Title of Invention: Method for manufacturing negative active material for secondary battery, negative electrode for secondary battery, and lithium secondary battery comprising same technical field [One] Cross Citation with Related Applications [2] This application claims the benefit of priority based on Korean Patent Application No. 10-2019-006690 dated January 18, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification. [3] technical field [4] The present invention relates to a method for manufacturing a negative active material for a secondary battery, a negative electrode for a secondary battery, and a lithium secondary battery including the same. background [5] As the price of energy sources increases due to the depletion of fossil fuels and interest in environmental pollution is increasing, eco-friendly alternative energy sources are becoming an indispensable factor for future life. [6] In particular, as technology development and demand for mobile devices increase, the demand for secondary batteries as an eco-friendly alternative energy source is rapidly increasing. [7] The secondary battery has conventionally used lithium metal as the negative electrode, but as the battery short circuit due to the formation of dendrites and the risk of explosion due to this become a problem, reversible intercalation and desorption of lithium ions are possible, The use of carbon-based active materials that maintain structural and electrical properties is emerging. [8] As the carbon-based active material, various types of carbon-based materials such as artificial graphite, natural graphite, and hard carbon have been applied. have. Since the graphite-based active material has a discharge voltage as low as -0.2V compared to lithium, a battery using the graphite-based active material can exhibit a high discharge voltage of 3.6V, providing many advantages in terms of energy density of a lithium battery. [9] Among them, in particular, natural graphite exhibits high output and capacity characteristics compared to other carbon-based active materials, but natural graphite receives a lot of mechanical stress due to low mechanical strength during electrode rolling, so side reactions with the electrolyte are deepened, and lifespan is increased. There is a problem that the characteristics may be deteriorated. [10] Accordingly, there is a need to develop natural graphite capable of minimizing the mechanical stress during electrode rolling, preventing the occurrence of a side reaction of the electrolyte solution and swelling, and improving the lifespan characteristics. [11] Japanese Patent Registration No. 4403327 discloses a graphite powder for a negative electrode of a lithium ion secondary battery, but does not provide an alternative to the above-mentioned problem. [12] [Prior art literature] [13] [Patent Literature] [14] Japanese Patent Registration Publication No. 4403327 DETAILED DESCRIPTION OF THE INVENTION technical challenge [15] One object of the present invention is to provide a negative electrode for a secondary battery that can improve the output performance of the negative electrode, and prevent side reactions and swelling with an electrolyte, and thus have excellent lifespan characteristics. [16] In addition, another object of the present invention is to provide a lithium secondary battery including the above-described negative electrode for secondary batteries. [17] In addition, another object of the present invention is that it is possible to manufacture a negative active material having a relatively uniform particle size distribution, so that it is possible to improve the output performance of the negative electrode, and to prevent side reactions and swelling with the electrolyte to improve lifespan characteristics. An object of the present invention is to provide a method of manufacturing a negative active material for a secondary battery that can be used. means of solving the problem [18] The present invention is a negative electrode current collector; and a negative active material layer formed on the negative electrode current collector and including a negative active material for secondary batteries, wherein the negative active material for secondary batteries contains natural graphite, has a sphericity of 0.58 to 1, and a tap density of 1.08 g/ cc to 1.32 g/cc, and D max -D min, which is the difference between the maximum particle diameter D max and the minimum particle diameter D min in the particle size distribution, is 16 μm to 19 μm. [19] In addition, the present invention is a secondary battery negative electrode described above; a positive electrode opposite to the negative electrode for the secondary battery; a separator interposed between the negative electrode for the secondary battery and the positive electrode; and an electrolyte; provides a lithium secondary battery comprising. [20] In addition, the present invention comprises the steps of adjusting the particle size distribution of the natural graphite raw material in scale; granulating the flaky natural graphite raw material with the particle size distribution controlled; and controlling the particle size distribution of the