TECHNICAL FIELD [1] [Cross Reference to Related Application] [2] This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0071071 filed on June 11, 2020, the entire contents 10 of which are incorporated herein by reference. [3] [Technical Field] [4] The present invention relates to a negative electrode and a secondary battery comprising the same. BACKGROUND ART 15 [5] In recent years, along with the fast spread of electronic devices using batteries such as mobile phones, notebook computers, and electric vehicles, demand for secondary batteries that are small in size, light in weight, and relatively high in capacity has rapidly increased. In particular, a lithium secondary battery is light in weight and has a high energy density, and is receiving attention as 20 a driving power source of a portable device. Accordingly, research and development efforts for improving the performance of lithium secondary batteries have been actively pursued. [6] Generally, lithium secondary batteries include a positive electrode, a negative electrode, a separator interposed between the positive electrode and the 25 negative electrode, an electrolyte, an organic solvent, etc. Further, in the 2 positive electrode and the negative electrode, an active material layer containing the positive electrode active material or the negative electrode active material may be formed on a current collector. A lithium-containing metal oxide such as LiCoO2 or LiMn2O4 is generally used as a positive electrode active material for the positive electrode, 5 and thus a carbon-based active material or silicon-based active material containing no lithium is used as a negative electrode active material for the negative electrode. [7] Among the negative electrode active materials, a silicon-based active material has attracted attention in that it has a capacity as high as about 10 times as that 10 of a carbon-based active material and have excellent high-speed charging characteristics. However, the silicon-based active material has a large degree of volume expansion/contraction due to charging/discharging, and there is a problem that an electrical short circuit between the active materials is likely to occur as charging/discharging is repeated, and the lifetime 15 characteristics of the negative electrode are deteriorated. When a binder is used in a large amount to suppress this, it is difficult to realize a desired high capacity electrode, and resistance is increased, so it is not widely used. [8] Korean Patent Publication No. 10-0794192 relates to a method for preparing a carbon-coated silicon-graphite composite negative electrode material for a 20 lithium secondary battery and a method for preparing a secondary battery comprising the same, but there is a limitation in solving the above problems. [9] [Prior Art Document] [10] [Patent Document] [11] Korean Patent Publication No. 10-0794192 25 DETAILED DESCRIPTION OF THE INVENTION 3 TECHNICAL PROBLEM [12] An object of the present invention is to provide a secondary battery that exhibits improved capacity characteristics, lifetime characteristics, and fast charging characteristics. 5 TECHNICAL SOLUTION [13] The present invention provides a negative electrode comprising: a negative electrode current collector; and a negative electrode active material layer formed on the negative electrode current collector, wherein the negative electrode active material layer comprises a silicon-based active material, a 10 binder, a first conductive material, and a second conductive material; a specific surface area of the second conductive material is larger than a specific surface area of the first conductive material; the first conductive material is contained in the negative electrode active material layer in an amount of 9.68 % by weight to 9.83 % by weight; and the second conductive material is 15 contained in the negative electrode active material layer in an amount of 0.17 to 0.32 % by weight. [14] The present invention also provides a secondary battery comprising the abovedescribed negative electrode; a positive electrode opposite to the negative electrode; a separator interposed between the negative electrode and the 20 positive electrode; and an electrolyte. ADVANTAGEOUS EFFECTS [15] The negative electrode of the present invention is a negative electrode using a silicon-based active material, and is characterized by containing specific contents of a conductive material having a small specific surface area (a first 4 conductive material) and a conductive material having a large specific area (a second conductive material). The first conductive material allows the conductive network to be preferably maintained between the active materials even when the silicon-based active material undergoes volume expansion/contraction through charging/di 5 scharging. In addition, the second conductive material can be adsorbed on the surface of the silicon-based active material to improve the conductivity of the surface of the silicon-based active material. Therefore, the negative electrode in which the first conductive material and the second conductive material are contained in specific contents 10 can improve the lifetime characteristics by preventing damage to the conductive network due to the volume expansion/contraction of the siliconbased active material and the electrical short circuit between the active materials, and the excellent capacity characteristics and the fast charging characteristics of the silicon-based active material can be preferably realized. 