Sodium-sulfur battery

Abstract

The invention discloses a sodium-sulfur battery in the field of energy storage. The sodium-sulfur battery comprises a ceramic electrolyte tube and a sodium storage tube which is sleeved inside the ceramic electrolyte tube, wherein the bottom surface of the sodium storage tube is provided with at least one through hole, a cathode chamber of the sodium-sulfur battery is formed between the sodium storage tube and the ceramic electrolyte tube, the bottom surface of the sodium storage tube is flat, a sodium storage tube hemispherical body is arranged right below the sodium storage tube, a gap is reserved between the sodium storage tube and the sodium storage tube hemispherical body, a fiber buffer layer is arranged between the bottom surfaces of the sodium storage tube hemispherical body and the inner wall of the ceramic electrolyte tube, and the fiber buffer layer is free from wetting liquid sodium. The sodium-sulfur battery has beneficial effects that under the situation that the through hole in the bottom surface of the sodium storage tube can be effectively sealed, the requirement on the dimensional precision of the ceramic electrolyte tube can be lowered, and the manufacturing cost of the sodium-sulfur battery can be reduced.

Description

technical field [0001] The invention relates to a sodium-sulfur battery in the field of energy storage. Background technique [0002] The core key component of sodium-sulfur battery is β”-Al 2 o 3 Made of ceramic electrolyte tubes, the cycle life of sodium-sulfur batteries depends largely on the quality of ceramic electrolyte tubes. Once the ceramic electrolyte tube has microcracks or breaks, the liquid sodium and liquid sulfur will directly contact and react violently, the temperature can reach up to 2000 ° C, and instantly melt the metal parts such as the sodium storage tube in the sodium-sulfur battery, resulting in liquid sodium and liquid sulfur. of leaks. [0003] The existing sodium-sulfur battery is mainly composed of a metal case, a ceramic electrolyte tube and a sodium storage tube. In addition, liquid sodium and liquid sulfur serve as active materials, the metal case serves as a current collector and stores liquid sulfur, and the sodium storage tube is a storag...

AI Technical Summary

Problems solved by technology

Once the ceramic electrolyte tube has microcracks or breaks, the liquid sodium and liquid sulfur will directly contact and react violently, the temperature can reach up to 2000 ° C, and instantly melt the metal parts such as the sodium storage tube in the sodium-sulfur battery, resulting in liquid sodium and liquid sulfur. the leak

[0003] The existing sodium-sulfur battery is mainly composed of a metal case, a ceramic electrolyte tube and a sodium storage tube. In addition, liquid sodium and liquid sulfur serve as active materials, the metal case serves as a current collector and stores liquid sulfur, and the sodium storage tube is a storage container for liquid sodium. and limit the flow rate of liquid sodium

The safety structure of the existing sodium-sulfur battery mainly utilizes the difference between the expansion coefficients of the ceramic electrolyte tube and the sodium storage tube. When the temperature of the sodium-sulfur battery rises, the expansion degree of the sodium storage tube is greater than that of the ceramic electrolyte tube. The gap between the outer wall of the tube and the inner wall of the ceramic electrolyte tube is closed, and the liquid sodium in the sodium storage tube no longer flows into the gap, limiting the reaction of liquid sodium and liquid sulfur, but once the temperature drops, the liquid sodium and liquid sulfur will continue to react, and the fatigue strength of the sodium storage tube is reduced

The bottom surface of the existing ceramic electrolyte tube and the bottom surface of the sodium storage tube are all hemispherical, and there is a certain tolerance in their roundness. At the same time, there is a certain deviation in the length of the ceramic electrolyte tube. The gap between the inner wall of the ceramic electrolyte tube and the inner wall of the ceramic electrolyte tube is difficult to be effectively closed. At the same time, the bottom surface of the sodium storage tube also produces compressive stress on the bottom surface of the inner wall of the ceramic electrolyte tube. Once the ceramic electrolyte tube ruptures, the sodium storage tube is damaged, and a large amount of liquid sodium It flows directly from the through hole at the bottom of the sodium storage tube and reacts violently with liquid sulfur

Therefore, the dimensional accuracy of the ceramic electrolyte tube in the prior art is very high, which increases the manufacturing cost of the sodium-sulfur battery.

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