JP-7856390-B2 - All solid state battery

Inventors

• 佐藤 万純

Assignees

• トヨタ自動車株式会社

Dates

Publication Date

20260511

Application Date

20210705

Claims (10)

1. This all-solid-state battery utilizes the deposition-dissolution reaction of metallic lithium as the reaction at the negative electrode. The positive electrode current collector layer, positive electrode active material layer, solid electrolyte layer, and negative electrode current collector layer are stacked in this order. The solid electrolyte layer has a plurality of recesses, The recess is localized on the surface of the solid electrolyte layer facing the negative electrode current collector layer, and is spaced apart from the negative electrode current collector layer. When fully charged, metallic lithium is deposited not only in the recess but also below the recess and between the negative electrode current collector layer and the solid electrolyte layer. The plurality of recesses are spaced apart from each other . The aforementioned interval is 2 μm or more when viewed from the stacking direction of the all-solid-state battery. Characterized by, All-solid-state battery.
2. The all-solid-state battery according to claim 1, wherein the recess is larger than the solid electrolyte particles contained in the solid electrolyte layer.
3. The all-solid-state battery according to claim 1 or 2, wherein the recess is dome-shaped.
4. The all-solid-state battery according to any one of claims 1 to 3, wherein the maximum length of the recess in the stacking direction of the all-solid-state battery is 2 μm to 200 μm.
5. The all-solid-state battery according to any one of claims 1 to 4, wherein the maximum length of the recess in the planar direction of the all-solid-state battery is 2 μm to 200 μm.
6. The all-solid-state battery according to any one of claims 1 to 5 , wherein the interval is 500 μm or less .
7. A conductive layer is provided between the solid electrolyte layer and the negative electrode current collector layer. The conductive layer is arranged along the solid electrolyte layer such that it is spaced apart from the negative electrode current collector layer in the portion along the recess, and in other portions is in electrical contact with the negative electrode current collector layer. All-solid-state battery according to any one of claims 1 to 6.
8. The all-solid-state battery according to claim 7, wherein the thickness of the conductive layer is 100 nm to 10 μm.
9. The all-solid-state battery according to claim 7 or 8, wherein the conductive layer is a layer of metal capable of forming an alloy with Li, or a layer of carbon.
10. The all-solid-state battery according to any one of claims 7 to 9, wherein the conductive layer contains Mg, Sn, In, or Au.

Description

This disclosure relates to all-solid-state batteries. In recent years, with the rapid proliferation of information-related devices and communication equipment such as personal computers, video cameras, and mobile phones, the development of batteries used as their power sources has become increasingly important. Furthermore, the automotive industry is also actively developing high-output, high-capacity batteries for electric and hybrid vehicles. Currently, among various types of batteries, lithium-ion batteries are attracting attention due to their high energy density. Patent Document 1 discloses a solid electrolyte layer structure for an all-solid-state battery, comprising a plate-shaped dense body made of ceramics containing a solid electrolyte, and a porous layer made of ceramics containing the same or a different solid electrolyte as the dense body, formed by firing and integrating it onto at least one surface of the dense body. The document states that such a structure makes it possible to reduce the connection resistance at the connection interface with the electrodes. Patent Document 2 discloses a method for manufacturing a lithium all-solid-state battery module. This document discloses that, in the manufacturing of a lithium all-solid-state battery module, when the restraining pressure used to restrain the lithium solid battery is P (MPa) and the average pore radius of the solid electrolyte layer determined by the mercury intrusion method is R (μm), the condition P ≤ -5900R + 74 is satisfied. The document states that this manufacturing method allows for the production of a lithium solid-state battery module that suppresses the occurrence of short circuits caused by dendrites. International Publication No. 2008/059987Japanese Patent Publication No. 2015-156297 Figure 1A is a schematic diagram of an all-solid-state battery 1 according to a first embodiment of the present disclosure.Figure 1B is a schematic diagram showing a state in which an all-solid-state battery 1 according to the first embodiment of this disclosure is being charged.Figure 1C is a schematic diagram showing the state of a fully charged all-solid-state battery 1 according to the first embodiment of this disclosure.Figure 2A is a schematic diagram of an all-solid-state battery 2 that differs from the embodiment of the present disclosure.Figure 2B is a schematic diagram showing a state in which an all-solid-state battery 2, different from the embodiment of the present disclosure, is being charged.Figure 2C is a schematic diagram showing a fully charged state of an all-solid-state battery 2, which differs from the embodiment of the present disclosure.Figure 3A is a schematic diagram of an all-solid-state battery 3 according to a second embodiment of the present disclosure.Figure 3B is a schematic diagram showing a state in which an all-solid-state battery 3 according to a second embodiment of the present disclosure is being charged.Figure 3C is a schematic diagram showing the fully charged state of the all-solid-state battery 3 according to the second embodiment of this disclosure.Figure 4A is a scanning electron microscope (SEM) image of the solid electrolyte coating layer of the all-solid-state battery of Example 1.Figure 4B is a scanning electron microscope (SEM) image of a cross-section in the stacking direction of the all-solid-state battery of Example 1 when fully charged.Figure 5A is a graph showing the relationship between the change in internal pressure and time when the all-solid-state battery of Comparative Example 1 is charged and discharged.Figure 5B is a graph showing the relationship between the change in internal pressure and time when the all-solid-state battery of Example 1 is charged and discharged.Figure 6 is a graph showing the relationship between current density and charging capacity during the 1st, 4th, 7th, and 13th charge-discharge cycles when the all-solid-state batteries of Example 1 and Comparative Example 1 were repeatedly charged and discharged at 25°C while changing the C rate every 3 cycles.Figure 7A is a scanning electron microscope (SEM) image of a cross-section in the stacking direction of the all-solid-state battery of Example 1 when fully charged.Figure 7B is a scanning electron microscope (SEM) image of a cross-section in the stacking direction of the all-solid-state battery of Example 2 when fully charged.Figure 8A is a graph showing the relationship between charge/discharge capacity and the number of cycles when the all-solid-state battery of Example 1 is repeatedly charged and discharged at a predetermined C rate.Figure 8B is a graph showing the relationship between charge/discharge capacity and the number of cycles when the all-solid-state battery of Example 2 is repeatedly charged and discharged at a predetermined C rate. The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the embodiments described below, and can be implemented in var