Carbon nanotube conductive material composite or dispersion thereof, cathode material composition comprising same, and method for manufacturing same

Abstract

The present invention relates to: a conductive material composite for a secondary battery or a dispersion thereof, which solves the problems of the prior art and simultaneously improves dispersibility and conductivity, and exhibits various effects and actions described in the present specification; a cathode material composition comprising same; and a method for manufacturing same.

Description

Carbon nanotube conductive material composite or dispersion thereof, cathode material composition including the same, and method for manufacturing the same

[0001] The present invention relates to a carbon nanotube conductive material composite or a dispersion thereof, an anode material composition containing the same, and a method for manufacturing the same, etc.

[0002] Carbon nanotubes are attracting attention as next-generation conductive materials for lithium-ion batteries due to their excellent electrical conductivity and mechanical strength, but they tend to aggregate due to their characteristic strong van der Waals bonds.

[0003] This leads to reduced dispersibility within the electrode, and to improve this, techniques involving dispersion in a polar dispersion medium through the addition of surfactants or surface treatment using strong acids are widely used.

[0004] However, when preparing carbon nanotube dispersions by adding surfactants, there is a problem in that the surfactants can lower the electrical conductivity of the electrodes, leading to performance degradation, or induce side reactions on the electrode surface, potentially shortening the battery's lifespan. Additionally, surface treatment using strong acids has the disadvantage of causing structural and chemical damage to the carbon nanotubes, resulting in reduced electrical conductivity.

[0005] Therefore, it is necessary to develop technology that disperses carbon nanotubes so they do not aggregate, enabling their use as conductive materials in secondary batteries and the like.

[0006] [Prior Art Literature]

[0007] [Patent Literature]

[0008] (Patent Document 1) 1. Korean Registered Patent No. 10-0994181

[0009] (Patent Document 2) 2. Korean Published Patent No. 10-2003-0093252

[0010] (Patent Document 3) 3. Japanese Registered Patent No. 11003704

[0011] The present invention aims to solve the problems of such prior art and to provide a conductive material composite or dispersion liquid for a secondary battery that can simultaneously improve dispersibility and conductivity and exhibit various effects and functions described in this specification, a cathode material composition containing the same, and a method for manufacturing the same.

[0012] One aspect of the present invention for solving the above problems relates to a conductive material composite for a secondary battery comprising ozone-treated multi-walled carbon nanotubes and ozone-untreated carbon nanotubes in a weight ratio of 90:10 to 99.9:0.1.

[0013] Another aspect of the present invention relates to a conductive material composite for a secondary battery according to various embodiments of the present invention and a conductive material composite dispersion for a secondary battery comprising a polar dispersion medium.

[0014] Another aspect of the present invention relates to an electrode slurry composition for a secondary battery comprising a conductive composite for a secondary battery, a positive or negative active material, and a binder according to various embodiments of the present invention.

[0015] Another aspect of the present invention relates to an electrode for a secondary battery comprising a conductive composite for a secondary battery according to various embodiments of the present invention, a secondary battery comprising the same, and a device such as a communication device, an energy storage device, or a transportation device comprising the same.

[0016] Another aspect of the present invention relates to a method for preparing a dispersion of a conductive material composite for a secondary battery or an electrode slurry composition for a secondary battery using a conductive material composite for a secondary battery according to various embodiments of the present invention.

[0017] According to various embodiments of the present invention, the problems of the prior art can be solved, dispersibility and conductivity can be simultaneously improved, and various effects and operations described in this specification can be exhibited.

[0018] Figure 1 schematically shows the structure of a three-dimensional network formed by the physical bonding of multi-walled carbon nanotubes surface-treated with ozone and single-walled carbon nanotubes evenly dispersed within it.

[0019] Figures 2 and 3 show the results of comparing the performance of conductive materials according to embodiments and comparative examples of the present invention.

[0020] Below, various aspects and embodiments of the present invention will be examined in more detail.

