Technical Field [4] The present invention relates to a method of evaluating the quality of an electrode by a simple means of measuring a color coordinate value of the electrode before roll-pressing and a method of manufacturing an electrode including evaluating the quality of the electrode thereby. 15 Background Art [5] Adhesion, thickness, and loading amount are some of the commonly known electrode quality inspection items. Among these electrode quality inspection items, adhesion is an item for filtering out electrodes detached in an electrode assembly 20 process, electrodes peeled off in the activation process, and the like, and is a very important quality inspection item. [6] However, there are problems in that the adhesion of an electrode can only be evaluated after roll-pressing, and electrode quality cannot be evaluated in real time. [7] Therefore, there is a need to develop a method capable of evaluating electrode 25 quality by evaluating properties before roll-pressing. 3 Disclosure Technical Problem [8] The present invention is directed to providing a method of evaluating 5 electrode quality which is capable of filtering out defective electrodes before rollpressing by the simple means of measuring a color coordinate value of electrodes before roll-pressing. Technical Solution 10 [9] One aspect of the present invention provides a method of evaluating electrode quality capable of simply and quickly filtering out defective electrodes by measuring a color coordinate value of electrodes before roll-pressing, which specifically includes: providing an electrode which includes a current collector and an active material layer formed on the current collector and has not been roll-pressed; measuring a color 15 coordinate value of the active material layer using an optical instrument; and evaluating the electrode as a good product when the measured color coordinate value satisfies a predetermined electrode quality evaluation criterion and as defective when the measured color coordinate value does not satisfy the predetermined electrode quality evaluation criterion. 20 [10] Another aspect of the present invention includes a method of manufacturing an electrode, which includes: forming an active material layer by applying a slurry including an active material, a conductive material, and a binder onto a current collector and drying, and thus manufacturing an electrode which has not been rollpressed; evaluating the quality of the electrode by the above-described method; and 25 roll-pressing an electrode evaluated as a good product. 4 Advantageous Effects [11] A method of evaluating electrode quality according to the present invention is capable of simply and quickly filtering out defective electrodes by measuring a color 5 coordinate value of electrodes before roll-pressing. That is, it is possible to filter out defective electrodes even before roll-pressing, and therefore, it is possible to significantly reduce a defect rate of finished electrode products. [12] In addition, according to the present invention, it is possible to predict adhesion, which is a property attained after roll-pressing, by the simple means of 10 measuring a color coordinate value before roll-pressing. Best Mode of the Invention [13] Terms and words used in this specification and the claims should not be interpreted as being limited to commonly used meanings or meanings in dictionaries, 15 and, based on the principle that the inventors can appropriately define concepts of terms in order to describe their invention in the best way, the terms and words should be interpreted with meanings and concepts which are consistent with the technical spirit of the present invention. [14] It will be understood that terms such as “comprises,” “comprising,” “includes,” 20 “including,” “has” or “having,” when used in the present specification, specify the presence of stated features, numbers, steps, components, or combinations thereof and do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. 25 [15] Hereinafter, the present invention will be described in detail. 5 [16] [17] A method of evaluating electrode quality according to the present invention is an electrode quality evaluation method capable of simply and quickly filtering out 5 defective electrodes by measuring a color coordinate value of an electrode before rollpressing, and the method specifically includes: providing an electrode which includes a current collector and an active material layer formed on the current collector and has not been roll-pressed; measuring a color coordinate value of the active material layer using an optical instrument; and evaluating the electrode as a good product when the 10 measured color coordinate value satisfies a predetermined electrode quality evaluation criterion and as defective when the measured color coordinate value does not satisfy the predetermined electrode quality evaluation criterion. [18] When a color coordinate value of an active material layer of an electrode 15 which has not been roll-pressed is measured using the optical instrument as described above and satisfies a predetermined electrode quality evaluation criterion, after the electrode is roll-pressed, since the adhesion between a current collector and an active material layer is excellent, an adhesion defect may not occur. For example, when an electrode classified as a good product according to the present invention is roll-pressed, 20 an adhesive strength of 40 gf/20 mm or more can be secured between a current collector and an active material layer of the electrode. [19] According to the present invention, it is possible to predict adhesion, which is a property attained after roll-pressing, by the simple means of measuring a color coordinate value before roll-pressing and filter out defective electrodes before roll25 pressing. That is, it is possible to filter out defective electrodes even before roll- 6 pressing, and therefore, it is possible to significantly reduce a defect rate of finished electrode products. [20] Hereinafter, each step of the method of evaluating electrode quality according 5 to the present invention will be described in more detail. [21] Provision of electrode which has not been roll-pressed [22] The present invention includes a step of providing an electrode which includes a current collector and an active material layer formed on the current collector and has 10 not been roll-pressed. [23] The present invention does not evaluate electrodes that have been roll-pressed as in conventional electrode quality evaluation but evaluates the quality of battery electrodes that have not been roll-pressed, so defective electrodes can be filtered out before roll-pressing, and a defect rate after roll-pressing can be significantly reduced. 15 [24] Measurement of color coordinate value of active material layer of electrode [25] The present invention includes a step of measuring a color coordinate value of the active material layer using an optical instrument. 