derived natural lignin to the lead oxide powder and kneading with sulfuric acid and purified water to prepare a paste, which is composed of a calcium-based lead alloy composition. It was prepared by filling an expanded lattice.

  After the produced positive electrode plate 2 and negative electrode plate 3 are aged and dried, the negative electrode plate 3 is accommodated in a polyethylene bag-like separator 4 and is alternately stacked with the positive electrode plates 2 to form seven positive electrode plates 2 and eight negative electrode plates. An electrode plate group 5 in which 3 and 3 were laminated via a separator 4 was produced. Each of the electrode plate groups 5 was accommodated in a cell chamber 6 partitioned into six, and a lead storage battery 1 in which six cells were directly connected was produced.

An electrolytic solution made of dilute sulfuric acid having a density of 1.28 g / cm ³ was put into the lead storage battery 1 and a battery case was formed to obtain a lead storage battery 1 of 12V48Ah.
(2) Characteristic evaluation of lead acid battery (2-1) Evaluation of life characteristic The life characteristic of the lead acid battery was evaluated by repeating charging / discharging which assumed idling stop with respect to the produced lead acid battery.

The test of the life characteristic was performed under the conditions shown below, which almost conformed to the battery industry association standard (SBA S 0101). The ambient temperature was 25 ° C. ± 2 ° C.
(A) After discharging at a discharge current of 45 A for 59 seconds, discharge at 300 A for 1 second.
(B) Thereafter, the battery is charged for 60 seconds at a charge voltage of 14.2 V (limit current 100 A).
(C) Charging / discharging of (A) and (B) is taken as one cycle, and after leaving for 48 hours every 3600 cycles, the cycle is started again.

The above cycle was repeated, and the number of cycles when the discharge voltage was less than 7.2 V was defined as the life characteristic. In the above test, water replenishment was not performed until 30000 cycles.
(2-2) Characteristic Evaluation of “Choide Ride” Mode For the produced lead storage battery 1, charge / discharge assuming the “Choide Ride” mode was repeated, and the characteristic evaluation of the “choi ride” mode of the lead storage battery was performed. . The ambient temperature was 25 ° C. ± 2 ° C.
(A) Discharge at 9.6 A for 2.5 hours and leave for 24 hours.
(B) Discharge at a discharge current of 20 A for 40 seconds.
(C) Charge for 60 seconds at a charge voltage of 14.2 V (limit current 50 A).
(D) Charge / discharge of (B) and (C) is repeated 18 times, and then discharged at a discharge current of 20 mA for 83.5 hours.
(E) Charging / discharging of (B) to (D) is set as one cycle, and 20 cycles are repeated.

The state of charge (SOC) of the lead-acid battery after the above 20 cycles was measured, and this value was taken as the “choy ride” mode characteristic.
(2-3) Low-temperature discharge characteristics Assuming the case where the lead-acid battery 1 is used in a “choi ride” mode in a low-temperature region where the lead-acid battery 1 is lower than 0 ° C. with respect to the produced lead-acid battery 1, The low temperature discharge characteristics were evaluated by the following methods.

  It was allowed to stand for 18 hours in a -15 ° C environment, and then discharged at a current of 300 A, and the discharge duration until the voltage dropped to 7.2 V was measured.

Example 1
A natural lignin derived from wood is added to the negative electrode active material, and when the mass of the positive electrode active material per cell chamber is M _P and the mass of the negative electrode active material is _MN , the mass ratio M _N / _{MP is set} to 0.00. Batteries 1 to 7 were prepared in the range of 65 to 1.15, and the life characteristics, “choy ride” mode characteristics, and low temperature discharge characteristics of each battery were evaluated.

  Here, the amount of natural lignin added to the negative electrode active material was 0.3% by mass with respect to the negative electrode active material. The negative electrode lattice was an expanded lattice of Pb-1.2Sn-0.1Ca, and the positive electrode lattice was an expanded lattice of Pb-1.6Sn-0.1Ca.

  Table 1 is a table showing the evaluation results of each characteristic. As a comparative example, a battery 8 in which natural lignin was not added to the negative electrode active material was produced.