granulated natural graphite; wherein the negative active material contains natural graphite, has a sphericity of 0.58 to 1, and a tap density of 1.08 g/cc to 1.32 g/cc, and D max -D min, which is the difference between the maximum particle diameter D max and the minimum particle diameter D min in the particle size distribution, is 16 μm to 19 μm. Effects of the Invention [21] The negative electrode for secondary batteries of the present invention includes natural graphite and a negative active material for secondary batteries having a specific range of sphericity, tap density, and D max -D min value. As a result, it is possible to increase the density of the negative electrode, thereby improving the output performance, and at the same time, it is possible to minimize the mechanical stress applied to the negative electrode active material during electrode rolling, and to minimize the reaction area with the electrolyte to prevent gas generation and swelling. Therefore, excellent life performance can be expected. Modes for carrying out the invention [22] The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention. [23] The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. [24] In this specification, terms such as "comprise", "comprising" or "have" are intended to designate the presence of an embodied feature, number, step, element, or a combination thereof, but one or more other features or It should be understood that the existence or addition of numbers, steps, elements, or combinations thereof is not precluded in advance. [25] In the present specification, the average particle diameter (D 50 ) may be defined as a particle diameter corresponding to 50% of the cumulative volume in the particle size distribution curve of the particles. The average particle diameter (D 50 ) may be measured using, for example, a laser diffraction method. In general, the laser diffraction method can measure a particle diameter of several mm from a submicron region, and can obtain high reproducibility and high resolution results. [26] Hereinafter, the present invention will be specifically described. [27] [28] [29] The present invention relates to a negative electrode for a secondary battery, and specifically to a negative electrode for a lithium secondary battery. [30] Specifically, the present invention is a negative electrode current collector; and a negative active material layer formed on the negative electrode current collector and including a negative active material for secondary batteries, wherein the negative active material for secondary batteries contains natural graphite, has a sphericity of 0.58 to 1, and a tap density of 1.08 g/ cc to 1.32 g/cc, and D max -D min, which is the difference between the maximum particle diameter D max and the minimum particle diameter D min in the particle size distribution, is 16 μm to 19 μm. [31] The negative electrode current collector is not particularly limited as long as it has high conductivity without causing a chemical change in the lithium secondary battery. For example, the negative electrode current collector may be copper, stainless steel, aluminum, nickel, titanium, calcined carbon, one in which the surface of copper or stainless steel is surface-treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. may be used. can [32] The negative electrode current collector may form fine irregularities on the surface to strengthen the bonding strength of the negative electrode active material, and may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven body, and the like. [33] The negative electrode current collector may generally have a thickness of 3 μm to 500 μm. [34] The anode active material layer is formed on the anode current collector. [35] The negative active material layer includes an anode active material for a secondary battery. [36] The negative active material for a secondary battery includes natural graphite. Since natural graphite exhibits high output and capacity characteristics compared to other carbon-based active materials, when an anode active material including the same is used, excellent output characteristics and capacity characteristics can be realized. However, natural graphite has many internal voids, blocks internal voids during electrode rolling, receives a lot of mechanical stress, and forms a passivation film (SEI film) during charging and discharging. have. [37] Accordingly, as a result of repeated research to solve the above problems of the negative active material containing natural graphite, the inventors of the present invention control the sphericity, tap density and particle size distribution of the negative active material containing natural graphite to a specific range. It is possible to realize the desired porosity even when rolling at a relatively low linear pressure by improving the performance, thus minimizing particle breakage during rolling, and effectively reducing the reaction area with the electrolyte to dramatically improve cycle swelling characteristics. found out [38] Specifically, the negative active material for a secondary battery according to the present invention has a sphericity of 0.58 to 1, a tap density