KR102125965B1 - Hybrid capacitor - Google Patents

Abstract

According to the present invention, rare earth or activated carbon is added and applied to LiNi _0.5 Mn _1.5 O ₄ , a high voltage anode material, to the anode, whereby Mn ³⁺ ions in the crystal react with an electrolyte in a high voltage region of 4.8 V (voltage) or higher by the rare earth or activated carbon. A hybrid capacitor capable of preventing a capacitor from rapidly decreasing in capacity or deteriorating output characteristics due to change over time by preventing impurities from forming on the surface, comprising: an anode; A cathode spaced apart from the anode; And a separator disposed between the positive electrode and the negative electrode, the positive electrode including an LNMO material electrode formed on the surface of the first current collector and the first current collector, and the negative electrode on the surfaces of the second current collector and the second current collector. It characterized in that it comprises an activated carbon material electrode formed.

Description

Hybrid capacitor {Hybrid capacitor}

The present invention relates to a hybrid capacitor, in particular by applying rare earth or activated carbon by adding a rare earth or activated carbon to the high voltage anode material LiNi _0.5 Mn _1.5 O ₄ to the anode, Mn ³⁺ in the crystal in the high voltage region of 4.8 V (voltage) or higher by the rare earth or activated carbon The present invention relates to a hybrid capacitor capable of preventing a sudden decrease in capacity or a decrease in output characteristics due to change over time by preventing ions from reacting with an electrolyte to form impurities on the electrode surface.

The electric double layer capacitor is composed of an electrode, a separator, an electrolyte, and a case. Since the electrode material applied to the electrode of the electric double layer capacitor must have a large electrical conductivity and a specific surface area, and must be electrochemically stable, activated carbon or activated carbon fibers are most frequently used, and the related technology is disclosed in Korean Patent Registration No. -1036378 (Patent Document 1).

Korean Registered Patent Publication No. 10-1036378 relates to an electrode for an electric double layer capacitor, a manufacturing method thereof, and an electric double layer capacitor, and a conductive adhesive, and an electrode for an electric double layer capacitor disclosed in Korean Patent Publication No. 10-1036378 A polarizable porous sheet composed of a carbonaceous electric double layer forming material, a carbon material for securing conductivity, and a constituent material comprising a binder is made integrally through one or more conductive intermediate layers on the current collector, and the conductive intermediate layer is glass. It includes styrene-butadiene rubber having a transition temperature of -5 to 30°C and two or more kinds of carbon materials having different particle diameters, and is composed of carbon black as a carbon material of a conductive intermediate layer.

The electric double layer capacitor disclosed in Korean Patent Registration No. 10-1036378 has a method of increasing the driving voltage to increase energy density, but increasing the driving voltage is limited to a range in which the decomposition of the electrolyte does not occur, so there is a limitation. There is a hybrid capacitor for that. Hybrid capacitors are configured to have different asymmetric electrode structures. For example, in the asymmetric electrode structure of the hybrid capacitor, the electrode material of the cathode (cathode) is used as a spinel-based LiMn ₂ O ₄ , and activated carbon is used as the electrode material of the anode (anode). These conventional hybrid capacitor is LiMn ₂ O in the spinel structure when the spinel LiMn ₂ O ₄ is sealed using the electrode material for the positive electrode (cathode) ₄ is the Mn ³⁺ ion in the crystal in the voltage region above 4.0 V (voltage) electrolyte There is a problem in that the capacity may be rapidly decreased or the output characteristics may be deteriorated due to a change over time due to the formation of impurities on the electrode surface by reacting with.

1): Korean Registered Patent Publication No. 10-1036378

The object of the present invention is to solve the above-mentioned problems, and by applying rare earth or activated carbon to the anode by adding rare earth or activated carbon to LiNi _0.5 Mn _1.5 O ₄ as a high voltage cathode material, it is determined in a high voltage region of 4.8 V (voltage) by rare earth or activated carbon. It is to provide a hybrid capacitor capable of preventing a sudden decrease in capacity or a decrease in output characteristics due to change over time by preventing the Mn ³⁺ ions in the reaction from reacting with an electrolyte to form impurities on the electrode surface.