[0021] One aspect of the present invention relates to a conductive composite for a secondary battery comprising (a) ozone-treated multiwalled carbon nanotubes and (b) a conductive material other than ozone-treated multiwalled carbon nanotubes.

[0022] As such, one embodiment of the present invention relates to a conductive composite for a secondary battery comprising (a) ozone-treated multiwalled carbon nanotubes and (b) a conductive material other than ozone-treated multiwalled carbon nanotubes, such as singlewalled carbon nanotubes, carbon black, graphene, two-dimensional carbon materials, and ozone-untreated multiwalled carbon nanotubes.

[0023] The conductive composite for secondary batteries according to the present invention has the advantage that dispersibility and conductivity can be simultaneously improved as ozone-treated multi-walled carbon nanotubes form a network structure and conductive materials other than ozone-treated multi-walled carbon nanotubes are composited into the network structure.

[0024] According to one embodiment, a conductive material other than the ozone-treated multi-walled carbon nanotube is selected from ozone-untreated single-walled carbon nanotubes, ozone-untreated carbon black, or a mixture thereof.

[0025] As such, in the present invention, particularly when the conductive material other than the ozone-treated multi-walled carbon nanotube is an ozone-untreated single-walled carbon nanotube, an ozone-untreated carbon black, or a mixture thereof, a battery containing such a conductive composite can achieve high dispersibility and conductivity during the charging and discharging process, thereby improving the performance of the battery and preventing or significantly suppressing the expansion of the internal material.

[0026] In other words, the internal material of a secondary battery may expand or contract due to repeated charging and discharging during use, which can lead to structural instability of the cell. However, in the case of the above configuration, the three-dimensional gel structure of multi-walled carbon nanotubes acts as a structural support for the electrode active material, thereby increasing the physical stability of the cell.

[0027] However, if the conductive material other than the ozone-treated multi-walled carbon nanotubes mentioned above is not an ozone-untreated single-walled carbon nanotube, an ozone-untreated carbon black, or a mixture thereof, the above effect may not be exhibited.

[0028] According to another embodiment, the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 90-99.8 : 0.2-10.

[0029] In this way, in particular, in the present invention, when the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated single-walled carbon nanotube is 90-99.8 : 0.2-10, the battery containing such a conductive composite can have the effect of blocking or significantly suppressing the occurrence of electromagnetic interference during the charging and discharging process.

[0030] In other words, when having the above configuration, multi-walled carbon nanotubes with polar functional groups imparted by ozone treatment can secure stable dispersibility in a solvent, and the three-dimensional network not only reduces the aggregation of single-walled carbon nanotubes but also makes the current flow uniform, thereby eliminating or significantly reducing electromagnetic interference that may occur during the charging and discharging process, and through this, signal interference of sensitive electronic devices around the battery can be reduced.

[0031] According to another embodiment, the ozone-untreated conductive material is ozone-untreated carbon black, and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated carbon black is 40-95:5-60.

[0032] As such, in the present invention, in particular, when the ozone-untreated conductive material is ozone-untreated carbon black and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated carbon black is 40-95:5-60, the battery containing such a conductive composite can have the effect of preventing or significantly suppressing high-temperature expansion, and also exhibits the effect of improving dispersibility and conductivity.

[0033] In other words, a battery containing a conductive material composite having the above composition can be constructed using a small amount of conductive material, and the expansion of the material is blocked or significantly suppressed even at high temperatures, which can lead to the effect of maintaining battery performance and enhancing safety even in high-temperature environments.

[0034] According to another embodiment, the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 94-99.5:0.5-6.

[0035] In the present invention, particularly when the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated single-walled carbon nanotube is 94-99.5:0.5-6, the battery containing such a conductive composite can block or significantly suppress internal gas generation in the event of overheating or overcharging.

[0036] In other words, some secondary batteries generate minute amounts of gas during the charging process, which can shorten their lifespan or cause safety issues. However, when equipped with the above configuration, ozone-treated polar functional groups mitigate unstable chemical reactions within the battery and effectively block or significantly suppress gas generation, which can be a significant advantage in maintaining long-term performance and ensuring stability.