As shown in Table 1, the batteries 2-6 range of mass ratio _M N / _{M P} is 0.70 to 1.10, lifetime characteristics at least 28,800 times, SOC indicating "Choi ride" mode characteristics Is 66% or more, and it can be seen that the discharge duration showing low-temperature discharge characteristics is 2.0 minutes or more. A lead-acid battery that satisfies these values can suppress the operation of the fail-safe mechanism while maintaining sufficient life characteristics even when the idling stop vehicle is used in a “choy ride” mode in a low temperature region. In particular, the mass ratio _M N / _{M P} in the range of battery 3-5 0.80 to 1.00 is the lifetime characteristics 32,400 times or more, with SOC indicating "Choi ride" mode characteristic 70% Both have excellent performance when using an idling stop vehicle in the “Choide” mode.

In contrast, in the battery 1 in mass ratio _M N / _{M P} 0.65, the lifetime characteristic is a 28,800 times, SOC indicating "Choi ride" mode characteristic is as low as 45%. This is presumably because the amount of the negative electrode active material is insufficient with respect to the amount of the positive electrode active material, so that the charge acceptance is reduced.

Further, the battery 7 of the mass ratio _M N / _{M P} 1.15, although SOC indicating "Choi ride" mode characteristic becomes 75%, the life characteristics are as low as 18,000 times. This is because the amount of the positive electrode active material is insufficient with respect to the amount of the negative electrode active material, and the softening of the positive electrode active material proceeds. It is considered that the deterioration of the positive electrode plate was advanced.

  On the other hand, in the battery 8 in which natural lignin is not added to the negative electrode active material, the life characteristic is 36,000 times, the SOC showing the “choy ride” mode characteristic is 75%, or the discharge duration showing the low temperature discharge characteristic. Is as short as 0.5 minutes. This is probably because natural lignin was not added to the negative electrode active material, and thus the effect of suppressing the shrinkage of the negative electrode active material due to repeated charge and discharge was not exhibited, and the high rate discharge characteristics were low.

From the above results, the natural lignin is added to the negative electrode active material, and the mass ratio _M N / _{M P} of the negative electrode active material for the positive electrode active material, ranging from 0.70 to 1.10, more preferably, 0. By setting it in the range of 80 to 1.00, it is possible to realize a lead storage battery suitable for an idling stop vehicle used in the “choy ride” mode, in which the operation of the fail-safe mechanism is suppressed.

(Example 2)
Batteries 9 to 15 in which the amount of natural lignin added to the negative electrode active material was changed to a range of 0.01 to 0.7 mass% with respect to the battery 4 produced in Example 1 in order to improve the low temperature discharge characteristics. The battery life characteristics, “choi riding” mode characteristics, and low-temperature discharge characteristics were evaluated. Here, the battery 12 is the same as the battery 4 produced in Example 1.

  Table 2 is a table showing the evaluation results of each characteristic.

  As shown in Table 2, in the batteries 10 to 14 in which the amount of natural lignin added is in the range of 0.02 to 0.6% by mass, the SOC having a life characteristic of 28,800 times or more and a “choy ride” mode characteristic is obtained. Is 70% or more, and it can be seen that the discharge duration showing low temperature discharge characteristics is 2.0 minutes or more. A lead-acid battery that satisfies these values can suppress the operation of the fail-safe mechanism while maintaining sufficient life characteristics even when the idling stop vehicle is used in a “choy ride” mode in a low temperature region. In particular, the batteries 11 to 13 in which the amount of natural lignin added is in the range of 0.05 to 0.5% by mass have a lifetime characteristic of 32,400 times or more and an SOC exhibiting a “choi riding” mode characteristic of 75% or more. The discharge duration time of 2.0 minutes or more, which shows low-temperature discharge characteristics, is excellent in all cases, and has a suitable performance when using an idling stop vehicle in the “choi ride” mode.

  On the other hand, in the battery 9 in which the amount of natural lignin added is 0.01% by mass, the discharge duration showing low-temperature discharge characteristics is as short as 0.1 minute. This is presumably because the effect of suppressing the shrinkage of the negative electrode active material by natural lignin was not sufficiently exhibited.

  Further, in the battery 15 in which the amount of natural lignin added is 0.7 mass%, the SOC showing the “choi riding” mode characteristic is as low as 66%. This is thought to be due to the fact that the amount of natural lignin added was excessive and the charge acceptance was reduced.

  From the above results, when the amount of natural lignin added is 0.02 to 0.6% by mass, more preferably 0.05 to 0.5% by mass, the low-temperature discharge characteristics are improved and the “choy ride” mode is achieved. Even when applied to an idling stop vehicle used in the above, the operation of the fail-safe mechanism can be more effectively suppressed.

