Electrode for electrochemical element and method for manufacturing the same

Abstract

One aspect of the present invention aims to provide an electrode that maintains a predetermined level of adhesive strength while reducing the interfacial resistance of the electrode, a method for manufacturing the same, and an electrochemical element including the same. One feature of the electrode according to one aspect of the present invention is that it is manufactured by providing an adhesive layer on an electrode film and then attaching it to a current collector, thereby improving the adhesion between the adhesive layer and the electrode film and reducing the interfacial resistance between the current collector and the electrode.

Claims

1. A self-supporting electrode film comprising an electrode active material and a fibrous electrode binder, wherein the electrode active material is bound by the fibrous electrode binder, The electrode film comprises an adhesive layer formed on at least a portion of at least one surface of the electrode film, which includes an adhesive binder. The adhesive layer comprises an adhesive layer forming portion where clusters of the adhesive binder are formed, and a non-adhesive layer forming portion where one surface of the electrode film is exposed to the outside, and is a preliminary electrode.

2. The opening ratio of the adhesive layer based on the following formula 1 is 25% or less, [Formula 1] Opening ratio (%) = A Ｏ / A Ｃ ×100 In the above formula 1, A Ｏ This indicates the area of ​​the portion where the adhesive layer is not formed. A Ｃ The preliminary electrode according to claim 1, wherein indicates the area of ​​the adhesive layer forming portion.

3. The preliminary electrode according to claim 2, wherein the aperture ratio is 5% to 25%.

4. The preliminary electrode according to claim 2, wherein the aperture ratio is 10% to 15%.

5. The surface of the electrode film includes at least one pore that is recessed inward towards the electrode film. The preliminary electrode according to claim 1, wherein at least one of the pores contains the adhesive binder.

6. Current collector and, A self-supporting electrode film is formed on at least one surface of the current collector and comprises an electrode active material and a fibrous electrode binder, wherein the electrode active material is bound by the fibrous electrode binder. The current collector and the electrode film are provided with an adhesive layer containing an adhesive binder, The interfacial resistance between the current collector and the electrode film is 0.1 Ω·cm. ２ The electrodes are as follows.

7. The electrode according to claim 6, wherein the adhesive strength between the current collector and the electrode film is 15 gf / 2 cm or more.

8. The electrode according to claim 6, wherein the adhesive layer includes an adhesive layer forming portion on which clusters of the adhesive binder are formed, and an adhesive layer non-forming portion on which one surface of the electrode film is exposed to the outside.

9. The opening ratio of the adhesive layer based on the following formula 1 is 25% or less, [Formula 1] Opening ratio (%) = A Ｏ / A Ｃ ×100 In the above formula 1, A Ｏ This indicates the area of ​​the portion where the adhesive layer is not formed. A Ｃ The electrode according to claim 8, wherein Ｃ represents the area of the adhesive layer forming portion.

10. The process includes the step of forming an adhesive layer on at least a portion of at least one surface of a self-supporting electrode film comprising an electrode active material and a fibrous electrode binder, wherein the electrode active material is bound by the fibrous electrode binder. A method for manufacturing an electrode, wherein the adhesive layer is formed to include an adhesive layer forming portion where clusters of adhesive binder are formed, and an adhesive layer non-forming portion where one surface of the electrode film is exposed to the outside.

11. The adhesive layer is formed such that the opening ratio of the adhesive layer is 25% or less, based on the following formula 1. [Formula 1] Opening ratio (%) = A Ｏ / A Ｃ ×100 In the above formula 1, A Ｏ This indicates the area of ​​the portion where the adhesive layer is not formed. A Ｃ The method for manufacturing an electrode according to claim 10, wherein indicates the area of ​​the adhesive layer forming portion.

12. The method for manufacturing an electrode according to claim 10, further comprising the step of attaching a current collector to one surface of the electrode film on which the adhesive layer is formed, so as to face the adhesive layer.

13. The method for manufacturing an electrode according to claim 10, wherein the step of forming the adhesive layer is performed by a non-contact coating method.

14. The adhesive layer is formed using an adhesive layer-forming composition containing the adhesive binder. The method for manufacturing an electrode according to claim 10, wherein the viscosity of the adhesive layer forming composition is 500 cP or less at 25°C.

15. An electrochemical element comprising a positive electrode, a negative electrode, and a separator sandwiched between the positive electrode and the negative electrode, wherein at least one of the positive electrode and the negative electrode is an electrode according to any one of claims 6 to 9.

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