KR102625316B1 - Edgeless activated carbon, manufacturing method thereof, lead-carbon battery including the same and method for producing the same - Google Patents

Abstract

The present invention relates to a method for producing activated carbon for lead-carbon batteries, and more specifically, to an edgeless activated carbon obtained by removing edge rules present in activated carbon to suppress reactivity due to edges present on the surface of activated carbon, a method for producing the same, and an edgeless activated carbon. It relates to a lead-carbon battery that includes a negative electrode manufactured using activated carbon, improves chargeability, and secures long-life performance by inducing reduction of metallic lead by facilitating electron transfer and a method of manufacturing the same.

Description

Edgeless activated carbon, manufacturing method thereof, lead-carbon battery including the edgeless activated carbon, and manufacturing method thereof {Edgeless activated carbon, manufacturing method thereof, lead-carbon battery including the same and method for producing the same}

The present invention relates to a method for producing activated carbon for lead-carbon batteries, and more specifically, to an edgeless activated carbon obtained by removing the edges present in the activated carbon to suppress reactivity due to the edges present on the surface of the activated carbon, a method for producing the same, and an edgeless activated carbon It relates to a lead-carbon battery that includes a negative electrode manufactured using activated carbon, improves chargeability, and secures long-life performance by inducing reduction of metallic lead by facilitating electron transfer and a method of manufacturing the same.

Lead-carbon batteries are long-life/low-cost hybrid energy storage devices that combine the advantages of lead-acid batteries and carbon-based supercapacitors.

In the case of ISG vehicle batteries, there is a need to improve chargeability in order to improve cycle characteristics according to partial state of charge (PSOC) operation. In other words, it is true that when driving an ISG vehicle, it is difficult to avoid the growth of lead sulfate crystals in the starting battery while continuously discharging in an excessively insufficient state of charge. In lead-carbon batteries, lead sulfate crystal growth due to electrode reaction increases electrode resistance, ultimately causing a problem that reduces the cycle life of the battery. In order to reduce the resistance, it is necessary to attempt to introduce carbon with excellent electrical conductivity to facilitate the transfer of electrons within the electrode, thereby inducing the reduction of lead sulfate to metallic lead and suppressing the increase in resistance. For this purpose, activated carbon physically impregnated with nano-lead is mixed with an electrode binder and then coated on the negative lead electrode plate to manufacture a carbon electrode to facilitate electron transfer within the electrode and reduce lead sulfate to metallic lead. This minimizes the increase in resistance within the electrode.

Therefore, in order to implement high-output, long-life battery performance that can be installed in cars with frequent sudden braking and sudden starts, such as ISG vehicles, an electrode active material based on carbon material with excellent electrical conductivity is introduced to improve charging performance and facilitate electron transfer. In this way, it is necessary to secure long-life performance by inducing reduction of metallic lead.

However, in the case of existing lead-carbon batteries, reactivity increases due to the edges present on the surface of activated carbon, resulting in problems such as increased resistance and reduced cell performance due to gas generation and battery component phenomena.

Domestic Patent Publication No. 10-2020-0045794

As a result of numerous studies, the present inventors completed the present invention by developing a technology that can solve problems such as increased resistance and reduced cell performance due to gas generation and battery component phenomena occurring in existing lead-carbon batteries.

Therefore, the purpose of the present invention is to provide edgeless activated carbon obtained by removing edges present in activated carbon below a certain ratio to suppress the reactivity of activated carbon, and a method for manufacturing the same.

Another object of the present invention is to provide an electrode for a lead-carbon battery that has high electrical conductivity by including edgeless activated carbon with suppressed reactivity and can suppress an increase in electrode resistance by accelerating the reduction of lead sulfate to metallic lead.

Another object of the present invention is that by using an electrode containing edgeless activated carbon as a cathode, the chargeability of the battery can be improved due to the improved electrical conductivity of the electrode, and the cycle characteristics can be improved by reducing moisture loss due to suppression of the hydrogen generation reaction. To provide an improved lead-carbon battery and its manufacturing method.

The object of the present invention is not limited to the object mentioned above, and even if not explicitly mentioned, the object of the invention that can be recognized by a person of ordinary skill in the art from the description of the detailed description of the invention described later may also naturally be included. .