of 1.08 g/cc to 1.32 g/cc, and a difference between the maximum particle diameter D max and the minimum particle diameter D min in the particle size distribution. phosphorus D max -D min is 16 μm to 19 μm. [39] Specifically, the sphericity of the negative active material for secondary batteries may be 0.58 to 1, preferably 0.76 to 1. If the sphericity is less than 0.58, it is difficult to increase the density of the negative electrode, and it is not preferable because there is a risk of deterioration of life characteristics due to deterioration of electrode adhesion. [40] The sphericity may be defined as a value obtained by dividing the circumference of a circle having the same area as the projected image of the negative active material for secondary batteries by dividing the circumference of the projected image of the negative active material for secondary batteries. Specifically, the sphericity may be defined by Equation 1 below. [41] [Equation 1] [42] Sphericity = (Circumference of a circle with the same area as the projected image of the negative active material for secondary batteries)/(The perimeter of the projected image of the negative active material for secondary batteries) [43] The sphericity may be measured using a particle analyzer, for example, sysmex FPIA3000 (manufactured by Mavern). The sphericity according to the present invention may be defined as an average value of the sphericity of 10 particles arbitrarily selected from the negative active material. [44] On the other hand, the tap density of the negative active material for a secondary battery is 1.08 g/cc to 1.32 g/cc, preferably 1.16 g/cc to 1.24 g/cc. When the tap density is less than 1.08 g/cc, it is difficult to increase the density of the negative electrode, and there is a risk of deterioration of life characteristics due to a decrease in electrode adhesion, and when it exceeds 1.32 g/cc, there is a risk of deterioration of output characteristics, which is not preferable. [45] The tap density may be measured by measuring the final volume obtained by charging a negative active material for a secondary battery in a container, vibrating it a specific number of times, and calculating an apparent density based on this. [46] In addition, the negative active material for a secondary battery of the present invention has a D max -D min difference between a maximum particle diameter D max and a minimum particle diameter D min in a particle size distribution of 16 μm to 19 μm, preferably 17 μm to 18.5 μm. μm. [47] When the D max -D min of the negative electrode active material is less than 16 μm, there is a fear that the output characteristics and lifespan characteristics may be deteriorated because fine particles that positively affect the output characteristics and the electrode adhesion are excessively removed. When the D max -D min is greater than 19 μm, the uniformity of the particle size is not good, so that when the negative active material is used for the negative electrode, the reaction area with the electrolyte cannot be sufficiently reduced, so the effect of improving the swelling properties is insignificant. [48] [49] As D max -D min in the particle size distribution of the negative active material for a secondary battery of the present invention is adjusted to the above range, the particle size can be uniformed to an appropriate level, for example, the particle size distribution graph can be formed sharper can Accordingly, when the negative electrode active material is used, it is possible to form a higher density negative electrode, so output characteristics can be improved, and the negative electrode can be formed with a relatively thin thickness, thereby minimizing the electrode rolling process and the reaction area with the electrolyte. can be minimized, so gas generation and swelling during cathode operation can be prevented to an excellent level. [50] [51] In addition, the negative active material for a secondary battery may further include a carbon coating layer formed on natural graphite. [52] The carbon coating layer can improve the mechanical strength of natural graphite, and thus the structural stability of the active material can be improved. can [53] The carbon coating layer may be included in an amount of 3.5 wt% to 8 wt%, preferably 4 wt% to 6 wt%, based on the total weight of the negative active material for a secondary battery, and when within the above range, mechanical strength can be further improved and lithium movement It is desirable in terms of realization of output characteristics because the resistance does not increase excessively. [54] The carbon coating layer is formed by providing at least one material selected from the group consisting of coal-tar pitch, rayon, and polyacrylonitrile-based resin or a precursor of the material to the surface of the natural graphite particles, and then pyrolyzing them. can be Preferably, the carbon coating layer includes soft carbon, which may be formed by sintering and pyrolysis of the coal tar pitch. The heat treatment process for forming the carbon coating layer may be performed in a temperature range of 1,000° C. to 4,000° C. in terms of forming a