The hybrid capacitor of the present invention includes a cathode; A cathode spaced apart from the anode; And a separator disposed between the positive electrode and the negative electrode, wherein the positive electrode includes a first current collector and an LNMO (LiNi _0.5 Mn _1.5 O ₄ ) material electrode formed on a surface of the first current collector, and the negative electrode. It characterized in that it comprises a second current collector and an activated carbon material electrode formed on the surface of the second current collector.

In the hybrid capacitor of the present invention, rare earth or activated carbon is added and applied to LiNi _0.5 Mn _1.5 O ₄ , a high voltage anode material, to the positive electrode, whereby Mn ³⁺ ions in the crystal in the high voltage region of 4.8 V (voltage) or higher by the rare earth or activated carbon By reacting to prevent the formation of impurities on the electrode surface, there is an advantage that it is possible to prevent the capacity from being rapidly reduced or the output characteristics are deteriorated due to changes over time.

1 is a cross-sectional view of a hybrid capacitor of the present invention,
Figure 2 is an enlarged view of the steam resurrection grenade shown in Figure 1,
3 is an enlarged view of the chemical resurrection grenade shown in FIG. 1.

Hereinafter, an embodiment of the hybrid capacitor of the present invention will be described with reference to the accompanying drawings.

1 to 3, the hybrid capacitor of the present invention includes an anode 10, a cathode 20, a separator 30, an electrolyte 40, and a case 50.

The anode 10 is disposed inside the case 50, and the anode 20 is spaced apart from the anode 10. The separator 30 is disposed between the positive electrode 10 and the negative electrode 20, and the electrolyte solution 40 is positioned inside the case 50 in an impregnated state with the positive electrode 10 and the negative electrode 20, and the case 50 ) Overall supports the hybrid capacitor of the present invention. Here, the positive electrode 10 includes a first current collector 11 and an LNMO (LiNi _0.5 Mn _1.5 O ₄ ) material electrode 12 formed on the surface of the first current collector 11 and the negative electrode 20 ) Includes the second current collector 21 and the activated carbon material electrode 22 formed on the surfaces of the second current collector 21.

The configuration of the hybrid capacitor of the present invention will be described in detail as follows.

The anode 10 is disposed inside the case 50 as shown in FIG. 1, and includes a first current collector 11 and an LNMO material electrode 12.

The first current collector 11 is formed in a sheet shape, and the material is used by selecting one of Al, Cu, and Ni, or by mixing two or more. The LNMO material electrode 12 is formed by mixing high voltage anode material LiNi _0.5 Mn _1.5 O ₄ (12a), rare earth 12b, and activated carbon 12c. LiNi _0.5 Mn _1.5 O ₄ (12a) is more specifically LiNi _0.5-x/2 Mn _1.5-x/2 O ₄ (0≤x≤0.1) is used. The mixing ratio of LiNi _0.5 Mn _1.5 O ₄ (12a), rare earth 12b, and activated carbon 12c of the LNMO material electrode 12 is 88 to 94 wt% of LiNi _0.5 Mn _1.5 O ₄ (12a), rare earth 12b 1 to 2 wt% and 5 to 10 wt% of activated carbon (12c). Here, rare earth (12b) is Dy (Dysprosium), Y (Yttrium), Eu (Europium) and one or more of Pr (Praseodymium) is selected and added, activated carbon (12c) using the chemical resurrection method shown in Figure 2 Chemical activated carbon 22a having a specific surface area of 1800 to 2500 m 2 /g and an average particle diameter (D1) of 6 to 8 μm is used. The positive electrode 10 is a high voltage positive electrode material LiNi _0.5 Mn _1.5 O ₄ (12a) by adding a rare earth (12b) or activated carbon (12c) by the hybrid capacitor of the present invention can improve the output characteristics or life characteristics.

The anode 20 is disposed spaced apart from the anode 10 inside the case 50, as shown in FIGS. 1 to 3, and the surfaces of the second collector 21 and the second collector 21 It is configured to include an active carbon material electrode 22 formed on.