[0037] According to another embodiment, the ozone-treated multiwalled carbon nanotube has a D / G peak ratio of 0.9 to 1.4 when measured in a Raman spectrum.

[0038] Another aspect of the present invention relates to a dispersion of a conductive material composite for a secondary battery comprising (i) a polar or non-polar dispersion medium, and (ii) a conductive material composite for a secondary battery according to various embodiments of the present invention dispersed in said polar or non-polar dispersion medium.

[0039] According to one embodiment, the polar dispersion medium is selected from N-methylpyrrolidone (NMP), water, ethanol, methanol, propanol, benzene, toluene, xylene, n-butyl butyrate, and mixtures of two or more of these.

[0040] Another aspect of the present invention relates to an electrode slurry composition for a secondary battery comprising a conductive composite for a secondary battery, a positive or negative active material, and a binder according to various embodiments of the present invention.

[0041] Another aspect of the present invention relates to an electrode for a secondary battery comprising a conductive composite for a secondary battery according to various embodiments of the present invention.

[0042] Another aspect of the present invention relates to a secondary battery comprising an electrode for a secondary battery according to various embodiments of the present invention.

[0043] Another aspect of the present invention relates to a device such as a communication device, an energy storage device, a transportation device, etc., comprising a secondary battery according to various embodiments of the present invention.

[0044] Another aspect of the present invention relates to a method for preparing a dispersion of a conductive material composite for a secondary battery, comprising the following steps.

[0045] (A) A step of obtaining an ozone-treated multiwalled carbon nanotube aqueous dispersion in which the ozone-treated multiwalled carbon nanotubes are dispersed in water by contacting the multiwalled carbon nanotubes in an aqueous solution with dissolved ozone to treat the surface of the multiwalled carbon nanotubes,

[0046] (B) a step of obtaining a composite comprising ozone-treated multiwalled carbon nanotubes by adding a conductive material other than ozone-treated multiwalled carbon nanotubes to the aqueous dispersion of the ozone-treated multiwalled carbon nanotubes to composite the conductive material other than ozone-treated multiwalled carbon nanotubes between the network structures of the multiwalled carbon nanotubes in an aqueous solution, followed by filtration and drying; and

[0047] (C) A step of redispersing the above complex in a polar dispersion medium to obtain a complex dispersion.

[0048] According to one embodiment, a conductive material other than the ozone-treated multi-walled carbon nanotube is selected from ozone-untreated single-walled carbon nanotubes, ozone-untreated carbon black, or a mixture thereof.

[0049] According to another embodiment, the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 90-99.8 : 0.2-10.

[0050] According to another embodiment, the ozone-untreated conductive material is ozone-untreated carbon black, and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated carbon black is 40-95:5-60.

[0051] According to another embodiment, the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 94-99.5:0.5-6.

[0052] According to another embodiment, the ozone-treated multiwalled carbon nanotube has a D / G peak ratio of 0.9 to 1.4 when measured in a Raman spectrum.

[0053] According to another embodiment, the polar dispersion medium is selected from N-methylpyrrolidone (NMP), water, ethanol, methanol, propanol, benzene, toluene, xylene, n-butyl butyrate, and mixtures of two or more of these.

[0054] Another aspect of the present invention relates to a method for preparing an electrode slurry composition for a secondary battery, comprising the following steps.

[0055] (A) A step of obtaining an ozone-treated multiwalled carbon nanotube aqueous dispersion in which the ozone-treated multiwalled carbon nanotubes are dispersed in water by contacting the multiwalled carbon nanotubes in an aqueous solution with dissolved ozone to treat the surface of the multiwalled carbon nanotubes,

[0056] (B) A step of obtaining a composite of ozone-treated multiwalled carbon nanotubes by adding a conductive material other than the ozone-treated multiwalled carbon nanotubes to the aqueous dispersion of the ozone-treated multiwalled carbon nanotubes to composite the conductive material other than the multiwalled carbon nanotubes between the network structures of the multiwalled carbon nanotubes in an aqueous solution, and then filtering under reduced pressure.