uniform carbon coating layer and preventing the carbon coating layer from being excessively formed. [55] [56] The average particle diameter (D 50 ) of the negative active material for a secondary battery of the present invention may be 8 μm to 16 μm, preferably 10 μm to 14 μm, and when the negative active material having an average particle diameter range in the above range is used for the positive electrode, the electrolyte and It is possible to reduce the reaction area of ​​the electrolyte, the effect of preventing side reactions of the electrolyte can be maximized. [57] The D max , D min , the average particle diameter (D 50 ), and the like may be measured by analyzing the particle size distribution of the negative active material. The particle size distribution can be analyzed using a particle size distribution measuring instrument such as Mastersizer2000 (manufactured by Malvern). [58] [59] The negative active material of the present invention as described above, for example, the step of adjusting the particle size distribution of the natural graphite raw material in scale; granulating the flaky natural graphite raw material with the particle size distribution controlled; and adjusting the particle size distribution of the granulated natural graphite. [60] First, a raw material of flaky natural graphite, which is a raw material of the anode active material of the present invention, is prepared, and then fine powder and fine powder are removed to adjust the particle size distribution of the raw material of flaky natural graphite. In this case, the particle size distribution control of the flaky natural graphite raw material may be performed through a particle size distribution control method well known in the art, such as filtering. For example, the particle size of the flaky natural graphite raw material has an average particle diameter of 100 to 400 nm, preferably 200 nm to 300 nm, and D max -D min is 150 to 400 nm, preferably, to be adjusted to be about 150 to 300 nm. However, the present invention is not limited thereto. [61] When the step of adjusting the particle size distribution of the raw material flaky graphite, which is a raw material, is performed as described above, natural graphite having a relatively uniform particle size distribution can be manufactured in the granulation step to be described later. [62] Then, the flaky natural graphite raw material with the particle size distribution controlled is mixed and aggregated with the binder pitch to be granulated. [63] The binder pitch is added to facilitate agglomeration of the flaky natural graphite raw material, and may be at least one selected from the group consisting of petroleum-based pitch and coal-based pitch. [64] The flaky natural graphite raw material and the binder pitch may be mixed in a weight ratio of 85:15 to 99:1, preferably 90:10 to 97:3. [65] The assembling of the flaky natural graphite raw material and the binder pitch may be performed at 2,000° C. to 3,000° C., preferably at 2,200° C. to 2,800° C., for smooth assembly therebetween. [66] The assembling of the flaky natural graphite raw material and the binder pitch is 1,000 rpm to 4,000 rpm, preferably 2,000 rpm to 3,000 of a mixture including the flaky natural graphite raw material and the binder pitch for smooth assembly and sufficient agglomeration therebetween It can be performed while rotating at a speed of rpm. [67] The assembling of the flaky natural graphite raw material and the binder pitch may be performed for 3 hours to 15 hours, preferably 5 hours to 10 hours for smooth assembly and sufficient cohesion therebetween. [68] Natural graphite granulated by the above method has an average particle diameter (D 50 ) of 8 μm to 16 μm, preferably 10 μm to 14 μm, and D max -D min of 10 μm to 35 μm, preferably 14 It may be about ㎛ to 26㎛, but is not limited thereto. [69] Next, a step of adjusting the particle size distribution of the granulated natural graphite is performed. [70] In this case, the step of controlling the particle size distribution of the granulated natural graphite may be performed through a particle size distribution control method well known in the art, such as sieving. [71] If necessary, the step of forming a carbon coating layer on the natural graphite may be further performed after the step of adjusting the particle size distribution of the granulated natural graphite, and thus, it is possible to improve the mechanical strength and structural stability of the natural graphite can [72] The carbon coating layer is formed by providing at least one material selected from the group consisting of coal-tar pitch, rayon, and polyacrylonitrile-based resin or a precursor of the material to the surface of the natural graphite particles, and then pyrolyzing them. can be Preferably, the carbon coating layer includes soft carbon, which may be formed by sintering and pyrolysis of the coal tar pitch. The heat treatment process for forming the carbon coating layer may be performed in a temperature range of 1,000° C. to 4,000° C. in terms of forming a uniform carbon coating layer and preventing the carbon coating layer from being excessively