JP2011171035A - Negative electrode plate for lead storage battery, and lead storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative electrode plate for lead storage battery which is equipped inside a secondary battery used for a hybrid electric vehicle (HEV) and other industrial uses to demand high-rate discharge, and attains superior high-rate discharge characteristics and improvement of cycle lifetime, without fail. <P>SOLUTION: In the negative electrode plate for the lead storage battery, a material formed by adding and mixing conductive carbon and active carbon to a negative electrode active material is supported by a substrate for current collection, and as the active carbon, the active carbon of 44.5° or less of a gravity point angle of 10 faces by X-ray diffraction is used. The lead storage battery equipped with such a negative electrode plate makes improvement of cycle lifetime, without fail. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a negative electrode plate for a lead storage battery and a lead storage battery used in an electric vehicle such as a hybrid vehicle that repeats rapid charge and discharge with PSOC, and in industries such as wind power generation and solar power generation.

Previously, the applicant disclosed in Japanese Patent Application Laid-Open No. 2003-51306 a negative electrode plate for a lead storage battery and a lead storage battery including the same. The negative electrode plate is made of an active material mixture paste prepared by adding and mixing a predetermined amount of two kinds of carbon materials mainly composed of a negative electrode active material, carbon for ensuring conductivity and activated carbon for ensuring capacitor capacity. A lead alloy substrate for current collection is filled and formed.
When the negative electrode plate is used for a lead storage battery, conductive carbon and activated carbon coexist in the negative electrode active material, so that the conductive carbon reduces the polarization of the negative electrode in which a large amount of lead sulfate exists in the PSOC state, and at the same time, The conductivity can be supplemented. On the other hand, the activated carbon can increase the electric double layer capacity together with the conductive carbon, and can maintain the battery voltage immediately after discharge. Thus, the lead-acid battery equipped with this negative electrode plate can greatly improve the discharge characteristics in the PSOC state, and is suitable for various electric uses such as electric vehicles such as hybrid vehicles and other high-rate discharges.

JP 2003-51306 JP

Conventionally, as for the activated carbon having the capacitor capacity used in the electric double layer as described above, various activated carbons can be selected and used to obtain a larger electric double layer capacity and rapid charge / discharge performance, We have studied the optimization of the pore volume increase and the pore diameter according to the adsorbed ion species, but the lead storage battery equipped with the negative electrode plate using these selected activated carbons is derived from the electrolyte In addition to sulfate ions and protons, lead ions derived from the negative electrode active material are involved in adsorption / desorption and redox reactions with activated carbon, making the selection of optimum activated carbon more complicated.
Accordingly, as a result of repeated trial and error, the inventors have found a specific activated carbon that reliably exhibits the excellent performance of the storage battery, and the object of the present invention is to solve the above-described conventional problems. Then, there exists in providing the lead storage battery which solves the question of selection of the conventional activated carbon, and can improve a cycle life reliably using the negative electrode plate for lead storage batteries using this.

The present invention provides a negative electrode plate for a lead storage battery in which a negative electrode active material added and mixed with conductive carbon and activated carbon is supported on a current collecting substrate as described in claim 1, wherein the activated carbon is an X-ray. The negative electrode plate for a lead storage battery is characterized by using activated carbon whose centroid point angle of 10 planes by diffraction is 44.5 ° or less.
Furthermore, the present invention resides in a lead storage battery including the negative electrode plate according to claim 1 as described in claim 2.

  The negative electrode plate for a lead storage battery containing the specific activated carbon according to claim 1 improves the discharge characteristics in the PSOC state of the lead storage battery equipped with the same, and also reliably improves the cycle life, so that the hybrid vehicle, the electric It can be applied to various industrial uses that require high rate discharge such as automobiles.

It is a graph which shows the relationship between the gravity center point angle of 10 diffraction lines of activated carbon, and cycle life.