In order to achieve the object of the present invention described above, first, the present invention is to reduce the content of the edge, which is a portion composed of oxygen functional groups or hydrogen located on the outside of the basal plane of activated carbon with a continuous hexagonal structure, at a certain ratio. Provides edgeless activated carbon that exists.

In a preferred embodiment, the constant ratio is a relative ratio of the specific surface area occupied by the edge measured to the specific surface area of the base surface, and is 2% by volume or less.

In a preferred embodiment, the total content of the edges is 500 μmol/g or less and the specific surface area occupied by the edges is 26 m ² /g or less.

In a preferred embodiment, the activated carbon is any one selected from the group consisting of palm shell-based activated carbon, phenolic resin-based activated carbon, and coke-based activated carbon.

In a preferred embodiment, the addition reaction is suppressed when the edges are present at a certain ratio.

In addition, the present invention includes a purification step of removing impurities present in activated carbon; and a heat treatment step of treating the purified activated carbon at a temperature of 1000-2000°C.

In a preferred embodiment, the purification step removes metal impurities by treating the activated carbon with 1 mole to 10 mole aqueous hydrochloric acid solution for 12 hours or less.

In a preferred embodiment, the heat treatment step is performed within 30 minutes in an argon gas atmosphere using a graphitization furnace.

In a preferred embodiment, a residual edge removal step of removing edges remaining on the surface of the heat-treated activated carbon is further included.

In a preferred embodiment, the remaining edge removal step is performed by amination of the heat-treated activated carbon.

In a preferred embodiment, the amination reaction is performed by adding an amination agent selected from the group consisting of anhydrous ethanol, diethylenetriamine, urea (CH ₄ N ₂ O), and ammonia (NH ₃ ) to the heat-treated activated carbon, and heating for 70 to 70 minutes. It is carried out by reacting at 100°C for more than 10 hours.

In a preferred embodiment, the activated carbon is any one selected from the group consisting of palm shell-based activated carbon, phenolic resin-based activated carbon, and coke-based activated carbon.

In a preferred embodiment, the edgeless activated carbon has a total content of the edges of 500 μmol/g or less and a specific surface area occupied by the edges of 26 m ² /g or less.

In addition, the present invention provides edgeless activated carbon containing any of the above-described edgeless activated carbon or edgeless activated carbon manufactured by any of the above-described manufacturing methods, and nano-lead-containing edgeless activated carbon comprising a nano-lead deposition layer formed on the surface of the activated carbon.

Additionally, the present invention provides an electrode slurry composition containing the above-described nano-lead-containing edgeless activated carbon.

In a preferred embodiment, 2 to 20 parts by weight of binder and 200 to 300 parts by weight of dispersion solvent are included per 100 parts by weight of the nano-lead-containing edgeless activated carbon.

In a preferred embodiment, the binder is at least one selected from the group consisting of polyvinylidenefloride, carboxymethylcellulose, and styrene-butadiene rubber, and the dispersion solvent is ethanol, acetone, and ispropyl alcohol. , methyl pyrrolidone, and propylene glycol.

Additionally, the present invention provides an electrode coated with the electrode slurry composition described above.

In a preferred embodiment, the electrode slurry composition is coated on a lead electrode plate.

Additionally, the present invention provides a lead-carbon battery including the above-described electrode as a cathode.

In addition, the present invention includes the steps of preparing edgeless activated carbon manufactured by any of the above-described edgeless activated carbon or any of the above-described manufacturing methods; A nano-lead deposition step of preparing nano-lead-containing edgeless activated carbon including a nano-lead deposition layer formed by depositing nano-lead on the edgeless activated carbon; An electrode slurry preparation step of preparing an electrode slurry composition containing the nano-lead-containing edgeless activated carbon; and an electrode manufacturing step of coating the electrode slurry composition on a lead electrode plate. It provides a lead-carbon battery manufacturing method including a.

The edgeless activated carbon of the present invention described above can suppress the reactivity of the activated carbon by removing the edges present in the activated carbon below a certain ratio. Therefore, according to the present invention, the content of the edges of activated carbon can be controlled, and based on this, excellent effects can be expected in various energy application fields such as carbon-based supercapacitors and fuel cell carbon-based carriers.

