JP2736243B2 - Electrolytic solution for lead-acid battery, lead-acid battery using the same, and method of determining whether lead-acid battery can be regenerated - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-acid battery electrolyte, a lead-acid battery using the same, and a method for judging whether or not the lead-acid battery can be regenerated. Alternatively, the present invention relates to a lead-acid battery electrolytic solution useful for reclaiming discarded lead-acid batteries, a lead-acid battery using the same, and a method for determining whether or not a lead-acid battery can be regenerated.

[0002]

2. Description of the Related Art Lead-acid batteries have performance problems and environmental problems. First, as a performance problem, the conventional lead-acid battery can only be charged with a low current at the time of charging, so that the charging time is too long and the weight is large. In addition, there is no battery function recovery technology that recycles discarded lead-acid batteries to the level of new ones, and additives to currently used electrolytes have the effect of slightly extending the performance of lead-acid batteries with reduced performance. Only.

Second, as an environmental problem, for example, lead-acid batteries for automobiles have been disposed of in about three years, and when they are disposed of, the cost for processing and regeneration is high. . Dilute sulfuric acid and lead constituting the discarded lead storage battery are pollutants, and secondary pollution caused by the pollutants becomes a problem. In addition, lead storage batteries used in large ships have been dumped in the deep sea, and global disposal of marine pollution by the disposed lead storage batteries is progressing.

As one means for improving the performance of a lead-acid battery, MnO ₂ , CuO, as a cathode active material (Cathode Active Material),
Carbon powders, metal powders, and the like are used as the conductive material of the cathode mixture (Cathode Mix) together with NiOOH, PbO ₂ , CFx, and the like, and several patent applications using carbon powders have been filed. For example, JP-A-53-10828 describes a PbO ₂ electrode coated with a carbon powder, JP-A-54-61642 describes a coating of a PbO ₂ electrode coated with a carbon suspension. No. -158955 describes that carbon fiber is contained inside metallic lead.

[0005]

In the present invention, a carbon suspension is also used for activating the positive electrode of a lead storage battery, but this is completely different from these conventional examples as described later.
The above is essentially the same, in which a carbon coating is formed on a lead grid or plastic grid, and PbO ₂ litharge is kneaded on it, and the lead grid electrode (electrode substrate) and the PbO ₂ litharge electrode material This is effective only for the first layer particles of the surface of the PbO ₂ litharge that is in contact with the electrode substrate, and is not effective for directly contacting the electrode substrate. It has no effect on many particles. Therefore, the influence on the overall electrochemical reaction is very small. In addition, carbon fibers are also included in the metal lead, which contributes to increasing the strength of the positive electrode substrate and reducing the weight to some extent.
Since the carbon fiber is shielded by the metal, it does not contribute to the electrochemical reaction of charging and discharging.

[0006] It is an object of the present invention to provide high performance, light weight, and long life, and also enable high-current short-time charging.
It is an object of the present invention to develop an electrolytic solution for greatly improving the performance of a lead-acid battery regardless of whether the lead-acid battery is new or used, and to provide a renewable electrolytic solution for a discarded lead-acid battery.
Until now, the performance degradation of lead-acid batteries has been caused by external distortion of the battery case and abnormally large amounts of white powder coming out of the terminals, or by the voltage and voltage of the battery tester.
Although the determination was made by a method such as measuring the presence or absence of a discharge current, a determination method using the regenerating solution of the present invention is established to increase the recycling rate of the waste battery.

[0007]

According to the present invention, a carbon suspension (Carbon Suspension) is used for activating an electrode of a lead storage battery, and has the following structure. First of all, this carbon suspension is water-based and electrolytic oxidation of carbon anode
(Electrolytic Oxidation), and the lead-acid battery anode (PbO ₂ ) is electrochemically doped (Eb
Electrolytic solution for lead-acid batteries activated by electrochemical doping. The feature of this electrolytic solution is that the carbon suspension is a colloidal suspension (suspensoid), and hydrophilic groups such as carbonyl group, carboxyl group or hydroxyl group are chemically modified on the surface of the carbon colloid particles (Chemical Modification). is there. The term “aqueous system” as used herein includes not only a pure water system, but also a dilute sulfuric acid aqueous system and an aqueous solution system of a small amount of an electrolyte which is added to an electrolytic solution and does not adversely affect the lead storage battery.

[0008] Second, for lead-acid batteries in use or discarded lead-acid batteries that have become difficult to regenerate due to long-term use, lead activated by using the above-mentioned carbon suspension as a replenisher for regenerating these batteries. It is a storage battery.

Third, when a new lead-acid battery is manufactured,
The carbon suspension is used as an aging solution for the aged positive electrode litharge to form a lead storage battery activated using the carbon suspension.

[0010] And fourth, improvements made to the electrodes of the lead-acid battery, there lead-acid battery anode (PbO ₂₎ cathode in contact with the carbon sheet of porous, charged with the addition condition of the carbon suspension A lead-acid battery activated by operation. Here, particularly preferable results are obtained when the porous carbon sheet is formed of a lead storage battery that is a carbon fiber fabric.

Fifth, paying attention to the fact that when the above-mentioned carbon suspension is added and charged, if the electrolytic carbon oxide particles are adsorbed on the anode, they can be activated, and the added electrolytic carbon oxide particles can be activated. When the turbidity of the electrolytic solution became transparent, a determination method was established which could determine that all of them could be regenerated. This is because the carbon suspension or the carbon powder is charged into each cell of the lead storage battery and charging is performed. When all the cells become transparent, it can be determined that the cell can be regenerated. Normally, even if the electrolytic carbon oxide particles are added and the charge and discharge are repeated two or three times, if the electrolytic solution in some cells is clouded, it can be determined that the cell cannot be regenerated.

The activation of the lead-acid battery is activated by electrochemically doping PbO _{2 as an} anode with the carbon in the carbon suspension. This electrochemical doping will be described later.

[0013]

As described in the Detailed Description of the Invention] A first aspect of the present invention, a lead-acid battery electrolyte of the present invention consists of carbon suspension obtained by the electrolytic oxidation of carbon anodes in an aqueous system, lead-acid battery anode (PbO ₂ )
Is an electrolyte for a lead-acid battery, which is activated by electrochemical doping.

As the carbon material used for the carbon anode, all types of carbon materials can be used regardless of whether they are crystalline, amorphous, natural, or artificial, and these can be used in either sintered or unsintered forms. Can be. Among them, graphite is most preferable.

The shape of the electrode may be any shape such as lump, plate, rod, fiber, sheet, felt, or powder. In the case of using the powder, it is difficult to form the electrode as it is, so the powder may be filled in a mesh basket to form the electrode. Alternatively, it may be used after being compacted.

