KR20200057465A - Composition of lead-carbon electrode paste, and manufacturing method of the paste - Google Patents

Abstract

The present invention relates to a negative electrode active material paste composition for an electrode plate of a lead storage battery, which can reduce a process cost and improve performance of a negative electrode by adding activated carbon to a negative electrode paste composition without an additional coating process. The present invention also relates to a manufacturing method thereof and a negative electrode manufacturing method using the same.

Description

A cathode active material paste composition for an electrode plate of a lead acid battery, and a manufacturing method thereof {Composition of lead-carbon electrode paste, and manufacturing method of the paste}

The present invention relates to a negative electrode active material paste composition for an electrode plate of a lead acid battery, and a method for manufacturing the same.

Lead acid batteries are batteries that have a relatively simple manufacturing process, low cost, and technical stability. Currently, lead acid batteries are used in a wide range of fields such as automobiles, hybrid electric vehicles (HEV), energy storage systems, uninterruptible power supplies (UPS), and communications. However, compared to batteries such as lithium-ion batteries and nickel-metal hydride batteries, the energy density is relatively low and light weight is difficult. In particular, output and cycle performance loss due to irreversible reaction of lead sulfate (PbSO ₄ ) crystals generated at the cathode occurs.

Ultra batteries have a longer lifespan than conventional lead-acid batteries when they inhibit the formation of lead sulfate crystals generated at the cathode and promote reversible reactions. These ultra-batteries are particularly suitable for HEVs because they have the ability to rapidly charge and power during vehicle acceleration and stoppage, and are 70% cheaper than HEV batteries. It is also a technology that is highly likely to enter the mass storage market.

Therefore, a technique for maximizing the advantages of the lead acid battery and compensating for the problems is required.

The object of the present invention is to reduce the process cost by adding activated carbon to the negative electrode paste composition without an additional coating process, and to improve the performance of the negative electrode, a negative electrode active material paste composition for an electrode plate of a lead acid battery, a method of manufacturing the same and using the same It is a cathode manufacturing method.

In order to achieve the object of the present invention as described above,

The negative electrode active material paste composition for the electrode plate of the lead acid battery of the present invention is characterized by containing fuel, sulfuric acid, distilled water, expander, fiber block, and activated carbon.

The activated carbon has a particle size of 2 μm to 10 μm and a specific surface area of 1000 m ² / g to 2500 m ² / g.

Containing 70 to 75% by weight, 5 to 10% by weight sulfuric acid, 14 to 18% by weight distilled water, 0.3 to 0.6% by weight expander, and 0.1 to 0.3% by weight fiber block relative to the total weight% of the paste composition It is characterized by.

With respect to the total weight% of the paste composition, the activated carbon is characterized in that it is contained 1 to 10% by weight.

The expander is characterized by having a composition of 70 to 90 wt% of barium sulfate, 10 to 13 wt% of lignin, and 6 to 10 wt% of carbon black.

Method for producing a negative electrode active material for an electrode plate of a lead acid battery according to various embodiments of the present invention comprises: mixing flour, sulfuric acid, distilled water, expander and fiber block; Adding activated carbon to the mixture; And stirring the mixture of the activated carbon.

In the stirring step, the mixture is stirred at a speed of 3000 rpm to 7000 rpm to obtain a mixture having a density of 3 g / cc to 7 g / cc.

After the stirring step, characterized in that it further comprises the step of aging and drying the mixture.

Method for manufacturing a negative electrode for a lead plate of a lead acid battery according to various embodiments of the present invention, applying the paste composition to a metal substrate; Applying a pressure of 1 psi to 2 psi to the substrate using a plate press; Drying the substrate; It characterized in that it comprises.

The ultra-battery made of the negative electrode active material paste composition for the electrode plate of the lead acid battery of the present invention has improved output characteristics and has a long lifespan of at least 4 times longer than the existing battery, which meets the development needs of hybrid vehicle and electric vehicle technologies. In addition, it is cheaper than the battery used in the existing HEV. In addition, stability can be secured during rapid charging / discharging.

On the other hand, the method for manufacturing a negative electrode for a lead plate of a lead acid battery of the present invention can omit an additional process, and thus has excellent process efficiency compared to an existing process, and can reduce process cost. In addition, it can be manufactured according to the performance of the cathode desired by the user.