15 MODES OF THE INVENTION [16] The terms or words used in the specification and claims should not be construed as being limited to ordinary or dictionary meanings, and should be construed as a meaning and concept that complies with the technical concept of the present invention given the principle that the inventors can 20 appropriately define the concepts of the terms in order to explain their own invention in the best way. [17] The terminology used herein is used for the purpose of describing exemplary embodiments only and is not intended to be limiting of the invention. The articles “a” and “an” include plural referents unless the context clearly dictates 25 otherwise. 5 [18] In this specification, the terms "comprising", "including", "having" etc. are intended to designate the presence of the implemented features, numbers, steps, components, or combinations thereof, and are not to be understood as precluding the possibility of the presence or addition of one or more other 5 features or numbers, steps, components or combinations thereof. [19] In the present specification, the average particle diameter (D50) can be defined as a particle diameter corresponding to 50 % of the cumulative volume in the particle diameter distribution curve of the particles. The average particle diameter (D50) can be measured using, for example, a laser diffraction method. 10 The laser diffraction method generally enables measurement of a particle diameter of from a submicron region to about several millimeters, and results of high reproducibility and high resolvability can be obtained. [20] [21] The present invention relates to a negative electrode, specifically, a negative 15 electrode for a lithium secondary battery. [22] Specifically, the negative electrode of the present invention includes a negative electrode current collector; and a negative electrode active material layer formed on the negative electrode current collector, wherein the negative electrode active material layer includes a silicon-based active material, a 20 binder, a first conductive material, and a second conductive material; a specific surface area of the second conductive material is larger than a specific surface area of the first conductive material; the first conductive material is contained in the negative electrode active material layer in an amount of 9.68 % by weight to 9.83 % by weight; and the second conductive material is 6 contained in the negative electrode active material layer in an amount of 0.17 to 0.32 % by weight. [23] Conventionally, a silicon-based active material has advantages of high capacity and fast charging characteristics, but since the silicon-based active material has a large degree 5 of volume expansion/contraction due to charging/discharging, and as charging and discharging continues, the active materials in the negative electrode lose contact with each other, and thus it is difficult to transfer lithium between active materials, and there are problems of lithium precipitation and fast deterioration of lifetime characteristics. 10 [24] In order to solve such problems, the negative electrode of the present invention is a negative electrode using a silicon-based active material and is characterized in that it contains specific contents of a conductive material having a small specific surface area (a first conductive material) and a conductive material having a large specific area (a second conductive 15 material). The first conductive material allows the conductive network between the active materials to be preferably maintained even when the silicon-based active material undergoes volume expansion/contraction through charging/discharging. In addition, the second conductive material can be adsorbed on the surface of the silicon-based active material to improve 20 the conductivity of the silicon-based active material surface. Therefore, the negative electrode in which the first conductive material and the second conductive material are contained in specific contents can improve the lifetime characteristics by preventing damage to the conductive network due to the volume expansion/contraction of the silicon-based active material and the 25 electrical short circuit between the active materials, and the excellent capacity 