(Example 3)
Next, in order to further improve the charge acceptability, synthetic lignin was added to the negative electrode active material in a range of 0.05 to 0.3% by mass to the batteries 14 and 15 produced in Example 2. Batteries 16 to 18 and 19 to 21 were prepared, and the life characteristics, “choy ride” mode characteristics, and low temperature discharge characteristics of each battery were evaluated. Here, the amount of natural lignin added to the batteries 16 to 18 is 0.6% by mass, and the amount of natural lignin added to the batteries 19 to 21 is 0.7% by mass.

  In addition, the synthetic lignin in this invention means the synthetic lignin containing the bisphenolsulfonic acid type condensate produced | generated by chemically synthesize | combining, In this Example, Nippon Paper Chemicals Co., Ltd. Vispaz P215 was used.

  Table 3 is a table showing the evaluation results of each characteristic.

  As shown in Table 3, in the batteries 16 to 18 in which the synthetic lignin is further added to the negative electrode active material, it is understood that the SOC showing the “choy ride” mode characteristic is 75% or more. In addition, in the batteries 19 to 21 in which synthetic lignin is further added to the negative electrode active material, it is understood that the SOC showing “choy riding” mode characteristics is 70% or more. This is considered to be because the charge acceptance of the lead storage battery was further improved by adding synthetic lignin. This effect is particularly effective for the negative electrode active material to which a relatively large amount of natural lignin is added, and the effect is exhibited by the addition of a small amount of synthetic lignin of 0.05 to 0.3% by mass.

From the above results, by further adding synthetic lignin in the range of 0.05 to 0.3% by mass to the negative electrode active material, the charge acceptance is further improved, and the idling stop vehicle used in the “choy ride” mode. Even if it applies to, the operation | movement of a fail safe mechanism can be suppressed more effectively.
Example 4
In order to further improve the charge acceptability, batteries 22 to 24 in which aluminum ions were added to the electrolyte solution in a range of 0.01 to 0.3 mol / L to the batteries 14 and 15 produced in Example 2 were added. 25 to 27 were prepared, and the life characteristics, “choy ride” mode characteristics, and low temperature discharge characteristics of each battery were evaluated. Here, the batteries 22 to 24 have a natural lignin addition amount of 0.6 mass%, and the batteries 25 to 27 have a natural lignin addition amount of 0.7 mass%.

  The amount of aluminum ion added was adjusted by changing the amount of aluminum sulfate added to the electrolyte.

  Table 4 is a table showing the evaluation results of each characteristic.

  As shown in Table 4, in the batteries 22 to 24 in which aluminum ions are added to the electrolytic solution, it is understood that the SOC showing the “choy ride” mode characteristic is 75% or more. In addition, in the batteries 25 to 27 in which aluminum ions are added to the electrolytic solution, it is understood that the SOC showing the “choi riding” mode characteristic is 70% or more. This is thought to be because the charge acceptability of the lead-acid battery was further improved by adding aluminum ions to the electrolyte. This effect is particularly effective for the negative electrode active material to which a relatively large amount of natural lignin is added, and the effect is exhibited by the addition of a small amount of aluminum ions of 0.01 to 0.3 mol / L.

From the above results, by adding aluminum ions to the electrolyte in the range of 0.01 to 0.3 mol / L, the charge acceptance is further improved and applied to the idling stop vehicle used in the “choi ride” mode. However, the operation of the fail-safe mechanism can be more effectively suppressed.
(Example 5)
In order to further improve the charge acceptance, the strap (electrode connection plate) that connects the positive electrode plate 2 and the negative electrode plate 3 constituting the electrode plate group 5 in parallel to the batteries 2, 3, and 4 produced in Example 1. ) 7, 8 and batteries 28, 29, 30 with different configurations of the connection body 11 connecting the electrode plate connection plates 7, 8 of the adjacent electrode plate group 5 are manufactured. The mode characteristics and the low temperature discharge characteristics were evaluated.

  FIGS. 3A and 3B are diagrams showing the configurations of the electrode plate connection plates 7 and 8 and the connection body 11 (hereinafter collectively referred to as “connection components”) used in the batteries 2, 3, and 4. . As shown in FIG. 3 (a), the electrode plate connection plates 7, 8 and the connection body 11 are supplied as separate members, and the connection parts are connected to the ears 9, 10 by welding as shown in FIG. 3 (b). It is configured to be connected together.

  On the other hand, as shown in FIG. 4, the connection parts used in the batteries 28, 29, and 30 are integrally formed with the ear parts 9 and 10 by casting (COS: Caston Strap). Make a configuration.

