JP2010257673A - Lead storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead storage battery capable of extending quick charge and discharge cycle lifetime on PSOC of the lead storage battery having a negative electrode in which a coated layer of a carbon mixture including a carbon material having conductivity and activated carbon having capacitor capacitance is prepared on the surface. <P>SOLUTION: In the lead storage battery including, as a negative electrode, a negative electrode plate having a coated layer of a carbon mixture made by mixing two kinds of carbon materials made of the carbon material having conductivity on the surface of a negative electrode active material filling plate and activated carbon having capacitor capacitance and/or pseudo-capacitor capacitance with at least a binder, the activated carbon included in the carbon mixture coated layer has a gravity point angle of less than 44.4° on a tenth face on the basis of X-ray diffraction. Thus, cycle lifetime of the lead storage battery shown in Fig.1 can be extended. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention has a negative electrode whose surface is coated with a carbon mixture, and is applied to a hybrid vehicle that repeats rapid charge and discharge with PSOC, an industrial product that is charged by a power source such as a windmill or a solar cell (PV), etc. It relates to a storage battery.

  A lead storage battery having a negative electrode whose surface is coated with a carbon mixture is disclosed in JP-T-2007-506230. The carbon mixture disclosed to the public is a mixture of two carbon materials consisting of a first carbon material having conductivity and a second carbon material having a capacitor capacity and / or a pseudo capacitor capacity, and a binder. There is a description that carbon black, ketjen black, graphite or the like is selected and used as the first carbon material, and activated carbon, carbon black, graphite or the like is selectively used as the second carbon material.

Special table 2007-506230 gazette

However, the above Patent Document 1 only describes that the activated carbon used for the electric double layer capacitor of the capacitor electrode is preferably one having a high surface area of 1000 to 2500 m ² / g, In order to improve the rapid discharge characteristics at PSOC of lead storage batteries used in various industrial fields and extend the cycle life, it has not been studied at all what kind of characteristics to use activated carbon.
This invention exists in providing the lead storage battery useful for said industrial field which solved this subject and achieved said objective.

  According to the present invention, as described in claim 1, the surface of the negative electrode active material-filled plate is bonded to at least two types of carbon materials comprising a carbon material having conductivity and activated carbon having a capacitor capacity and / or a pseudo capacitor capacity. In a lead-acid battery having a negative electrode plate provided with a coating layer of a carbon mixture formed by mixing an adhesive as a negative electrode, the activated carbon contained in the carbon mixture coating layer has a centroid point angle of 104.4 by X-ray diffraction of 44.4. It exists in the lead acid battery characterized by using activated carbon which is less than °.

  According to the invention of claim 1, since the performance of the negative electrode is improved, the life of the lead storage battery can be extended. Therefore, it leads to an improvement in lead-acid batteries in hybrid vehicle applications that repeatedly charge and discharge rapidly with PSOC, and in industrial applications that are charged by a power source such as a windmill or solar cell (PV).

The figure which shows the relationship between the gravity center angle of 10 diffraction lines of activated carbon, and cycle life.

Embodiments of the present invention will be described below.
The negative electrode of the lead-acid battery of the present invention is a carbon mixture prepared by applying a carbon mixture on both sides, one side, or both sides or part of one side of a normal negative electrode plate, drying, and providing a porous carbon mixture coating layer It is.
The carbon mixture is a carbon material composed of a first carbon material that secures conductivity such as carbon black such as acetylene black and furnace black, ketjen black, and graphite, and activated carbon that secures capacitor capacity and / or pseudo capacitor capacity. And at least a binder. In this case, at least one of the first carbon materials is selectively used.

  As the activated carbon mixed in such a carbon mixture, the present invention, etc., as a result of intensive studies, the use of activated carbon having a 10-point center of gravity angle of less than 44.4 ° in X-ray diffraction is excellent as will be clarified below. It was found that the battery performance was exhibited.

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 of less than 44.4 ° is greater than a certain value in the a-axis direction in addition to the c-axis direction disturbance. By enlarging, it is considered that the adsorption / desorption of ions is further facilitated, and the improvement in the activity for the oxidation-reduction reaction is also affected.

