Sodium-ion battery is a rechargeable battery that uses sodium ions as charge carriers. Its working principle and structure are similar to lithium-ion batteries. The only difference is that lithium is replaced by sodium, which is in the same group of the periodic table and has similar chemical properties. The earth is rich in sodium resources, although its energy density is not good as lithium batteries, it has low cost, good low-temperature performance, great safety and high interoperability with lithium battery manufacturing. For energy storage and other applications, sodium batteries may It can provide a new development direction for the battery industry.