formed. [73] [74] Meanwhile, the anode active material layer may further include at least one additive selected from the group consisting of a binder, a thickener, and a conductive material in addition to the anode active material for a lithium secondary battery. [75] The binder is a component that assists in bonding of the conductive material, the active material, the negative electrode current collector, and the like, and may be included in an amount of typically 1% to 30% by weight based on the total weight of the negative electrode active material layer. [76] The binder is polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene , polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, fluororubber, or a combination of two or more thereof. [77] As the thickener, any thickener used in conventional lithium secondary batteries may be used, and an example thereof includes carboxymethyl cellulose (CMC). [78] The thickener may be included in an amount of 1 wt% to 30 wt% based on the total weight of the anode active material layer. [79] The conductive material is a component for further improving the conductivity of the anode active material, and may be included in an amount of 1 wt% to 30 wt% based on the total weight of the anode active material layer. [80] The conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, graphite such as natural graphite or artificial graphite; carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskeys such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; A conductive material such as a polyphenylene derivative may be used. Specific examples of commercially available conductive materials include acetylene black-based Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company, etc.), Ketjenblack, EC series (products of the Armak Company), the Vulcan XC-72 (products of the Cabot Company) and the Super P (products of the Timcal Company). [81] The anode active material layer is prepared by mixing at least one additive selected from the above-described anode active material for a lithium secondary battery and a binder, a conductive material and a thickener in a solvent to prepare an anode slurry, and applying the anode slurry to the anode current collector, rolling, It can be prepared by drying. [82] The solvent may include water or an organic solvent such as N-methyl-2-pyrrolidone (NMP), and may be used in an amount having a desirable viscosity when including the negative active material, and optionally a binder and a conductive material. . For example, a negative active material for a lithium secondary battery, and optionally a binder, a thickener, and a concentration of solids including a conductive material may be included so that the concentration of 50% to 95% by weight, preferably 70% to 90% by weight. [83] [84] [85] In addition, the present invention provides a lithium secondary battery comprising the above-described negative electrode for a secondary battery. [86] Specifically, the lithium secondary battery includes the above-described negative electrode for secondary batteries; a positive electrode opposite to the negative electrode for the secondary battery; a separator interposed between the negative electrode and the positive electrode for the secondary battery; and electrolyte; [87] The positive electrode may include a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. [88] The positive active material layer includes a positive active material and optionally a binder, a conductive material [89] The positive electrode current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon on the surface of aluminum or stainless steel. , nickel, titanium, silver, etc. may be used. [90] The positive electrode current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon on the surface of aluminum or stainless steel. , nickel, titanium, silver, etc. may be used. [91] The positive electrode current collector may generally have a thickness of 3 μm to 500 μm. [92] The positive electrode active material layer is formed on the negative electrode current collector and includes a positive electrode active material. [93] The positive active material is a compound capable of reversible intercalation and deintercalation of lithium, and specifically, may include a lithium composite metal oxide including lithium and one or more metals such as cobalt, manganese, nickel or aluminum. have. More specifically, the lithium composite metal oxide is a lithium-manganese oxide (eg, LiMnO 2 , LiMn 2 O 4 , etc.), a lithium-cobalt-based oxide (eg, LiCoO 2 , etc.), lithium-nickel-based oxide (eg, LiNiO 2 , etc.), lithium-nickel-manganese oxide (eg, LiNi 1-Y Mn Y O 2 (here, 0 [114] By preparing a raw material for flaky natural graphite, and removing fine powder and dust through filtering, the average particle diameter (D 50 ) was adjusted to 250 nm and D max -D min to 200 nm. Granulated natural graphite (average particle diameter (D 50 ) 11 μm, D max -D min =22 μm) was prepared. [115] The particle size distribution was controlled by particle sieving of the granulated natural graphite to remove fine powder and coarse powder. A negative active material for a secondary battery in which a soft