7 characteristics and the fast charging characteristics of the silicon-based active material can be preferably realized. [25] The negative electrode current collector may include at least one selected from copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and an aluminum-cadmium alloy 5 , and preferably may include copper. [26] The thickness of the negative electrode current collector may typically range from 3 μm to 500 μm, preferably from 5 to 30 μm. [27] The negative electrode current collector may be formed with fine irregularities on its surface to enhance the binding force of the negative electrode active 10 material. For example, a negative electrode current collector in various forms, such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric etc., may be used. [28] The negative electrode active material layer is formed on the negative electrode current collector. Specifically, the negative electrode active 15 material layer may be formed on at least one surface of the negative electrode current collector, specifically, on one surface or both surfaces of the negative electrode current collector. [29] The negative electrode active material layer contains a silicon-based active material, a binder, and a conductive material. 20 [30] The silicon-based active material may contain a compound represented by the following Chemical formula 1. [31] [Chemical formula 1] [32] SiOx 8 [33] In the Chemical formula 1, 0≤x<2. In the case of SiO2, it does not react with lithium ions and cannot store lithium. Therefore, x is preferably within the above range. [34] Specifically, the silicon-based active material may contain Si. Conventionally, Si is advantageous in 5 that the capacity is about 2.5 to 3 times higher than that of silicon oxide (e.g. SiOx (0 [74] The present invention also provides a negative electrode slurry. The 15 negative electrode slurry may be applied onto a negative electrode current collector to form the negative electrode described above. Specifically, the negative electrode can be prepared by applying the negative electrode slurry on the negative electrode current collector and drying and rolling it. [75] The negative electrode slurry contains silicon-based active material, a binder, 20 a first conductive material, and a second conductive material; the specific surface area of the second conductive material is larger than that of the first conductive material; the first conductive material are contained in an amount of 9.68 % by weight to 9.83 % by weight based on the solid content; and the second conductive material is contained in an amount of 0.17 % by weight to 25 0.32 % by weight based on the solid content. 20 [76] The negative electrode slurry is characterized in that two kinds of conductive material having different specific surface areas (the first conductive material and the second conductive material) are contained in specific contents, and thus, the first and second conductive materials can be uniformly distributed in the slurry without occurrence 5 of a clumping phenomenon, and the first and second conductive materials are uniformly distributed in the negative electrode upon production of a negative electrode, so that the conductive network at the silicon-based active material surface and between the active materials can be smoothly maintained. 10 [77] The description of the silicon-based active material, the binder, the first conductive material, and the second conductive material may be the same as described in the negative electrode described above. [78] The negative electrode slurry may further include a solvent for forming the negative electrode slurry. The solvent for forming the negative electrode 15 slurry may contain, for example, at least one selected from the group consisting of distilled water, ethanol, methanol and isopropyl alcohol, preferably distilled water from the viewpoint of facilitating the dispersion of the silicon-based active material, the binder and the conductive material. [79] The solvent for forming a negative electrode slurry may be contained in the 20 negative electrode slurry so that the concentration of the solid content in the negative electrode slurry ranges from 15 % by weight to 45 % by weight, preferably from 20 % by weight to 30 % by weight in consideration of the viscosity, coatability, dispersibility, etc. of the negative electrode slurry. [80] The viscosity of the negative electrode slurry at 25 °C may range from 4,200 25 cP to 8,500 cP, preferably from 4,800 cP to 7,200 cP, more preferably from 21 5,200 cP to 6,800 cP, and more preferably 6,000 cP to 6,600 cP. When the viscosity is in the above range, the problem of sedimentation of the negative electrode slurry due to an excessively low viscosity can be prevented, a problem of deterioration of coatability and workability such as mixing can be avoided due to an excessively high 5 viscosity, and the