Salt water batteries, also known as salt batteries or sodium-ion batteries, are a new type of battery technology. They use a salt water electrolyte as the core chemical material, making them one of the safest potential future energy storage solutions as an alternative to lithium-ion batteries.

In saltwater batteries, a liquid solution of salt water is used to capture, store, and eventually discharge energy. Whereas a traditional lithium-ion battery uses lithium as its primary ingredient for conducting electricity, a saltwater battery uses sodium, the same element found in table salt.