1 is a process flow diagram of a method for manufacturing a negative electrode active material for an electrode plate of a lead acid battery according to an embodiment of the present invention.
2 is a process flow diagram of a method for manufacturing an anode for a lead plate of a lead acid battery.
3 is a photograph of a cathode prepared according to Example 1.
4 is a photograph of a negative electrode manufactured according to a comparative example.
5 is a result of evaluating the life characteristics of ultra batteries manufactured according to Examples 1 to 3 and Comparative Examples.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings. It should be understood that the examples and terms used therein are not intended to limit the technology described in this document to specific embodiments, but include various modifications, equivalents, and / or substitutes of the examples.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Ultra batteries are manufactured by containing or coating a carbon material in an existing lead acid battery. A cathode containing or coated with a carbon material affects the amount or rate of reduction to metal lead when a positive current is applied due to the excellent electrical conductivity of the carbon material. In addition, it prevents the formation of lead sulfate crystals formed on the surface of the cathode during charging *? * Discharging of the battery, and improves the performance of the ultra battery by improving the reversible reaction. Such an ultra battery exhibits various characteristics depending on a method of containing or coating, and also exhibits different characteristics depending on the carbon material used.

A negative electrode active material paste composition for an electrode plate of a lead acid battery according to various embodiments of the present invention may include flour, sulfuric acid, distilled water, expander, fiber flock, and activated carbon.

The paste composition of the present invention can improve the performance of a lead acid battery by containing activated carbon. Specifically, the paste composition of the present invention may include high specific surface area activated carbon. At this time, the particle size of the activated carbon may be 2 μm to 10 μm and the specific surface area may be 1000 m ² / g to 2500 m ² / g. When the particle size of the activated carbon is smaller than 2 μm or larger than 10 μm, improvement in life characteristics and output characteristics of the lead acid battery negative electrode may be insignificant. Similarly, when the specific surface area of the activated carbon is less than 1000 m ² / g or greater than 2500 m ² / g, improvement in life characteristics and output characteristics of the lead acid battery negative electrode may be negligible.

The packing density of activated carbon may be 0.2 g / cc to 0.6 g / cc. In addition, other impurity contents of activated carbon may be 100 ppm or less of Ca, K, Na, or 20 ppm or less of Fe and Ni.

Activated carbon may be included in 1 to 10% by weight based on the total weight of the paste composition. When less than 1% by weight of activated carbon is added, the desired life characteristics and retention capacity cannot be secured. When more than 10% by weight is added, the meaning of addition is lost because the life characteristics and retention capacity are no longer improved. do. Preferably, the activated carbon may be included in 1% to 3% by weight.

On the other hand, with respect to the total weight% of the paste composition, 70 to 75% by weight of oil, 5 to 10% by weight of sulfuric acid, 14 to 18% by weight of distilled water, 0.3 to 0.6% by weight of expander, and 0.1 to 0.3% of fiber block % Can be included. In this case, the sulfuric acid may be sulfuric acid having a specific gravity of 1.2 to 1.4.

Here, the expander may have a composition of 70 to 90 wt% of barium sulfate, 10 to 13 wt% of lignin, and 6 to 10 wt% of carbon black. Barium sulfate acts as a nucleus for the production of lead sulfate and may serve to increase the capacity of the negative electrode plate. Lignin is strongly adsorbed to lead (Pb) and lead sulfate (PbSO4) and may serve to increase and maintain the surface area and porosity of the electrode. Carbon black can serve to increase the conductivity while allowing the positive and negative electrodes to be visually identified.

The fiber block increases the bonding force between the negative electrode active materials and can maintain moisture in the negative electrode active material.

Hereinafter, a method of manufacturing a negative electrode active material for an electrode plate of a lead acid battery will be described with reference to FIG. 1.

Method for producing a negative electrode active material for an electrode plate of a lead acid battery according to various embodiments of the present invention, mixing the flour, sulfuric acid, distilled water, expander and fiber block (S100); Adding activated carbon to the mixture (S200); And it may include the step of stirring the mixture of the activated carbon (S300).

In the mixing step (S100), 70 to 75% by weight, 5 to 10% by weight of sulfuric acid having a specific gravity of 1.2 to 1.4, 14 to 18% by weight of distilled water, 0.3 to 0.6% by weight of expander, and 0.1 to 0.3% by weight of fiber block You can mix.