dispersibility of the above-described first conductive material and the second conductive material is improved, whereby it is possible to produce a negative electrode having improved lifetime characteristics and fast charging performance. [81] The viscosity of the negative electrode slurry at 25 °C may be the viscosity of 10 a negative electrode slurry that has been rotated at a 1,500 shear rate (1/s) for at least 250 seconds using a viscometer or the like and then allowed to rest for 80 to 120 seconds. Specifically, the viscosity of the negative electrode slurry at 25 °C may be that of a negative electrode slurry that has been rotated for 300 seconds at a 1,500 shear rate (1/s) using a viscometer or the like, and then 15 allowed to rest for 100 seconds. [82] [83] The present invention provides a secondary battery, specifically a lithium secondary battery. Specifically, the secondary battery may include the above-described negative electrode. 20 [84] Specifically, the secondary battery may include a negative electrode; a positive electrode opposite to the negative electrode; a separator interposed between the negative electrode and the positive electrode; and an electrolyte. The negative electrode may be the negative electrode described above. 22 [85] The positive electrode may include a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. [86] The positive electrode current collector is not particularly limited as long as it has high conductivity without causing a chemical 5 change in the battery. Specifically, as the positive electrode current collector, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or copper or stainless steel whose surface is treated with carbon, nickel, titanium or silver, an aluminumcadmium alloy or the like may be used. 10 [87] The positive electrode current collector may typically have a thickness of 3 to 500 μm. [88] The positive electrode current collector may be formed with fine irregularities on the surface to enhance the binding force of the positive electrode active material. For example, a positive electrode current collector in various forms 15 such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric etc., may be used. [89] The positive electrode active material layer may contain a positive electrode active material. [90] The positive electrode active material is a compound capable of reversible 20 intercalation and deintercalation of lithium, and may specifically include a lithium-transition metal composite oxide containing lithium and at least one transition metal selected from nickel, cobalt, manganese, and aluminum, preferably a lithium-transition metal composite oxide including lithium and a transition metal including nickel, cobalt, and manganese. 23 [91] More specifically, examples of the lithium-transition metal composite oxide include lithium-manganese-based oxides (e.g., LiMnO2, LiMn2O4, etc.), lithium-cobalt-based oxides (e.g., LiCoO2, etc.), lithium-nickel-based oxides (e.g., LiNiO2, etc.), lithium-nickel-manganese-based oxides (e.g., LiNi1- YMnYO2 (wherein, 0 [118] Example 1: Manufacture of Negative Electrode [119] Si (average particle diameter (D50): 2.3 μm) as a silicon-based active material, a first conductive material, a second conductive material and a copolymer of polyvinyl alcohol and polyacrylic acid as a binder (containing a vinyl alcohol25 derived unit and an acrylic acid-derived unit at 66:34, weight-average 30 molecular weight: about 360,000 g/mol) were added to distilled water as a solvent for forming a negative electrode slurry in a weight ratio of 85.00:9.78:0.22:5.00 to prepare a negative electrode slurry (solid content concentration: 25 % by weight). [120] The first conductive material was plate-like graphite 5 (specific surface area: 17 m2/g, average particle diameter (D50): 3.5 μm, aspect ratio: 1.95), and the second conductive material was a single-walled carbon nanotube (specific surface area: 520 m2/g, diameter: 0.0015 μm (1.5 nm), length: 15 μm and aspect ratio; 10,000). 10 [121] On both sides of a copper current collector (thickness: 15 μm) as a negative electrode current collector, the negative electrode slurry was applied at a loading amount of 80.5 mg/25cm2, roll-pressed, and dried in a vacuum oven at 130 °C for 10 hours to form a negative electrode active material layer (thickness: 29 μm), which was used as a negative electrode (thickness of 15 negative electrode: 44 μm, porosity of negative electrode: 38.0 %). [122] Example 2: Manufacture of Negative Electrode [123] A negative electrode of Example 2 was produced in the same manner as in Example 1 except that the negative electrode slurry was formed by mixing the silicon-based active material, the first conductive material, the second 20 conductive material and the binder at a weight ratio of 85.0:9.8:0.2:5.0. [124] Comparative Example 1: Manufacture of Negative Electrode [125] A negative