carbon carbon coating layer was formed on natural graphite was prepared by mixing coal tar pitch on natural graphite having the particle size distribution controlled, and calcining it at 2,500°C. The soft carbon carbon coating layer was formed in an amount of 4.5% by weight based on the total weight of the negative active material for secondary batteries. [116] The negative active material for secondary batteries had a sphericity of 0.8, a tap density of 1.2 g/cc, an average particle diameter (D 50 ) of 11 μm, and a D max -D min of 17.5 μm. [117] [118] [119] The anode active material for secondary batteries prepared above, super C65 as a conductive material, styrene-butadiene rubber (SBR) as a binder, and carboxymethyl cellulose (CMC) as a thickener were mixed in a weight ratio of 96.6:1:1.3:1.1, and water was added thereto. was added to prepare a negative electrode slurry. [120] The negative electrode slurry prepared above was applied to a copper current collector and vacuum-dried at about 130° C. for 10 hours to prepare a negative electrode for a secondary battery of Example 1. At this time, the loading of the negative electrode was set to 3.61mAh/cm 2 . [121] [122] Examples 2 to 7, Comparative Examples 1 to 5 [123] Except for controlling the process conditions at the time of removing fine powder and dust so that the negative electrode active material has the sphericity, tap density, average particle diameter (D 50 ) and D max -D min shown in Table 1 below , Example 1 and Negative active materials of Examples 2 to 7 and Comparative Examples 1 to 5 were prepared in a similar manner. Then, negative electrodes of Examples 2 to 7 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1 using the prepared negative active materials. [124] [125] [Table 1] [126] [127] The sphericity, tap density, average particle size (D 50 ) and D max -D min of the negative active material for secondary batteries used in the negative electrodes for secondary batteries of Examples 1 to 7 and Comparative Examples 1 to 5 were measured by the following method. [128] [129] (1) Sphericity [130] The sphericity of the negative active material for secondary batteries used in Examples and Comparative Examples was measured using a particle analyzer (sysmex FPIA3000, manufactured by Mavern). The sphericity was expressed as an average value of ten sphericity arbitrarily selected from negative active materials for secondary batteries. [131] The degree of sphericity is defined as a value obtained by dividing the circumference of a circle having the same area as the projected image of the negative active material for secondary batteries by the perimeter of the projected image of the negative active material for secondary batteries, and is specifically defined by Equation 1 below. [132] [Equation 1] [133] Sphericity = (Circumference of a circle with the same area as the projected image of the negative active material for secondary batteries)/(The perimeter of the projected image of the negative active material for secondary batteries) [134] [135] (2) tap density [136] The tap density was measured by measuring the final volume obtained by vibrating the anode active material for a secondary battery in a container, and then vibrating it 2,000 times, and calculating the apparent density based on this. [137] [138] (3) Average particle diameter (D 50 ), D max -D min [139] The average particle size (D 50 ) and D max -D min were measured by analyzing the particle size distribution of each of the Examples and Comparative Examples with a particle size distribution measuring device (Mastersizer2000, manufactured by Malvern). [140] [141] Experimental example [142] [143] LiCoO 2 as a positive electrode active material, Li-435 (manufactured by Denka) as a conductive material, KF9700 (manufactured by Kureha) as a binder, and BH-730H (manufactured by Zeon) as a thickener are mixed in a weight ratio of 96.25:1.0:1.5:1.25 and , water was added to prepare a positive electrode slurry, and the positive electrode slurry was applied to aluminum foil, and vacuum dried and rolled at about 130° C. for 8 hours to prepare a positive electrode. At this time, the loading of the positive electrode was prepared to be 3.61 mAh/cm 2 . [144] After interposing a polyolefin separator between each negative electrode and positive electrode prepared in Examples 1 to 7 and Comparative Examples 1 to 5, ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed in a volume ratio of 1:4. Lithium secondary batteries of Examples and Comparative Examples were prepared by injecting an electrolyte in which 1M LiPF 6 was dissolved in an electrolyte solvent, respectively. [145] [146] Experimental Example 1: Swelling evaluation [147] With the lithium secondary batteries of Examples 1 to 7 and Comparative Examples 1 to 5 prepared above in the charging range from SOC 0 to SOC 95, the first cycle is 0.1C, the second cycle is 0.2C, and the third cycle is 30 It was charged and discharged at 0.5C until the second cycle. Then, the swelling ratio was measured by Equation 1 below. [148] [Equation 1] [149] Swelling rate (%) = {(d 2 -d 1 )/d 1 }×100 [150] (d 1 is the thickness of the secondary battery