Abstract: Provided is a Na based secondary battery including: an anode containing sodium or a sodium alloy; a cathode containing a metal halide, which is a halide of at least one metal selected from a group consisting of alkali metals, transition metals, and Groups 12 to 14 metals, and a solvent dissolving the metal halide; and a sodium ion conductive solid electrolyte separating the cathode and the anode from each other.

Abstract: Provided is a cathode active material for a secondary battery, specifically, a cathode active material for a secondary battery including sodium transition metal pyrophosphate satisfying Na3.12?x2Acx1M1ay1M2by2 (P2O7)z, which has an advantage of structural stability due to a strong P—O bond of sodium transition metal phosphate having an olivine structure, and also performs proper intercalation and deintercalation of Na ions having a large ion radius, thereby significantly improving reversibility during charging and discharging, and a charge and discharge rate.

Abstract: Provided is a current collector including a laminate in which a conductive substrate and an insulator are laminated, wherein the insulator is a porous insulator formed with an open pore channel penetrating through the insulator. The current collector may be used as a current collector for an electrode of a secondary battery and stably maintain capacity of the secondary battery at the time of repeating charge and discharge cycles.

Abstract: Provided is a sodium secondary battery including: a sodium ion conductive solid electrolyte separating an anode space and a cathode space from each other; an anode positioned in the anode space and containing sodium; a cathode solution positioned in the cathode space; and a cathode immersed in the cathode solution and including graphite felt formed with open pore channel of which an opening part is formed on a surface of the graphite felt facing the solid electrolyte.

Abstract: Provided are a solid electrolyte for a sodium secondary battery, and a surface treatment method thereof, and more specifically, a solid electrolyte for a sodium secondary battery capable of having excellent electrochemical performance by improving wettability with respect to molten sodium, even under a low temperature operation environment of 250° C. or less, and a surface treatment method thereof.

Abstract: Provided is a sodium secondary battery including a graphite felt having a maximum porosity on a surface facing a solid electrolyte and a decreased porosity in a thickness direction, as a cathode current collector impregnated with an electrolyte.

Abstract: Provided is a Na based secondary battery including: an anode containing sodium or a sodium alloy; a cathode containing a metal halide, which is a halide of at least one metal selected from a group consisting of alkali metals, transition metals, and Groups 12 to 14 metals, and a solvent dissolving the metal halide; and a sodium ion conductive solid electrolyte separating the cathode and the anode from each other.

Abstract: Provided is a cathode active material for a secondary battery, specifically, a cathode active material for a secondary battery including sodium transition metal pyrophosphate satisfying Na3.12?x2Acx1M1ay1M2by2 (P2O7) z, which has an advantage of structural stability due to a strong P—O bond of sodium transition metal phosphate having an olivine structure, and also performs proper intercalation and deintercalation of Na ions having a large ion radius, thereby significantly improving reversibility during charging and discharging, and a charge and discharge rate.

Abstract: Provided is a method for manufacturing a silicon carbide single crystal using a solution process including coming a seed crystal substrate for growing silicon carbide into contact with a Si—C alloy solution including at least one additive metal and growing the silicon carbide single crystal on a seed crystal for growing silicon carbide, including feeding a silicon feedstock into an alloy solution when a molar ratio of Si and the additive metal is lower than an initially set value as the reaction progresses. The method increases a crystal growth speed, maintains the growth speed, and prevents the growth from unwillingly stopping when the silicon carbide single crystal is manufactured using a solution growth process.

Abstract: Provided are a solid electrolyte for a sodium secondary battery, and a surface treatment method thereof, and more specifically, a solid electrolyte for a sodium secondary battery capable of having excellent electrochemical performance by improving wettability with respect to molten sodium, even under a low temperature operation environment of 250° C. or less, and a surface treatment method thereof.

Abstract: Provided is a sodium secondary battery including: a sodium ion conductive solid electrolyte separating an anode space and a cathode space from each other; an anode positioned in the anode space and containing sodium; a cathode solution positioned in the cathode space; and a cathode immersed in the cathode solution and including graphite felt formed with open pore channel of which an opening part is formed on a surface of the graphite felt facing the solid electrolyte.

Abstract: Provided is a sodium secondary battery including: a sodium ion conductive solid electrolyte separating an anode space and a cathode space from each other; an anode positioned in the anode space and containing sodium; a cathode solution positioned in the cathode space; and a cathode immersed in the cathode solution and including graphite felt formed with grooves arranged in parallel with each other in a surface of the graphite felt facing the solid electrolyte.

Abstract: Provided is a sodium secondary battery including a graphite felt having a maximum porosity on a surface facing a solid electrolyte and a decreased porosity in a thickness direction, as a cathode current collector impregnated with an electrolyte.

Abstract: Provided is a current collector including a laminate in which a conductive substrate and an insulator are laminated, wherein the insulator is a porous insulator formed with an open pore channel penetrating through the insulator. The current collector may be used as a current collector for an electrode of a secondary battery and stably maintain capacity of the secondary battery at the time of repeating charge and discharge cycles.

Abstract: Provided is a method for manufacturing a silicon carbide single crystal using a solution process including coming a seed crystal substrate for growing silicon carbide into contact with a Si—C alloy solution including at least one additive metal and growing the silicon carbide single crystal on a seed crystal for growing silicon carbide, including feeding a silicon feedstock into an alloy solution when a molar ratio of Si and the additive metal is lower than an initially set value as the reaction progresses. The method increases a crystal growth speed, maintains the growth speed, and prevents the growth from unwillingly stopping when the silicon carbide single crystal is manufactured using a solution growth process.

Abstract: Provided are a burner and an aftertreating device of exhaust gas, which employs a simple construction using the flame protection tube, thereby increasing stability in forming the flame without the loss of back pressure and also uniformly heating the exhaust gas.

Abstract: The present invention is directed to a solid electrolyte and a process for making the same for a sodium-sulfur secondary cell including a composition of 7.0 to 10.0 weight percent of Na.sub.2 O, 0.5 to 3.5 weight percent of MgO or 0.7 to 1.0 weight percent of Li.sub.2 O, 0.01 to 0.6 weight percent of WO.sub.3, and the balance of Al.sub.2 O.sub.3. The solid electrolyte is prepared by mixing Na.sub.2 O, MgO, Li.sub.2 O, WO.sub.3, and Al.sub.2 O.sub.3, calcining the resulting mixture, pulverizing the calcined body, and subjecting the resulting powders to sintering. Alternatively, the solid electrolyte is prepared by mixing Na.sub.2 O, MgO, or Li.sub.2 O, and Al.sub.2 O.sub.3 with one another, calcining the mixture, adding WO.sub.3 to the calcined body, pulverizing the resulting material, and subjecting the resulting powders to sintering.