In fact, considering the fact that the electrolytic oxidation of carbon using water as the electrolytic solution changes the pH of the electrolytic solution to the acidic side of 2 to 3, the identity of the acid seems to be carboxylic acid.
With electrolytic oxidation of carbon, when a DC voltage is applied in water using a carbon material as an electrode and the current is gradually increased, a certain current value is used as a boundary (the voltage changes depending on the distance between the electrodes) Carbon powder is deposited around the anode like a mist. The precipitated powder is suspended in water in a colloidal state. When a DC voltage is applied by inserting an electrode into the carbon suspension, the precipitated carbon powder is adsorbed on the anode.

In the present invention, the electrolytically precipitated carbon powder is used as an electrolytically oxidized carbon powder.
der). This treatment is also called electrolytic oxidation treatment.
(Treatment of Electrolytic Oxidation).

In the present invention, a current value at which deposition of carbon powder is visually recognized is referred to as a critical current for convenience (strictly speaking, the deposition occurs to such an extent that it is invisible with a smaller current. It is presumed that). The critical current varies depending on the area of the carbon anode, the distance between the anode and the cathode, the presence or absence of an electrolyte, and the amount thereof. When tap water is used as the electrolyte, the distance between the anode and the cathode is 3 mm or less, and the anode area is 200 cm ² ,
3 to 5 A is the critical current.

The electrolytic solution at the time of electrolytic oxidation is preferably aqueous.
Although water alone may be used, an acid component of the battery electrolyte and other electrolytes, such as dilute sulfuric acid such as NaCl and LiCl, may be added to the water depending on the purpose. When pure water is used as the electrolyte, an acid component of the above-described electrolyte and other electrolytes may be added to improve conductivity. Water containing a trace amount of mineral components, such as tap water, can secure appropriate conductivity without adding any chemicals, and can provide a high-quality carbon powder dispersion.

The suspension of carbon in which the electrolytically oxidized powder is dispersed in the electrolyte is a colloidal solution, which is synthesized by electrochemical oxidation, in which the carbon colloid is doped with a dopant (a acting as a dopant for cathode). (In electrochemical terms, the cathode and anode are defined as the anode and cathode, respectively, of the battery system.) The behavior of the carbon colloid on the cathode has the following consequences: (1) regeneration of a degenerated battery, (2) extremes. Large charging current without significant temperature rise, (3) increased discharge current, (4) extended battery life. According to the detailed description of the present invention, the preparation of the carbon colloid solution is as follows.

There are many ways to oxidize carbon. They are (1) chemical oxidation by oxidizing agents. Oxidizing agents include
There are concentrated nitric acid, concentrated sulfuric acid, fuming nitric acid and potassium hypochlorite or potassium permanganate. (2) oxidation by ozone, (3) discharge oxidation or plasma discharge oxidation, and (4) electron beam irradiation. Oxidation of carbon by electrochemical means (electrolytic oxidation) is currently known, but has not been industrially adopted as far as the inventors know. In the present invention, when this electrochemical oxidation treatment is applied to carbon, an aqueous stable carbon suspension is obtained.

Here, the adjustment of the carbon suspension will be described. Our procedure for obtaining a carbon suspension consists of an electrolyte containing a small amount of salt, such as lithium chloride, an anode (anode) purified from shaped and sintered carbon particles, and a platinum cathode.
(Cathode). The voltage between the electrodes was a sufficiently high voltage for the electrolyte. As the electrolysis proceeds, the carbon particles become suspended. Electrolysis continues until the pH value of the solution decreases to 2.5. The carbon particles are suspended in the solution without any other dispersants. No sedimentation of carbon particles is seen even after 10 days of conditioning.

The electrolytic carbon oxide particles, once dry powder, are well dispersed and suspended in water. Therefore, it may be used as a regenerating agent for a lead storage battery in the form of carbon powder. In this case, the addition of a small amount of powder is sufficient, so handling is easy, and when there are many existing electrolytes, there is no need to remove the electrolyte for replenishment of the carbon suspension, preventing a decrease in sulfuric acid concentration. . This carbon powder may be kneaded with dilute sulfuric acid and added to the electrolyte in the form of a paste or a thick liquid. In other words, electrolytic carbon oxide particles have good dispersibility in water and dilute sulfuric acid. Is possible.

The mechanism of the electrochemical oxidation is considered as follows. That is, electrochemical oxidation is initiated by a reduction reaction of oxygen. e ~ + O ₂ → O ₂ ~ (1) The source of oxygen is either dissolved in a solution or an electrolysis product made at the anode. reaction
Since (1) is dominant near the cathode, oxygen molecules drift from the anode to the cathode. The product of the reaction (1), that is, O ₂ ~ finally becomes OH-. O ₂ + 2H ₂ O + 4e ~ → 4OH ~ (2) It is considered that this OH 反 応 reacts with the carbon anode to generate —OH groups on the carbon surface. Further, the -OH group is changed to an aldehyde (-CHO) and / or a carboxyl (-COOH) group by the second-stage oxidation. We succeeded in obtaining evidence for the presence of these groups on the surface of the carbon.

FIG. 1 shows ESC of carbon subjected to electrolytic oxidation treatment.
1 shows an A (Electron Spectroscopy for Chemical Analysis) spectrum. The measurement was performed using an X-ray photoemission spectroscope (Photoelectric Emission Spectroscope, PW) using an AlKα X-ray source (350 W).
hysical Electronics, 5600 Ci).

ESCA provides information on the inner-shell electron binding energy, such as 1s, 2s, 2p, by measuring the kinetic energy of electrons emitted by X-rays on the surface atoms of the sample. This is a powerful weapon for surface analysis.
FIG. 1 shows peaks in which C and O are present together with small amounts of N and S. ESCA is the surface (1 or 2 from the surface)
Information is given only to the atomic layer of the layer, and foreign matter (co
ntamination) very well. N may be from nitrogen in the air and S may have been entrained during the electrolytic oxidation of carbon. From FIG. 1, the amount of oxygen on the carbon surface is 15.3.
It can be determined that it is 3%. For comparison, we measured the ESCA spectrum of carbon not subjected to electrolytic oxidation treatment. The results are shown in FIG. It is obvious that the amount of oxygen is very small. Therefore, it is concluded that the carbon particles were oxidized as a result of the electrolytic oxidation treatment. Further information can be obtained from this ESCA spectrum. FIG. 3 shows the spectrum of C ₁ s in FIG. 1 in which the peak protrudes in the range of 280 to 300 eV. The red curve at the top in FIG. 3 shows the spectrum. It can be clearly seen that this peak curve is composed of several peaks. It is possible to obtain the respective components shown in FIG. 3 by the measurement work. The measurement must be performed so that the sum of each component matches the original peak (top red). Table 1 shows the respective peaks.