[0057] (C) a step of redispersing the ozone-treated multiwalled carbon nanotube composite in a polar dispersion medium to obtain a solvent-exchanged composite dispersion, and

[0058] (D) A step of dispersing an anode or cathode active material and a binder into the solvent-exchange complex dispersion.

[0059] According to one embodiment, a conductive material other than the ozone-treated multi-walled carbon nanotube is selected from ozone-untreated single-walled carbon nanotubes, ozone-untreated carbon black, or a mixture thereof.

[0060] According to another embodiment, the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 90-99.8 : 0.2-10.

[0061] According to another embodiment, the ozone-untreated conductive material is ozone-untreated carbon black, and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated carbon black is 40-95:5-60.

[0062] According to another embodiment, the ozone-untreated conductive material is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 94-99.5:0.5-6.

[0063] According to another embodiment, the ozone-treated multiwalled carbon nanotube has a D / G peak ratio of 0.9 to 1.4 when measured in a Raman spectrum.

[0064] According to another embodiment, the polar dispersion medium is selected from N-methylpyrrolidone (NMP), water, ethanol, methanol, propanol, benzene, toluene, xylene, n-butyl butyrate, and mixtures of two or more of these.

[0065] Expressions such as 'includes', 'has', 'is made up', and 'is composed' in this specification may have other parts added unless 'only' is used.

[0066] In addition, where a component is expressed in the singular in this specification, it may also be a plurality of components unless specifically stated otherwise.

[0067] In addition, numerical values ​​or numerical ranges described in this specification are interpreted to include a margin of error, even if not explicitly stated otherwise.

[0068] Additionally, the expression "X to Y" indicating a numerical range in this specification means "X or greater and Y or less."

[0069] Embodiments of the present invention will be described in detail below with reference to the drawings. However, detailed descriptions of known functions or configurations that may obscure the essence of the present invention in the following description and the attached drawings are omitted. Additionally, throughout the specification, the term 'comprising' a component means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0070] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "comprising" are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0071] Unless specifically defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0072] The present invention is to be explained in more detail below through examples, etc.; however, the scope and content of the present invention shall not be interpreted as being narrowed or limited by the examples, etc. below. Furthermore, based on the disclosure of the present invention including the examples below, it is evident that a person skilled in the art can easily practice the present invention even without specific experimental results presented, and it is natural that such variations and modifications fall within the scope of the appended claims.

[0073] Furthermore, the experimental results presented below describe only the representative experimental results of the above examples and comparative examples, and the respective effects of various embodiments of the present invention not explicitly presented below will be described in detail in the relevant sections.

[0074] Preparation Example 1: Surface modification of multi-walled carbon nanotubes (MWCNT) through ozone treatment

[0075] Ozone-treated MWCNTs were prepared through the following process. First, 0.8 g of MWCNTs with a diameter of 15 to 25 nm, a length of 20 to 100 m, and a thickness of 7 to 12 layers were weighed and added to 0.4 L of distilled water. A bubble generator was connected to an ozone generator and fixed inside a beaker. After injecting oxygen for 1 minute, the reaction was carried out on a stirrer while injecting ozone at a rate of 5 g / hr (injection flow rate 12.5 g / hr·L). After 120 minutes, the ozone generator was turned off, and a separation process was performed using a centrifuge. 200 mL of NMP was poured three times to terminate the oxidation reaction, and solvent exchange was performed.

[0076] Preparation Example 2: Surface modification of single-walled carbon nanotubes (SWCNT) through ozone treatment

[0077] Ozone-treated SWCNT was prepared by proceeding in the same manner as Preparation Example 1, except that SWCNT was used instead of MWCNT.

[0078] Preparation Example 3: Surface modification of carbon black through ozone treatment

[0079] Ozone-treated carbon black was prepared by proceeding in the same manner as Preparation Example 1, except that carbon black (SUPER-P) was used instead of MWCNT.