In addition, the cathode of the present invention contains edgeless activated carbon with suppressed reactivity, so it has high electrical conductivity and can suppress an increase in electrode resistance by accelerating the reduction of lead sulfate to metallic lead.

In addition, the lead-carbon battery of the present invention uses an electrode containing edgeless activated carbon as a cathode, which improves the chargeability of the battery due to the improved electrical conductivity of the electrode and reduces moisture loss by suppressing the hydrogen generation reaction. As cycle characteristics are improved, problems such as increased resistance and reduced cell performance due to gas generation and battery component phenomena that occur in existing lead-carbon batteries can be solved.

These technical effects of the present invention are not limited to the scope mentioned above, and even if not explicitly mentioned, the effects of the invention that can be recognized by a person of ordinary skill in the art from the description of the specific contents for implementing the invention described later. Of course it is included.

Figure 1a is a schematic diagram showing the base and edge of a carbon material, Figure 1b is a schematic diagram showing the microstructure of the carbon material and the microstructure of activated carbon after a general activation process, and Figure 1c is a schematic diagram showing the microstructure of activated carbon after a general activation process of activated carbon. This is a schematic diagram to show the difference between the structure and the edgeless activated carbon of the present invention.
Figure 2a is a flowchart schematically showing a process for manufacturing edgeless activated carbon according to an embodiment of the present invention, and Figure 2b is a nano-lead-containing activated carbon, nano-lead produced by depositing nano-lead on the edgeless activated carbon obtained in Figure 2a. This is a flowchart schematically showing the process of manufacturing a lead-carbon battery including an electrode slurry containing lead-containing activated carbon and a negative electrode manufactured by coating it on a lead electrode plate.
Figure 3 shows the results of SEM, TEM, and STM analysis of edgeless activated carbon according to heat treatment temperature when manufacturing edgeless activated carbon.
Figure 4 shows (a) Raman spectrum, (b) X-ray diffraction pattern, (c) nitrogen adsorption and desorption curve, (d) micropore distribution, and (e) oxidation onset temperature of edgeless activated carbon according to heat treatment temperature when manufacturing edgeless activated carbon. , (f) shows electrical conductivity.
Figure 5 shows (a) the total amount of gas, (b) the amount of CO, (c) the amount of CO ₂ , (d) the amount of H ₂ O, (e) Result drawing showing the amount of _H2 .
Figure 6 is a diagram showing the linear scanning potential method (a) current-voltage curve and (b) Tafel diagram of untreated activated carbon and high-temperature heat-treated activated carbon.
Figure 7 shows (a) chargeability, (b) charge capacity, (c) cycle characteristics, (d) of a lead-carbon battery unit cell with untreated activated carbon impregnated with nano-lead and a lead negative electrode plate coated with activated carbon heat-treated at 1600°C. ) This is a diagram showing moisture loss.

The terms used in the present invention are merely used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the description of the invention, but are intended to indicate the presence of one or more other It should be understood that this does not exclude in advance the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component without departing from the scope of the present invention.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present invention, should not be interpreted in an idealized or excessively formal sense. No.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description. In particular, when terms of degree such as "about", "substantially", etc. are used, they may be interpreted as being used at or close to that value when manufacturing and material tolerances inherent in the stated meaning are presented. .

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as ‘~after’, ‘after~’, ‘~next’, ‘before’, etc., ‘immediately’ or ‘directly’ This also includes non-consecutive cases unless used.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to the attached drawings and preferred embodiments.

However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Like reference numerals used to describe the invention throughout the specification represent like elements.

The technical features of the present invention are edgeless activated carbon, which was developed to suppress the reactivity of activated carbon by removing the edges present in activated carbon below a certain ratio, and edgeless activated carbon, which was developed so that the edge content can be controlled depending on the use of the edgeless activated carbon. Activated carbon manufacturing method, an electrode that has high electrical conductivity by including edgeless activated carbon with suppressed reactivity and can suppress an increase in electrode resistance by accelerating the reduction of lead sulfate to metallic lead, and an improved electrode by using the electrode as a cathode. There is a lead-carbon battery and its manufacturing method that can improve the charging ability of the battery due to electrical conductivity and have improved cycle characteristics by reducing moisture loss by suppressing the hydrogen generation reaction.