[0027]

[Table 1]

It is important to note that the presence of carboxyl and -CO- groups could be clearly identified. It can be assumed that these groups have a hydrogen atom at one end. That is, -COOH and -OH
It is. However, this requires further investigation. A similar approach was taken for the non-oxidized particles of FIG. FIG. 4 shows the results. In this case, two peaks are seen. That is, 290.69 eV (satelite peak of
π-π *) and 284.39 eV (graphite), and the carbonyl group is also -C-
No O- groups were found either. In conclusion, the carbon particles in the carbon suspension obtained by electrolytic oxidation have -C
An OOH group and a -CO- group are added to electrochemically modified carbon particles.
article). Considering that a neutral aqueous solution is modified to be acidic (e.g., pH 2-3.5) by electrochemical oxidation treatment, the carbonyl group is probably -CO
May exist as OH. Considering the process of the above-mentioned electrochemical reaction, -CO- is probably -C-OH.
It will exist as. These -COOH groups and -C-
The OH groups play an important role in the dispersion of the carbon particles and the activation of the PbO ₂ cathode of the lead-acid battery. Although carbon particles are inherently hydrophobic, they are chemically modified (che
The surface is hydrophilized by mical modification to form a stable suspension.

When the carbon is graphite, it is considered that during the electrolytic oxidation of graphite, the layer structure of the graphite particles may undergo cleavage, and the graphite particles are expected to be flaked by electro-oxidation. This process also contributes to the dispersion of the particles, resulting in a very stable colloidal carbon suspension.

According to the second invention, when the carbon suspension obtained in the first invention is charged as an electrolyte in the original acid electrolyte, the carbon powder is adsorbed on the anode and the performance is dramatically improved. Another object of the present invention is to obtain an improved lead storage battery. On the other hand, the powder that has not been oxidized is neither suspended in water nor adsorbed on the anode, and even if it is simply coated on the anode, the characteristics of the battery are not improved. Here, the suspension of the carbon powder in the electrolytic solution may cause an electrical short between the anode and the cathode, but the carbon powder in the carbon suspension of the present invention is attracted to the anode when a voltage is applied. As a result, the electrolyte is visually returned to its original clear state, and no electrical short circuit occurs.
The concentration of the carbon powder itself in the electrolytic solution used in the present invention is the percolation threshold (percolation threshold).
Since the concentration is much lower than d), no electrical short circuit occurs.

In order to adsorb the carbon powder on the anode, it is necessary to apply a DC plus voltage to the anode, which corresponds to charging the battery. When used as a storage battery for an automobile, the storage battery is constantly charged during traveling, so that the carbon powder naturally adsorbs to the anode even if the charging operation is not performed again. In other words, in a vehicle such as an automobile that has a discharge and charging mechanism integrated into the device, simply add the carbon suspension to the electrolyte without having to perform a charging operation again. The carbon powder is automatically adsorbed on the anode alone, and the characteristics of the battery are improved. On the other hand, in a mechanism in which a charger is not integrated, it is necessary to adsorb the carbon powder to the anode by performing a charging operation prior to use.

Here, how the cathode of the lead storage battery is activated will be described. One of the features of the present invention is the revival of a degraded battery. We chose a degraded battery that does not start the motor immediately after charging. Then, the electrolyte (dilute sulfuric acid) of the lead storage battery was partially replaced with a carbon suspension and charged. As a result of the charging, it was confirmed that the carbon particles were adsorbed on the cathode and the battery could start the cell motor. If no carbon suspension was added, the power storage was not sufficient, but the degraded battery was able to store power as a result of treatment with the carbon suspension.

The partial replacement of the carbon suspension with the electrolyte also
(1) High charge current without temperature rise, (2) Realization of high discharge current,
And (3) the life of the battery can be increased. The carbon suspension has such an effective function. At first glance, it may seem strange that carbon colloid particles have such an effective function. However, current scientific knowledge can explain:

First, the structure mechanism of the carbon colloid will be described. The structure of a carbon colloid obtained by an electrochemical process is already known. It can be easily understood that a carbon colloid can be formed by observing the reduction of the carbon electrode used for the electrolysis. However, this has not been addressed in the industrial field. Generally, in order to obtain a carbon suspension, carbon particles are ground in the presence of a dispersant. The use of carbon suspensions to improve lead-acid batteries has not been done so far. Currently used carbon suspensions are generally alkaline (alkaline solution) and contain a dispersant. Conversely, the carbon suspension of the present invention is acidic and does not contain a dispersant.
Carbon particles are inherently hydrophobic. However, they are electrolytically oxidized to become hydrophilic.

It is experimental fact that the carbon particles in the carbon suspension are adsorbed on the PbO ₂ cathode. There may be PbO ₂ particles that are not sufficiently electrically coupled to the electrodes. As is well known, PbO ₂ is a semiconductor material,
The cathode is an aggregate of PbO ₂ particles. The carbon particles adsorbed on the surface of the PbO ₂ particles are the Pb
It functions to impart conductivity to the O ₂ particles and enhance the discharge effect.

The improvement due to the adsorption of carbon particles can also be expected for PbSO ₄ generated as a result of discharge. P
bSO ₄ is an insulator. This changes to PbO ₂ as a result of charging. In this charging process, PbSO ₄ must move electrons to the cathode. Therefore, the cathode of the electrical coupling is essential problems for PbSO _4. Anode material
(Some are being converting thereinto in PbSO ₄₎ Carbon adsorbed on it is possible to change the PbSO ₄ to form a conductive path between the anode against PbSO ₄ to PbO _2. Thus, in the present invention, the PbO ₂ cathode is activated by playing an important role in both charging and discharging of the adsorbed carbon particles.

The carbon particles in the carbon suspension of the present invention have undergone a chemical modification and have a -COOH and -COH structure.
In the case of a neutral aqueous solution, these dissociate immediately, resulting in -CO
O ~ and -CO-. This releases electric charge at the anode and combines with the anode, but it is considered that -COO ~ and -CO ~ do not dissociate in the acidic solution. However, in a lead storage battery, the above-described dissociation is possible because the proton concentration in the vicinity of the anode is sufficiently low, and it is considered that -COO ~ and -CO ~ lose charge at the anode and are adsorbed.

