KR-20260062203-A - ANODELESS ALL SOLID STATE BATTERY AND MANUFACTURING METHOD THEREOF

KR20260062203AKR 20260062203 AKR20260062203 AKR 20260062203AKR-20260062203-A

Abstract

The present invention relates to a cathode-free all-solid-state battery using a negative electrode current collector coated with a metal sulfide layer and a method for manufacturing the same. The anode-free all-solid-state battery according to the present invention is characterized by comprising the following structure in a charged state: Cathode current collector; A lithium alloy layer located on the above-mentioned negative current collector; A lithium sulfide layer located on the above lithium alloy layer; A solid electrolyte layer located on the lithium sulfide layer; and Anode located on the solid electrolyte layer above.

Inventors

조우석
유지상
김경수
최승호

Assignees

한국전자기술연구원

Dates

Publication Date: 20260507
Application Date: 20241025

Claims (13)

A non-cathode all-solid-state battery comprising the following structure in a charged state: Cathode current collector; A lithium alloy layer located on the above-mentioned negative current collector; A lithium sulfide layer located on the above lithium alloy layer; A solid electrolyte layer located on the lithium sulfide layer; and Anode located on the solid electrolyte layer above.
In paragraph 1, A non-cathode all-solid-state battery in which the above lithium alloy layer and lithium sulfide layer are separated into layers by converting a metal sulfide layer.
In paragraph 1, The above metal sulfide layer is a non-cathode all-solid-state battery containing Ag₂S .
In paragraph 1, The above lithium alloy layer is a non-cathode all-solid-state battery comprising Li and Ag.
In paragraph 1, The above solid electrolyte layer comprises one or more types of sulfide-based solid electrolytes and oxide-based solid electrolytes, in a non-cathode all-solid-state battery.
In paragraph 1, The above anode A negative electrode all-solid-state battery comprising a positive current collector and a positive material disposed on at least one surface of the positive current collector.
In paragraph 1, The above-mentioned cathode material is a non-anode all-solid-state battery comprising one or more cathode active materials selected from lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese oxide, lithium manganese oxide, and lithium iron phosphate oxide.
(a) A step of providing a negative current collector coated with a metal layer; (b) a step of manufacturing a cathode current collector coated with a metal sulfide layer by impregnating the above cathode current collector with an aqueous sodium sulfide ( Na₂S ) solution; and (c) a step of manufacturing a non-anode all-solid-state battery by stacking a solid electrolyte layer and an anode on the metal sulfide layer; comprising, A method for manufacturing a non-cathode all-solid-state battery by charging the above-mentioned non-cathode all-solid-state battery to convert the metal sulfide layer into a lithium alloy layer located on a negative electrode current collector and a lithium sulfide layer located on the lithium alloy layer.
In paragraph 8, A method for manufacturing a non-cathode all-solid-state battery in which the metal layer of step (a) above contains Ag.
In paragraph 8, A method for manufacturing a non-cathode all-solid-state battery in which the above lithium alloy layer comprises Li and Ag.
In paragraph 8, A method for manufacturing a non-anode all-solid-state battery in which the impregnation of step (b) above is performed for 24 hours or more.
In paragraph 8, A method for manufacturing a non-anode all-solid-state battery in which the above-mentioned solid electrolyte layer comprises one or more of a sulfide-based solid electrolyte and an oxide-based solid electrolyte.
In paragraph 8, The above anode A method for manufacturing a non-anode all-solid-state battery comprising a positive current collector and a positive material disposed on at least one surface of the positive current collector.

Description

Anodeless all-solid-state battery and manufacturing method thereof The present invention relates to a cathode-free all-solid-state battery using a negative electrode current collector coated with a metal sulfide layer and a method for manufacturing the same. All-solid-state batteries based on lithium precipitation reactions can achieve significantly improved energy density by simplifying the battery structure through the minimization of anode material. It is a charging reaction in which lithium ions generated from the positive electrode during charging undergo a reduction reaction on the surface of the negative electrode current collector and are stored in the form of lithium metal. However, during the charging process, the growth of lithium metal dendrites occurs, which causes an internal short circuit in the battery. Electrochemical reactions between lithium ions and electrons at the interface between the lithium-inactive current collector and the solid electrolyte, where there is physical contact, cause localized lithium growth. To ensure long-life battery performance, lithium deposition must occur uniformly between the electrolyte and the current collector, rather than within the electrolyte. Cu, Ni, and SUS, which are generally used as cathode current collectors, are characterized by high electrical conductivity and low lithium reactivity. This is because only materials that are inactive with the electrolyte within the battery's operating voltage can be used as current collectors. However, in anode-free battery systems, the low lithium reactivity of the current collector induces localized lithium generation, which significantly degrades the battery's lifespan. Therefore, a strategy of coating lithium-affinity materials onto the surface of the current collector is being introduced, and representative materials such as Ag, Mg, Zn, and Sn are being utilized. When a negative current collector coated with a lithium-affinity material thinly to a thickness of 1 µm or less is applied, lithium deposition can occur horizontally along the material present on the surface. Even when a modified current collector is applied, direct contact between the deposited lithium metal and the electrolyte cannot be avoided. The risk of internal short circuits still exists at high current densities or long lifespans. Therefore, technology for a protective layer capable of inducing uniform lithium deposition while suppressing physical contact between the deposited lithium and the solid electrolyte is required. FIG. 1 is a cross-sectional view showing the structure of a non-cathode all-solid-state battery according to the present invention in a charged state. Figure 2 is a schematic diagram of the preparation of a metal sulfide layer ( Ag₂S ) through an aqueous Na₂S impregnation process. Figure 3 shows the XRD structural analysis results according to impregnation time. Figure 4 shows photographs of SUS current collectors coated with Ag₂S according to impregnation time. a) 0 hours, b) 6 hours, c) 12 hours, d) 24 hours Figure 5 is an SEM-EDS image of a SUS current collector coated with 500 nm Ag powder. Figure 6 is an SEM-EDS image of a SUS current collector coated with Ag2S after 24 hours of impregnation. Figure 7 is a schematic diagram of a non-cathode all-solid-state battery and an operating mechanism including a negative electrode current collector coated with a metal sulfide layer. Figure 8 shows the results of a half-cell evaluation of a non-cathode all-solid-state battery with a negative electrode current collector coated with a metal sulfide layer. Figure 9 is a cross-sectional SEM-EDS image of a cathode-free all-solid-state battery after Li deposition of 5.0 mAh/ cm² . The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components. In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component. In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be dire