Thereafter, in the step (S200) of adding activated carbon to the mixture, activated carbon having a particle size of 2 μm to 10 μm and a specific surface area of 1000 m ² / g to 2500 m ² / g may be added. At this time, the activated carbon may be included 1 to 10% by weight.

In the stirring step (S300), the mixture may be stirred at a speed of 3000 rpm to 7000 rpm using a homo mixer. Through this, a mixture having a density of 3 g / cc to 7 g / cc can be obtained.

On the other hand, although not shown in the drawing, after the step of stirring (S300), the mixture may further include a step of aging and drying. At this time, the mixture can be aged for 10 hours or more in a humidity chamber where the relative humidity is maintained at 90% and the temperature is maintained at 35 ° C to 55 ° C.

Hereinafter, a method for manufacturing a negative electrode for an electrode plate of a lead acid battery according to various embodiments of the present invention will be described with reference to FIG. 2. Referring to Figure 2, applying the paste composition described above to a metal substrate (S400); Applying pressure to the substrate (S500); And drying the substrate (S600).

In the step of applying to the metal substrate (S400), the metal substrate may be a metal grid having Pb-0.04Ca-1.1Sn as a composition.

In the step of applying pressure to the substrate (S500), the chrome plate is placed on both sides and a pressure of 1 psi to 2 psi can be applied using a plate press.

Thereafter, in the step of drying the substrate (S600), the electrode plate on which the pressing process is completed may be dried for 15 hours or more in a dryer where the temperature is maintained at 30 ± 10 ° C.

Example  One

The present invention is to improve performance by additionally adding activated carbon when preparing a paste as a method for reforming a cathode of an ultra battery. The electrochemical performance test was conducted according to the added carbon content. The carbon material used is activated carbon having a high specific surface area and has excellent electrical conductivity. The size is about 2-5 μm, and the packing density is 0.2-0.6 g / cc. Other impurity contents are 100 ppm or less of Ca, K, Na, and 20 ppm or less of Fe and Ni. In the paste formulation for the ultra-battery negative electrode plate, 100 g of lead pulverized using a ball mill, 21.6 mL of distilled water, 12 mL of an aqueous sulfuric acid solution having a specific gravity of 1.360, an expander of 0.68 g, and 0.15 g of a fiber block were mixed. In the examples, 1 wt% activated carbon was additionally added when mixing the paste for the negative electrode plate. After adding the compositions, each time the composition was added using a glass rod, the mixture was mixed for a total of 10 minutes. Thereafter, the mixture was mixed for 15 minutes at a speed of 5000 rpm using a homo mixer. The paste has a density of 4.40 ± 0.05 g / cc, and the composition of the prepared expander is lignin (11.5 wt%), barium sulfate (80.0 wt%), and carbon black (8.5 wt%). The paste, which has been completely blended, undergoes aging for 10 hours or more in a humidity chamber where the relative humidity is maintained at 90% and the temperature is maintained at 35-55 ℃ by continuously generating water vapor.

For the design of a battery with a capacity of 400 mAh, the aged paste was applied to a metal grid having a composition of Pb-0.04Ca-1.1Sn and a chrome plate was placed on both sides, and a pressure of 1.5 psi was applied using a plate press. . After the pressing process was completed, the plate was dried for 15 hours or more in a dryer where the temperature was maintained at 30 ± 10 ° C. After that, to make the area where the anode and the anode meet, the part off the grid was cut out. A battery was assembled using the prepared anode and PbO ₂ anode, and an AGM (Absorptive Glass Mat) separator was used to prevent direct contact between the anode and the anode. For comparison with an existing lead acid battery, an H ₂ SO ₄ aqueous solution having a specific gravity of 1.28, which is generally used as an electrolyte for a lead acid battery, was used as an electrolyte. The manufactured ultra battery was placed in a constant temperature water bath maintained at 25 ° C. for at least 24 hours for voltage stabilization. A voltage of 0.1 C (40 mA) was applied for 48 hours to the battery, where the voltage stabilization process was completed, and the primary charging was performed, so that lead of the negative electrode was formed in the sea level. Secondary charging was performed by applying a current of 0.05 C (20 mA) for 24 hours. The 1st and 2nd charging process is an electrochemical activation step, and then the voltage stabilization step was performed for 24 hours. Meanwhile, FIG. 3 is a photograph of a negative electrode manufactured according to Example 1.