The idea of producing conductive particles near the cathode has been reported, for example, for Ag ₂ WO ₄ / LiClO ₄ / Li batteries, where the conductive Ag particles are produced as a result of a discharge, A conductive path with the cathode is secured. According to the mechanism for the role of electrochemically modified carbon, the application of electrochemically modified carbon can be expected to reduce the internal resistance of the battery. This has been confirmed in Example 10 as described later.

Carbon is known as “active material” (“ac
tive material "). One example is the cathode active material in a potassium manganese dioxide cell is a mixture of manganese dioxide and carbon, where the carbon increases the electrical conduction between the manganese dioxide and the cathode. At present, in all known cases, the carbon material is pre-mixed with the active material during the manufacture of the battery, and the interaction between the carbon material and the active material is a mere mechanical contact. In general, carbon materials are used only for either one of the effects of charging and discharging.

In the present invention, experimental results show that electrochemically modified carbon is effective not only during charging but also during discharging. The application process of electrochemically modified carbon is not just mixing. Activation of a PbO ₂ cathode by electrochemically modified carbon is an electrochemical process involving chemical reactions and electron transfer. This process is considered "electrochemical doping". Thus, this is a completely new technology in the battery field.

Here, “electrochemical doping” is defined as follows. First, doping will be described. Generally, it is used to mean taking a drug in athletics, but here it is closest to the term used in the field of semiconductors. A semiconductor is a substance having intermediate conductivity between a conductor and an insulator. This is the well-known silicone semiconductor. Semiconductors made of pure substances are called intrinsic semiconductors. A substance obtained by adding a small amount of impurities such as aluminum and arsenic to this intrinsic semiconductor is called an impurity semiconductor. In this case, they are p-type and n-type semiconductors, respectively. Adding this impurity is called doping, and the added impurity is called a dopant. The contact between the p-type and the n-type is called a pn junction, which is an indispensable part of the transistor configuration. This term is used for conductive polymers, although it is different from semiconductors such as silicone. Polyacetylene, which is a typical conductive polymer, is almost an insulator in the case of a cis-type, and has improved conductivity in the case of a trans-type, and exhibits conductivity of a semiconductor region. It has been found that when iodine is doped into trans-type polyacetylene as in the case of a silicone semiconductor, the conductivity increases by several orders of magnitude. In addition to polyacetylene, polymers such as polyaniline, polypyrrole, and polythiophene also exhibit conductivity, and conductivity is improved by doping. In the case of these polymers, a polymer film can be obtained on the electrode electrochemically by an electrolytic polymerization method.
porting electrolyte) is also doped simultaneously with polymerization. Doping agents doped using electrochemical methods
(dopant) can be removed (this is called undoping) and the desired dopant can be doped electrochemically. The latter case is called electrochemical doping.

As described above, attention must be paid to the carbon content in the electrolytic solution. If enough carbon particles are added to the electrolyte, the battery will short out. The relationship between conductivity and carbon content has been studied, and the calculation model has already been termed the "percolation model". According to this model, the rise threshold value for conductivity is from about 30 vol%. If the carbon content is one order of magnitude smaller than the percolation threshold, the carbon contribution is certainly negligible. In the present invention, as seen in the sixth embodiment, even a very small amount of 5 wt% or less, 0.01 wt% or 0.02 wt% is effective, and there is no concern about battery short-circuit.

As described above, when the carbon suspension is added to the electrolytic solution, it becomes black and turbid. However, when charged, the electrolytically oxidized carbon particles are adsorbed on the anode and the electrolytic solution returns to the original transparent state. However, when the lead storage battery is significantly deteriorated, the carbon particles are not adsorbed on the anode, so that turbidity cannot be obtained. Since such a lead-acid battery is difficult to regenerate, it is useful as a simple method for judging whether or not reproducibility is possible. Details of the determination method will be described later.

The above description is directed to a battery that has already been completed, regardless of whether it is new, used, or discarded. However, in the present invention, carbon powder is used in the intermediate process of anode production, particularly in the chemical conversion process. Adsorption can also be performed.

That is, the third invention is to provide a lead-acid battery activated by using the carbon suspension as an aging solution for the aged positive electrode litharge. When the anode grid is filled with the anode active material and subjected to chemical conversion treatment, if the carbon suspension or the diluted sulfuric acid solution in which carbon powder is suspended is used as the chemical conversion treatment solution, the carbon powder is adsorbed on the anode in the same manner. It is. When the obtained anode is mounted on a storage battery, the same activation occurs as in the case of the completed electrode described above.

The activation (electrochemical doping) of the PbO ₂ cathode is carried out not only during the manufacture of the lead-acid battery but also in the partial PbO ₂
It is also effective for electrodes. The cathode material of a lead-acid battery is basically a Pb lattice filled with Pb grains and lead oxide particles. This is converted into PbO ₂ by electrolysis in a dilute sulfuric acid solution.
rocess). In this chemical conversion process, when the electrolytic oxidation number manufacturing method, that is, the electrochemically modified carbon colloid is used, the chemical conversion and activation proceed at the same time.
PbO ₂ doped with electrochemically modified carbon particles is obtained in this chemical conversion process.

A mixture of ordinary carbon particles and PbO ₂ was compared with PbO ₂ activated by electrochemical doping in the carbon suspension of the present invention and compared and examined as the effect of simple carbon particle mixing. However, as can be seen in the examples, no improvement in battery performance was obtained from the mere mixture.

The fourth invention is a lead-acid battery in which the anode surface of a lead-acid battery is coated with a porous carbon material, and electrolytically oxidized carbon powder is adsorbed on the anode surface and the surface of the porous carbon material. Here, the porous carbon material means a porous sheet having a water permeability, a felt shape, an aggregate of carbon particles, or the like, and is a woven fabric using carbon fibers, a porous material as a nonwoven fabric, or a plate. Any of those having fine holes may be used, but a sheet or felt using carbon fiber is most preferable in consideration of the area ratio of the holes, flexibility, price, durability and the like. It is not necessary that the porous carbon material covers the entire anode surface with one sheet, and a plurality of sheets of the porous carbon material may cover the anode.

As the carbon material, all carbonaceous materials can be used regardless of whether they are crystalline, amorphous, natural, or artificial, and these can be used in any form, such as sintered or unsintered. Usually, a separator having a function as a mesh insulator is interposed between the anode and the cathode. In the present invention,
The gap between the anode and the separator is filled with a sheet, felt, or granular carbon material to coat the anode surface.

