CN-122000301-A - Negative electrode structure and method for manufacturing negative electrode structure

Abstract

The negative electrode structure according to one embodiment of the present invention is a negative electrode structure applied to a negative electrode of a lithium ion secondary battery. The negative electrode structure has a negative electrode current collector and a lithium alloy layer formed on the negative electrode current collector. The stoichiometric ratio of the lithium alloy layer is Li 1‑x‑y Bi x Mg y (0 < x+y is not less than 0.124,0 and not more than x is not more than 0.024,0< y is not more than 0.10), and the thickness of the lithium alloy layer is not less than 1 μm and not more than 20 μm. The negative electrode structure of the present invention can extend the life of a lithium ion secondary battery.

Inventors

• KIMOTO TAKAHITO
• SASAKI SHUNSUKE
• SHIMIZU KEISUKE
• NOMOTO KUNIHARU
• Villous themeda open country time

Assignees

• 株式会社爱发科
• 国立大学法人东京科学大学

Dates

Publication Date

20260508

Application Date

20251030

Priority Date

20241107

Claims (7)

1. 1. A negative electrode structure is applied to a negative electrode of a lithium ion secondary battery, The negative electrode structure has a negative electrode current collector and a lithium alloy layer formed on the negative electrode current collector, The stoichiometric ratio of the lithium alloy layer is Li 1-x-y Bi x Mg y (0 < x+y is not less than 0.124,0 and not more than 0.024,0< y is not more than 0.10), The thickness of the lithium alloy layer is 1 [ mu ] m or more and 20 [ mu ] m or less.
2. 2. The negative electrode structure according to claim 1, wherein, The Young's modulus of the lithium alloy layer is 4GPa or more and 30GPa or less.
3. 3. The negative electrode structure according to claim 1, wherein, The relative density of the lithium alloy layer is 80% or more.
4. 4. The negative electrode structure according to claim 1, wherein, A layer having a relatively large bismuth content is formed in the lithium alloy layer.
5. 5. A method for manufacturing a negative electrode structure for use in a negative electrode of a lithium ion secondary battery, Forming any one of a lithium-containing layer and a finishing layer on the negative electrode current collector, After forming the one layer, forming the other of the lithium-containing layer and the finishing layer on the one layer, As the modification layer, a magnesium layer, a bismuth layer, a layer containing lithium and magnesium, or a layer containing magnesium and bismuth is used, The stoichiometric ratio of the alloy layer formed by combining the lithium-containing layer and the modification layer and formed on the negative electrode current collector is Li 1-x-y Bi x Mg y (0 < x+y is not less than 0.124,0 and not more than 0.024,0< y is not more than 0.10), The thickness of the alloy layer is 1 μm or more and 20 μm or less.
6. 6. The method for manufacturing a negative electrode structure according to claim 5, wherein, The lithium-containing layer comprises magnesium.
7. 7. The method for manufacturing a negative electrode structure according to claim 5, wherein, In the case of using a layer containing magnesium and bismuth as the finishing layer, after forming a film of any one of the magnesium and bismuth, the other of the magnesium and bismuth is formed into a film.

Description

Negative electrode structure and method for manufacturing negative electrode structure Technical Field The present invention relates to a negative electrode structure for a lithium ion secondary battery and a method for manufacturing the negative electrode structure. Background With the development of mobile devices such as mobile phones and smart phones, lithium ion secondary batteries mounted in these devices have been attracting attention. In such a lithium battery, a lithium metal layer as a negative electrode structure is formed on a negative electrode current collector (for example, see patent document 1). Prior art literature Patent literature Patent document 1, japanese patent application laid-open No. 2012-017478. Disclosure of Invention Problems to be solved by the invention In recent years, among the above-mentioned lithium ion secondary batteries, all-solid-state batteries having an electrolyte composed of a solid have been attracting attention. In such an all-solid-state battery, for example, an attempt has been made to reduce the thickness of the lithium metal layer and increase the volumetric energy density (w·h/L) of the battery. However, if the thickness of the lithium metal layer is reduced, dendrite growth may occur from the lithium metal layer to the solid electrolyte layer or peeling may occur between the lithium metal layer and the solid electrolyte layer, for example, and the life of the lithium ion secondary battery may be shortened with degradation of the lithium metal layer. In view of the above, an object of the present invention is to provide a negative electrode structure capable of extending the lifetime of a lithium ion secondary battery, and a method for manufacturing the same. Solution for solving the problem In order to achieve the above object, an anode structure according to one embodiment of the present invention is an anode structure applied to an anode of a lithium ion secondary battery. The negative electrode structure has a negative electrode current collector and a lithium alloy layer formed on the negative electrode current collector. The stoichiometric ratio of the lithium alloy layer is Li 1-x-yBixMgy (0 < x+y is not less than 0.124,0 and not more than 0.024,0< y is not more than 0.10), The thickness of the lithium alloy layer is 1 μm or more and 20 μm or less. In the case of such a negative electrode structure, the lifetime of the lithium ion secondary battery can be prolonged. In the negative electrode structure, the Young's modulus of the lithium alloy layer may be 4GPa to 30 GPa. In the case of such a negative electrode structure, the lifetime of the lithium ion secondary battery can be prolonged. In the negative electrode structure, the relative density of the lithium alloy layer may be 80% or more. In the case of such a negative electrode structure, the lifetime of the lithium ion secondary battery can be prolonged. In the negative electrode structure, a layer having a relatively large bismuth content may be formed in the lithium alloy layer. In the case of such a negative electrode structure, the lifetime of the lithium ion secondary battery can be prolonged. In order to achieve the above object, a method for manufacturing a negative electrode structure according to one embodiment of the present invention is a method for manufacturing a negative electrode structure applied to a negative electrode of a lithium ion secondary battery. In the method for manufacturing the negative electrode structure, one of a lithium-containing layer and a modified layer is formed on a negative electrode current collector, After forming the one layer, forming the other of the lithium-containing layer and the finishing layer on the one layer, As the above-mentioned modification layer, a magnesium layer, a bismuth layer, a layer containing lithium and magnesium, or a layer containing magnesium and bismuth is used. The stoichiometric ratio of the alloy layer formed on the negative electrode current collector and formed by combining the lithium-containing layer and the modification layer is Li 1-x-yBixMgy (0 < x+y is not less than 0.124,0 and not more than 0.024,0< y is not more than 0.10), The thickness of the alloy layer is 1 μm or more and 20 μm or less. Such a manufacturing method can lengthen the lifetime of the lithium ion secondary battery. In the method for manufacturing a negative electrode structure, the lithium-containing layer may contain magnesium. Such a manufacturing method can lengthen the lifetime of the lithium ion secondary battery. In the above-described method for producing a negative electrode structure, In the case of using a layer containing magnesium and bismuth as the above-described finishing layer, after forming a film of any one of the magnesium and bismuth, the other of the magnesium and bismuth may be formed into a film. Such a manufacturing method can lengthen the lifetime of the lithium ion secondary battery. Effects of the invention According to t