  Measurement of the center-of-gravity point angle of the activated carbon by the X-ray powder diffraction method was performed as follows. RINT2200 Ultima (trade name) manufactured by Rigaku Denki Kogyo Co., Ltd. was used as the X-ray diffractometer. As a sample, activated carbon mechanically pulverized so as to have an average particle size of 30 microns or less was set in a glass sample holder. Then, Cu and Kα rays were used as the X-ray source, and measurement was performed at 2θ = 10-90 °. The obtained diffraction lines were subjected to line broadening and background processing using the X-ray diffraction comprehensive analysis software JADE + (trade name), and the barycentric angle of 10 diffraction lines appearing around 40-50 ° was calculated.

  Thus, in preparing a paste-like carbon mixture having the composition shown in Table 1 below, as the activated carbon, the above-mentioned centroid point angle of commercially available activated carbon with different raw materials and activation conditions was examined, and the centroid angle of the activated carbon was 43.90 to 44.85. Different activated carbons were prepared in the range of.

Lead acid battery manufacturing:
A positive electrode plate and a negative electrode plate used for a control valve type lead storage battery were manufactured by a known method. Each manufactured negative electrode plate is further mixed with activated carbon having different angles of the center of gravity described above on both surfaces of the negative electrode active material-filled plate excluding the ears of the lead porous current collector plate filled with the negative electrode active material. Each paste-like carbon mixture containing an amount was prepared, and this was applied so as to be 5 wt.% Of the weight of the negative electrode active material in terms of dry weight to produce each negative electrode plate. The negative electrode was oxidized at the same time of drying at 1 ° C. for 1 hour.

  Next, each of these negative electrodes and positive electrodes was accommodated in a tank and subjected to chemical conversion treatment prior to assembly of the lead-acid battery by chemical conversion. The negative electrode conversion plate and the positive electrode conversion plate thus obtained are alternately laminated via AGM separators to form an electrode plate group, and this is placed in a battery case in the same manner as a known assembly method using a control valve type lead battery. The batteries were assembled, and 2V lead-acid batteries with a 5-hour rate capacity of 10Ah were assembled under positive electrode capacity regulations. Each electrode plate group was prepared by inserting a spacer between the battery case and the electrode plate group so that the degree of compression was 50 kPa.

  Next, for each lead-acid battery, a sulfuric acid aqueous solution having a specific gravity of 1.30 in which aluminum sulfate / 18 hydrate was dissolved at 30 g / l was injected into the battery case as an electrolytic solution, and then charged at 1A for 20 hours. The battery was discharged at 2A until the voltage reached 1.75V. Thereafter, the battery was charged again at 1A for 15 hours and discharged at 2A to a battery voltage of 1.75 V. When the 5-hour rate capacity was measured, the capacity was about 10 Ah.

Life test:
Next, using each of these lead-acid batteries, a life test was conducted by repeating rapid charge and discharge with PSOC while simulating running by HEV. That is, after each lead-acid battery was discharged at 2A for 1 hour to 80% PSOC, 50A, 1 second discharge and 20A, 1 second charge were repeated 500 times in an atmosphere of 40 ° C, then 30A, 1 second charge and 1 The pause in seconds was repeated 510 times, and this was taken as one cycle. And the time when the storage battery voltage at the time of discharge reached 0V was defined as the lifetime, and the number of cycles until reaching the lifetime was measured.
The results are shown in FIG. As is clear from FIG. 1, it can be seen that the cycle life differs depending on the angle of the center of gravity of the 10 diffraction lines of activated carbon. It was confirmed that the cycle life of the lead-acid battery increased as the centroid point angle decreased, and in particular, activated carbon having a centroid point angle of 10 diffraction lines of less than 44.4 ° had a cycle life of 500 cycles or more.

Claims (1)

  The surface of the negative electrode active material-filled plate is coated with a carbon mixture formed by mixing at least a binder with two types of carbon materials consisting of a carbon material having conductivity and activated carbon having a capacitor capacity and / or pseudo-capacitor capacity. In the lead-acid battery having a negative electrode plate provided with a layer as a negative electrode, the activated carbon contained in the carbon mixture coating layer is activated carbon whose 10-plane gravity point angle by X-ray diffraction is less than 44.4 °. Lead acid battery.

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