Embodiment examples of the present invention will be described below.
The negative electrode plate for a lead storage battery of the present invention, for example, as described in Patent Document 1 above, 1 to 5 parts by weight of conductive carbon and 1 to 5 parts by weight of activated carbon ensuring conductivity with respect to 100 parts by weight of the negative electrode active material. 2 parts by weight of the carbon mixture of the conductive carbon and the activated carbon is preferably added and mixed with 100 parts by weight of the negative electrode active material. Not. However, the activated carbon must be a specific activated carbon described in detail below.
As the conductive carbon, at least one type of conductive carbon selected from carbon types such as carbon black such as conventionally known furnace black, ketjen black, graphite, etc., which ensures conductivity is added.
A mixture of the negative electrode active material thus obtained and the above-mentioned two types of carbon mixture in a paste form with water or the like is filled into a current collecting substrate such as a lattice substrate made of lead or a lead alloy and dried. Then, an unchemically formed negative electrode plate is manufactured, and then, this is converted into a negative electrode plate for a lead storage battery of the present invention. Furthermore, the lead storage battery which uses this as a negative electrode plate is manufactured.

The identification of the activated carbon of the present invention was found by sequentially performing the following steps.
1) Measurement of various activated carbons by X-ray diffraction:
For example, nine kinds of activated carbons were selected as samples, and each of the activated carbons was pulverized with a pulverizer to an average particle size of 30 microns or less, and each activated carbon powder was prepared as a sample. On the other hand, RINT2200Ultima manufactured by Rigaku Denki Kogyo Co., Ltd. was used as the X-ray diffractometer, each sample was set in its glass sample holder, Cu Kα ray was used as the X-ray source, and 2θ = 10-90 ° was measured. It was. The obtained diffraction lines were subjected to line broadening and background processing using the X-ray diffraction comprehensive analysis software JADE +, and the barycentric angle of 10 diffraction lines appearing around 40-50 ° was calculated. As a result, the center-of-gravity point angles of the nine types of activated carbon samples were as shown on the vertical axis of the chart in FIG.

2) Production method of unformed lead-acid battery negative electrode plate:
To the negative electrode active material powder made of lead oxide produced by the ball mill method, carbon black with a specific surface area of 70 m ² / g and each of the above nine types of activated carbon powder are added as conductive carbon powder, and further, barium sulfate powder is added. Dry mixed. In this case, 0.5 parts by weight of the carbon black, 2 parts by weight of the activated carbon powder, and parts by weight of barium sulfate powder were added to 100 parts by weight of the lead oxide. In this way, nine kinds of mixtures were prepared, and an aqueous solution of lignin was added to each mixture, followed by kneading with addition of ion exchange water to prepare an aqueous paste, and further adding dilute sulfuric acid and kneading with addition of dilute sulfuric acid. An active material paste was prepared. Next, this paste is filled into a current-collecting cast substrate made of lead-calcium alloy, pressed and pressure-bonded, aged for 24 hours in an atmosphere of 40 ° C. and 95% humidity, and then dried to form 9 types of unformed chemicals. A number of negative plates for lead-acid batteries were manufactured.

3) Production of unformed positive plate:
10 parts by weight of ion-exchanged water was added to 100 parts by weight of the positive electrode active material comprising lead oxide, and then 10 parts by weight of dilute sulfuric acid having a specific gravity of 1.27 was added and kneaded to prepare a positive electrode active material paste. This paste was filled in a current collecting cast substrate made of a lead-calcium alloy, aged in an atmosphere of 40 ° C. and 95% humidity for 24 hours, and then dried to produce a large number of unformed positive plates.