Therefore, the edgeless activated carbon of the present invention is one in which the content of edges, which are parts composed of oxygen functional groups or hydrogen located outside the basal plane of activated carbon with a continuous hexagonal structure, exists at a certain ratio.

As shown in Figure 1a, the carbon material is divided into a basal plane composed of a continuous hexagonal structure and an edge composed of oxygen functional groups or hydrogen on the outside of the basal plane, and the edge portion is on the outside of the basal plane. It is a part composed of oxygen functional groups or hydrogen located at and shows higher reactivity than the basal surface. As shown in Figure 1b, it can be seen that the edges of carbon materials generally increase compared to the base surface when an activation process is performed. As shown in Figure 1c, the edgeless activated carbon of the present invention has structurally unstable edges in general activated carbon. It can be seen that the edge content is adjusted because the edge is removed as it is converted into a loop.

Here, the constant ratio refers to the relative ratio of the specific surface area occupied by the measured edge to the specific surface area of the base, and the edge content of the edgeless activated carbon of the present invention may be adjusted to 2% by volume or less.

In the edgeless activated carbon of the present invention, the edge content present in the activated carbon can be controlled in various ways. In one embodiment, the total edge content may be 500 μmol/g or less and the specific surface area occupied by the edges may be 26 m ² /g or less. At this time, the activated carbon is not limited as long as it is a carbon material with a large internal surface area of 1000 m2 or more per gram, but may be any one selected from the group consisting of palm shell-based activated carbon, phenolic resin-based activated carbon, and coke-based activated carbon.

In this way, if the edges are present at a certain ratio in the edgeless activated carbon of the present invention, the reactivity of the edges can be suppressed and various side reactions can be suppressed.

Next, the edgeless activated carbon manufacturing method of the present invention includes a purification step of removing impurities present in the activated carbon; and a heat treatment step of treating the purified activated carbon at a temperature of 1000-2000°C.

Here, in the purification step, metal impurities are removed by treating the activated carbon with an aqueous solution of 1 to 10 moles of hydrochloric acid for 12 hours or less. If the aqueous hydrochloric acid solution exceeds 10 moles, there may be a problem of oxidation of the activated carbon due to the high acid concentration. , if it is less than 1 mole, it may not be purified properly and a large amount of impurities may remain.

The heat treatment step is a high-temperature treatment step to remove the edges present in activated carbon. If the temperature is less than 1000℃, surface defects including edges may not be sufficiently removed, and if the temperature exceeds 2000℃, the specific surface area is 700 ^m2. If it falls below /g, it may be difficult to display electrode activity. As an embodiment, the heat treatment step can be performed within 30 minutes in an argon gas atmosphere using a graphitization furnace. Since nitrogen is unstable above 1200°C, it is performed in argon (Ar), and the gas flow rate is 50-2000 sccm. It may be to some extent. Since the heat treatment step is carried out at a high temperature, if the heat treatment time is too long, it consumes a lot of energy and is uneconomical, so it was treated not to exceed 30 minutes.

The activated carbon used in the edgeless activated carbon manufacturing method of the present invention is not limited as long as it is a carbon material with a large internal surface area of 1000 m2 or more per gram, but is any one selected from the group consisting of palm shell-based activated carbon, phenolic resin-based activated carbon, and coke-based activated carbon. It can be.

If necessary, a residual edge removal step of removing edges remaining on the surface of the heat-treated activated carbon may be further included. In order to perform the residual edge removal step or perform other processing after performing the heat treatment step, the temperature must be lowered to a certain temperature. However, it may be advantageous to proceed while maintaining the argon gas atmosphere while lowering the temperature. The remaining edge removal step can be performed by amination of heat-treated activated carbon as shown in Figure 2a. In one embodiment, the amination reaction is performed by adding anhydrous ethanol and diethylenetriamine to the heat-treated activated carbon and heating for 10 minutes at 70 to 100°C. It can be performed by reacting over time. At this time, urea (CH ₄ N ₂ O) or ammonia (NH ₃ ) can be used as the amination agent. The reaction temperature and reaction time are experimentally determined. If it exceeds the set range, the entire amination reaction does not occur. there is.

Edgeless activated carbon obtained by the edgeless activated carbon production method of the present invention as described above may have a total edge content of 500 μmol/g or less and a specific surface area occupied by the edges of 26 m ² /g or less.