The sheet, felt, and carbon particles contact the anode active material surface and hold it to prevent the active material from falling off. In addition, since this portion is electrically connected to the anode at the same time, this portion also has the same potential as the anode. By covering the anode surface with a porous carbon material, the charging capacity is improved. Even if the number of electrode plates is reduced from a combination of two anodes and three cathodes of a conventional battery to one anode and two cathodes, it is possible to obtain about twice or more the charge amount. That is, the weight of the lead storage battery can be reduced.

A fifth aspect of the present invention is a method for determining whether or not a lead-acid battery can be regenerated using electrolytic carbon oxide particles according to the first aspect. In this method, the carbon particles are uniformly introduced into each cell of the lead storage battery, and an appropriate current is applied. For example, if the capacity is 40 Ah, 8 Ah is charged in 5 hours. It is also important to measure the specific gravity and the liquid temperature of the electrolytic solution after charging is completed. If it is a normal cell (electrode), it becomes a completely transparent liquid. It takes more time to completely become transparent in a cell having a slight abnormality, but gradually becomes transparent. It is activated by the electrochemical doping of the electrode of the carbon particles of the present invention. In particular, in cells with abnormalities, it can be clearly seen that carbon particles are present in a dark state as in the case of the mixed liquid. Has high impedance and cannot be electrochemically doped. Therefore, the degree of damage to the electrode of each cell of the battery can be visually checked by the change in the color of the injected carbon suspension. Further, if it becomes transparent over time, the electrode can be improved by the carbon suspension, which is effective in improving the performance of the lead storage battery.
If the carbon suspension is injected again into the lead storage battery and the same test is performed, each cell becomes transparent on average, and the battery electrode can be repaired. This determination method can be used for a battery loaded in an automobile or the like in a similar manner.

When the electrolytic solution of the present invention is used as a regenerant for a used battery or a chemical solution for producing a new battery, the following characteristics can be obtained. That is, 1) the time required for constant current discharge to decrease to a voltage that can be used as a battery (usable limit voltage), that is, the capacity Ah of the battery increases by 5 to 10%. 2) Temperature dependency of battery terminal voltage is reduced. The terminal voltage of a battery is greatly affected by the temperature, and falls when the temperature rises in summer and rises when the temperature falls in winter. Therefore, during charging, the voltage applied to the battery must be changed in accordance with the fluctuation of the terminal voltage of the battery, that is, the voltage must be high in winter and low in summer. However, when used as a storage battery in a car, the charging voltage is rarely changed in accordance with changes in the temperature, so in summer, charging is performed by applying a voltage higher than the terminal voltage of the battery. To be overcharged.
On the other hand, in winter, the battery is charged by applying a voltage lower than the terminal voltage of the battery, resulting in a state of insufficient charging. As a result,
In summer and winter, so-called battery rising accidents frequently occur.However, in the case of using the electrolytic solution of the present invention, the property that this terminal voltage depends on temperature change becomes small, Even if the charging voltage is not changed, stable charge / discharge characteristics can be obtained throughout the year regardless of summer or winter. 3) High current charge / discharge is possible. The charging characteristics show no remarkable temperature rise even when the battery is charged with a current value several times to 10 times or more that of a conventional battery, and the temperature rise is comparable to that of a conventional battery. Therefore, the battery can be charged in a short time (1/10 or less). On the other hand, the discharge characteristics are such that a high current discharge of 2.5 times or more of the rated value can be performed. Therefore, the battery of a normal mini car (550cc) can be used for a 3,000cc class diesel car. It was also confirmed that the battery life was extended.

[0053]

The present invention will be described in more detail with reference to the following examples. Example 1 (Production of carbon suspension 1) Example of crystalline carbon, rod-shaped electrode Inside a cylindrical cathode having a diameter of 100 mm formed by bending a stainless steel mesh plate using water (pH: 7) as an electrolyte. To
A graphite rod having a diameter of 20 mm and a length of 100 mm was used as an anode, and a DC current of 3 A was passed for 24 hours to form a colloidal carbon suspension. The carbon suspension did not settle even after standing for 10 days, and the carbon powder was dispersed as a carbon colloid. The concentration of the carbon powder in the suspension was 3.1% by weight. The pH of the electrolyte changed to 2.5.

(Carbon Surface Analysis) As described above, the atoms present on the surface of the carbon subjected to the electrolytic oxidation treatment were analyzed by ESCA. FIG. 1 shows an ESCA analysis chart of the carbon subjected to the electrolytic oxidation treatment, and FIG. 2 shows an ESCA analysis chart of the untreated carbon. On the surface of the carbon electrode, C
(Peak of C ₁ s), O (peak of O ₁ s, O ₂ s) and a small amount of N
(Peak of N ₁ s) and S (peak of S ₂ s, S ₂ p). Oxygen: 15.33% Nitrogen: 0.18% Carbon: 84.39% Sulfur: 0.10% The carbon surface is chemically modified with oxygen by electrolytic oxidation (chemical
modification). It should be noted that only traces of O ₁ s appeared in those not subjected to electrolytic oxidation treatment.

(Existing Form of Oxygen) As a result of similarly examining the existing form of oxygen on the carbon surface by ESCA, the following peak was confirmed. -CO- (286.78 eV) 8.40% -COO- (carboxyl) (288.77 eV) 9.98%, it seems that hydrogen is bonded to the right side of O, and the presence of this -OH Is presumed to contribute to hydrophilization and suspension of the carbon surface. The reason why the pH of the electrode solution changed to pH 2 to 3 seems to be particularly due to the presence of a carboxyl group.

(Production of Carbon Suspension 2) Examples of crystalline carbon and felt electrode A stainless steel mesh plate is used on both sides at intervals of 2 mm with a felt made of graphite fiber having a length of 100 mm, a width of 100 mm and a thickness of 10 mm as an anode. (Cathode). At this time, a 2 mm-thick resin mesh sheet was sandwiched between the anode and the cathode so as not to short-circuit and to keep the interval constant. Tap water was used as the electrolyte. A DC current of 3 A was passed for 24 hours. The concentration of the suspended carbon powder was 4.8 wt%. The pH of the electrolyte was 2.

(Production of Carbon Suspension 3) Example of Amorphous Carbon, Powder Electrode A cylindrical stainless steel mesh (325 # under) having a diameter of 20 mm, a length of 100 mm and a bottom has an average diameter of 1 mm.
A 50 mm x 100 mm stainless steel plate was used as a cathode, and this was immersed in a beaker filled with tap water and a direct current of 3 A was passed for 30 hours. This produced a colloidal carbon suspension of amorphous carbon powder.
This carbon suspension did not settle even if left for 10 days as in Example 1. The concentration of the carbon powder was 5.5 wt%. The pH of the electrolyte was 2. 24 for dispersal ability
After hours it was 99.3%. Dispersion stability (%) = {Sample concentration after 24 hours (wt%) / Sample concentration at 0 hours (wt%)} × 100 The numerical value of the dispersion ability was determined by the above method.