electrode of Comparative Example 1 was prepared in the same manner as in Example 1 except that the negative electrode slurry was formed by mixing the silicon-based active material, the first conductive material, the 31 second conductive material and the binder at a weight ratio of 85.00:9.96:0.04:5.00. [126] Comparative Example 2: Manufacture of Negative Electrode [127] A negative electrode of Comparative Example 2 was produced in the same manner as in Example 1 except that the negative 5 electrode slurry was formed by mixing the silicon-based active material, the first conductive material, the second conductive material and the binder at a weight ratio of 85.00:9.92:0.08:5.00. [128] Comparative Example 3: Manufacture of Negative Electrode 10 [129] A negative electrode of Comparative Example 3 was produced in the same manner as in Example 1 except that the negative electrode slurry was formed by mixing the silicon-based active material, the first conductive material, the second conductive material and the binder at a weight ratio of 85.00:9.88:0.12:5.00. 15 [130] Comparative Example 4: Manufacture of Negative Electrode [131] A negative electrode of Comparative Example 4 was produced in the same manner as in Example 1 except that the negative electrode slurry was formed by mixing the silicon-based active material, the first conductive material, the second conductive material and the binder at a weight ratio of 20 85.00:9.86:0.14:5.00. [132] Comparative Example 5: Manufacture of Negative Electrode [133] A negative electrode of Comparative Example 5 was produced in the same manner as in Example 1 except that the negative electrode slurry was formed by mixing the silicon-based active material, the first conductive material, the 32 second conductive material and the binder at a weight ratio of 85.00:9.57:0.43:5.00. [134] Comparative Example 6: Manufacture of Negative Electrode [135] A negative electrode of Comparative Example 6 was produced in the same manner as in Example 1 except that the negative 5 electrode slurry was formed by mixing the silicon-based active material, the first conductive material and the binder at a weight ratio of 85:10:5 without using the second conductive material. [136] Comparative Example 7: Manufacture of Negative Electrode 10 [137] A negative electrode of Comparative Example 7 was prepared in the same manner as in Example 1 except that the negative electrode slurry was formed by mixing the silicon-based active material, the second conductive material and the binder at a weight ratio of 94:1:5 without using the first conductive material. 15 [138] Table 1 First Conductive Material Second Conductive Material Content (% by weight, based on weight of negative electrode active material layer) Specific Surface Area (m2/g) Aspect Ratio Content (% by weight, based on weight of negative electrode active material layer) Specific Surface Area (m2/g) Aspect Ratio Example 1 9.78 17 1.95 0.22 520 10,000 Example 2 9.80 17 1.95 0.20 520 10,000 Comparative Example 1 9.96 17 1.95 0.04 520 10,000 Comparative Example 2 9.92 17 1.95 0.08 520 10,000 Comparative Example 3 9.88 17 1.95 0.12 520 10,000 Comparative Example 4 9.86 17 1.95 0.14 520 10,000 33 Comparative Example 5 9.57 17 1.95 0.43 520 10,000 Comparative Example 6 10 17 1.95 0 - - Comparative Example 7 0 - - 1 520 10,000 [139] [140] 1. Manufacture of Secondary Battery [141] A positive electrode slurry was prepared by adding Li[Ni0.6Co0.2Mn0.2]O2 (average particle diameter (D50): 15 5 μm) as a positive electrode active material, carbon black (product name: Super C65, manufactured by Timcal) as an conductive material, and polyvinylidene fluoride (PVdF) as the binder at a weight ratio of 97:1.5:1.5 to N-methyl-2-pyrrolidone (NMP), which is a solvent for forming a positive electrode slurry (solid content concentration: 78 10 % by weight). [142] On both sides of an aluminum current collector (thickness: 12 μm) as a positive electrode current collector, the positive electrode slurry was applied at a loading amount of 450 mg/25 cm2, roll-pressed, and dried in a vacuum oven at 130 °C for 10 hours to form a positive electrode active material layer 15 (thickness: 54 μm), thereby producing a positive electrode (thickness of positive electrode: 66 μm, porosity: 24 %). [143] A polyethylene separator was interposed between the positive electrode and the negative electrode of Example 1 and an electrolyte was injected to produce a secondary battery of Example 1. 