The present invention provides a novel method for producing a calcium aluminate compound having a modified surface. The present invention provides: a method for producing a modified calcium aluminate compound characterized by irradiating a calcium aluminate compound dispersed in an organic dispersion medium with a femtosecond laser, thereby modifying the surface of the calcium aluminate compound; and a modified calcium aluminate compound characterized by being obtained by this method and having at least one of an OH group, a CO group, a CH group, and an NH group.

A chalcogen-containing compound of the following Chemical Formula 1 which exhibits excellent phase stability at a temperature corresponding to the driving temperature of a thermoelectric element, and also exhibits an excellent thermoelectric performance index (ZT) through an increase in a power factor and a decrease in thermal conductivity, a method for preparing the same, and a thermoelectric element including the same:
V.sub.1-xM.sub.xSn.sub.4-yPb.sub.yBi.sub.2Se.sub.7-zTe.sub.z  [Chemical Formula 1]
In the above Formula 1, V is a vacancy, M is an alkali metal, x is greater than 0 and less than 1, y is greater than 0 and less than 4, and z is greater than 0 and less than or equal to 1.

A sulfide solid electrolyte is provided having: diffraction peak A observed within a range of 2θ=20.0° to 24.0°; and diffraction peak B observed within a range of 2θ=24.4° to 26.4°, diffraction peak A and diffraction peak B being observed by performing X-ray diffraction measurement using CuKα1 radiation, and the ratio of I.sub.A to I.sub.B, I.sub.A/I.sub.B, being 2.0 or less, wherein I.sub.A is an intensity of diffraction peak A and I.sub.B is an intensity of diffraction peak B. Preferably, the sulfide solid electrolyte contains elemental lithium, elemental phosphorus, elemental sulfur, and an elemental halogen. It is also preferable that the sulfide solid electrolyte has an argyrodite-type crystal structure. It is also preferable that the sulfide solid electrolyte contains a lithium halide hydrate.

A modified garnet-type solid electrolyte, includes: a garnet-type solid electrolyte; a modification layer, such that the modification layer is formed on at least one side of the garnet-type solid electrolyte, and possesses a three-dimensional crosslinking structure comprising at least one strongly acidic lithium salt and at least one weakly acidic lithium salt. A method of forming a modified garnet-type solid electrolyte, includes: exposing a garnet-type solid electrolyte in air to form a pre-passivation layer; mixing solutions of strong acid and weakly acidic salt to form a mixed solution; chemically treating at least one side of the garnet-type solid electrolyte with the mixed solution; and forming a modification layer on the at least one side of the garnet-type solid electrolyte.

Silicon-carbon composite materials and related processes are disclosed that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Compared to other, inferior materials and processes described in the prior art, the materials and processes disclosed herein find superior utility in various applications, including energy storage devices such as lithium ion batteries.

To provide a hydroxide precursor having a high density, a method for producing a lithium transition metal composite oxide using the precursor, a positive active material having a large discharge capacity per unit volume, which uses the composite oxide, an electrode for nonaqueous electrolyte secondary battery, and a nonaqueous electrolyte secondary battery. A method for producing a transition metal hydroxide precursor for use in production of a lithium transition metal composite oxide, including adding a solution containing a transition metal (Me) into a reaction tank in which a water solvent of dissolution of a complexing agent and a reducing agent has been charged in advance to coprecipitate a transition metal hydroxide that includes Mn and Ni, or Mn, Ni and Co, and has a mole ratio Mn/Me of larger than 0.5 and a mole ratio Co/Me of 0.15 or less. Further, a lithium transition metal composite oxide having an α-NaFeO.sub.2-type crystal structure, in which a mole ratio Li/Me is larger than 1, the mole ratios of Mn and Co are as described above, and which has an X-ray diffraction pattern attributable to R3-m, a ratio (FWHM (003)/FWHM (114)) of a full width at half maximum of a diffraction peak of a (003) plane to a full width at half maximum of a diffraction peak of a (104) plane of 0.72 or less, and a peak differential pore volume of 0.50 mm.sup.3/(g.Math.nm) or less as determined by a BJH method from an adsorption isotherm using a nitrogen gas adsorption method.

An intermediate temperature solid oxide fuel cell (IT-SOFC) includes an anode layer, an electrolyte adjacent to the anode layer, and a cathode layer adjacent to the electrolyte and including a material of formula (I) or (II): Sr.sub.2OsO.sub.4 (I) or Ba.sub.2MO.sub.4 (II), where M is a transition metal or post-transition metal.

A compound includes indium element (In), gallium element (Ga), aluminum element (Al) and oxygen element (O), the compound having a triclinic crystal system with lattice constants being a=10.07±0.15 Å, b=10.45±0.15 Å, c=11.01±0.15 Å, α=111.70±0.50°, β=107.70±0.50° and γ=90.00±0.50°.

To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body is grown by a melting method employing a Li.sub.5La.sub.3Ta.sub.2O.sub.12 polycrystal body as a raw material. With the growing method, a Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.

The present invention relates to magnetocaloric materials comprising manganese, iron, silicon, phosphorus, nitrogen and optionally boron.