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 are an electrolyte for a sodium secondary battery and a sodium secondary battery using the same. More particularly, the sodium secondary battery includes an anode containing sodium, a cathode containing a transition metal, and a sodium ion conductive solid electrolyte provided between the anode and the cathode, wherein the cathode is impregnated in an electrolyte containing a molten sodium salt and an electrolyte additive, the electrolyte additive including an inorganic sodium salt.

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 capable of operating at a low temperature. More particularly, the sodium secondary battery according to the present invention includes: an anode containing sodium; a cathode containing a transition metal and an alkali metal halide; and a sodium ion conductive solid electrolyte provided between the anode and the cathode, wherein the cathode is impregnated in a molten salt electrolyte containing a sodium.metal halogen salt including at least two kinds of halogens.

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 are an electrolyte for a sodium secondary battery and a sodium secondary battery using the same. More particularly, the sodium secondary battery includes an anode containing sodium, a cathode containing a transition metal, and a sodium ion conductive solid electrolyte provided between the anode and the cathode, wherein the cathode is impregnated in an electrolyte containing a molten sodium salt and an electrolyte additive, the electrolyte additive including an inorganic sodium salt.

Abstract: Provided is a sodium secondary battery capable of operating at a low temperature. More particularly, the sodium secondary battery according to the present invention includes: an anode containing sodium; a cathode containing a transition metal and an alkali metal halide; and a sodium ion conductive solid electrolyte provided between the anode and the cathode, wherein the cathode is impregnated in a molten salt electrolyte containing a sodium.metal halogen salt including at least two kinds of halogens.

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: Disclosed is a vehicle charging device for generating electricity by applying pressure to a piezoelectric element through tire rotation by preparing the piezoelectric element in a tire portion of a vehicle. The vehicle charging device according to one embodiment of the present invention includes: an elastic part interposed between a wheel and a tire of the vehicle to be expansible in a radius direction of the wheel and the tire; and a piezoelectric element prepared at an end (or ends) of one side of both sides of the elastic part to generate power by receiving a pressure from the elastic part and connected to a battery of the vehicle to charge the battery with the generated power.