KR-102963310-B1 - NEGATIVE ELECTRODE FOR RECHARGEABLE LITHIUM BATTERY, RECHARGEABLE LITHIUM BATTERY, AND ALL-SOLID RECHARGEABLE BATTERY

KR102963310B1KR 102963310 B1KR102963310 B1KR 102963310B1KR-102963310-B1

Abstract

The present invention relates to a negative electrode for a lithium secondary battery comprising a negative current collector, a negative catalyst layer located on the negative current collector, and a lithium ion conductive layer located on the negative catalyst layer, a lithium secondary battery comprising the same, and an all-solid-state secondary battery.

Inventors

신혁수
양휘철
이중호
손주희
양진훈
정성원

Assignees

삼성에스디아이 주식회사

Dates

Publication Date: 20260508
Application Date: 20220922

Claims (18)

An all-solid-state secondary battery comprising a positive electrode, a negative electrode, and a solid electrolyte layer located between the positive electrode and the negative electrode, The above cathode comprises a cathode current collector, a cathode catalyst layer located on the cathode current collector, and a lithium ion conductive layer located on the cathode catalyst layer. The above lithium ion conductive layer comprises a lithium-metal composite oxide, and The above metal is one or more elements selected from the group consisting of B, Ba, Ca, Ce, Co, Cr, Cu, Fe, La, Mg, Mn, Mo, Nb, Si, Sr, Ta, Ti, V, W, Zn and Zr, and The thickness of the above cathode catalyst layer is 100 nm to 50 μm, and The thickness of the lithium ion conductive layer is 1 nm to 50 nm, and The above solid electrolyte layer comprises a sulfide-based solid electrolyte, and The above-mentioned negative current collector comprises copper foil, nickel foil, or a combination thereof, in an all-solid-state secondary battery.
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In Paragraph 1, The above-described cathode catalyst layer comprises a metal, a carbon material, or a combination thereof, in an all-solid-state secondary battery.
In Paragraph 3, The above metal comprises gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof, in an all-solid-state secondary battery.
In Paragraph 3, The above carbon material is an all-solid-state secondary battery containing amorphous carbon.
In Paragraph 1, The above-described cathode catalyst layer comprises a metal and a carbon material in a weight ratio of 1:1 to 1:50, for an all-solid-state secondary battery.
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In Paragraph 1, A solid-state secondary battery in which the above-mentioned cathode further comprises a lithium metal layer formed during initial charging between the above-mentioned cathode current collector and the above-mentioned cathode catalyst layer.
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In Paragraph 1, The above lithium ion conductive layer comprises a lithium titanium oxide, lithium zirconium oxide, lithium aluminum oxide, lithium niobium oxide, lithium lanthanum oxide, lithium tantalum oxide, lithium zinc oxide, lithium titanium zirconium oxide, lithium lanthanum titanium oxide, lithium lanthanum zirconium oxide, lithium lanthanum titanium zirconium oxide, lithium lanthanum zirconium aluminum oxide, lithium strontium tantalum zirconium oxide, or a combination thereof, in an all-solid-state secondary battery.
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In Paragraph 1, The above sulfide-based solid electrolyte is an all-solid-state secondary battery comprising an azirodite-type sulfide.
In Paragraph 15, The above - mentioned azirodite-type sulfide comprises Li₃PS₄ , Li₆P₃S₁¹¹ , Li₆PS₆ , Li₆PS₅Cl , Li₆PS₅Br , Li₅8PS₄Cl₁¹² , Li₅8PS₅8Br₁¹² , or a combination thereof , in an all- solid -state secondary battery.
In Paragraph 1, An all-solid-state secondary battery in which the average particle size (D50) of the above-mentioned sulfide-based solid electrolyte is 0.1 μm to 5.0 μm.
In Paragraph 1, The above-mentioned negative current collector is a solid-state secondary battery comprising copper foil.

Description

Negative electrode for lithium secondary battery, lithium secondary battery and all-solid-state secondary battery This relates to a negative electrode for a lithium secondary battery, a lithium secondary battery, and an all-solid-state secondary battery. Lithium-ion batteries are widely used in portable information terminals, portable electronic devices, small home power storage devices, motorcycles, electric vehicles, and hybrid electric vehicles due to their high electrochemical capacity, operating potential, and excellent charge-discharge cycle characteristics. With the expansion of these applications, there is a demand for improved safety and high performance of lithium-ion batteries. A lithium secondary battery consists of a positive electrode, a negative electrode, and an electrolyte. Recently, a precipitation type negative electrode has been proposed as a negative electrode for lithium secondary batteries. A precipitation type negative electrode refers to a negative electrode that does not contain a negative electrode active material during battery assembly, but in which high-density lithium metal is precipitated or electrodeposited on the negative electrode during battery charging, and this acts as the negative electrode active material. However, there is a technical challenge in precipitation type negative electrodes that the lithium metal must be precipitated in a flat shape at a high concentration rather than in a dendrite shape, and the reversible capacity due to the precipitated lithium must be high. Meanwhile, such precipitation-type cathodes may be suitable for application in all-solid-state secondary batteries. However, side reactions may occur at the interface between the solid electrolyte layer of the all-solid-state secondary battery and the precipitation-type cathode; there are problems such as corrosion of the current collector of the precipitation-type cathode due to the solid electrolyte, degradation of the electrolyte caused by the influx of cathode current collector components into the solid electrolyte, and reduction of the solid electrolyte due to the voltage difference between the solid electrolyte and the cathode; thus, solutions to these issues are required. FIG. 1 is a schematic cross-sectional view of an all-solid-state secondary battery according to one embodiment. Figures 2 and 3 are the results of the cyclic voltammetry (CV) evaluation for the half cell of Comparative Example 1. Figure 4 is the CV evaluation result for the half cell of Comparative Example 2. Figure 5 shows an actual photograph of the copper foil negative current collector of Comparative Example 1 (left) and a photograph of the copper foil negative current collector taken after 30 cycles of the half-cell of Comparative Example 1 (right). Figure 6 is the result of analyzing the depth profile of the surface of the copper foil negative current collector using TOF-SIMS after 100 cycles of the all-solid-state half-cell of Comparative Example 1. Figure 7 is the CV evaluation result for the half cell of Example 1. Figure 8 shows the CV evaluation results for the half cell of Comparative Example 3. Figure 9 is a graph showing a Nyquist plot as an initial impedance evaluation for the half-cells of Example 1 and Comparative Example 3. Figure 10 is a graph of the lifespan characteristics for the full cells prepared in Example 1, Comparative Example 2, and Comparative Example 3. Specific embodiments are described below in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. The terms used herein are merely for describing exemplary embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. Here, "combinations of these" refers to mixtures of components, laminates, composites, copolymers, alloys, blends, reaction products, etc. The terms "include," "equip," or "have" used herein are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. 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