20 [144] The electrolyte was obtained by adding vinylene carbonate at 3 % by weight based on the total weight of the electrolyte to an organic solvent in which fluoroethylene carbonate (FEC) and diethyl carbonate (DMC) were mixed at 34 a volume ratio of 30:70, and adding LiPF6 as a lithium salt at a concentration of 1 M. [145] The secondary batteries of Example 2 and Comparative Examples 1 to 7 were produced in the same manner as in Example 1 except that the negative electrodes of the above-described Example 5 2 and Comparative Examples 1-7 were used. [146] 2. N/P ratio measurement and calculation of secondary battery [147] A coin-type half-cell containing a negative electrode of Example 1, a lithium metal counter electrode opposite to the negative electrode, a polyethylene 10 separator interposed between the negative electrode and the lithium metal counter electrode, and an electrolyte was produced and the discharge capacity was determined (units: mAh/g). The discharge capacity was multiplied by the loading amount to obtain the discharge capacity per unit area of the negative electrode of Example 1 (units: mAh/cm2). 15 [148] In addition, a coin-type half-cell containing the positive electrode prepared above, a lithium metal counter electrode opposite to the positive electrode, a polyethylene separator interposed between the positive electrode and the lithium metal counter electrode, and an electrolyte was produced and the discharge capacity was determined (units: mAh/g). The discharge capacity 20 was multiplied by the loading amount to obtain the discharge capacity per unit area of the positive electrode (units: mAh/cm2). [149] The N/P ratio of the secondary battery of Example 1 was determined by the following equation 1 (N/P ratio = 2.76). [150] [Equation 1] 35 [151] N/P ratio = {(discharge capacity per unit area of the negative electrode) / (discharge capacity per unit area of the positive electrode)}. [152] The N/P ratio of the secondary batteries of Example 2 and Comparative Examples 1 to 7 was determined in the same manner as in Example 1 except that the negative electrodes of Example 5 2 and Comparative Examples 1-7 were used. [153] The results are shown in Table 2. [154] Table 2 N/P ratio Example 1 2.76 Example 2 2.69 Comparative Example 1 2.67 Comparative Example 2 2.65 Comparative Example 3 2.68 Comparative Example 4 2.68 Comparative Example 5 2.63 Comparative Example 6 2.66 Comparative Example 7 2.67 10 [155] Experimental Examples [156] Experimental Example 1: Measurement of Resting Viscosity of Negative Electrode Slurry [157] The resting viscosities of the negative electrode slurries prepared in Examples 1 and 2 and Comparative Examples 1 to 7 were measured. The resting 15 viscosity was measured using a viscometer (product name: HAAKE viscometer, manufactured by ThermoFisher Scientific). [158] Specifically, 5 mL of the negative electrode slurries prepared in Examples 1- 2 and Comparative Examples 1-7 were prepared, and the negative electrode slurry was put in the viscometer, rotated at a 1,500 shear rate (1/s) at 25 °C for 36 300 seconds, then, the rotation was stopped and the viscosity after resting for 100 seconds was measured. [159] Table 3 Resting Viscosity (cP @ 25 °C) Example 1 6,420 Example 2 5,880 Comparative Example 1 2,550 Comparative Example 2 2,570 Comparative Example 3 3,110 Comparative Example 4 3,860 Comparative Example 5 16,800 Comparative Example 6 1,560 Comparative Example 7 11,830 [160] Referring to Table 3, it can 5 be confirmed that the negative electrode slurries of Examples 1 and 2 exhibit a favorable level of resting viscosity as compared with Comparative Examples, and that the active material, the first conductive material, a second conductive material and a binder are smoothly dispersed. However, it can be confirmed that the negative electrode slurries of 10 Comparative Examples 1 to 7 have an excessively low or high resting viscosity. When the resting viscosity is too low, there is a risk of slurry sedimentation, and when the resting viscosity is too high, there may be a risk that coatability is lowered, and difficulty in transfer of the slurry makes it difficult to produce a negative electrode, which may affect the lifetime 15 characteristics of the negative electrode as described later. [161] Experimental Example 2: Evaluation of Cycle Capacity Retention Rate [162] The capacity retention rate of the secondary batteries produced in Examples 1 and 2 and Comparative Examples 1 to 7 was evaluated using an electrochemical charger/discharger. 37 [163] The secondary battery was charged and discharged to the 100th cycle under charging (1.0 C CC/CV charging 4.2 V 0.05 C cut) and discharging (0.5 C CC discharge 3.2 V cut) conditions. [164] The capacity retention rate was evaluated by the following formula. The 5 results are shown in Table 4 below. [165] Capacity retention rate (%) = {(discharge capacity at 100th cycle) / (discharge capacity at first cycle)}×100 [166] Table 4 Cycle Capacity Retention Rate (%) @ 100cycle Example 1 93.9 Example 2 92.0 Comparative Example 1 74.4 Comparative Example 2 75.8 Comparative Example 3 81.3 Comparative Example 4 86.6 Comparative Example 5 87.4 Comparative Example 6 70.8 Comparative Example 7 69.1 10 [167] Referring to Table 4, it can be seen that the secondary batteries of Examples 1 and 2 in which the first conductive material and the second conductive material were added in a preferable amount in the negative electrode exhibited a superior level of cycle capacity retention rate as compared to the Comparative Examples. 