KR-20260062730-A - ALL-SOLID RECHARGEABLE BATTERY MANUFACTURING METHOD

KR20260062730AKR 20260062730 AKR20260062730 AKR 20260062730AKR-20260062730-A

Abstract

A method for manufacturing an all-solid-state secondary battery is provided. The method for manufacturing an all-solid-state secondary battery comprises: a first step of preparing an elastic sheet; a second step of preheating the elastic sheet; a third step of preparing unit cells by stacking a positive electrode, a solid electrolyte layer, and a negative electrode; a fourth step of forming a laminate by alternately stacking the unit cells and the elastic sheet within an open case; and a fifth step of welding the case by applying pressure to the laminate.

Inventors

송경선
김백건
조익환
유지완
우창희

Assignees

삼성에스디아이 주식회사

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (16)

Step 1: Preparing the elastic sheet; A second step of preheating the above elastic sheet; A third step of preparing unit cells by stacking an anode, a solid electrolyte layer, and a cathode; A fourth step of forming a laminate by alternately stacking the unit cells and the elastic sheets within an open case; and 5th step of welding the case by applying pressure to the laminate A method for manufacturing an all-solid-state secondary battery including
In paragraph 1, The above second step is A method for manufacturing an all-solid-state secondary battery, wherein the preheating temperature range of the elastic sheet formed from a polymer series is set based on the time of completion of the phase change from glass to rubber.
In paragraph 1, The above second step is A method for manufacturing an all-solid-state secondary battery, wherein the preheating process temperature is set to be greater than the glass transition temperature of the elastic sheet.
In paragraph 1, The above second step is A method for manufacturing an all-solid-state secondary battery by preheating the above elastic sheet and utilizing the fact that the stress of the same compression ratio (strain) is inversely proportional to the temperature.
In paragraph 1, The above second step is A method for manufacturing an all-solid-state secondary battery, which sets the preheating process temperature based on the storage modulus (G) value among the thermal analysis results (Dynamic Mechanical Analyzer) data.
In paragraph 5, In the second step above A method for manufacturing an all-solid-state secondary battery, wherein the glass transition temperature of the elastic sheet is -40 to 70℃.
In paragraph 6, In the second step above A method for manufacturing an all-solid-state secondary battery, wherein the glass transition temperature of the elastic sheet is 0 to 50℃.
In paragraph 5, In the second step above A method for manufacturing an all-solid-state secondary battery, wherein the glass transition temperature serving as the basis for the preheating process temperature is the median value range of the storage modulus inflection section on the thermal analysis (DMA) result graph.
In paragraph 5, In the second step above A method for manufacturing an all-solid-state secondary battery in which, based on the above storage modulus (G'), the ratio (G2'/G1') of the storage modulus (G2') at 70°C to the storage modulus (G1') at 20°C of the elastic sheet is 50% to 90%.
In paragraph 1, The above 5th step is A method for manufacturing an all-solid-state secondary battery, wherein a first bending member and a second bending member, each having three sides of a rectangular prism and three sides open, are welded to form a contact line facing each other to form a case that accommodates a laminated body that is open in both directions and subjected to pressure.
In paragraph 1, The above first step is A method for manufacturing an all-solid-state secondary battery, wherein the elastic sheet is prepared as one of a polyurethane-based, a polyacrylate-based, and a silicone rubber-based material.
Step 1: Preparing the elastic sheet; A second step of preparing unit cells by stacking an anode, a solid electrolyte layer, and a cathode; A third step of forming a laminate by alternately stacking the unit cells and the elastic sheets within an open case; A fourth step of preheating a laminate having the above elastic sheets stacked thereon; and 5th step of welding the case by applying pressure to the laminate A method for manufacturing an all-solid-state secondary battery including
In Paragraph 12, The above fourth step is The preheating process temperature of the laminate including the elastic sheet formed from a polymer series A method for manufacturing an all-solid-state secondary battery, wherein the glass transition temperature of the elastic sheet is set to be greater than and the electrode degradation occurrence temperature is set to be smaller.
In Paragraph 13, In the above fourth step A method for manufacturing an all-solid-state secondary battery, wherein the electrode degradation occurrence temperature is 70℃.
In Paragraph 13, In the above fourth step A method for manufacturing an all-solid-state secondary battery, wherein the temperature at which electrode degradation occurs is the temperature at which the solid electrolyte in the solid electrolyte layer decomposes.
In Paragraph 13, In the above fourth step A method for manufacturing an all-solid-state secondary battery, wherein the first temperature at the point of completion of the phase change from glass to rubber of the above elastic sheet is lower than the second temperature at which the solid electrolyte causes a side reaction.