Next, the nano-lead-containing edgeless activated carbon of the present invention includes an edgeless activated carbon of the above-described configuration and a nano-lead deposition layer formed on its surface. When the nano-lead deposition layer is formed on the surface of the edgeless activated carbon, It has the effect of improving problems such as voltage reduction.

Next, the electrode slurry composition includes the above-described nano-lead-containing edgeless activated carbon, and may include 2 to 20 parts by weight of a binder and 200 to 300 parts by weight of a dispersion solvent per 100 parts by weight of nano-lead-containing edgeless activated carbon. Here, the binder and dispersion solvent are not limited as long as they are used in the electrode slurry composition for lead-carbon batteries, but in one embodiment, the binder is a group consisting of polyvinylidenefloride, carboxymethylcellulose, and styrene butadiene rubber. and the dispersion solvent may be any one or more selected from the group consisting of ethanol, acetone, isopropyl alcohol, methyl pyrrolidone, and propylene glycol.

The electrode of the present invention may be coated with the electrode slurry composition described above, particularly on a lead electrode plate.

Next, the lead-carbon battery of the present invention includes the above-described electrode as a cathode, and the chargeability of the battery can be improved due to the improved electrical conductivity of the electrode, and the lifespan characteristics can be improved by reducing moisture loss due to suppression of the hydrogen generation reaction. This can be improved.

Next, the lead-carbon battery manufacturing method of the present invention includes preparing edgeless activated carbon manufactured by any of the above-described edgeless activated carbon or any of the above-described manufacturing methods; A nano-lead deposition step of preparing nano-lead-containing edgeless activated carbon including a nano-lead deposition layer formed by depositing nano-lead on the edgeless activated carbon; An electrode slurry preparation step of preparing an electrode slurry composition containing the nano-lead-containing edgeless activated carbon; and an electrode manufacturing step of coating the electrode slurry composition on a lead electrode plate.

At this time, the electrode manufacturing step, as an example, can be performed by coating the electrode slurry composition on the surface of the lead electrode plate using a dip coater and drying it with hot air at 60°C for 24 hours.

Then, as shown in Figure 2b, the present invention uses the electrode manufactured as described above as a cathode, a PbO ₂ positive electrode, an AGM separator, and an aqueous sulfuric acid solution with a specific gravity of 1.28 as an electrolyte to manufacture a lead-carbon battery. There is (S500).

Example 1

Edgeless activated carbon was prepared as follows according to the flow chart shown in Figure 2a.

1. Purification step

Metal impurities were removed by treating 10 g of coconut shell-based activated carbon (PCT9, Power Carbon Technology Inc.) with 100 g of 5 mole hydrochloric acid aqueous solution for less than 12 hours.

2. Heat treatment step

The purified activated carbon was placed in a graphite furnace (Nasil Tech) and treated at 1400°C for 25 minutes with argon gas flowing at 1000 sccm. The temperature increase rate was 10°C per minute, reaching 1400°C over 2 hours and 20 minutes. The temperature was maintained for 25 minutes and then lowered to room temperature to prepare heat-treated activated carbon.

3. Remaining edge removal step

Edgeless activated carbon 1 (HTT1400) with residual edges removed was prepared by adding 75 g of diethylenetriamine and 5 g of heat-treated activated carbon to 25 g of anhydrous ethanol and reacting at 80°C for 12 hours to perform amination.

Example 2

Edgeless activated carbon 2 (HTT1600) was manufactured in the same manner as in Example 1, except that the heat treatment temperature in the heat treatment step was 1600°C.

Example 3

Edgeless activated carbon 3 (HTT1800) was manufactured in the same manner as in Example 1, except that the heat treatment temperature in the heat treatment step was 1800°C.

Example 4

Edgeless activated carbon 4 (HTT2000) was manufactured in the same manner as in Example 1, except that the heat treatment temperature in the heat treatment step was 2000°C.

Example 5

After 10 g of edgeless activated carbon 1 (HTT1400) obtained in Example 1 was sufficiently dispersed in anhydrous ethanol, 2.5 g of 0.1 M lead nitrate aqueous solution was added and sufficiently dispersed through ultrasonic treatment. After manufacturing, it was sufficiently washed with distilled water, and then dried in a vacuum oven at 80°C for more than 24 hours to obtain nanolead-containing edgeless activated carbon 1 (HTT1400) with a nanolead deposition layer formed on the surface of the edgeless activated carbon.