On average, the carbon suspension water after electrolytic production is p
H 2.0 to 3.5. 200 ml of the suspension water having a concentration of 3.1 wt% obtained by “Production 1 of carbon suspension” was put into a vacuum drier, and
200 ml was heated and dried under reduced pressure of 93 mmHg. Tap water was added to the obtained dry carbon powder, and the resulting mixture was observed for sedimentation and dispersion. 96% dispersion of the first liquid after standing for 96 hours
As described above, the treated water after heating had a dispersing power of not less than 85% in 48 hours. Moreover, the pH of the dried pre-solution is 2.5, 2
After the drying treatment, the pH was 3.15 and 223 mV with respect to the value of 60 mV, and there was no problem if used as it was.

Embodiment 2 (Regeneration of Used Battery) A lead-acid battery (model GX80D2)
After extracting the electrolyte solution from 6) and washing the inside with water, the carbon colloid solution of the carbon powder of Production 1 of Example 1 was put in the inside, and a DC plus voltage of 15 V was applied to the anode for 12 hours. The anode was coated with carbon powder. Next, the carbon suspension was drained from the battery, and the drained electrolyte was returned to the battery, and then charged at 15 V, 3 A for 24 hours. The voltage before charging was 9 V, and the specific gravity of the battery solution was 1.18. After charging, the voltage returned to 14V, and the engine was able to start. After that, the engine was left again for 10 days and then started again. Thereafter, this was repeated for 6 months, but there was no change in performance. By the way, battery not coated with carbon powder
In (disabled), after charging, the specific gravity changed to 1.20, but the engine could not be started.

Example 3 (Regeneration of Used Battery) 3 vol%, 5 vol%, 10 vol%, 30 vol%, 50 vol of the battery fluid of the unusable lead storage battery (model GX80D26)
%, 70 vol%, and 90 vol% were replaced with the carbon suspension of Preparation 2 of Example 1 and charged at 14 V, 3 A for 24 hours. The electrolyte in each cell turned black with the carbon particles before charging, but after one charge, the electrolyte in each cell became transparent, indicating that the carbon particles were adsorbed on the electrodes. After that, as a result of the engine start test, all of the engines could be started. After leaving the engine for 10 days, the engine was started again. Thereafter, this was repeated for 6 months, but there was no change in performance.

Example 4 (Regeneration of Used Battery) Example 1 was applied to an unusable lead-acid battery (model 38B20R).
The carbon suspension prepared in Preparation 3 was charged at 14 V and 3 A for 12 hours while adding 50 cc per cell (the total electrolyte volume per cell was 416 cc). The specific gravity of the battery solution before charging was 1.10. After charging, the voltage returned to 14V, the specific gravity recovered to 1.26, and the engine was started. After that, the engine was left again for 10 days and then started again. Thereafter, this was repeated for 6 months, but there was no change in performance. By the way, in the battery to which the carbon colloid solution was not added (the battery became unusable), the specific gravity was unchanged at 1.120 just by charging, and the engine could not be started.

Example 5 (Regeneration of Used Battery) A rapid charging of a lead storage battery (model GS (trademark) 38B20L) manufactured by Nippon Battery Co., Ltd., for which an ordinary passenger car became unusable, was attempted. Normal electrolyte was replenished before charging, but voltage 5V, specific gravity 1.110
Met. On the other hand, the normal charging voltage is 14V, 3.
It was 8A, but was quickly charged at 15V, 10A. However, only the liquid temperature rose, electrolysis did not proceed, and charging was impossible.

Next, 21 to 30 cc of the carbon colloid solution of Production 1 of Example 1 was injected into each of the cells (total electrolyte amount of one cell is 416 cc) and the above-mentioned voltage was applied to the storage battery. Was. Even when the voltage was further increased and a current of 20 A was applied, no increase in the liquid temperature was observed, and the battery was charged smoothly. Two hours later, when the engine was started, the engine was able to operate smoothly. After running for three hours, the specific gravity of the battery electrolyte was measured. The standard value was 1.250 or less, which was 1.20. There was no problem. Normal charging requires about 5 to 10 hours, but in this example, charging was completed in only 2 hours. The same test was performed on lead-acid batteries of model Hitachi (trademark) 46B25L and model Yuasa (trademark) 55B24L, and 100% recovery was observed. There was no problem with the electromotive force even if left for four months. Although spontaneous discharge occurs when left for 4 months, it could be used without any problem.

Example 6 (Regeneration of Used Battery) The electrolyte of a lead-acid battery of model GS38 (trademark) which was no longer usable was withdrawn, and the following electrolyte was injected instead. The same sulfuric acid concentration of the electrolytic solution was used, and the amount of the suspended carbon powder was changed at the following five levels. Carbon concentration (wt%) (1) 0.02, (2) 0.1, (3) 1.0, (4) 3.0,
(5) 5.0 The carbon concentration was adjusted by concentrating and diluting the carbon colloid solution of Production 2 of Example 1. The battery was charged at 15 V and 2 A for 2 hours. We were able to charge without problem. Next, I attached it to the car and started the engine. The engine started without any problems. He ran for two hours a day for 60 days, for a total of 120 hours, without any problems during that time.

Example 7 (Regeneration of Used Battery) A used battery (GS28) for a mini car (550 cc) was reclaimed and used for a 2,000 cc class car. About 10% of the electrolyte is replaced with the carbon suspension of Preparation 2 of Example 1
A for 1 hour. The 2,000cc engine was able to start under normal conditions. It turned out that a 2,000 cc class engine can be started with a mini car battery.

Example 8 (Regeneration of Battery of Imported Car) A battery loaded with Mercedes-Benz (trademark), which was loaded from Germany and landed in Japan, passed completely below the equator during transportation due to the influence of the outside temperature. Discharge progresses, making it unusable and unchargeable. An attempt was made to regenerate a battery that could not be used due to deep discharge. Each cell of the battery (estimated 100Ah) of the 4.5-liter engine of the Benz 4.5 liter engine that could not be charged was supplied with a total amount of 250cc and charged at 60A for 15 minutes. When mounted on a Mercedes-Benz and started, it could be started in one shot. From this, it was found that the carbon suspension liquid can recover a deeply discharged battery by quick charging in a short time.

