An electrochromic device according to an embodiment includes a first transparent conductive layer, an ion storage layer, an electrolyte layer, an electrochromic layer, and a second transparent conductive layer. The electrolyte layer includes a tantalum atom. The electrochromic layer includes a tungsten atom. The ion storage layer includes an iridium atom and a tantalum atom. The ion storage layer is hydrogenated in bleached state and the electrochromic device has a transmittance of 64.1% or more in bleached state. A difference between the transmittance of the electrochromic device in bleached state and the transmittance of the electrochromic device in colored state is 8.4% or more.

The present invention aims to provide a lithium-ion-conducting oxide sintered body capable of providing a solid electrolyte with an excellent ion conductivity, and a solid electrolyte, an electrode and an all-solid-state battery using the same. The lithium-ion-conducting oxide sintered body including at least lithium, tantalum, phosphorus, silicon, and oxygen as constituent elements, and having a polycrystalline structure consisting of crystal grains and grain interfaces formed between the crystal grains.

According to the present invention, there are provided a composite body that enables the formation of a lithium ion conductor that exhibits good lithium ion conductivity by a pressurization treatment without sintering at a high temperature (about 1,000° C.) while using a lithium-containing oxide having excellent safety and stability, as well as a lithium ion conductor, an all-solid state lithium ion secondary battery, an electrode sheet for an all-solid state lithium ion secondary battery, and lithium tetraborate. The composite body according to the embodiment of the present invention contains a lithium compound having a lithium ion conductivity of 1.0×10.sup.−6 S/cm or more at 25° C. and lithium tetraborate that satisfies the following requirement 1.

The requirement 1: In a reduced two-body distribution function G(r) obtained from an X-ray total scattering measurement of the lithium tetraborate, a first peak in which a peak top is located in a range where r is 1.43±0.2 Å and a second peak in which a peak top is located in a range where r is 2.40±0.2 Å are present, G(r) of the peak top of the first peak and G(r) of the peak top of the second peak indicate more than 1.0, and an absolute value of G(r) is less than 1.0 in a range where r is more than 5 Å and 10 Å or less.

A solid electrolyte material is made of Li, Ca, Y, Gd, X, O, and H, where X is at least one selected from the group consisting of F, Cl, Br, and I; and the molar ratio of O to the sum of Y and Gd is greater than 0 and less than 0.82.

The solid electrolyte material of the present disclosure is a solid electrolyte material made of Li, Ca, Y, Gd, X, and O, where X is at least one selected from the group consisting of F, Cl, Br, and I; the molar ratio of O to the sum of Y and Gd in the entire solid electrolyte material is greater than 0 and 0.42 or less; and O is present in a surface region of the solid electrolyte material.

The production method of the present disclosure includes heat-treating a material mixture containing a compound containing Y, a compound containing Sm, NH.sub.4α, Liβ, and Caγ.sub.2 in an inert gas atmosphere. The compound containing Y is at least one selected from the group consisting of Y.sub.2O.sub.3 and Yδ.sub.3, and the compound containing Sm is at least one selected from the group consisting of Sm.sub.2O.sub.3 and Smε.sub.3. The material mixture contains at least one selected from the group consisting of Y.sub.2O.sub.3 and Sm.sub.2O.sub.3, and α, β, γ, δ, and ε are each independently at least one selected from the group consisting of F, Cl, Br, and I.

The invention relates to a solid electrolyte material, solid electrolyte, method for producing the solid electrolyte, and all-solid-state battery, and the solid electrolyte material includes lithium, tantalum, phosphorus, and oxygen as constituent elements and includes at least one element selected from boron, niobium, bismuth, and silicon as a constituent element, and satisfies any of requirements (I) to (III). Requirement (I): A peak top of a .sup.31P-NMR spectrum of the solid electrolyte material is in the range of −9.5 to 5.0 ppm. Requirement (II): A peak top of a .sup.7Li-NMR spectrum of the solid electrolyte material is in the range of −2.00 to 0.00 ppm. Requirement (III): A peak top of a .sup.31P-NMR spectrum of the solid electrolyte material is in the range of −9.5 to 5.0 ppm, and a peak top of a .sup.7Li-NMR spectrum of the solid electrolyte material is in the range of −2.00 to 0.00 ppm.

One embodiment of the present invention relates to a solid electrolyte material, a solid electrolyte, a method for producing the solid electrolyte, or an all-solid-state battery, and the solid electrolyte material includes lithium, tantalum, phosphorus, and oxygen as constituent elements and has a content of the phosphorus element of more than 5.3 atomic % and less than 8.3 atomic %, and is amorphous.

One embodiment of the present invention relates to a solid electrolyte material, a solid electrolyte, a method for producing the solid electrolyte, or an all-solid-state battery, and the solid electrolyte material includes lithium, tantalum, boron, phosphorus, and oxygen as constituent elements, wherein a peak position of a peak having the maximum peak intensity among an .sup.11B-NMR peak is in the range of -15.0 to -5.0 ppm.

Provided is a sintered body electrode, a battery member, and sintered body electrode and battery member manufacturing methods all of which can increase the safety and operate a battery at low temperatures. A sintered body electrode 3 according to the present invention contains: a carbon electrode material made of graphite or hard carbon; and an alkali-ion conductive solid electrolyte.