[0080] Examples 1 to 3: Composite dispersion of ozone-treated MWCNT and ozone-untreated SWCNT and preparation of a lithium half cell using the same

[0081] Ozone-untreated SWCNTs having a diameter of 0.5 to 1.5 nm and a thickness of one layer were added to the ozone-treated MWCNTs of Preparation Example 1. At this time, the weight ratio of ozone-treated MWCNTs to ozone-untreated SWCNTs was set to 99:1, 97:3, and 95:5, respectively, and mixed (Examples 1 to 3 in order).

[0082] NMP was added to the total solution to obtain a solid content of 5 wt%, and ball milling was performed at 600 rpm for 3 hours to obtain three types of conductive material dispersions with different weight ratios. Then, an electrode slurry was prepared by mixing an active material and a binder, etc., into the conductive material dispersions in the usual manner, and then the electrodes were manufactured by coating the slurry onto an electrode current collector, and a lithium half cell in the form of a coin cell was assembled.

[0083] Examples 4 to 6: Composite dispersion of ozone-treated MWCNT and ozone-untreated carbon black and preparation of a lithium half cell using the same

[0084] Except for setting the weight ratio of ozone-treated MWCNT and ozone-untreated SWCNT of Preparation Example 1 to 99:1, and setting the weight ratio of ozone-treated MWCNT and ozone-untreated carbon black (SUPER-P) nanoparticles of Preparation Example 1 to 90:10, 70:30, and 50:50, respectively (in order of Examples 4 to 6), the rest of the process was carried out in the same manner as Example 1 to sequentially prepare a conductive material dispersion, an electrode slurry, an electrode, and a lithium half cell in the form of a coin cell.

[0085] Example 7: Composite dispersion of ozone-treated MWCNT and ozone-untreated SWCNT and preparation of a lithium half cell using the same

[0086] Except for changing the weight ratio of ozone-treated MWCNT and ozone-untreated SWCNT of Preparation Example 1 to 85:15 instead of 99:1, the rest of the process was carried out in the same manner as Example 1 to sequentially prepare a conductive material dispersion, an electrode slurry, an electrode, and a lithium half cell in the form of a coin cell.

[0087] Example 8: Composite dispersion of ozone-treated MWCNT and ozone-untreated carbon black and preparation of a lithium half cell using the same

[0088] Except for changing the weight ratio of ozone-treated MWCNT and ozone-untreated carbon black in Preparation Example 1 to 38:62 instead of 90:10, the rest of the process was carried out in the same manner as in Example 4 to sequentially prepare a conductive material dispersion, an electrode slurry, an electrode, and a lithium half cell in the form of a coin cell.

[0089] Comparative Examples 1 and 2: Dispersion of only ozone-treated MWCNT or dispersion of only ozone-untreated SWCNT and manufacture of a lithium half cell using the same

[0090] A conductive material dispersion, an electrode slurry, an electrode, and a lithium half cell in the form of a coin cell were sequentially prepared by performing the rest in the same manner as Example 1, except that instead of using a weight ratio of ozone-treated MWCNT and ozone-untreated SWCNT of Preparation Example 1 at 99:1, only the ozone-treated MWCNT of Preparation Example 1 or only the ozone-untreated SWCNT was used (in order Comparative Examples 1 and 2).

[0091] Comparative Examples 3 to 5: Dispersion of ozone-treated MWCNT and preparation of a lithium half cell using the same

[0092] Instead of using the ozone-treated MWCNT of Preparation Example 1 and the ozone-untreated SWCNT in a weight ratio of 99:1, ① the ozone-treated MWCNT of Preparation Example 1 and the ozone-untreated MWCNT were used in a weight ratio of 97:3, ② the ozone-treated MWCNT of Preparation Example 1 and the ozone-treated SWCNT of Preparation Example 2 were used in a weight ratio of 97:3, and ③ the ozone-treated MWCNT of Preparation Example 1 and the ozone-treated carbon black of Preparation Example 3 were used in a weight ratio of 70:30 (in order of Comparative Examples 3 to 5), and the rest were performed in the same manner as in Example 1 to sequentially prepare a conductive material dispersion, an electrode slurry, an electrode, and a lithium half cell in the form of a coin cell.