Example 9 (Changes in electrolyte temperature) Changes in the electrolyte temperature during rapid charging were examined. Battery brand: GS (TM) 6N4-2A A conventional dilute sulfuric acid solution was charged for one hour at 10 times the current (4A). The temperature after charging was 64 ° C. Next, this electrolytic solution 50
%, And charged with the carbon suspension prepared in Production 1 of Example 1, and charged at the same 10-fold current (4 A) for 1 hour. The temperature after charging was 47 ° C. The conventional dilute sulfuric acid solution charged under normal conditions (0.4 A x 10 hours) is 45 to 5
0 ° C., which was found to be comparable for the invention.

Example 10 (Change of internal resistance) Battery brand: GS (trademark) 6N4-2A Conventional dilute sulfuric acid solution: 691Ω 50% by volume of electrolyte solution was prepared using the carbon suspension prepared in Production 3 of Example. Substitution: 316Ω This indicates that the rapid charging of the battery of the present invention is largely due to the decrease in internal resistance due to the injection of the carbon suspension.

Example 11 Test of storage battery capacity (normal temperature 25 ° C.)
Battery brand: GS (trademark) 6N4-2A Charging method: 1 A x 1 hour Discharging method: The above batteries were connected in series in three rows and a 37.5 W headlamp was turned on to discharge a constant current (1.2 A). . Test method: Comparison was made between a conventional dilute sulfuric acid electrolytic solution as it was and a solution in which 10 vol% of the electrolytic solution was replaced with the carbon suspension prepared in Production 2 of Example 1. Fig. 5 shows the results.
Is shown by a voltage-time relationship curve. The battery of the present invention has a voltage of 4.
The discharge time until the voltage drops to 8 V, that is, the time that can be used as a battery, was extended by 27% compared with the conventional battery.

Example 12 (Enrichment and Startability of Carbon Suspension) The electrolyte of a battery GS ™ 28Ah for a mini vehicle was
10% was tested for enrichment and startability of the carbon suspension of Preparation 2 of Example 1. The test was performed with a 3,000 cc Mitsubishi Pajero ™ diesel. Concentrations are 2x, 4x, 6x and 10x
It is twice. The engine started without any problem at any concentration.

Example 13 (Storage Battery Capacity at Normal Temperature) A storage battery (model 6N4-2A) consisting of a combination of two anodes and three cathodes of one cell, one anode was removed, and the anode was removed.
And a cathode, and a 50 mm × 50 mm × 2 mm thick graphite felt was inserted between the anode and the separator. The battery was charged with 1 A × 1 hour by replacing 5 vol% of the electrolyte solution with the carbon suspension prepared in Production 1 of Example 1.
After charging, it was connected to a 37.5 W headlamp for 1.2 V and discharged at a constant current (1.2 A). Its discharge curve (voltage-time curve)
Is shown in FIG. For comparison, FIG. 6 shows a discharge curve in a case where a combination of one anode and two cathodes has no graphite felt insert between the anode and the cathode and no addition of a carbon suspension to the electrolyte. As is clear from FIG. 6, it was confirmed that when the carbon suspension was used in combination with the carbon felt, the discharge amount increased and the discharge voltage also increased.

Example 14 (Battery capacity at 65 ° C.) Battery brand: GS (trademark) 6N4-2A Charging method: 1 A × 1 hour Discharging method: The above batteries were connected in series in three rows, and a 37.5 W headlight was turned on. To discharge at a constant current (1.2 A). Test method: Comparison was made between a conventional dilute sulfuric acid electrolytic solution as it was and a solution in which 10 vol% of the electrolytic solution was replaced with the carbon suspension prepared in Production 2 of Example 1. Fig. 7 shows the results.
Is shown by a voltage-time curve. The battery of the present invention has a voltage of 4.8 V
The time required for the battery to be reduced to a lower value, that is, the time that it can be used as a battery, could be extended 1.8 times that of the conventional battery. At higher temperatures, the difference in performance from conventional batteries further widened.

Example 15 (Battery capacity at -20 ° C.) Battery brand: GS (trademark) 6N4-2A Charging method: 1 A × 1 hour Discharging method: Connect the above batteries in series in three rows and turn on the 37.5 W headlights Then, a constant current (1.2 A) was discharged. Test method: Comparison was made between a conventional dilute sulfuric acid electrolytic solution as it was and a solution in which 10 vol% of the electrolytic solution was replaced with the carbon suspension prepared in Production 2 of Example 1. Fig. 8 shows the results.
Is shown by a voltage-hour curve. The battery of the present invention has a voltage of 4.8 V
Although the discharge time until the battery was reduced, that is, the time during which it could be used as a battery, was not much different from that of the conventional battery, it was found from the voltage-hour curve during charging that the battery of the present invention can be charged at a low voltage. That is, it was found that the internal resistance was small and charging was easy.

Example 16 (Production of Electrode) The anode used was GS (trademark) 6N4-2A from which the lead lattice active material had been removed, and the cathode used was GS6N4-2A as it was. The anode active material is a paste made by kneading 30 g of lead oxide, 6 g of lead tetroxide, and 8 ml of dilute sulfuric acid having a specific gravity of 1.12. This is uniformly filled from the anode grid, and aged at room temperature for 12 hours. did. In the chemical conversion treatment, a nonwoven fabric made of glass fiber is interposed between an aged anode and a cathode and insulated and fixed, then immersed in the carbon powder colloid solution prepared in Production 1 of Example 1, and a direct current is applied between the anode and the cathode. A voltage was applied and the current was flowed at 200 mA for 12 hours. The carbon powder was adsorbed on the anode after the chemical conversion treatment. The charge / discharge test is
After the chemical conversion solution was taken out, it was charged with dilute sulfuric acid (specific gravity: 1.25) instead, charged at 0.5 A for an hour, discharged at a constant current (0.4 A), and the change in voltage was examined. FIG. 9 shows the results. In addition, the adsorption of the carbon powder to the anode by this method is effective not only in the activation of a used battery but also in the intermediate process of manufacturing a new anode.

