A high vacuum packaging method for sodium-sulfur batteries

Abstract

The invention discloses a high-vacuum packaging method of a sodium-sulfur battery. The high-vacuum packaging method comprises the following steps of: carrying out a vacuum pumping step on a container, to be specific, installing a battery into the sealed container with a press inside, and carrying out vacuum pumping on the sealed container until the vacuum degree of 1*10<-2>Pa; carrying out a vacuum press mounting step, to be specific, firstly starting the press, pressing a bottom seal cover into a battery positive electrode shell when the pressure of a pressure head of the press reaches 780-820Kg, then releasing the pressure of the press, charging air into the sealed container to enable the pressure inside the sealed container to reach the atmospheric pressure, and then taking the battery to be welded out of the sealed container; and carrying out an atmospheric welding step, to be specific, welding and fixing a joint surface between the bottom seal cover and the positive electrode shell through a laser welding way under an atmospheric working condition. Due to the adoption of the high-vacuum packaging method, a positive electrode container of the sodium-sulfur battery can stay in high vacuum, the positive electrode shell and the bottom seal cover can be finally welded and sealed through the laser welding way in an atmospheric environment, and stable welding quality can be guaranteed.

Description

technical field [0001] The invention relates to a high vacuum packaging method for a sodium-sulfur battery. Background technique [0002] Sodium-sulfur (NaS) battery is a rechargeable battery composed of sodium for the negative electrode, sulfur for the positive electrode, and ceramic alumina materials for the electrolyte. It has the advantages of high energy storage density, high efficiency, low operating cost, easy maintenance, no pollution to the environment, and long service life. [0003] The key component of the sodium-sulfur battery is the positive electrode container, which is composed of the positive electrode casing and the bottom sealing cover. Therefore, the packaging of the positive electrode casing and the bottom sealing cover is the key to ensuring the sealing of the positive electrode container. The existing fixed connection of the positive electrode casing and the bottom sealing cover is carried out in a vacuum box: first put the positive electrode casing a...

AI Technical Summary

Problems solved by technology

The problems brought about are: first, due to the large volume of the confined space, the time required for vacuuming to reach the required vacuum degree is relatively long, and the loading and unloading process of the battery is also relatively cumbersome. , resulting in insurmountable production time and production cost problems; secondly, the high degree of vacuum requires high structural strength of the vacuum box, which will double the cost of the vacuum box; in addition, the carbon felt at the bottom of the positive container is often There is a phenomenon of carbon fiber falling off. When vacuuming, the carbon fiber is often drawn out and stays at the junction of the bottom sealing cover and the positive electrode casing. The carbon fiber can withstand high temperature (1000 degrees Celsius), and the high temperature during laser welding will not melt. Therefore, the bottom sealing cover and the positive electrode shell will not melt. The carbon fiber filaments at the seam of the positive electrode case often cause the vacuum state in the positive electrode container to drop