[0093] Test Example 1: Evaluation of Anode Half-Cell Performance

[0094] Rate capability characteristics were evaluated for the lithium half cells of Examples 1 to 3 and Comparative Examples 1 and 2. After charging at a rate of 0.2 C in a 25 ℃ constant temperature chamber, discharge was performed at rates of 0.2 C, 0.5 C, 1 C, 2 C, 5 C, 10 C, and 0.2 C, and the respective rate capability characteristics were compared, and the results are shown in FIG. 2.

[0095] In the cell of the example, ozone-treated multi-walled carbon nanotubes form a network structure and ozone-untreated conductive material is composited into the network structure, thereby simultaneously improving dispersibility and conductivity; whereas in the cell of the comparative example, such performance improvement is not observed, confirming that a difference in performance occurs.

[0096] Test Example 2: Analysis of Cell Expansion During Charge / Discharge Process

[0097] For the lithium half cells of Examples 1 to 8 and the lithium half cells of Comparative Examples 3 to 5, whether the cells expanded during the charging and discharging process was observed.

[0098] The volume expansion and contraction of the electrode due to the rocking chair phenomenon during the lithium ion insertion and removal process were analyzed using an Electrode Expansion Test Bench, and the analysis was performed in a sealed test chamber capable of fixing the cell samples under test and in a controlled atmospheric environment.

[0099] As a result, no cell expansion was observed in the cells of Examples 1 to 8 during the charging and discharging process, whereas cell expansion was observed in the cells of Comparative Examples 3 to 5, and it was confirmed that the degree of expansion increased as the charging and discharging cycles were repeated.

[0100] Test 3: High-temperature expansion analysis of cells

[0101] High-temperature expansion of the cells was observed for the lithium half cells of Examples 4 to 6 and the lithium half cell of Example 8. Analysis was performed in an environment controlled at 40°C using the electrode expansion test bench used in Test Example 2.

[0102] As a result, it was confirmed that while no expansion was observed in the cells of Examples 4 to 6, an observable degree of expansion occurred in the cell of Example 8.

Claims

1. A conductive composite for a secondary battery comprising (a) ozone-treated multiwalled carbon nanotubes and (b) a conductive material other than ozone-treated multiwalled carbon nanotubes.

2. In claim 1, the conductive material other than the ozone-treated multi-walled carbon nanotube is a conductive composite for a secondary battery selected from ozone-untreated single-walled carbon nanotube, ozone-untreated carbon black, or a mixture thereof.

3. A conductive material composite for a secondary battery according to claim 2, wherein the conductive material other than the ozone-treated multi-walled carbon nanotube is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube and the ozone-untreated single-walled carbon nanotube is 90-99.8 : 0.2-10.

4. A conductive material composite for a secondary battery according to claim 2, wherein the conductive material other than the ozone-treated multi-walled carbon nanotube is ozone-untreated carbon black, and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated carbon black is 40-95:5-60.

5. A conductive material composite for a secondary battery according to claim 2, wherein the conductive material other than the ozone-treated multi-walled carbon nanotube is an ozone-untreated single-walled carbon nanotube, and the weight ratio of the ozone-treated multi-walled carbon nanotube to the ozone-untreated single-walled carbon nanotube is 94-99.5 : 0.5-6.

6. The ozone-treated multiwalled carbon nanotube according to claim 1 is a conductive composite for a secondary battery having a D / G peak ratio of 0.9 to 1.4 when measured in a Raman spectrum.

7. A conductive composite according to claim 1, characterized in that a conductive material other than the ozone-treated multiwalled carbon nanotube is composited between the network structures of the ozone-treated multiwalled carbon nanotube.

8. (i) a polar or non-polar dispersion medium, and (ii) a conductive material composite for a secondary battery according to any one of claims 1 to 5 dispersed in the polar or non-polar dispersion medium.