Example 6

Nanolead-containing edgeless activated carbon 2 (HTT1600) was obtained by performing the same method as Example 5, except that edgeless activated carbon 2 (HTT1600) obtained in Example 2 was used.

Example 7

Nanolead-containing edgeless activated carbon 3 (HTT1800) was obtained by performing the same method as Example 5, except that edgeless activated carbon 3 (HTT1800) obtained in Example 3 was used.

Example 8

Nanolead-containing edgeless activated carbon 4 (HTT2000) was obtained by performing the same method as Example 5, except that edgeless activated carbon 4 (HTT2000) obtained in Example 4 was used.

Example 9

Electrode slurry composition 1 was obtained by mixing 9.5 g of nano-lead-containing edgeless activated carbon 1 obtained in Example 5, 0.5 g of binder (PVdF, Polyvinylidene fluoride, Sigma-Aldrich), and 190 g of dispersion solvent (ethanol).

Example 10

Electrode slurry composition 2 was obtained in the same manner as in Example 9, except that the nano lead-containing edgeless activated carbon 2 obtained in Example 6 was used.

Example 11

Electrode slurry composition 3 was obtained in the same manner as in Example 9, except that the nano-lead-containing edgeless activated carbon 3 obtained in Example 7 was used.

Example 12

Electrode slurry composition 4 was obtained in the same manner as in Example 9, except that the nano-lead-containing edgeless activated carbon 4 obtained in Example 8 was used.

Example 13

100 g of electrode slurry composition 1 obtained in Example 9 was coated on the surface of a lead electrode plate (25ㅧ25 mm, Lead (Pb) Sheet, Alfa Aesar) using a dip coating machine, and then dried with hot air at 60°C for 24 hours to form an electrode. got 1

Example 14

Electrode 2 was obtained in the same manner as in Example 13, except that electrode slurry composition 2 obtained in Example 10 was used.

Example 15

Electrode 3 was obtained in the same manner as in Example 13, except that electrode slurry composition 3 obtained in Example 11 was used.

Example 16

Electrode 4 was obtained in the same manner as in Example 13, except that electrode slurry composition 4 obtained in Example 12 was used.

Example 17

Lead-carbon battery 1 of a known structure was prepared using electrode 1 obtained in Example 13 as the cathode, a PbO ₂ positive electrode, an AGM separator, and an aqueous sulfuric acid solution with a specific gravity of 1.28 as an electrolyte. At this time, in order to prevent the coating component of the electrode plate from falling off, the cathode and anode were fixed by applying uniform pressure to the band.

Example 18

Lead-carbon battery 2 was prepared in the same manner as in Example 17, except that electrode 2 obtained in Example 14 was used as the cathode.

Example 19

Lead-carbon battery 3 was prepared in the same manner as in Example 17, except that electrode 3 obtained in Example 15 was used as the cathode.

Example 20

Lead-carbon battery 4 was prepared in the same manner as in Example 17, except that electrode 4 obtained in Example 16 was used as the cathode.

Comparative Example 1

A known activated carbon (PCT9, Power Carbon Technology Inc.) was prepared as a comparative activated carbon (Pristine/Pristine AC).

Comparative Example 2

Nano-lead-containing comparative activated carbon was obtained in the same manner as Example 5, except that comparative activated carbon (Pristine/Pristine AC) was used.

Comparative Example 3

A comparative electrode slurry was obtained in the same manner as in Example 9, except that nano lead-containing comparative activated carbon was used.

Comparative Example 4

A comparative electrode was obtained in the same manner as in Example 13, except that the comparative electrode slurry was used.

Comparative Example 5

A comparative pre-lead carbon battery was obtained in the same manner as in Example 17, except that a comparative electrode was used.

Experimental Example 1

The concentration of metal impurities in the activated carbon used in Example 1 before and after the purification step was confirmed using ICP-OES (Inductively coupled plasma optical emission spectroscopy), and the results are shown in Table 1 below.

From Table 1, it can be seen that activated carbon contains metal impurities and that when the purification step is performed according to the method of the present invention, high purity activated carbon in which no metal impurities are observed can be obtained.