Example  2

An anode was prepared in the same manner as in Example 1, except that the active carbon composition in Example 1 was changed from 1 wt% to 2 wt%, and an ultra battery was manufactured using the same.

Example  3

An anode was prepared in the same manner as in Example 1, except that the active carbon composition in Example 1 was changed from 1 wt% to 3 wt%, and an ultra battery was manufactured using the same.

Comparative example  One

An anode was prepared in the same manner as in Example 1, except that the activated carbon in Example 1 was not added, and an ultra battery was manufactured using the same. On the other hand, Figure 4 is a photo of the negative electrode prepared according to the comparative example.

Experimental Example -Battery performance evaluation

Cycle test was performed using ZIVE LAB MP2 (Won A Tech) to evaluate the life characteristics and electrochemical performance of the ultra batteries manufactured according to Examples 1 and 2 and Example 3 and Comparative Examples. 5 is shown.

The cycle test is performed after at least 24 hours of aging after assembling the battery to reach an electrochemical equilibrium, and then discharge the battery voltage to 1.75 V by applying a discharge constant current of 0.1 C (40 mA), and the battery voltage with a current of 0.1 C of constant charge current. After charging to 2.60 V, it was discharged with 50% DOD (Depth Of Discharge). The process of charging as much as it was discharged again with a pause of 10 seconds was repeated as 1 cycle. When the voltage became 1.7 V after discharge of the battery, the experiment was stopped and the number of cycles was measured.

As a result, as a result of evaluating the life characteristics of the battery manufactured using the negative electrode of Comparative Example 1, the performance of 374 cycles was shown. On the other hand, the performance of the negative electrode for an ultra battery prepared in Example 1 showed an improved lifespan characteristic of 844 cycles. In Example 2 and Example 3, as the amount of activated carbon was increased, 898, 952 cycles, which were improved performances compared to Comparative Example 1 and Example 1, were shown. It is known that battery life is reduced by lead sulfate crystals formed on the surface during charging and discharging of the existing lead acid battery negative electrode. In Examples 1 to 3, the carbon contained properly prevented the formation of lead sulfate crystals on the negative electrode surface, and promoted a reversible reaction, thereby improving battery life performance. In addition, it appears that in the electrochemical aging step, activated carbon having excellent electrical conductivity helps to evenly form lead in the sea surface at the cathode. The negative electrode prepared with the paste containing the largest amount of activated carbon and Example 3, which is an ultra battery, showed the best performance.

So far, the present invention has been focused on the preferred embodiments. Those skilled in the art to which the present invention pertains will appreciate that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in terms of explanation, not limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent range should be interpreted as being included in the present invention.

Claims (8)

A negative electrode active material paste composition for an electrode plate of a lead acid battery containing soft powder, sulfuric acid, distilled water, expander, fiber block, and activated carbon. According to claim 1,
The particle size of the activated carbon is 2 ㎛ to 10 ㎛ and the specific surface area of 1000 m ² / g to 2500 m ² / g The negative electrode active material paste composition for an electrode plate of a lead acid battery. According to claim 1,
With respect to the total weight percent of the paste composition,
A cathode active material for the electrode plate of a lead acid battery, comprising 70 to 75% by weight, 5 to 10% by weight of sulfuric acid, 14 to 18% by weight of distilled water, 0.3 to 0.6% by weight of expander, and 0.1 to 0.3% by weight of fiber block Paste composition. According to claim 1,
With respect to the total weight percent of the paste composition,
The active carbon is a negative electrode active material paste composition for an electrode plate of a lead acid battery, characterized in that contained 1 to 10% by weight. According to claim 1,
The expander is 70 to 90 wt% of barium sulfate, 10 to 13 wt% of lignin, and 6 to 10 wt% of carbon black. Mixing flour, sulfuric acid, distilled water, expander and fiber block;
Adding activated carbon to the mixture; And
A method of manufacturing a negative electrode active material for an electrode plate of a lead acid battery comprising agitating a mixture of the activated carbon. The method of claim 6,
In the stirring step,
A method of manufacturing a negative electrode active material for an electrode plate of a lead acid battery, wherein the mixture is stirred at a speed of 3000 rpm to 7000 rpm to obtain a mixture having a density of 3 g / cc to 7 g / cc. The method of claim 6,
After the stirring step,
Method for producing a negative electrode active material for a positive electrode of a lead acid battery, characterized in that it further comprises the step of aging and drying the mixture.

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