US-20260128293-A1 - ANODE STRUCTURE AND METHOD OF PRODUCING AN ANODE STRUCTURE

Abstract

An anode structure according to an embodiment of the present disclosure is an anode structure applied to an anode of a lithium-ion secondary battery. The anode structure includes: an anode current collector, and a lithium alloy layer formed on the anode current collector. The lithium alloy layer has a stoichiometric composition represented by the formula Li 1-x-y Bi x Mg y (0<x+y≤0.124, 0≤x≤0.024, 0<y≤0.10), and the lithium alloy layer has a thickness of 1 μm or more and 20 μm or less.

Inventors

• Takahito KIMOTO
• Shunsuke Sasaki
• Keisuke Shimizu
• Kuniharu Nomoto
• Ryoji Kanno

Assignees

• ULVAC, INC.
• INSTITUTE OF SCIENCE TOKYO

Dates

Publication Date

20260507

Application Date

20251106

Priority Date

20241107

Claims (7)

1. 1 . An anode structure applied to an anode of a lithium-ion secondary battery, comprising: an anode current collector; and a lithium alloy layer formed on the anode current collector, the lithium alloy layer having a stoichiometric composition represented by the formula Li 1-x-y Bi x Mg y (0<x+y≤0.124, 0≤x≤0.024, 0<y≤0.10), the lithium alloy layer having a thickness of 1 μm or more and 20 μm or less.
2. 2 . The anode structure according to claim 1 , wherein the lithium alloy layer has a Young's modulus of 4 GPa or more and 30 GPa or less.
3. 3 . The anode structure according to claim 1 , wherein the lithium alloy layer has relative density of 80% or more.
4. 4 . The anode structure according to claim 1 , wherein the lithium alloy layer includes a layer with a relatively large content of bismuth.
5. 5 . A method of producing an anode structure applied to an anode of a lithium-ion secondary battery, comprising: forming one of a lithium-containing layer and a modification layer on an anode current collector; and forming, after forming the one layer, the other of the lithium-containing layer and the modification layer on the one layer, a magnesium layer, a bismuth layer, a layer containing lithium and magnesium, or a layer containing magnesium and bismuth being used as the modification layer, an alloy layer having a stoichiometric composition represented by the formula Li 1-x-y Bi x Mg y (0<x+y≤0.124, 0≤x≤0.024, 0<y≤0.10), the alloy layer being formed on the anode current collector and including the lithium-containing layer and the modification layer, the alloy layer having a thickness of 1 μm or more and 20 μm or less.
6. 6 . The method of producing an anode structure according to claim 5 , wherein the lithium-containing layer contains magnesium.
7. 7 . The method of producing an anode structure according to claim 5 , further comprising depositing, where the layer containing magnesium and bismuth is used as the modification layer, one material of magnesium and bismuth and then depositing the other material of magnesium and bismuth.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of Japanese Application No. 2024-194907, filed Nov. 7, 2024, the entire contents of which are incorporated herein by reference. FIELD The present disclosure relates to an anode structure applied to a lithium-ion secondary battery, and a method of producing an anode structure. BACKGROUND With the advancement of mobile devices such as mobile phones and smartphones, attention has been focused on lithium-ion secondary batteries mounted on these devices. In such lithium batteries, a lithium metal layer as an anode structure is formed on an anode current collector (see, for example, Japanese Patent Application Laid-open No. 2012-017478). SUMMARY In recent years, attention has been focused on all-solid batteries in which the electrolyte is solid, as the above lithium-ion secondary batteries. In such all-solid batteries, for example, attempts have been made to increase the volumetric energy density (W·h/L) of the battery by reducing the thickness of the lithium metal layer. However, reducing the thickness of the lithium metal layer causes, for example, dendrite growth from the lithium metal layer toward the solid electrolyte layer or peeling between the lithium metal layer and the solid electrolyte layer in some cases, which shortens the cycle life of the lithium-ion secondary battery due to deterioration of the lithium metal layer in some cases. In view of the circumstances as described above, it is desired to provide an anode structure that allows the cycle life of the lithium-ion secondary battery to be made longer, and a method of producing the same. According to an embodiment of the present disclosure, there is provided an anode structure applied to an anode of a lithium-ion secondary battery. The anode structure includes: an anode current collector; and a lithium alloy layer formed on the anode current collector. The lithium alloy layer has a stoichiometric composition represented by the formula Li1-x-yBixMgy (0<x+y≤0.124, 0≤x≤0.024, 0<y≤0.10), and the lithium alloy layer has a thickness of 1 μm or more and 20 μm or less. With such an anode structure, it is possible to make the cycle life of the lithium-ion secondary battery longer. In the anode structure, the lithium alloy layer may have a Young's modulus of 4 GPa or more and 30 GPa or less. With such an anode structure, it is possible to make the cycle life of the lithium-ion secondary battery longer. In the anode structure, the lithium alloy layer may have relative density of 80% or more. With such an anode structure, it is possible to make the cycle life of the lithium-ion secondary battery longer. In the anode structure, the lithium alloy layer may include a layer with a relatively large content of bismuth. With such an anode structure, it is possible to make the cycle life of the lithium-ion secondary battery longer. According to an embodiment of the present disclosure, there is provided a method of producing an anode structure applied to an anode of a lithium-ion secondary battery. The method of producing an anode structure includes: forming one of a lithium-containing layer and a modification layer on an anode current collector; andforming, after forming the one layer, the other of the lithium-containing layer and the modification layer on the one layer,a magnesium layer, a bismuth layer, a layer containing lithium and magnesium, or a layer containing magnesium and bismuth being used as the modification layer. An alloy layer has a stoichiometric composition represented by the formula Li1-x-yBixMgy (0<x+y≤0.124, 0≤x≤0.024, 0<y≤0.10), the alloy layer being formed on the anode current collector and including the lithium-containing layer and the modification layer, and the alloy layer has a thickness of 1 μm or more and 20 μm or less. With such a production method, it is possible to make the cycle life of the lithium-ion secondary battery longer. In the method of producing an anode structure, the lithium-containing layer may contain magnesium. With such a production method, it is possible to make the cycle life of the lithium-ion secondary battery longer. The method of producing an anode structure may further include depositing, where the layer containing magnesium and bismuth is used as the modification layer, one material of magnesium and bismuth and then depositing the other material of magnesium and bismuth. With such a production method, it is possible to make the cycle life of the lithium-ion secondary battery longer. According to an embodiment of the present disclosure, there is provided an anode structure that allows the cycle life of the lithium-ion secondary battery to be made longer, and a method of producing the same. BRIEF DESCRIPTION OF FIGURES FIG. 1 is a schematic cross-sectional view showing an example of an anode structure according to this embodiment; FIGS. 2A-2D are schematic cross-sectional views showing an example of a method of producing an anode structure ac