Electrode manufacturing method

Abstract

This technology provides a way to suppress the collapse of electrode active materials that have been oriented by a magnetic field. [Solution] The method for manufacturing the electrode involves adding a slurry-like electrode material containing an electrode active material at a concentration of 30 mg / cm³. 2 The method comprises a first step of applying a magnetic field to the electrode material without heating it while it is in the state described above, and a second step of drying the electrode material by heating it while continuously applying the magnetic field to it from the first step.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a method for manufacturing an electrode.

Background Art

[0002] Patent Document 1 discloses a magnetic field orientation method. In the magnetic field orientation method of Patent Document 1, after applying a magnetic paint mainly composed of magnetic powder and a binder on a traveling non-magnetic support, the magnetic paint is dried using a drying device and the magnetic powder is oriented. In the magnetic field orientation method of Patent Document 1, after applying the magnetic paint, before drying the magnetic paint by the drying device, first magnetic field orientation is performed by a first magnetic field generating means, and then, in the drying device, second magnetic field orientation is performed by a second magnetic field generating means.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the magnetic field orientation method of Patent Document 1, since there is a period during which no magnetic field orientation is performed on the magnetic paint between the first magnetic field orientation and the second magnetic field orientation, the orientation of the magnetic powder is disturbed during this period, and there is a problem that the magnetic powder in the magnetic paint falls down.

[0005] This specification provides a technology capable of suppressing the falling of an electrode active material oriented by a magnetic field.

Means for Solving the Problems

[0006] In the first aspect of this technology, a method for manufacturing an electrode includes a slurry-like electrode material containing an electrode active material at 30 mg / cm 2The method comprises a first step of applying a magnetic field to the electrode material without heating it while it is in the state described above, and a second step of drying the electrode material by heating it while the magnetic field is continuously applied to it from the first step.

[0007] With this configuration, by continuously applying a magnetic field to the electrode material in the first and second steps, the application of the magnetic field is not interrupted between the first and second steps. Therefore, the orientation of the electrode active material contained in the electrode material is not disturbed, and the deformation of the electrode active material, which is oriented by the magnetic field, can be suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram illustrating the manufacturing method of the electrode in the example. [Figure 2] A diagram showing the test results of a sample test. [Modes for carrying out the invention]

[0009] The method for manufacturing the electrode in the embodiment will be described with reference to the drawings. As shown in Figure 1, the method for manufacturing the electrode in the embodiment is a method for manufacturing an electrode 12 from an electrode material 10 using an electrode manufacturing apparatus 100.

[0010] First, let's describe the electrode manufacturing apparatus 100. The electrode manufacturing apparatus 100 includes a transport device 40 for transporting the electrode material 10, a magnet 32 ​​for applying a magnetic field to the electrode material 10, and a heating furnace 30 for heating the electrode material 10.

[0011] The conveying device 40 conveys the electrode material 10 from the upstream side (left side in Figure 1) to the downstream side (right side in Figure 1). The conveying device 40 is equipped with support means (not shown) for supporting the electrode material 10. The support means of the conveying device 40 may be, for example, a roller conveyor or a belt conveyor. In a modified example, the support means of the conveying device 40 may be configured to support the electrode material 10 by gas pressure.

[0012] The magnet 32 ​​generates a magnetic field to be applied to the electrode material 10. The magnet 32 ​​is positioned from outside the heating furnace 30 to inside the heating furnace 30. The magnet 32 ​​generates a magnetic field both outside and inside the heating furnace 30. The magnet 32 ​​is, for example, a permanent magnet or an electromagnet.

[0013] The heating furnace 30 heats the electrode material 10 that is transported by the transport device 40. The heating furnace 30 dries the electrode material 10 by heating it. The heating temperature of the heating furnace 30 can be set as appropriate. The heating furnace 30 is equipped with, for example, a heat gun or a hot plate.

[0014] Next, the electrode material 10 will be described. The electrode material 10 in the example includes, for example, an electrode active material for the negative electrode or the positive electrode. The electrode material 10 may also contain resin or the like. The electrode material 10 may also contain additives or binders. The electrode active material for the negative electrode included in the electrode material 10 is, for example, graphite, carbon nanotubes, etc. The electrode active material for the positive electrode is, for example, a metal oxide containing lithium ions, etc.

[0015] The electrode material 10 is in a slurry state before being heated by the heating furnace 30, and becomes a solid electrode 12 after being heated by the heating furnace 30. The electrode material 10 becomes a solid electrode 12 by drying through heating in the heating furnace 30.

[0016] Next, a method for manufacturing electrodes will be described. The electrode manufacturing method in the example comprises a coating step, a non-heating application step, and a heating application step.