4) Manufacture of lead acid battery:
After each of the unformed lead-acid battery negative plates and the unformed positive plates are alternately laminated via a fine glass mat separator, the laminate is an ear row of pole plates of the same polarity in the COS method. Were electrode plates. This was put into a battery case made of polypropylene and covered by heat sealing. At this time, the pressure of the group was adjusted by inserting a spacer so as to be 50 kPa. Subsequently, an electrolytic solution in which 0.1 mol / l of Al ions were added with sulfate was injected to form a battery case, and a control valve type lead storage battery equivalent to 12 V and 40 Ah was manufactured. The electrolyte had a specific gravity of 1.32. In this way, 9 types of lead storage batteries having the above 9 types of negative electrode plates for lead storage batteries with different activated carbons were produced.

5) Life test of the above 9 types of lead-acid batteries:
For each of the nine types of lead-acid batteries, a life test was conducted by simulating power storage by wind power generation and repeating rapid charge and discharge with PSOC. In this test, the storage battery was discharged at 8A for 1 hour to make SOC 80%, followed by repeating 400A, 1 second discharge and 80A, 1 second charge 500 times in an atmosphere of 25 ° C, then charging 120A, 1 second. And a one-second pause were repeated 510 times, and this was taken as one cycle. Then, the time when the cell voltage at the time of discharge reached 0 V was defined as the lifetime, and the number of cycles until the lifetime was reached was measured. The results are shown in FIG. As is clear from FIG. 1, it was found that the activated carbon having an angle of 10 diffraction lines of 44.5 ° or less has an excellent cycle life exceeding 500 cycles. Thus, in the production of the present invention, the activated carbon uses an activated carbon having an angle of 10 diffraction lines of 44.5 ° or less, thereby bringing about an effect of reliably obtaining a storage battery having an extended cycle life.

Activated carbon is said to have greatly disturbed the crystal structure of graphite with hexagonal mesh layers laminated, and the hexagonal mesh surface is maintained, but the c-axis direction takes a disordered layer structure, so the peak is unclear even if X-ray diffraction is performed. The 00l diffraction line and the hkl diffraction line become broad, and the hkl diffraction line is not recognized. That is, 002 diffraction lines appear at 2θ = 20-30 °, 10 diffraction lines appear at 40-50 ° (corresponding to 100, 101, 102 diffraction lines of graphite), and 11 diffraction lines (corresponding to 110, 112 diffraction lines of graphite) appear at 75-85 °. . In general, it is known that when the 002 diffraction line moves to the low angle side, the surface interval in the c-axis direction increases, and ions easily enter between layers.
Although the action of the above-specified activated carbon of the present invention is not clear, activated carbon having a centroid point angle of 10 planes by X-ray diffraction of less than 44.4 ° has a surface spacing in the a-axis direction in addition to disturbance in the c-axis direction. It is thought that by expanding beyond a certain value, the adsorption and desorption of ions was further facilitated, and the improvement in the activity for the redox reaction was also affected.

  Furthermore, among the specific activated carbons of the present invention, for example, a negative electrode plate for a lead-acid battery manufactured by adding 4 parts by weight of an activated carbon having a 10-plane gravity point angle of 44.2 ° to 100 parts by weight of the negative electrode active material. The cycle life of the lead-acid battery equipped with was 1500 cycles. On the other hand, the life of the lead storage battery including the capacitor composite negative electrode plate produced by adding 4 parts by weight of activated carbon having an angle of 10 diffraction lines of 44.9 ° to 100 parts by weight of the negative electrode active material was only 200 cycles.

  As is clear from the above, the lead storage battery using the negative electrode plate for the lead storage battery of the present invention is a hybrid electric vehicle that repeats rapid charge and discharge in the state of PSOC, other electric vehicles, windmills, solar cells (PV), etc. It can be used for industrial purposes that are charged by a power source.

Claims (2)

  In a negative electrode plate for a lead storage battery in which a negative electrode active material is added and mixed with conductive carbon and activated carbon, and the current collector substrate is supported, the activated carbon has an angle of gravity of the center of gravity of 10 faces by X-ray diffraction of 44.5 ° or less. The negative electrode plate for lead acid batteries characterized by using activated carbon.   A lead-acid battery comprising the negative electrode plate according to claim 1.

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