The second current collector 21 is formed in a sheet shape, and the material is used by selecting one of Al, Cu, and Ni, or by mixing two or more. The material of the activated carbon material electrode 22 is formed by mixing the chemical activated carbon 22a and the steam activated carbon 22b. The mixing ratio of the activated carbon material electrode 22 is formed by mixing 20 to 80 wt% of the chemical activated carbon 22a and 20 to 80 wt% of the steam activated carbon 22b. Here, the chemical activated carbon 22a has a specific surface area of 1800 to 2500 m 2 /g using a chemical activated method and is formed to have an average particle diameter (D1) of 6 to 8 μm, and the steam activated carbon 22b is steam activated By using a method (steam activation) having a specific surface area of 1000 to 1500 m 2 /g and an average particle diameter (D2) of 10 to 13 μm, it is possible to improve the output efficiency of the hybrid capacitor of the present invention.

The separator 30 is disposed inside the case 50 as shown in FIG. 1 so that the separator 30 is positioned between the positive electrode 10 and the negative electrode 20 so that the positive electrode 10 and the negative electrode 20 are physically connected to each other. It prevents contact, and a material applied to a known hybrid capacitor is used.

The electrolytic solution 40 is included in the hybrid capacitor as shown in FIG. 1, and can be applied to the hybrid capacitor of the present invention by mixing and using an organic solvent, a salt, and an additive.

Organic solvents are Acetonitrile (ACN), Ethylene carbonate (EC), Propylene carbonate (PC), Dimethyl carbonate (DMC), Diethyl carbonate (DEC), Ethylmethyl carbonate (EMC), 1,2-dimethoxyethane (DME), γ-buthrolactone It is used after selecting three or more of (GBL), Methyl formate (MF), and Methyl propionate (MP). Here, the organic solvent is Acetonitrile (ACN), Ethylene carbonate (EC), Propylene carbonate (PC), Dimethyl carbonate (DMC), Diethyl carbonate (DEC), Ethylmethyl carbonate (EMC), 1,2-dimethoxyethane (DME), γ Three or more organic solvents selected from -buthrolactone (GBL), Methyl formate (MF), and Methyl propionate (MP) are used by mixing at the same wt% ratio.

The salt is a mixture of a lithium salt and a non-lithium salt, and the lithium salt is LiBF ₄ , LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiN(SO ₂ CF3)2, LiC(SO2CF3)3 , LiBOB (LiBOB: Lithium bis(oxalato)borate). The non-lithium salt is used by selecting one or more of Tetraethylammonium tetrafluoroborate (TEABF4), triethylmethylammonium tetrafluorborate (TEMABF4) and spiro-(1,1′)-bipyrrolidium tetrafluoroborate (SBPBF4). The lithium salt contained in the salt is used in the 0.8 to 2M (molarity), the non-lithium salt is used to be 0.1 to 0.5M (molarity).

The additive is selected from one or more of VC (Vinylene Carbonate), VEC (Vinyl ethylene carbonate) and FEC (Fluoroethylene carbonate).

For the electrical test of the hybrid capacitor of the present invention, first, as shown in Table 1, the LNMO material electrode 12 and the activated carbon material electrode 22 of various embodiments were manufactured, respectively.

LNMO material electrode (wt%) Activated carbon material electrode (wt%) LiNi _0.5 Mn _1.5 O ₄ Rare earth Activated carbon Chemical activated carbon [specific surface area (1500㎡/g), particle diameter (㎛)] Steam revitalized coal [specific surface area (1500㎡/g), particle diameter (㎛)] Example 1 88 2 10 80[1800,6] 20[1000,10] Example 2 94 One 5 Example 3 88 2 10 20(2500,8) 80(1500,13) Example 4 94 One 5

