Search

CN-116583979-B - Solid-state battery and method for manufacturing solid-state battery

CN116583979BCN 116583979 BCN116583979 BCN 116583979BCN-116583979-B

Abstract

In one embodiment of the present invention, a solid state battery is provided. The solid-state battery is characterized by comprising a battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer, an end surface electrode provided so as to face the end surface of the battery element, a cover layer provided so as to cover the battery element with the end surface electrode, and an insulating buffer layer provided so as to be located between the cover layer and the battery element and to surround the battery element, wherein the insulating buffer layer is interposed between the battery element and the end surface electrode at the end surface electrode facing region side of the end surface of the battery element, and is provided intermittently.

Inventors

  • Hayakawa takehiro
  • SHIMIZU KEIICHI

Assignees

  • 株式会社村田制作所

Dates

Publication Date
20260508
Application Date
20211126
Priority Date
20201127

Claims (16)

  1. 1. A solid-state battery is provided with: a battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; an end surface electrode disposed so as to face an end surface of the battery element; a cover layer provided to cover the battery element with the end face electrode, and An insulating buffer layer disposed between the cover layer and the battery element and surrounding the battery element, The insulating buffer layer is interposed between the battery element and the end face electrode at the end face electrode facing region side of the end face of the battery element, and is intermittently provided.
  2. 2. The solid-state battery according to claim 1, wherein, The insulating buffer layer is disposed in contact with at least the battery element.
  3. 3. The solid-state battery according to claim 1 or 2, wherein, An opposing region and a non-opposing region are formed between the battery element and the end surface electrode, the opposing region being a region in which the battery element directly opposes the insulating buffer layer, and the non-opposing region being a region in which the battery element does not oppose the insulating buffer layer.
  4. 4. The solid-state battery according to claim 3, wherein, The opposing regions and the non-opposing regions are alternately formed between the battery element and the end face electrode.
  5. 5. The solid-state battery according to any one of claims 1 to 4, wherein, The insulating buffer layer is intermittently formed to form a portion where at least one of the positive electrode layer and the negative electrode layer can directly face the end surface electrode.
  6. 6. The solid-state battery according to claim 5, wherein, Only the electrode layer is directly opposed to the end face electrode.
  7. 7. The solid-state battery according to any one of claims 1 to 6, wherein, The battery element has a substantially rectangular parallelepiped shape, The insulating buffer layer is configured to be directly opposed to an upper surface, a lower surface, and a side surface of the end surface of the battery element constituting the substantially rectangular parallelepiped shape.
  8. 8. The solid-state battery according to any one of claims 1 to 7, wherein, Between the battery element and the end face electrode, a ratio of a formation area of the insulating buffer layer to a total area of the electrode layers located at the end face of the battery element is greater than 0.1% and less than 95%.
  9. 9. The solid-state battery according to claim 8, wherein, The ratio is 0.5% or more and 75% or less.
  10. 10. The solid-state battery according to any one of claims 1 to 9, wherein, The heat-resistant temperature of the insulating buffer layer is above 300 ℃.
  11. 11. The solid-state battery according to any one of claims 1 to 10, wherein, The insulating buffer layer is composed of at least one material selected from the group consisting of boron nitride, molybdenum sulfide, and tungsten sulfide.
  12. 12. The solid-state battery according to any one of claims 1 to 11, wherein, The insulating buffer layer is a stress relaxation layer.
  13. 13. The solid-state battery according to any one of claims 1 to 12, wherein, The cover layer is provided with a barrier layer capable of preventing the permeation of water vapor.
  14. 14. The solid-state battery according to claim 13, wherein, The barrier layer has a water vapor transmission rate of 1.0X10 -2 g/(m 2 days or less).
  15. 15. The solid-state battery according to any one of claims 1 to 14, wherein, The positive electrode layer and the negative electrode layer are layers capable of inserting and extracting lithium ions.
  16. 16. A method of manufacturing a solid state battery, comprising: a step (i) of stacking a positive electrode layer sheet, a solid electrolyte layer sheet, and a negative electrode layer sheet in a stacking direction to form an unfired stack; a step (ii) of supplying an insulating material to the surface of the unfired laminate; a step (iii) of firing the unfired laminate with the insulating material to form a fired laminate; A step (iv) of providing an end face electrode on the surface of the fired laminate, and A step (v) of forming a film layer so as to cover the fired laminate with the end surface electrode, In the step (ii), the insulating material is intermittently supplied to the surface of the unfired laminate to be opposed to the end surface electrode.