Description

All-Solid Rechargeable Battery Manufacturing Method The present disclosure relates to a method for manufacturing an all-solid-state secondary battery. Recently, driven by industrial demands, the development of batteries with high energy density and safety is actively underway. For example, lithium-ion batteries are being commercialized not only in the fields of information and communication devices but also in the automotive sector. In the automotive sector, safety is considered particularly important because it is directly related to human life. Currently commercially available lithium-ion batteries use electrolytes containing flammable organic solvents, so there is a possibility of overheating and fire in the event of a short circuit. In response to this, all-solid-state secondary batteries using solid electrolytes instead of liquid electrolytes are being proposed. All-solid-state secondary batteries can significantly reduce the likelihood of fire or explosion in the event of a short circuit by not using flammable organic solvents. Therefore, these all-solid-state batteries can offer significantly higher safety compared to lithium-ion batteries that use liquid electrolytes. The information described above, disclosed in the background technology of this invention, is intended only to enhance understanding of the background of this disclosure and may therefore include information that does not constitute prior art. FIG. 1 is a cross-sectional view showing an all-solid-state secondary battery according to one embodiment. FIG. 2 is a cross-sectional view showing the formation of a lithium metal layer of an all-solid-state secondary battery according to one embodiment. FIG. 3 is a flowchart of a method for manufacturing an all-solid-state secondary battery according to a first embodiment of the present invention. Figure 4 is a cross-sectional view showing the step of preheating an elastic sheet. Figure 5 is a cross-sectional view showing the step of preparing a unit cell. FIG. 6 is a cross-sectional view showing the step of forming a laminate by alternately stacking unit cells and elastic sheets in an open case. FIG. 7 is a cross-sectional view showing the step of pressing an open case and a laminate. FIG. 8 is a cross-sectional view showing the step of welding a case containing a pressurized laminate. FIG. 9 is a flowchart of a method for manufacturing an all-solid-state secondary battery according to a second embodiment of the present invention. FIG. 10 is a cross-sectional view showing the step of forming a laminate by alternately stacking unit cells and elastic sheets in an open case and preheating the laminate. Figure 11 is a graph showing the relationship between the compression ratio (Strain) and the load magnitude (Stress) for the elastic sheets of the first to third experimental examples. Figure 12 is a graph showing the relationship between the temperature and storage modulus of the thermal analysis results (DMA) for the elastic sheets of the 4th and 5th experimental examples as measured values. Figure 13 is a graph showing the relationship between the temperature and storage modulus of the thermal analysis (DMA) results for the elastic sheet of the 6th experimental example on a logarithmic scale. Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. In the drawings, thicknesses have been enlarged to clearly represent various layers and regions, and the same reference numerals have been used for similar parts throughout the specification. When a part such as a layer, film, region, or plate is described as being "on" or "on" another part, this includes not only cases where it is "immediately on" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately on" another part, it means that there is no other part in between. In addition, the term "layer" here includes not only shapes formed on the entire surface when viewed in a plan view, but also shapes formed on some surfaces. Here, "or" is not interpreted in an exclusive sense, and for example, "A or B" is interpreted to include A, B, A+B, etc. cathode for all-solid-state secondary batteries In one embodiment, a positive electrode for an all-solid-state secondary battery is provided, comprising a current collector and a positive active material layer located on the current collector, wherein the positive active material layer comprises at least one of a positive active material, a sulfide-based solid e