Experimental Example 2

SEM, TEM, and STM analyzes were performed on the edgeless activated carbons 1 to 4 obtained in Examples 1 to 4 and the comparative example activated carbon to confirm structural changes depending on the heat treatment temperature, and the resulting photographs are shown in Figure 3. .

In Figure 3, a is an SEM image of activated carbon known as pristine (PCT9, Power Carbon Technology Inc.), and b to f are TEM images of activated carbon known as pristine and activated carbon heat-treated at 1400, 1600, 1800, and 2000°C, respectively. , and g to I represent STM photographs of activated carbon known as pristine and activated carbon heat-treated at 1600°C and 2000°C.

From Figure 3, it can be seen that as the heat treatment temperature increases, the corrugated graphene structure grows into a flat structure, and the size of the domains present on the surface of activated carbon grows according to the heat treatment temperature.

Experimental Example 3

Raman spectroscopy, X-ray diffraction analysis, specific surface area, pore size, oxidation onset temperature and The electrical conductivity of the powder phase was analyzed and the results are shown in Figure 4. In Figure 4, (a) is the Raman spectrum analysis result, (b) is the X-ray diffraction pattern analysis result, (c) is the nitrogen adsorption and desorption curve, (d) is the micropore distribution, (e) is the oxidation onset temperature, (f) represents electrical conductivity.

As shown in Figure 4, the decrease in R ( I _D /I _G ) value and the increase in (002) peak show that as the heat treatment temperature increases, defects including edges are removed and crystallinity increases, and pores In the structure, micropores were mainly reduced, and the increase in electrical conductivity along with the increase in oxidation onset temperature suggests that defects were reduced along with the increase in crystallinity.

Experimental Example 4

In order to quantitatively analyze the edge density present on the surface of the edgeless activated carbons 1 to 4 obtained in Examples 1 to 4 and the comparative example activated carbon according to the heat treatment temperature, a high temperature desorption method [high temperature TPD (temperature- programmed desorption] to measure the amount of (a) total gas desorbed, (b) amount of CO, (c) amount of CO ₂ , (d) amount of H ₂ O, and (e) amount of H ₂ And the results are shown in Figure 5 and Table 2 below.

a) N _edge : total number of edges, b) N _H : number of edges with hydrogen attached, c) S _total : specific surface area, d) S _edge : Specific surface area occupied by the edge, e) S _basal : Specific surface area occupied by the basal plane f) Edge ratio: Relative ratio of the edge to the basal plane.

From Figure 5 and Table 2, it can be seen that the total edge content and edge ratio can be controlled according to the heat treatment temperature. In particular, it can be seen that the edgeless activated carbon obtained by heat treatment at 1600 ° C shows the lowest edge ratio. .

Experimental Example 5

For edgeless activated carbons 1 to 4 obtained in Examples 1 to 4, surface changes according to heat treatment temperature were measured using a linear scanning potential method for hydrogen evolution reaction, and the results are shown in FIG. 6. In Figure 6, (a) is the current-voltage curve and (b) is the Tafel city.

As shown in Figure 6, the sequential increase in the hydrogen evolution reaction overvoltage and Tafel slope as the heat treatment temperature increases suggests that the surface activity caused by defects including edges is gradually passivated.

Experimental Example 6

(a) chargeability, (b) charge capacity, (c) cycle characteristics, and (d) water loss per unit cell for the lead-carbon battery 2 obtained in Example 18 and the comparative pre-lead-carbon battery obtained in Comparative Example 5. was measured and the results are shown in Figure 7.

As shown in Figure 7, the lead-carbon battery of the present invention shows excellent chargeability compared to the comparative pre-lead-carbon battery and shows more than twice the characteristics even in extreme life tests, which is due to the edge existing on the surface of activated carbon. It is believed that the hydrogen generation reaction was suppressed and the water loss was lowered.

Although the present invention has been illustrated and described by way of preferred embodiments as discussed above, it is not limited to the above-described embodiments and is intended to be used by those skilled in the art without departing from the spirit of the invention. Various changes and modifications will be possible.