Example 17 A battery brand is a battery G for a mini car (550 cc).
For the production of the electrode using S (trademark) 28, an electrode paste having the same composition as in Example 16 was filled in a lead grid of the positive electrode, and left to stand at room temperature for 12 hours to ripen. Next, in the chemical conversion treatment of this electrode, the negative electrode of the GS28 battery was diverted as it was as the negative electrode, a nonwoven fabric of glass fiber was sandwiched between the aged positive electrode and the negative electrode, fixed, then the electrode was taken out and the electric wire was attached. After being stored in a glass container, a chemical conversion solution having the following composition was put into the glass container until the electrode was immersed in the electrode, and a current of 200 mA DC was supplied for 10 hours to perform a chemical conversion treatment. As the chemical conversion solution, a solution in which the solvent was water and the amount of suspended carbon powder was changed at the following five levels was used. Carbon concentration (wt%) (1) 0.02, (2) 0.1, (3) 1.0, (4) 3.0, (5)
5.0 The carbon concentration was adjusted by concentrating and diluting the suspension of Preparation 2 of Example 1. After the chemical conversion treatment, the chemical conversion treatment solution was withdrawn, and dilute sulfuric acid having a specific gravity of 1.25 (the electrolyte solution of a normal lead-acid battery) was put in place, and a 2,000 cc gasoline engine was subjected to a start test. All could be started in one shot. After that, the engine was left again for 10 days and then started again. On the other hand, a battery using ordinary dilute sulfuric acid as a chemical conversion solution prepared for comparison had a too small capacity for a light vehicle and could not be started.

Example 18 The battery brand is a battery G for a mini car (550 cc).
For the production of the electrode using S (trademark) 28, an electrode paste having the same composition as in Example 16 was filled in a lead grid of the positive electrode, and left to stand at room temperature for 12 hours to ripen. Next, in the chemical conversion treatment of this electrode, the negative electrode of the GS28 battery was used as it is as the negative electrode, a nonwoven fabric of glass fiber was sandwiched and fixed between the aging-completed positive electrode and the negative electrode, and an electrode extraction wire was attached. After storing in a container, a chemical conversion solution having the following composition was put into the container until the electrode was completely immersed, and a current of 200 mA DC was supplied for 10 hours to perform a chemical conversion treatment. As a chemical conversion solution, 3 vol% of dilute sulfate chemical conversion solution, 5
Seven types of suspensions having compositions in which the vol%, 10 vol%, 30 vol%, 50 vol%, 70 vol%, and 90 vol% were replaced with the suspension of Production 1 of Example 1 were used. After the chemical conversion treatment, the chemical conversion treatment liquid was extracted, and instead, a dilute sulfuric acid (specific electrolyte solution of a lead-acid battery) having a specific gravity of 1.25 was added, and a start test of a 2,000 cc gasoline engine was performed. I could start. Thereafter 10
I left it for a few days and started the engine again.

Example 19 (Addition of carbon powder for severe charge / discharge) A new battery of GS (trademark) 6N4-2A was prepared as a battery, and the battery was deteriorated by repeating charge / discharge of (STD50) 50 times continuously. 0.3 g (0.9 g in total) of the electrolytic carbon oxide powder obtained in Example 1 (production of carbon powder) was added to each cell, and a charge / discharge test was performed. As a result, as shown in FIG.
(DVD) shows a remarkable improvement in performance, and the first charge / discharge (STD
1) and a discharge curve close to the 25th time (STD25) were shown, and a state similar to a new product could be reproduced.

[0078]

The present invention has the following effects. 1) It is possible to judge the quality of a lead storage battery that can no longer be used, and it can be easily regenerated by simply adding the electrolytic carbon oxide powder or its paste or suspension to the electrolyte solution, which was previously unreproducible. This regeneration has improved performance over conventional new batteries, and can achieve high current rapid charging and increased discharge capacity. 2) When used as a chemical solution for aging positive electrode litharge during the manufacture of lead-acid batteries, new performance can be improved,
In addition to the above performance improvement, a current higher than the rated current can be taken out, the size of the lead storage battery can be reduced, the sulfuric acid concentration of the electrolyte can be reduced, and the life can be extended. 3) When the PbO ₂ cathode is in contact with the porous carbon sheet and fills the gap with the separator, the active material can be prevented from falling off and the charging capacity can be improved, miniaturization and long life can be achieved. can do. Therefore, it is suitable not only for reusing resources and reducing pollution, but also for reducing the weight of the entire vehicle and for use as a lead storage battery for electric vehicles.

[Brief description of the drawings]

FIG. 1 is an ESCA chart of the electrolytic carbon oxide particles of the present invention.

FIG. 2 is an ESCA chart of ordinary carbon particles.

FIG. 3 is an ESCA chart showing a spectrum of C ₁ s in which the peak in FIG. 1 protrudes in the range of 280 to 300 eV.

FIG. 4 is an ESCA chart showing a spectrum of C ₁ s in FIG. 2;

FIG. 5 is a graph showing a voltage-time curve (charge / discharge curve) during charge / discharge.

FIG. 6 is a graph showing a voltage-time curve (charge / discharge curve) during charge / discharge.

FIG. 7 is a graph showing a voltage-time curve (charge / discharge curve) during charge / discharge.

FIG. 8 is a graph showing a voltage-time curve (charge / discharge curve) during charge / discharge.

FIG. 9 is a graph showing a voltage-time curve (discharge curve) during discharging.

FIG. 10 is a graph showing a voltage-time curve (charge / discharge curve) during charge / discharge.

Claims (8)

(57) [Claims] 1. A lead-acid battery electrolyte comprising a carbon suspension obtained by electrolytic oxidation of a carbon anode in an aqueous system and having the ability to activate a lead-acid battery anode (PbO ₂ ) by electrochemical doping. 2. The carbon suspension according to claim 1, wherein the carbon suspension is a colloidal suspension, wherein carbon colloid particles have carbonyl groups,
Electrolyte for lead-acid batteries chemically modified with hydrophilic groups such as carboxyl groups and hydroxyl groups. 3. An activated lead-acid battery obtained by adding the carbon suspension according to claim 1 as a replenisher to an electrolytic solution as a regenerating agent for the lead-acid battery. 4. An activated lead-acid battery obtained by adding a carbon powder obtained by drying the carbon suspension according to claim 1 to an electrolyte as a regenerant for the lead-acid battery. 5. An activated lead-acid battery using the carbon suspension according to claim 1 as an aging solution for the aged positive electrode litharge. 6. PbO ₂ cathode Ri contact near the carbon sheet of porous, lead-acid battery that is activated by the charging operation in addition the state of the carbon suspension 請 Motomeko 1 wherein. 7. The lead-acid battery according to claim 6, wherein the porous carbon sheet is a carbon fiber fabric or felt. 8. When the carbon suspension according to claim 1 or a carbon powder obtained by drying the carbon suspension as a regenerant for a lead storage battery is charged into an electrolyte, the carbon particles in the electrolyte are adsorbed on the anode. When the electrolyte in all the cells of the lead storage battery becomes transparent, the battery is recyclable. When the electrolyte in some or all of the cells does not become transparent and turns black, the battery cannot be recycled. A method for determining whether a lead-acid battery can be reproduced.