  Table 5 is a table showing the evaluation results of each characteristic.

  As shown in Table 5, the batteries 28, 29, and 30 in which the connecting parts are integrally formed by casting show “choy ride” mode characteristics as compared with the batteries 2, 3, and 4 in which the connecting parts are connected by welding. It can be seen that the SOC is increased. This is considered to be due to the following reasons.

  When the connection parts are integrally formed by casting, as shown in FIG. 4, the connection body 11 can be positioned on a line where the electrode plate connection plates 7 and 8 extend (in the stacking direction of the electrode plates). On the other hand, when connecting parts are connected by welding, in order to ensure the connection between the ears 9 and 10 and the electrode plate connecting plates 7 and 8, the connection body 11 is positioned on the line where the electrode plate connecting plates 7 and 8 extend. I can't. Therefore, in the connection parts integrally formed by casting, the connection path (current path) is linear between the cell chambers, whereas in the connection parts connected by welding, a bent portion is formed in the connection path between the cell chambers. Occurs. As a result, in the batteries 28, 29, and 30 in which the connection parts are integrally formed by casting, the internal resistance of the lead storage battery is reduced, and the charge acceptance of the lead storage battery is further improved, so that “choy ride” mode characteristics are exhibited. It is thought that the SOC has increased.

  From the above results, by forming the connection body 11 integrally with the electrode plate connection plates 7 and 8 on the line where the electrode plate connection plates 7 and 8 extend, the charge acceptability of the lead storage battery is further improved. Even if it is applied to an idling stop vehicle used in the “choi riding” mode, the operation of the fail-safe mechanism can be more effectively suppressed. Here, it is preferable that the electrode plate connection plates 7 and 8 and the connection body 11 are integrally formed on the respective ear portions 9 and 10 of the positive electrode plate 2 and the negative electrode plate 3 by casting.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

  The present invention is useful for a lead storage battery used in an idling stop vehicle.

1 Lead acid battery
2 Positive plate
3 Negative electrode plate
4 Separator
5 plate group
6 Cell room
7 Positive strap
8 Negative strap
9, 10 Ear
11 Connecting body
12 Positive terminal
13 Negative terminal
14 Lids 15 Ribs

Claims (9)

A plurality of electrode plates in which a plurality of positive electrode plates and negative electrode plates are laminated via separators are lead storage batteries respectively housed in a plurality of cell chambers together with an electrolyte solution,
The positive electrode plate includes a positive electrode grid and a positive electrode active material filled in the positive electrode grid,
The negative electrode plate includes a negative electrode lattice and a negative electrode active material filled with the negative electrode lattice,
Natural negative lignin derived from wood is added to the negative electrode active material,
The mass of the positive electrode active material _{M P} per the cell chamber, when the mass of the negative active material was _{M N,} by mass ratio _M N / _{M P} is in the range of 0.70 to 1.10, a lead storage battery . The mass ratio _M N / _{M P} is in the range of 0.80 to 1.00, a lead acid battery according to claim 1.   The lead acid battery according to claim 1 or 2, wherein the natural lignin is added to the negative electrode active material in a range of 0.02 to 0.6 mass% with respect to the negative electrode active material.   The lead acid battery according to claim 3, wherein the natural lignin is added to the negative electrode active material in a range of 0.05 to 0.5 mass% with respect to the negative electrode active material.   The lead acid battery according to claim 1 or 2, wherein a synthetic lignin containing a bisphenolsulfonic acid-based condensate is further added to the negative electrode active material.   The lead acid battery according to claim 5, wherein the synthetic lignin is added to the negative electrode active material in a range of 0.05 to 0.3 mass% with respect to the negative electrode active material.   The lead acid battery according to claim 1, wherein aluminum ions are added to the electrolytic solution in a range of 0.01 to 0.3 mol / L. The positive electrode plate and the negative electrode plate of the electrode plate group are each connected in parallel by an electrode plate connecting plate extending in the stacking direction of the electrode plates,
The electrode plate connection plates of the adjacent electrode plate groups are connected in series via a connection body,
The lead-acid battery according to claim 1, wherein the connection body is formed integrally with the electrode plate connection plate on a line on which the electrode plate connection plate extends. The electrode plate connection plate is connected to the ears of the positive electrode plate and the negative electrode plate,
The lead storage battery according to claim 8, wherein the electrode plate connection plate and the connection body are integrally formed on the ear portion by casting.

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