Claims (21)

In activated carbon, the content of the edge, which is a portion composed of oxygen functional groups or hydrogen located on the outside of the basal plane composed of a continuous hexagonal structure, exists at a certain ratio.
The constant ratio is a relative ratio of the specific surface area occupied by the edge measured with respect to the specific surface area of the base surface, and is 2% by volume or less. Edgeless activated carbon.
delete In activated carbon, the content of the edge, which is a portion composed of oxygen functional groups or hydrogen located on the outside of the basal plane composed of a continuous hexagonal structure, exists at a certain ratio.
Edgeless activated carbon, characterized in that the total content of the edges is 500 μmol/g or less and the specific surface area occupied by the edges is 26 m ² /g or less.
According to claim 1,
Edgeless activated carbon, characterized in that the activated carbon is any one selected from the group consisting of palm shell-based activated carbon, phenolic resin-based activated carbon, and coke-based activated carbon.
According to any one of paragraphs 1, 3, and 4,
Edgeless activated carbon, characterized in that addition reactions are suppressed when the edges are present at a certain ratio.
A purification step of removing impurities present in activated carbon; and
An edgeless activated carbon manufacturing method comprising a heat treatment step of treating the purified activated carbon at a temperature of 1000-2000°C,
The edgeless activated carbon is a method of manufacturing edgeless activated carbon, characterized in that the total content of the edges is 500 μmol/g or less and the specific surface area occupied by the edges is 26 m ² /g or less.
According to claim 6,
The purification step is a method for producing edgeless activated carbon, characterized in that the activated carbon is treated with 1 mole to 10 mole aqueous hydrochloric acid solution for 12 hours or less to remove metal impurities.
According to claim 6,
The heat treatment step is a method of producing edgeless activated carbon, characterized in that it is processed within 30 minutes in an argon gas atmosphere using a graphitization furnace.
According to claim 6,
An edgeless activated carbon manufacturing method further comprising a residual edge removal step of removing edges remaining on the surface of the heat-treated activated carbon.
According to clause 9,
The method of producing edgeless activated carbon, characterized in that the remaining edge removal step is performed by amination of the heat-treated activated carbon.
According to claim 10,
The amination reaction is performed by adding an amination agent selected from the group consisting of anhydrous ethanol, diethylenetriamine, urea (CH ₄ N ₂ O), and ammonia (NH ₃ ) to the heat-treated activated carbon and heating at 70 to 100° C. for more than 10 hours. A method for producing edgeless activated carbon, characterized in that it is carried out by reaction.
According to claim 6,
A method of producing edgeless activated carbon, characterized in that the activated carbon is any one selected from the group consisting of palm shell-based activated carbon, phenolic resin-based activated carbon, and coke-based activated carbon.
delete It includes the edgeless activated carbon of any one of claims 1, 3, and 4, or the edgeless activated carbon manufactured by the manufacturing method of any one of claims 6 to 12, and a nano-lead deposition layer formed on the surface of the activated carbon. Edgeless activated carbon containing nano lead.
An electrode slurry composition comprising the nano-lead-containing edgeless activated carbon of claim 14.
According to claim 15,
An electrode slurry composition comprising 2 to 20 parts by weight of a binder and 200 to 300 parts by weight of a dispersion solvent per 100 parts by weight of the nano lead-containing edgeless activated carbon.
According to claim 16,
The binder is at least one selected from the group consisting of polyvinylidenefloride, carboxymethylcellulose, and styrene butadiene rubber, and the dispersion solvent is ethanol, acetone, ispropyl alcohol, methyl pyrrolidone, An electrode slurry composition comprising at least one selected from the group consisting of propylene glycol.
An electrode coated with the electrode slurry composition of claim 15.
According to claim 18,
An electrode, characterized in that the electrode slurry composition is coated on a lead electrode plate.
A lead-carbon battery comprising the electrode of claim 18 as a cathode.
Preparing the edgeless activated carbon of any one of claims 1, 3, and 4 or the edgeless activated carbon manufactured by the production method of any one of claims 6 to 12;
A nano-lead deposition step of preparing nano-lead-containing edgeless activated carbon including a nano-lead deposition layer formed by depositing nano-lead on the edgeless activated carbon;
An electrode slurry preparation step of preparing an electrode slurry composition containing the nano-lead-containing edgeless activated carbon; and
A lead-carbon battery manufacturing method comprising: an electrode manufacturing step of coating the electrode slurry composition on a lead electrode plate.