Provided is a ceramic composite material and a wavelength converter. The ceramic composite material includes: an alumina matrix, a fluorescent powder uniformly distributed in the alumina matrix, and scattering centers uniformly distributed in the alumina matrix, wherein the alumina matrix is an alumina ceramics, the scattering centers are alumina particles, the alumina particles each have a particle diameter of 1 μm to 10 μm, and the fluorescent powder has a particle diameter of 13 μm to 20 μm.

Provided is a ceramic composite material and a wavelength converter. The ceramic composite material includes: an alumina matrix, a fluorescent powder uniformly distributed in the alumina matrix, and scattering centers uniformly distributed in the alumina matrix, wherein the alumina matrix is an alumina ceramics, the scattering centers are alumina particles, the alumina particles each have a particle diameter of 1 μm to 10 μm, and the fluorescent powder has a particle diameter of 13 μm to 20 μm.

Embodiments relate to a method for fabricating a sintered sodium-ion material. The method involves mixing a parent phase sodium-ion compound with a secondary transient phase to form a powder mixture. The method involves applying pressure and heat above a melting point or boiling point of the secondary transient phase to drive dissolution at particle contacts and subsequent precipitation at newly formed grain boundaries. The method involves generating a sintered sodium-ion material with >90% relative density.

Embodiments relate to a method for fabricating a sintered sodium-ion material. The method involves mixing a parent phase sodium-ion compound with a secondary transient phase to form a powder mixture. The method involves applying pressure and heat above a melting point or boiling point of the secondary transient phase to drive dissolution at particle contacts and subsequent precipitation at newly formed grain boundaries. The method involves generating a sintered sodium-ion material with >90% relative density.

Provided are a sodium ion-conductive crystal-containing solid electrolyte sheet capable of giving excellent battery characteristics even when reduced in thickness, and an all-solid-state battery using the same. The solid electrolyte sheet contains at least one type of sodium ion-conductive crystal selected from β″-alumina and NASICON crystal and has a thickness of 500 μm or less and a flatness of 200 μm or less.

A NaNiCl battery and a module using the same are provided. A NaNiCl battery according to the present invention include: a case that forms an exterior shape of the battery; and a beta alumina solid electrolyte (BASE) tube that is provided in the case and having a clover-shaped cross-section, wherein the case has a clover-shaped cross-section like the clover-shaped cross-section of the BASE tube to minimize a space between the case and the BASE tube.

Provided is a ceramic composite material and a wavelength converter. The ceramic composite material includes: an alumina matrix, a fluorescent powder uniformly distributed in the alumina matrix, and scattering centers uniformly distributed in the alumina matrix, wherein the alumina matrix is an alumina ceramics, the scattering centers are alumina particles, the alumina particles each have a particle diameter of 1 μm to 10 μm, and the fluorescent powder has a particle diameter of 13 μm to 20 μm.

Provided is a ceramic composite material and a wavelength converter. The ceramic composite material includes: an alumina matrix, a fluorescent powder uniformly distributed in the alumina matrix, and scattering centers uniformly distributed in the alumina matrix, wherein the alumina matrix is an alumina ceramics, the scattering centers are alumina particles, the alumina particles each have a particle diameter of 1 μm to 10 μm, and the fluorescent powder has a particle diameter of 13 μm to 20 μm.

Provided are a sodium ion-conductive crystal-containing solid electrolyte sheet capable of giving excellent battery characteristics even when reduced in thickness, and an all-solid-state battery using the same. The solid electrolyte sheet contains at least one type of sodium ion-conductive crystal selected from β″-alumina and NASICON crystal and has a thickness of 500 μm or less and a flatness of 200 μm or less.

A preparation method for a ceramic composite material, a ceramic composite material, and a wavelength converter. The preparation method comprises: preparing an aluminium salt solution and a fluorescent powder; dispersing the fluorescent powder into a buffer solution having a pH 4.5-5.5 to obtain a suspension; titrating the suspension with the aluminium salt solution to obtain a fluorescent powder coated with Al.sub.2O.sub.3 hydrate film; calcining the fluorescent powder coated with Al.sub.2O.sub.3 hydrate film to obtain a Al.sub.2O.sub.3-coated fluorescent powder; mixing aluminium oxide powder with a particle size of 0.1 μm-1 μm and aluminium oxide powder with a particle size of 1 μm-10 μm to obtain mixed aluminium oxide powder; mixing the Al.sub.2O.sub.3-coated fluorescent powder and the mixed aluminium oxide powder to obtain mixed powder, the Al.sub.2O.sub.3-coated fluorescent powder being present in 40%-90% by weight of the mixed powder; and pre-pressing and sintering the mixed powder to obtain the ceramic composite material.