As shown in Table 1, the LNMO material electrode 12 and the activated carbon material electrode 22 were manufactured in Examples 1 to 4. As shown in Table 1, the LNMO material electrode 12 has 88 wt% of LiNi _0.5 Mn _1.5 O ₄ (12a), 2 wt% of rare earth (12b) and 10 wt% of activated carbon (12c), respectively, as shown in Table 1. It was formed by mixing as much as possible, and Example 2 and Example 4 were formed to be mixed such that LiNi _0.5 Mn _1.5 O ₄ (12a) 94 wt%, rare earth (12b) 1 wt%, and activated carbon (12c) 5 wt%, respectively. Among the rare earths 12b and activated carbons 12c listed in Table 1, rare earths 12b are selected and added to one or more of Dy (Dysprosium), Y (Yttrium), Eu (Europium), and Pr (Praseodymium). 1 to 4, each of the rare earth (12b) was used to select one Dy (Dysprosium). As the activated carbon 12c, chemical activated carbon 22a having a small average particle diameter D1 was used, and as in Examples 1 to 4, the specific surface area and average particle diameter D1 were chemical activated carbon applied to the electrode 22 of the activated carbon material. The same was applied as in (22a).

The activated carbon material electrode 22 was formed by mixing 20 wt% of the chemical activated carbon 22a and 80 wt% of the steam activated carbon 22b in Examples 1 and 2, respectively, and the specific surface area of the chemical activated carbon 22a. Silver was 1800 m 2 /g, the average particle diameter (D1) of 6 µm was used, and the specific surface area of the steam resurrection coal 22b was 1000 m 2 /g and the average particle diameter (D2) of 10 µm was used. The activated carbon material electrode 22 was formed by mixing 80 wt% of the chemical activated carbon 22a and 20 wt% of the steam activated carbon 22b in Examples 3 and 4, respectively, and the specific surface area of the chemical activated carbon 22a. Silver was 2500 m 2 /g, the average particle diameter (D1) of 8 µm was used, and the specific surface area of the steam activated carbon 22b was 1500 m 2 /g and the average particle diameter (D2) of 13 µm was used.

When the LNMO material electrode 12 and the activated carbon material electrode 22 were prepared in Examples 1 to 4, respectively, as shown in Table 1, hybrid capacitors of the present invention were manufactured using each.

Preparation of the hybrid capacitors according to Examples 1 to 4, first, as shown in Table 1, when the LNMO material electrode 12 prepared in Examples 1 to 4 is prepared, the LNMO material electrode 12 has a binder and a conductivity After mixing the agent, it was applied to the surface of the first current collector 11 to prepare an anode 10. Here, the binder was selected from one of polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR) and carboxymethylcellulose (CMC). black) and carbon black were used.

The mixing ratio of the LNMO material electrode 12, the binder, and the conducting agent was 86 to 88 wt% of the LNMO material electrode 12, 6 to 7 wt% of the binder, and 6 to 7 wt% of the conducting agent. For example, in the case of Examples 1 and 2, 86 wt% of the LNMO material electrode 12, 7 wt% of the binder, and 7 wt% of the conductive agent were mixed, respectively, and in the case of Examples 3 and 4, respectively. 88 wt% of the LNMO material electrode 12, 6 wt% of the binder, and 6 wt% of the conductive agent were mixed.

When the positive electrode 10 according to Examples 1 to 4 was manufactured, a negative electrode 20 was manufactured using the activated carbon material electrode 22 according to Examples 1 to 4. The negative electrode 20 was prepared by mixing a binder and a conductive agent on the active carbon material electrode 22 and then applying it to the surface of the second current collector 21. Here, the binder and the conductive agent are respectively applied in the same manner as the positive electrode 10, that is, the binder was selected from PVDF (polyvinylidene difluoride), PTFE (polytetrafluoroethylene), SBR (styrene butadiene rubber) and CMC (carboxymethylcellulose). , Conductive agent was used to select one of super-P (Super-P), Ketjen black (carbon) and carbon black (carbon black).

The mixing ratio of the activated carbon material electrode 22, the binder, and the conductive agent was 86 to 88 wt% of the activated carbon material electrode 22, 6 to 7 wt% of the binder, and 6 to 7 wt% of the conductive agent as in the positive electrode 10. . For example, in the case of Examples 1 and 2, 86 wt% of the activated carbon material electrode 22, 7 wt% of the binder, and 7 wt% of the conductive agent were mixed, respectively, in the case of Examples 3 and 4 88 wt% of the activated carbon material electrode 22, 6 wt% of the binder, and 6 wt% of the conductive agent were mixed.

