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KR-102962294-B1 - Method for manufacturing negative electrode for lithium secondary battery, and negative electrode for lithium secondary battery

KR102962294B1KR 102962294 B1KR102962294 B1KR 102962294B1KR-102962294-B1

Abstract

The present invention relates to a method for manufacturing a negative electrode for a lithium secondary battery, a negative electrode for a lithium secondary battery manufactured by the method, and a lithium-air battery comprising the negative electrode for a lithium secondary battery. Since the method for manufacturing a negative electrode for a lithium secondary battery according to the present invention allows for the uniform formation of a protective film (Solid electrolyte interphase; SEI) on a metal layer, when the negative electrode for a lithium secondary battery manufactured thereby is applied to a lithium-air battery, side reactions between the positive active electrolyte and the metal layer can be suppressed, thereby improving reversibility. Consequently, battery performance can be improved by increasing battery life without reducing initial efficiency.

Inventors

  • 오광석

Assignees

  • 현대자동차주식회사
  • 기아 주식회사

Dates

Publication Date
20260507
Application Date
20201014

Claims (14)

  1. A step of preparing a working electrode comprising a resistive layer and a metal layer; Step of preparing a stable electrolyte in a metal layer; A step of preparing a half-cell comprising the above-mentioned working electrode, reference electrode, counter electrode, and electrolyte; A step of driving the above half-battery to remove the resistance layer; A step of forming a protective film (Solid electrolyte interphase; SEI) on the metal layer through a reaction between the metal and the electrolyte within the metal layer; and A method for manufacturing a negative electrode for a lithium-air battery, comprising the step of separating a metal layer having the above-mentioned protective film (SEI) formed thereon from a half-cell to obtain a negative electrode.
  2. In paragraph 1, The above metal layer is a method for manufacturing a negative electrode for a lithium-air battery containing lithium (Li).
  3. In paragraph 1, A method for manufacturing a negative electrode for a lithium-air battery , wherein the above-mentioned resistive layer comprises one or more selected from the group consisting of Li₂CO₃ , LiO₂ , and LiOH.
  4. In paragraph 1, The above electrolyte is in one or more organic solvents selected from the group consisting of dimethyl ether (DME), fluoroethylene carbonate, TEGDME (Tetraethylene glycol dimethyl ether), and TFOFE (2,2,2-Trifluoroethanol); A method for manufacturing a negative electrode for a lithium-air battery by adding one or more lithium salts selected from the group consisting of LiFSI, LiNO3 , LITFSI, LiDFBP, and LiPO2F2 .
  5. In paragraph 4, A method for manufacturing a negative electrode for a lithium-air battery, wherein the concentration of the electrolyte is 1 to 4 M.
  6. In paragraph 1, A method for manufacturing a negative electrode for a lithium secondary battery, wherein the above-mentioned half-cell is driven at a current density of 0.1 to 2.0 mA/ cm² .
  7. In paragraph 1, A method for manufacturing a negative electrode for a lithium-air battery, wherein the above-mentioned half-cell is driven so that lithium ions (Li + ) move to the counter electrode and remove the resistance layer.
  8. In paragraph 1, A method for manufacturing a negative electrode for a lithium-air battery, wherein the protective film (SEI) is uniformly formed on the metal layer.
  9. In paragraph 1, A method for manufacturing a negative electrode for a lithium-air battery, wherein the above protective film (SEI) comprises one or more selected from the group consisting of LiF and Li₃N .
  10. In paragraph 1, A method for manufacturing a negative electrode for a lithium-air battery, wherein a protective film (SEI) is formed on the metal layer, and then the metal layer on which the protective film (SEI) is formed is separated from the half-cell after 2 to 6 hours.
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Description

Method for manufacturing negative electrode for lithium secondary battery, and negative electrode for lithium secondary battery The present invention relates to a method for manufacturing a highly durable negative electrode for a lithium-air battery, and a negative electrode for a lithium-air battery manufactured according to the same. We are currently facing various problems resulting from rapid economic growth, such as the depletion of fossil fuels, environmental pollution, and global warming. Although we are developing new and renewable energy sources as a countermeasure, we have not yet achieved significant results. Consequently, interest in energy storage technologies, particularly in the field of batteries, is surging. As a result, remarkable progress has been made in lithium-ion batteries, but the lithium-ion batteries developed to date are considered insufficient to replace fossil fuels due to their low energy density. Accordingly, the development of metal-air batteries, particularly lithium-air batteries, has recently been actively underway, centered around developed countries such as the United States and Japan. Lithium-air batteries use oxygen, which can be supplied indefinitely from the air, as an active material. Therefore, theoretically, a very high energy density can be achieved. Calculating the theoretical energy density of a lithium-air battery yields approximately 3,200 Wh/kg, which is about 10 times higher than that of a lithium-ion battery. Additionally, since oxygen is used as an active material, it has the advantage of being environmentally friendly. However, lithium-air batteries use an electrolyte containing a highly soluble polar solvent to easily dissolve products generated at the cathode. Since the negative electrode in the lithium-air battery undergoes deterioration due to side reactions caused by reduction with the electrolyte, there are problems such as reduced initial efficiency and performance degradation. Figure 1 is a figure showing the formation of a protective film on a lithium metal negative electrode in a lithium-air battery using deposition equipment, etc., according to the prior art. FIG. 2 is a simplified flowchart illustrating a method for manufacturing a negative electrode for a lithium-air battery according to one embodiment of the present invention. Figure 3 is a graph showing the resistance value of the negative electrode for a lithium-air battery according to Experimental Example 1. Figure 4 is a graph showing the resistance value of the negative electrode for a lithium-air battery according to Experimental Example 1 over time. The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the invention is sufficiently conveyed to a person skilled in the art. In this specification, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "immediately above" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "immediately below" the other part, but also the case where there is another part in between. Unless otherwise specified, all numbers, values, and/or expressions used herein to represent amounts of ingredients, reaction conditions, polymer compositions, and formulations should be understood to be modified by the term “approximately” in all cases, as these numbers are essentially approximations reflecting the various uncertainties of measurement that occur in obtaining these values among other things. Furthermore, where numerical ranges are disclosed herein, such ranges are continuous and, unless otherwise indicated, include all values from the minimum value of such range to the maximum value including said maximum value. Moreover, where such ranges refer to integers, they include all integers from the minimum value to said maximum value including said maximum value, unless otherwise indicated. In this specification, where a range is described for a variable, it will be understood that the variable includes all values within the described range,