Advantages of sodium-sulfur batteries: One is higher than energy. Its theoretical specific energy is 760W·h/kg, which is actually more than 100W·h/kg, which is 3-4 times that of lead-acid batteries; the other is high-current, high-power discharge. The discharge current density is generally up to 200-300 mA/mm2, and its intrinsic energy can be released three times instantaneously; the other is high charging and discharging efficiency. Since a solid electrolyte is used, there is no self-discharge and side reaction which usually employs a liquid electrolyte secondary battery, and the charge and discharge current efficiency is almost 100%.
The disadvantage of sodium-sulfur battery is that its working temperature is 300-350 °C. Therefore, the battery needs certain heating and heat preservation when working. The high temperature corrosion is serious and the battery life is short. High-performance vacuum insulation technology has been used to effectively solve this problem. There are also problems such as poor performance stability and poor safety of use.