negative electrode before the first charge/discharge cycle is performed, d 2 is the thickness of the secondary battery negative electrode after the 30th charge/discharge cycle is performed) [151] [152] [Table 2] [153] [154] Referring to Table 2, the negative electrode and lithium secondary battery for secondary batteries including the negative active material for secondary batteries of Examples satisfying the tap density, sphericity, and D max -D min range of the present invention have excellent resistance to mechanical stress, and , it can be confirmed that since the reaction area with the electrolyte can be minimized, gas generation and swelling during operation of the cathode are prevented to an excellent level compared to Comparative Examples. [155] [156] Experimental Example 2: Output evaluation [157] The output characteristics of the secondary batteries of Examples 1 to 7 and Comparative Examples 1 to 5 prepared above were evaluated. For output characteristics, the secondary batteries of Examples and Comparative Examples were set to SOC 50 according to a hybrid pulse power characterization (HPPC) test method, and output resistance at room temperature (25° C.) was measured. [158] Specifically, the secondary battery was charged and discharged for 3 cycles at 0.33C under 2.5V discharge and 4.2V charging conditions. After discharging the battery to SOC 50 state, it was charged at 2.5C (10 minutes), paused (30 minutes), discharged at 2.5C (10 minutes), and paused (30 minutes), and the voltage change during charging and discharging at this time The output resistance was measured by dividing the applied current. [159] [160] [Table 3] [161] [162] Referring to Table 3, the negative electrode and lithium secondary battery for secondary batteries including the negative active material for secondary batteries of Examples satisfying the tap density, sphericity, and D max -D min range of the present invention have higher energy density than Comparative Examples and output characteristics. Claims [Claim 1] negative electrode current collector; and a negative active material layer formed on the negative electrode current collector and including a negative active material for secondary batteries, wherein the negative active material for secondary batteries contains natural graphite, has a sphericity of 0.58 to 1, and a tap density of 1.08 g/ cc to 1.32 g/cc, and D max -D min, which is the difference between the maximum particle diameter D max and the minimum particle diameter D min in the particle size distribution, is 16 μm to 19 μm. [Claim 2] The negative electrode for a secondary battery according to claim 1, wherein an average particle diameter (D 50 ) of the negative active material for a secondary battery is 8 μm to 16 μm. [Claim 3] The negative electrode for a secondary battery according to claim 1, wherein the sphericity of the negative active material for a secondary battery is 0.76 to 1. [Claim 4] The negative electrode for a secondary battery according to claim 1, wherein a tap density of the negative active material for a secondary battery is 1.16 g/cc to 1.24 g/cc. [Claim 5] The negative electrode for a secondary battery according to claim 1, wherein in the particle size distribution of the negative active material for a secondary battery , D max -D min, which is a difference between a maximum particle diameter D max and a minimum particle diameter D min , is 17 μm to 18.5 μm. [Claim 6] The negative electrode for a secondary battery according to claim 1, wherein the negative active material for a secondary battery further comprises a carbon coating layer formed on the natural graphite. [Claim 7] The negative electrode for a secondary battery according to claim 6, wherein the carbon coating layer includes soft carbon. [Claim 8] The negative electrode for a secondary battery according to claim 6, wherein the anode active material for a secondary battery comprises 3.5 wt% to 8 wt% of the carbon coating layer. [Claim 9] A negative electrode for a secondary battery according to claim 1; a positive electrode opposite to the negative electrode for the secondary battery; a separator interposed between the negative electrode for the secondary battery and the positive electrode; and an electrolyte; and a lithium secondary battery. [Claim 10] adjusting the particle size distribution of the natural graphite raw material in scale; granulating the flaky natural graphite raw material with the particle size distribution controlled; and controlling the particle size distribution of the granulated natural graphite; wherein the negative active material contains natural graphite, has a sphericity of 0.58 to 1, and a tap density of 1.08 g/cc to 1.32 g/cc, and D max -D min, which is the difference between the maximum particle diameter D max and the minimum particle diameter D min in the particle size distribution, is 16 µm to 19 µm, a method for producing a negative active material for a secondary battery. [Claim 11] The method according to claim 10, further comprising the step of forming a carbon coating layer on the natural graphite after adjusting the particle size distribution of the granulated natural graphite.