9. In Paragraph 7, The above polar dispersion medium is a conductive material composite dispersion for a secondary battery selected from N-methylpyrrolidone (NMP), water, ethanol, methanol, propanol, benzene, toluene, xylene, n-butyl butyrate, and mixtures of two or more of these.

10. A secondary battery electrode slurry composition comprising a conductive material composite for a secondary battery according to any one of claims 1 to 5, a positive or negative active material, and a binder.

11. An electrode for a secondary battery comprising a conductive material composite for a secondary battery according to any one of claims 1 to 5.

12. A secondary battery comprising an electrode for a secondary battery according to paragraph 11.

13. A device comprising a secondary battery pursuant to Paragraph 12, A device selected from communication devices, energy storage devices, and transportation devices.

14. Method for manufacturing a conductive material composite for a secondary battery comprising the following steps: (A) a step of treating the surface of the multiwalled carbon nanotubes by contacting the multiwalled carbon nanotubes with dissolved ozone over a water or alcohol solution to obtain an ozone-treated multiwalled carbon nanotube aqueous dispersion or an alcohol dispersion in which the ozone-treated multiwalled carbon nanotubes are dispersed in the water or the alcohol, and (B) A step of obtaining a composite containing ozone-treated multiwalled carbon nanotubes by introducing a conductive material other than the ozone-treated multiwalled carbon nanotubes into the aqueous dispersion or alcohol dispersion of the ozone-treated multiwalled carbon nanotubes and compounding the conductive material other than the ozone-treated multiwalled carbon nanotubes between the network structures of the multiwalled carbon nanotubes.

15. A method for manufacturing a conductive material composite according to claim 14, wherein the composite is a conductive material composite according to any one of claims 1 to 7.

16. A method for manufacturing a conductive material composite according to claim 14, further comprising the step of filtering and / or drying the composite obtained in step (B).

17. A method for preparing a conductive material composite dispersion comprising any one of the following steps (C1) or (C2): (C1) A step of redispersing the complex powder according to paragraph 14 in water or alcohol, or (C2) A step of redispersing the complex powder according to Clause 14 in a polar dispersion medium other than water and alcohol.

18. A method for preparing a conductive material composite dispersion for a secondary battery, wherein the polar dispersion medium other than water and alcohol is selected from N-methylpyrrolidone (NMP), benzene, toluene, xylene, n-butyl butyrate, and mixtures of two or more of these.

19. A method for manufacturing a conductive material composite dispersion, wherein, in claim 17, the composite is a conductive material composite according to any one of claims 1 to 7.

20. Method for preparing an electrode slurry composition for a secondary battery comprising the following steps: (A) A step of treating the surface of the multiwalled carbon nanotubes by contacting the multiwalled carbon nanotubes with dissolved ozone over a water or alcohol solution to obtain an ozone-treated multiwalled carbon nanotube aqueous dispersion or an alcohol dispersion in which the ozone-treated multiwalled carbon nanotubes are dispersed in the water or alcohol, (B) A step of obtaining a composite of ozone-treated multiwalled carbon nanotubes by introducing a conductive material other than the ozone-treated multiwalled carbon nanotubes into the aqueous dispersion or alcohol dispersion of the ozone-treated multiwalled carbon nanotubes to composite the conductive material other than the multiwalled carbon nanotubes between the network structures of the multiwalled carbon nanotubes, and then filtering under reduced pressure. (C) a step of redispersing the ozone-treated multiwalled carbon nanotube composite in a polar dispersion medium to obtain a solvent-exchanged composite dispersion, and (D) A step of dispersing an anode or cathode active material and a binder into the solvent-exchange complex dispersion.

21. A method for preparing an electrode slurry composition for a secondary battery, wherein the polar dispersion medium in claim 20 is selected from N-methylpyrrolidone (NMP), water, ethanol, methanol, propanol, benzene, toluene, xylene, n-butyl butyrate, and mixtures of two or more of these.

22. A method for manufacturing an electrode slurry composition for a secondary battery, characterized in that, in claim 20, the composite is a conductive material composite according to any one of claims 1 to 7.

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