[0017] (Coating process) In the coating process, a slurry-like electrode material 10 is applied in a thin layer. More specifically, the slurry-like electrode material 10 is applied at a rate of 30 mg / cm³. 2 The above basis weight is used. The thickness of the electrode material 10 when coating can be set as appropriate. The thickness of the electrode material 10 is set according to the thickness of the electrode 12 to be manufactured. The electrode material 10 is coated thinly using, for example, an applicator, coater, or squeegee (not shown).

[0018] (Non-heating application process) In the non-heating application process, a magnetic field generated by the magnet 32 is applied to the electrode material 10 coated by the above coating process. Also, in the non-heating application process, the electrode material 10 is not heated. The non-heating application process is carried out outside the heating furnace 30. In the non-heating application process, a magnetic field is applied to the electrode material 10 by the magnet 32 outside the heating furnace 30 while the electrode material 10 is not heated in the heating furnace 30. The time of the non-heating application process is, for example, about 2 seconds to 25 seconds.

[0019] (Heating application process) In the heating application process, a magnetic field generated by the magnet 32 is continuously applied to the electrode material 10 following the above non-heating application process. In the heating application process, a magnetic field by the magnet 32 is continuously applied to the electrode material 10 from the non-heating application process. The application of the magnetic field to the electrode material 10 is not interrupted between the heating application process and the non-heating application process.

[0020] Also, in the heating application process, the electrode material 10 is heated by the heating furnace 30 while a magnetic field is applied to the electrode material 10. The heating application process is carried out inside the heating furnace 30. In the heating application process, a magnetic field is applied to the electrode material 10 by the magnet 32 inside the heating furnace 30. The heating temperature of the electrode material 10 in the heating application process can be set as appropriate. For example, in the heating application process, the electrode material 10 is heated at an ambient temperature of 200 °C or higher.

[0021] The configuration of the embodiment has been described above. As is clear from the above description, the method for manufacturing the electrode of the embodiment includes a non-heating application process (an example of the first step) in which a magnetic field is applied to the electrode material 10 in a state where the slurry-like electrode material 10 containing the electrode active material has a basis weight of 30 mg / cm 2 without heating the electrode material 10, and a heating application process (an example of the second step) in which the electrode material 10 is dried by heating the electrode material 10 while continuously applying a magnetic field to the electrode material 10 from the non-heating application process.

[0022] With this configuration, by continuously applying a magnetic field to the electrode material 10 in both the non-heating application step and the heating application step, the application of the magnetic field is not interrupted between the two steps. Therefore, the orientation of the electrode active material contained in the electrode material 10 is not disturbed, and the deformation of the electrode active material oriented by the magnetic field is suppressed.

[0023] (Example test) The tests were conducted using the electrode manufacturing method described above. Test Examples 1-4 were used in these tests. In Test Example 1-4, the main component of the electrode active material contained in electrode material 10 was graphite. Electrode material 10 in Test Example 1-4 contains graphite, CNTs, CMC, SBR, and laponite.

[0024] In Test Examples 1 and 2, the basis weight of the electrode material 10 was set to 30 mg / cm² before heating. 2 In Test Example 1, the heating temperature of the electrode material 10 in the heating furnace 30 was set to 200°C. In Test Example 2, the heating temperature of the electrode material 10 in the heating furnace 30 was set to 100°C.

[0025] In Test Examples 3 and 4, the basis weight of the electrode material 10 was set to 10 mg / cm² before heating. 2 In Test Example 3, the heating temperature of the electrode material 10 in the heating furnace 30 was set to 200°C. In Test Example 4, the heating temperature of the electrode material 10 in the heating furnace 30 was set to 100°C.

[0026] For Test Examples 1-4, the degree of orientation of the electrode active material in electrode 12 manufactured by the electrode manufacturing method described above was measured by X-ray diffraction. The degree of orientation of the electrode active material was defined as the ratio of the integrated intensities of the peaks originating from graphite (002) and graphite (110) that appear around 2θ = 26.5° and 77.5° (110) / (002).

[0027] The test results for Test Examples 1-4 are shown in Figure 2. As shown in Figure 2, in Test Example 1, the degree of orientation of the electrode active material in the electrode 12 manufactured by the electrode manufacturing method described above was 0.09 or higher. In Test Example 2, this degree of orientation was 0.06 or higher and less than 0.07. In Test Example 3, this degree of orientation was 0.05 or higher and less than 0.06. In Test Example 4, this degree of orientation was less than 0.05. As shown in Figure 2, it was confirmed that the degree of orientation of the electrode active material in the electrode 12 of Test Example 1 was the highest.

[0028] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of symbols]

[0029] 10: Electrode material 12: Electrode 30:Heating furnace 32: Magnet 40: Conveyor equipment 100: Electrode manufacturing equipment

Claims

[Claim 1] 30 mg / cm³ of slurry-like electrode material containing electrode active material ２ The first step involves applying a magnetic field to the electrode material without heating it while it is in the state described above, A method for manufacturing an electrode, comprising: a second step of drying the electrode material by heating it while continuously applying the magnetic field to the electrode material from the first step.

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