Description

Solid-state battery and method for manufacturing solid-state battery Technical Field The present invention relates to a solid-state battery and a method for manufacturing the same. Background Conventionally, secondary batteries capable of repeatedly charging and discharging have been used for various purposes. For example, secondary batteries are used as power sources for electronic devices such as smart phones and notebook computers. In such a secondary battery, a liquid electrolyte (electrolyte solution) such as an organic solvent has been conventionally used as a medium for moving ions. However, in a secondary battery using an electrolyte, there are problems such as leakage of the electrolyte. For this reason, development of solid batteries having a solid electrolyte instead of a liquid electrolyte is being advanced. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2018-49839 Disclosure of Invention Technical problem to be solved by the invention As a solid battery, there is a solid battery including a battery element, an exterior package enclosing a surface of the battery element, and a lubricant between the battery element and the exterior package, wherein the battery element includes a positive electrode layer and a negative electrode layer facing each other, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer (see patent document 1). Such a lubricant may be provided between the entire peripheral surface of the battery element and the inner surface of the exterior cover facing the entire peripheral surface. Here, the present inventors have noted that there are matters to be further improved in the above-mentioned solid-state battery. Specifically, when the end face electrode is provided on the end face side of the battery element, if the lubricant is present on the entire peripheral surface of the battery element, the lubricant is also provided between the battery element and the end face electrode. For this reason, the electrode layer of the battery element and the end face electrode may become difficult to contact due to the presence of the lubricant. In addition, since the electrode layers (positive electrode layer/negative electrode layer) of the solid-state battery may expand and contract during charge and discharge, there is a possibility that the exterior package may be peeled off from the battery element having the end face electrode due to such expansion and contraction, and the end face of the battery element may be damaged. The present invention has been made in view of such circumstances. That is, a main object of the present invention is to provide a solid-state battery capable of simultaneously securing contact between an electrode layer and an end face electrode and suppressing damage to an end face of a battery element, and a method for manufacturing the same. Technical scheme for solving technical problems In order to achieve the above object, in one embodiment of the present invention, there is provided a solid-state battery including a battery element having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer, an end surface electrode provided so as to face an end surface of the battery element, a cover layer provided so as to cover the battery element with the end surface electrode, and an insulating buffer layer provided so as to be interposed between the cover layer and the battery element and to surround the battery element, the insulating buffer layer being interposed between the battery element and the end surface electrode at an end surface electrode facing region side of the end surface of the battery element and being intermittently provided. In order to achieve the above object, according to one embodiment of the present invention, there is provided a method for producing a solid-state battery, comprising the steps of (i) laminating a positive electrode layer sheet, a solid electrolyte layer sheet, and a negative electrode layer sheet in a lamination direction to form an unfired laminate, (ii) supplying an insulating material to a surface of the unfired laminate, (iii) firing the unfired laminate with the insulating material to form a fired laminate, (iv) providing an end surface electrode on the surface of the fired laminate, and (v) forming a coating layer so as to cover the fired laminate with the end surface electrode, and in the step (ii), intermittently supplying the insulating material to the surface of the unfired laminate to be opposed to the end surface electrode. Effects of the invention According to an embodiment of the present invention, it is possible to simultaneously ensure contact between the electrode layer and the end face electrode and suppress damage to the end face of the battery element. Drawings Fig. 1 is a cross-sectional view s