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JP-2026076059-A - secondary battery

JP2026076059AJP 2026076059 AJP2026076059 AJP 2026076059AJP-2026076059-A

Abstract

[Problem] To provide a secondary battery that can maintain and repair the conductive path even if the current collector foil breaks. [Solution] The secondary battery 1 comprises a battery element 2 having a negative electrode layer, an electrolyte layer containing a solid electrolyte, and a positive electrode layer; a pair of current collector foils 3 and 4 arranged to sandwich the battery element 2; a tab 5 arranged on the surface of the leading edge of the current collector foil 3; and a conductive resin layer 6. The resin layer 6 is arranged on the current collector foil 3 and the tab 5 so as to cover the boundary portion 7 between the current collector foil 3 and the tab 5 on the surface side of the current collector foil 3. Alternatively, the resin layer 6 is arranged on the current collector foil 3 so as to straddle the boundary portion 7 between the current collector foil 3 and the tab 5 on the back side of the current collector foil 3. [Selection Diagram] Figure 2

Inventors

  • 片瀬 菜津子

Assignees

  • 日産自動車株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (8)

  1. A battery element having a negative electrode layer, an electrolyte layer containing a solid electrolyte, and a positive electrode layer, A pair of current-collecting foils are arranged so as to sandwich the aforementioned battery element, A tab is placed on the surface of the tip of the current collector foil, A conductive resin layer, Equipped with, The resin layer is disposed on the current collector foil and the tab so as to cover the boundary between the current collector foil and the tab on the surface side of the current collector foil, or disposed on the current collector foil so as to straddle the boundary between the current collector foil and the tab on the back side of the current collector foil. Secondary battery.
  2. A secondary battery according to claim 1, The aforementioned resin layer contains metal, Secondary battery.
  3. A secondary battery according to claim 2, The negative electrode layer contains lithium, The aforementioned metal includes copper and/or nickel. Secondary battery.
  4. A secondary battery according to any one of claims 1 to 3, The aforementioned resin layer includes a conductive resin. Secondary battery.
  5. A secondary battery according to any one of claims 1 to 3, The aforementioned resin layer includes a thermoplastic resin. Secondary battery.
  6. A secondary battery according to any one of claims 1 to 3, The resin layer is disposed on the current collector foil and the tab so as to cover the entire circumference of the boundary on the surface side of the current collector foil, or disposed on the current collector foil so as to straddle the entire circumference of the boundary on the back side of the current collector foil. Secondary battery.
  7. A secondary battery according to any one of claims 1 to 3, The thickness of the resin layer decreases towards the edges of the resin layer. Secondary battery.
  8. A secondary battery according to any one of claims 1 to 3, When the resin layer is positioned on the surface side of the current collector foil, the resin layer is attached to the current collector foil and the tab so as to be in close contact with the boundary. Secondary battery.

Description

This invention relates to a secondary battery. A known secondary battery has a configuration in which a negative electrode current collector foil, a negative electrode layer, an electrolyte layer containing a solid electrolyte, a positive electrode layer, and a positive electrode current collector foil are laminated in this order. In this specification, the laminated structure consisting of the negative electrode layer, the electrolyte layer containing a solid electrolyte, and the positive electrode layer may be referred to as a battery element. The manufacturing process for such secondary batteries includes a step of pressurizing the battery elements in order to obtain good charge and discharge characteristics. In relation to the above, Patent Document 1 discloses a method for manufacturing an electrode body in which a positive electrode having a positive electrode layer and a solid electrolyte layer on both sides of a positive electrode current collector foil, and a negative electrode having a negative electrode layer and a solid electrolyte layer on both sides of a negative electrode current collector foil and having a size larger than that of the positive electrode, are laminated. In this manufacturing method, the amount of film thickness displacement that does not cause current collector foil breakage is determined in advance by measuring the film thickness of the press portion where press pressure is applied and the non-press portion that is not laminated to the positive electrode and is not subjected to press pressure, and the laminated electrodes are pressed using the press pressure based on this amount of film thickness displacement. According to the invention of Patent Document 1, even if the current collector foil is pressed together with the battery elements, the occurrence of current collector foil breakage can be suppressed. Japanese Patent Publication No. 2015-026530 Figure 1 is a view of the secondary battery according to the first embodiment, seen from above.Figure 2 is a cross-sectional view showing the XX' section of Figure 1.Figure 3 is a cross-sectional view showing the XX' section of Figure 1, illustrating the state in which the current collector foil has broken.Figure 4 is a schematic diagram illustrating the process by which the resin layer repairs the severed conductive paths due to heating.Figure 5 is a view of the secondary battery according to the first embodiment, seen from above, showing the resin layer arranged to cover the entire circumference of the boundary.Figure 6 is a view of the secondary battery according to the second embodiment, seen from above.Figure 7 is a cross-sectional view showing the YY' section of Figure 6.Figure 8 is a cross-sectional view showing the YY' section of Figure 6, illustrating the state in which the current collector foil has broken.Figure 9 is a view from above of the secondary battery according to the second embodiment, showing the resin layer arranged to span the entire circumference of the boundary.Figure 10A is a cross-sectional view of a modified secondary battery.Figure 10B is a cross-sectional view of a modified secondary battery.Figure 11A is a cross-sectional view illustrating a secondary battery having multiple negative electrode current collector foils and positive electrode current collector foils.Figure 11B is a cross-sectional view illustrating a secondary battery having multiple negative electrode current collector foils and positive electrode current collector foils. The embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) Figure 1 is a view from above of a secondary battery 1 according to the first embodiment. As shown in Figure 1, the secondary battery 1 has a battery element 2, a negative electrode current collector foil 3, and a positive electrode current collector foil 4. The battery element 2, the negative electrode current collector foil 3, and the positive electrode current collector foil 4 are housed inside a sheet-like outer casing 8. The secondary battery 1 also has a configuration in which tabs 5, which function as input/output terminals, protrude from the inside of the outer casing 8 toward the outside, and is provided as a so-called laminated cell. Figure 2 is a cross-sectional view showing the XX' section of Figure 1. As shown in Figure 2, the battery element 2 is positioned between the negative electrode current collector foil 3 and the positive electrode current collector foil 4. The battery element 2 has a structure in which a negative electrode layer (not shown), an electrolyte layer containing a solid electrolyte, and a positive electrode layer are laminated. The negative electrode layer is positioned on the negative electrode current collector foil 3 side, and the positive electrode layer is positioned on the positive electrode current collector foil 4 side. The electrolyte layer is positioned between these negative electrode and positive electrode la