20 [26] The optical instrument is an instrument including a light source and an image sensor, and when an active material layer of each of the electrodes is analyzed using the optical instrument, color information from the surface of the active material layer of each of the electrodes is converted into color coordinate values and detected. The image sensor is a device capable of converting incoming light into an electrical signal 25 and may be, for example, a charge coupled device (CCD) sensor or a complementary 7 metal-oxide-semiconductor (CMOS) sensor. [27] According to the present invention, the optical instrument may be a spectrophotometer or a colorimeter. [28] The color coordinate value collectively refers to numerical values expressed 5 as coordinates in a three-dimensional color space, and, for example, the color coordinate value may be an L* value, an a* value, or a whiteness value. [29] According to the present invention, the color coordinate value of an active material layer may be measured by a contact colorimeter or a non-contact colorimeter. That is, the colorimeter may be a contact colorimeter or a non-contact colorimeter. 10 In the case of using a non-contact colorimeter, since measurement is possible without direct contact with a sample, measurement is convenient, and measurement can be performed in a continuous manufacturing process. [30] The color coordinate value of an active material layer may be measured, for example, using a CM2600d colorimeter manufactured by Konica Minolta, Inc. 15 Specifically, the color coordinate value may be measured using a CM2600d colorimeter manufactured by Konica Minolta, Inc., by setting the measurement mode to Specular Component Included (SCI) or Specular Component Excluded (SCE) and selecting a D65 standard light source (color temperature: 6,500 K) and the CIE 1976 10° standard observer, performing white correction, and then bringing the colorimeter 20 into contact with a location to be measured. [31] Evaluation of electrode as good or defective through comparison of measured color coordinate value with predetermined electrode quality evaluation criterion 25 [32] The present invention includes a step of evaluating the electrode as a good 8 product when the measured color coordinate value satisfies a predetermined electrode quality evaluation criterion and as defective when the measured color coordinate value does not satisfy the predetermined electrode quality evaluation criterion. [33] When the measured color coordinate value satisfies the predetermined 5 electrode quality evaluation criterion, since excellent adhesion between a current collector and an active material layer can be secured after roll-pressing, a defect rate of an electrode which has been roll-pressed can be significantly reduced. [34] According to the present invention, when the color coordinate value is an L* value, the predetermined electrode quality evaluation criterion for the L* 10 value may be 35.4 or more and preferably 35.4 or more and 40 or less. [35] According to the present invention, when the color coordinate value is an a* value, the predetermined electrode quality evaluation criterion for the a* value may be 0.78 or more and preferably 0.78 or more and 0.96 or less. 15 [36] According to the present invention, when the color coordinate value is a whiteness value, the predetermined electrode quality evaluation criterion for the whiteness value may be 7 or more and preferably 7 or more and 9 or less. [37] This is because only when the L* , a* , and whiteness values satisfy the predetermined electrode quality evaluation criteria ranges described above, can 20 excellent adhesion between a current collector and an active material layer be secured after roll-pressing, and thus a defect rate of finished electrode products be significantly reduced. [38] An electrode which is classified as a good product as a result of the above25 described comparison because the measured color coordinate value satisfies the 9 predetermined electrode evaluation criterion may have excellent electrode quality after roll-pressing. Specifically, an electrode classified as a good product according to the electrode quality evaluation method of the present invention may exhibit excellent adhesion between a current collector and an active material layer after roll-pressing. 5 For example, an adhesive strength of 40 gf/20 mm or more can be secured between a current collector and an active material layer. [39] [40] A method of manufacturing an electrode according to the present invention 10 includes: forming an active material layer by applying a slurry including an active material, a conductive material, and a binder onto a current collector and drying, and thus manufacturing an electrode which has not been roll-pressed; evaluating the quality of the electrode by the above-described method; and roll-pressing an electrode evaluated as a good product. 15 [41] Hereinafter, each step of the method of manufacturing an electrode according to the present invention will be described in more detail. [42] Manufacture of electrode which has not been roll-pressed 20 [43] The present invention includes a step of forming an active material layer by applying a slurry including an active material, a conductive material, and a binder onto a current collector and drying, and thus manufacturing an electrode which has not been roll-pressed. The active material layer may be formed on one or both sides of the current collector. 25 10 [44] The current collector is not particularly limited as long as it does not cause a chemical change in a battery and has conductivity, and in the case of a positive electrode current collector, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, aluminum or stainless steel whose surface has been treated with 5 carbon, nickel, titanium, silver, or the like may be used, and in the case of a negative electrode current collector, for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel whose surface has been treated with carbon, nickel, titanium, silver, or the like, an aluminum-cadmium alloy, or the like may be used. 10 [45] The current collector may typically have a thickness of 3 μm to 500 μm and may have fine irregularities formed in a surface thereof to increase the adhesion of a positive electrode material or a negative electrode material. For example, the current collector may be used in any of various forms such as a film, a sheet, a foil, a net, a porous material, a foam, a non-woven fabric, and the like. 15 [46] The slurry may be prepared by dissolving or dispersing an active material, a conductive material, and a binder in a solvent. [47] When the active material is a positive electrode active material, the positive electrode active material is a compound enabling the reversible intercalation and 20 deintercalation of lithium and, specifically, may include a lithium composite metal oxide including lithium and one or more transition metals such as cobalt, manganese, nickel, or aluminum. More specifically, the lithium composite metal oxide may be a lithium-manganese-based oxide (e.g., LiMnO2, LiMn2O4, etc.), a lithium-cobalt-based oxide (e.g., LiCoO2, etc.), a lithium-nickel-based oxide (e.g., LiNiO2, etc.), a lithium25 nickel-manganese-based oxide (e.g., LiNi1-YMnYO2 (0