When the positive electrode 10 and the negative electrode 20 are prepared and prepared, the positive electrode 10 and the negative electrode 20 are electrolytic solutions as shown in FIG. 1 with a separator 30 interposed between the positive electrode 10 and the negative electrode 20. After being impregnated into 40, it is housed inside the case 50 and assembled. When assembling the positive electrode 10 and the negative electrode 20 to the inside of the case 50, the positive electrode 10 and the negative electrode 20 have respective terminals 13 and 23 having a first current collector 11 of the positive electrode 10. It is assembled to be exposed to the outside of the case 50 while being connected to the second current collector 21 of the negative electrode 20. Here, a description of the separator 30 applied to the known hybrid capacitor (not shown) of the separator 30 is applied, so that description is omitted.

The electrolytic solution 40 is included in the hybrid capacitor as shown in FIG. 1, and can be applied to the hybrid capacitor of the present invention by mixing and using an organic solvent, a salt, and an additive. As the organic solvent, Ethylene carbonate (EC), Dimethyl carbonate (DMC), and Ethylmethyl carbonate (EMC) were mixed in a ratio of 1:1 to 1:1, respectively, and lithium salt was used as LiBF ₄ , as the salt. TEABF4 (Tetraethylammonium tetrafluoroborate) was selected as the non-lithium salt, and VC (Vinylene Carbonate) was selected as the additive, and in Examples 1 and 2, the lithium salt was 0.8M (molarity) and the non-lithium salt was 0.5M (molarity) was used, and in Example 3 and Example 4, the lithium salt was 2M, and the non-lithium salt was 0.1M.

The hybrid capacitors according to Examples 1 to 4 were manufactured to have the same thickness and surface area of the positive electrode 10 and the negative electrode 20, respectively, and when the hybrid capacitors according to Examples 1 to 4 were manufactured, according to the comparative example Hybrid capacitors were prepared. In the hybrid capacitor according to the comparative example, the positive electrode used LiMn ₂ O ₄ known as the electrode material, and the electrode material of the negative electrode applied known activated carbon, and the thickness and surface area of the positive electrode and the negative electrode according to Examples 1 to 4 It was manufactured in the same manner as the anode 10 and the cathode 20 of the hybrid capacitor.

When the hybrid capacitors according to Examples 1 to 4 and the hybrid capacitors according to the Comparative Examples were manufactured, electrical characteristics of each were tested, and the results are shown in Table 2.

Energy density (Wh/L) Output efficiency (%) 1C 15C 1C 15C Example 1 12 10.9 100 91 Example 2 14 11.9 100 85 Example 3 8 6.8 100 86 Example 4 10 8.1 100 81 Comparative example 10 7.5 100 75

As shown in Table 2, among the results of examining the energy densities and output efficiencies according to Examples 1 to 4 and Comparative Examples, the energy density was 15 Wh/L at 1C and 10.9 Wh/L at 15C in Example 1 Was measured. Example 2 was 14 Wh/L at 1C (seed) and 11.9 Wh/L at 15C, Example 3 was 8 Wh/L at 1C and 6.8 Wh/L at 15C. Example 4 was measured at 10 Wh/L at 1C and 8.1 Wh/L at 15C, and comparative example was measured at 10 Wh/L at 1C and 7.7 Wh/L at 15C.

In the case of Example 1, the output efficiency was 100% at 1C and 91% at 15C, and Example 2 was 100% at 1C and 85% at 15C. Example 3 was 100% at 1C and 86% at 15C, Example 4 was 100% at 1C and 81% at 15C, Comparative Example was 100% at 1C and 75% at 15C. Here, the 1C (seed) discharge condition indicates a discharge condition with C-rate = 1, indicating that the discharge current is equal to the rated capacity of the battery, and inspection or measurement of energy density and output efficiency is a known inspection. Detailed description is omitted by using equipment.