15 [168] Experiment Example 3: Evaluation of Fast Charging Lifespan [169] With respect to the secondary batteries produced in Examples 1 and 2 and Comparative Examples 1 to 7, the capacity retention rate during fast charging was evaluated using an electrochemical charger/discharger. The secondary battery was subjected to 1) charging (0.2C CC/CV charging 4.2V 0.05C cut) 38 and discharging (0.2C CC discharge 3.2V cut), which is the first cycle, and 2) charging and discharging to the 100th cycle from the second cycle under charging (2.0 C CC/CV charging 4.2 V 0.05C cut) and discharging (0.5C CC discharge 3.2V cut) conditions. [170] The capacity retention rate was evaluated 5 by the following formula. The results are shown in Table 5 below. [171] Capacity retention rate (%) = {(discharge capacity at 100th cycle)/(discharge capacity at first cycle)}×100 [172] Table 5 Cycle Capacity Retention Rate (%) @ 100thcycle Example 1 74.2 Example 2 72.4 Comparative Example 1 57.3 Comparative Example 2 57.6 Comparative Example 3 63.4 Comparative Example 4 66.7 Comparative Example 5 67.3 Comparative Example 6 53.8 Comparative Example 7 51.8 10 [173] Referring to Table 5, it can be seen that the secondary batteries of Examples 1 and 2, in which the first conductive material and the second conductive material were added in a preferable amount in the negative electrode, exhibited excellent levels of fast charging characteristics as compared with the 15 comparative examples. CLAIMS 1. A negative electrode, comprising: a negative electrode current collector; and a negative electrode active material layer formed on the negative electrode 5 current collector, wherein the negative electrode active material layer comprises a silicon-based active material, a binder, a first conductive material, and a second conductive material, a specific surface area of the second conductive material is larger than a specific surface area of the first conductive material, 10 the first conductive material is contained in the negative electrode active material layer in an amount of 9.68 % by weight to 9.83 % by weight, and the second conductive material is contained in the negative electrode active material layer in an amount of 0.17 % by weight to 0.32 % by weight. 15 2. The negative electrode according to claim 1, wherein the specific surface area of the first conductive material is 5 m2/g to 40 m2/g. 3. The negative electrode according to claim 1, wherein the first conductive material comprises at least one selected from the group consisting of graphite and 20 carbon black. 4. The negative electrode according to claim 1, wherein an average particle diameter (D50) of the first conductive material is 1 μm to 20 μm. 40 5. The negative electrode according to claim 1, wherein an aspect ratio of the first conductive material is 1.1 to 30.0. 6. The negative electrode according to claim 1, wherein a specific surface area of the 5 second conductive material is 400 m2/g to 1,000 m2/g. 7. The negative electrode according to claim 1, wherein the second conductive material comprises at least one selected from single-walled carbon nanotubes and multi-walled carbon nanotubes. 10 8. The negative electrode according to claim 1, wherein an aspect ratio of the second conductive material is 5,000 to 15,000. 9. The negative electrode according to claim 1, wherein the silicon-based active 15 material is contained in an amount of 75 % by weight to 89 % by weight. 10. The negative electrode according to claim 1, wherein an average particle diameter (D50) of the silicon-based active material is 1 μm to 10 μm. 20 11. The negative electrode according to claim 1, wherein a ratio of an average particle diameter (D50) of the silicon-based active material to an average particle diameter (D50) of the first conductive material is 1:1 to 1:5. 12. The negative electrode according to claim 1, wherein the binder comprises at 25 least one selected from the group consisting of styrene-butadiene rubber, acrylonitrile41 butadiene rubber, acrylic rubber, butyl rubber, fluoro rubber, carboxymethyl cellulose, starch, hydroxypropyl cellulose, polyvinyl alcohol, polyacrylic acid, polyethylene glycol, polyacrylonitrile, and polyacryl amide. 13. The negative electrode according 5 to claim 1, wherein the binder is contained in the negative electrode active material layer in an amount of 1 % by weight to 15 % by weight. 14. A secondary battery, comprising: 10 the negative electrode according to claim 1; a positive electrode opposite to the negative electrode; a separator interposed between the negative electrode and the positive electrode; and an electrolyte.