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JP-7856863-B2 - Electrolytes, electrolyte compositions, and electrochemical elements

JP7856863B2JP 7856863 B2JP7856863 B2JP 7856863B2JP-7856863-B2

Inventors

  • 梶浦 龍之介
  • 片岡 和樹
  • 渡辺 裕
  • 鈴木 章弘
  • 彦坂 英昭
  • 北村 昌大

Assignees

  • 日本特殊陶業株式会社

Dates

Publication Date
20260511
Application Date
20240827
Priority Date
20230831

Claims (9)

  1. An electrolyte containing a non-aqueous solvent, In the color coordinates of the CIE 1976L * a * b * color space, b * ≥ 2 , An electrolyte where 1 ≤ L * ≤ 3 in the aforementioned color coordinate system.
  2. An electrolyte containing a non-aqueous solvent, In the color coordinates of the CIE 1976L * a * b * color space, b * ≥ 2 , An electrolyte in which the saturation represented by the color coordinate c * = {(a * ) ² + (b * ) ² } 1/2 is 2 ≤ c * ≤ 8 .
  3. An electrolyte containing a non-aqueous solvent, In the color coordinates of the CIE 1976L * a * b * color space, b * ≥ 2 , An electrolyte consisting of non-aromatic compounds, in which the proton nuclear magnetic resonance spectrum signal is in the chemical shift range of 6 ppm to 8 ppm .
  4. The electrolyte according to claim 3 , wherein the absorption spectrum obtained by Fourier transform infrared spectroscopy is in the wavenumber range of 1100 cm⁻¹ to 1120 cm⁻¹ .
  5. The electrolyte according to any one of claims 1 to 4, wherein a lithium salt is dissolved in the non-aqueous solvent.
  6. An electrolyte composition comprising an electrolyte solution and particles of an oxide solid electrolyte, The electrolyte is an electrolyte composition comprising a non-aqueous solvent, wherein b * ≥ 2 in the color coordinates of the CIE 1976 L * a * b * color space .
  7. The electrolyte composition according to claim 6 , wherein the oxide solid electrolyte has a garnet-type crystalline structure containing Li, La, and Zr.
  8. An electrochemical element including electrodes, The electrode is an electrochemical element containing the electrolyte according to any one of claims 1 to 4 .
  9. An electrochemical element including electrodes, The electrode is a positive electrode and contains an electrolyte, The electrolyte comprises a non-aqueous solvent and is an electrochemical element in which b * ≥ 2 in the color coordinates of the CIE 1976 L * a * b * color space .

Description

This invention relates to an electrolyte, electrolyte composition, and electrochemical element containing a non-aqueous solvent. Electrochemical elements, such as lithium-ion secondary batteries, convert chemical energy into electrical energy. Prior art in which an electrolyte containing a non-aqueous solvent is included in an electrochemical element is disclosed in Patent Document 1. The electrolyte plays the role of a medium for ion movement. Japanese Patent Publication No. 2011-44252 This is a cross-sectional view of the electrochemical element in the first embodiment.This is a schematic diagram showing the crystal structure of a garnet-type crystal.This is a cross-sectional view of the electrochemical element in the second embodiment. Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Figure 1 is a schematic cross-sectional view of the electrochemical element 10 in the first embodiment. The electrochemical element 10 is an element that directly converts chemical energy and electrical energy. Examples of ions that contribute to the energy conversion of the electrochemical element 10 (hereinafter referred to as "charge carriers") include cations such as Li + , Na + , K + , Mg2 + , Cu + , and Ag + . An example of an electrochemical element 10 is described as an energy storage device. Examples of energy storage devices include ion batteries such as lithium-ion batteries, redox reactions of electrodes and ions in the electrolyte, and electrochemical capacitors that utilize an electric double layer. The electrochemical element 10 includes, in order, a positive electrode 11, a separator 14, and a negative electrode 15. The separator 14 is made of a porous material that is durable against the active materials 19 and 20 contained in the positive electrode 11 and negative electrode 15, as well as the electrolyte, and allows the charge carrier to pass through but does not have electron conductivity. Examples of separators 14 include nonwoven fabrics and porous membranes made of cellulose, polypropylene, polyethylene, polyimide, alumina, etc. The positive electrode 11 consists of a current collector 12 and an active material layer 13 superimposed on each other. The current collector 12 is a conductive material. Examples of materials for the current collector 12 include metals selected from Ni, Ti, Fe, and Al, alloys containing two or more of these elements, stainless steel, and carbon materials. The active material layer 13 contains an active material 19. The active material 19 is appropriately selected depending on the type of charge carrier or energy storage device. When the energy storage device is an electrochemical capacitor, the active material 19 is a material that can reversibly support anions, and examples of carbon-based materials include porous carbon, natural graphite, artificial graphite, easily graphitizable carbon (hard carbon), difficult-to-graphitize carbon (soft carbon), and carbon fiber. When the energy storage device is an ion battery, the active material 19 may include metal oxides containing transition metals, sulfur-based active materials, and organic active materials. When the charge carrier is Li + , examples of metal oxides containing transition metals include metal oxides containing Li and one or more elements selected from Mn, Co, Ni, Fe, Cr , and V. Examples of metal oxides containing transition metals include LiCoO₂ , LiNi 0.8 Co 0.15 Al 0.05 O₂ , LiMn₂ O₄ , LiNiVO₄ , LiNi 0.5 Mn 1.5 O₂ , LiNi 1/3 Mn 1/3 Co 1/3 O₂ , and LiFePO₄ . Examples of sulfur-based active materials include S, TiS₂ , NiS, FeS₂ , Li₂S , MoS₃ , and sulfur-carbon composites. Examples of organic active materials include radical compounds such as 2,2,6,6-tetramethylpiperidinoxyl-4-yl methacrylate and polytetramethylpiperidinoxyl vinyl ether, quinone compounds, radialene compounds, tetraciaquinodimethane, and phenazine oxide. To lower the resistance of the active material layer 13, the active material layer 13 may contain a conductive additive. Examples of conductive additives include carbon black, acetylene black, Ketjen black, carbon fiber, Ni, Pt, and Ag. In this embodiment, the active material layer 13 includes an electrolyte composition. The electrolyte composition includes oxide solid electrolyte particles 18 and an electrolyte solution. Examples of the particles 18 include oxides having a NASICON-type structure, oxides having a perovskite structure, and oxides having a garnet-type structure. Oxides having a NASICON-type structure include oxides containing at least Li, M (where M is one or more elements selected from Ti, Zr, and Ge) and P, such as Li(Al,Ti) 2 ( PO4 ) 3 and Li(Al,Ge) 2 ( PO4 ) 3 . Oxides having a perovskite structure include oxides containing at least Li, Ti, and La, such as La2 /3- XLi3XTiO3 . Particle 18 is preferably a composite oxide having a garnet-type crystal structure containing Li, La, and Zr. This is because it has an ionic