As a result of examining the energy density and output efficiency according to Examples 1 to 4 and Comparative Examples, it can be seen that the hybrid capacitors according to Examples 1 to 4 have a decreasing rate at 15C lower than that of the comparative example. That is, the hybrid capacitor of the present invention is applied to the electrode 10 of the LNMO material formed by mixing LiNi _0.5 Mn _1.5 O ₄ (12a), rare earth (12b) and activated carbon (12c) to the anode 10, the cathode (20) ) By applying the activated carbon material electrode 22 formed by mixing the chemical activated carbon 22a and the steam activated carbon 22b to prevent energy density at 15C, i.e., a rapid decrease in capacity due to change over time, and maintain output efficiency for a long time It is possible to improve the life characteristics.

The hybrid capacitor of the present invention can be applied to the capacitor or battery manufacturing industry.

10: anode
20: cathode
30: separator
40: electrolyte
50: case

Claims (7)

A cathode;
A cathode spaced apart from the anode; And
And a separator disposed between the anode and the cathode,
The positive electrode includes a first current collector and an LNMO (LiNi _0.5 Mn _1.5 O ₄ ) material electrode formed on the surface of the first current collector, and the negative electrode is formed on the surface of the second current collector and the second current collector. Comprising an activated carbon material electrode,
The LNMO (LiNi _0.5 Mn _1.5 O ₄ ) material electrode is formed by mixing LiNi _0.5 Mn _1.5 O ₄ 88 to 94 wt%, rare earth 1 to 2 wt%, and activated carbon 5 to 10 wt%, and the rare earth is Dy (Dysprosium) , Y (Yttrium), Eu (Europium) and one or more of Pr (Praseodymium) are selected and added, and the activated carbon has a specific surface area of 1800 to 2500 m 2 /g and an average particle size of 6 to 8 μm using a chemical revitalization method. The manufactured chemical resurrection grenade is used,
The activated carbon material electrode is formed by mixing 20 to 80 wt% of chemical activated carbon and 20 to 80 wt% of steam activated carbon, and the chemical activated carbon among the chemical activated carbon and the steam activated carbon has a specific surface area using a chemical activation method. This is 1800 to 2500 m2/g, and an average particle diameter of 6 to 8 m is used, and the steam activated carbon has a specific surface area of 1000 to 1500 m2/g using a steam activation method and an average particle size of 10. Hybrid capacitors used to be formed to be 13 µm. delete delete delete According to claim 1,
The first current collector and the second current collector are hybrid capacitors used by selecting one of Al, Cu, and Ni, or by mixing two or more of them. According to claim 1,
The hybrid capacitor contains an electrolyte,
The electrolyte is used by mixing an organic solvent, a salt and an additive, and the organic solvent is Acetonitrile (ACN), Ethylene carbonate (EC), Propylene carbonate (PC), Dimethyl carbonate (DMC), Diethyl carbonate (DEC), Ethylmethyl carbonate (EMC), 1,2-dimethoxyethane (DME), γ-buthrolactone (GBL), Methyl formate (MF), Methyl propionate (MP) is used after mixing three or more selected, the salt is lithium salt and non-lithium Salt is used by mixing, and the lithium salt is LiBF ₄ , LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiN(SO ₂ CF3)2, LiC(SO2CF3)3, LiBOB(LiBOB: Lithium One or more of bis(oxalato)borate) is used, and the non-lithium salt is selected from one or more of TEABF4 (Tetraethylammonium tetrafluoroborate), TEMABF4 (triethylmethylammonium tetrafluorborate) and SBPBF4 (spiro-(1,1′)-bipyrrolidium tetrafluoroborate) Used, the additive is a VC (Vinylene Carbonate), VEC (Vinyl ethylene carbonate) and FEC (Fluoroethylene carbonate) selected from one or more of the hybrid capacitor used. The method of claim 6,
Among the organic solvent, the lithium salt, and the non-lithium salt, the organic solvent is Acetonitrile (ACN), Ethylene carbonate (EC), Propylene carbonate (PC), Dimethyl carbonate (DMC), Diethyl carbonate (DEC), Ethylmethyl carbonate (EMC). , 1,2-dimethoxyethane (DME), γ-buthrolactone (GBL), Methyl formate (MF), Methyl propionate (MP), three or more organic solvents selected from each other are used in a proportion of the same wt%, the lithium The salt is 0.8 to 2M (molarity) is used, and the non-lithium salt is a hybrid capacitor in which 0.1 to 0.5M (molarity) is used.

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