Electric current flows in two ways, an alternating current (AC) or direct current (DC).
In alternating current, the current keeps switching directions periodically – forward and backward.
While in the direct current it flows in a single direction steadily.
All lithium or lithium-ion batteries that are used in different electronic devices operate with direct current (DC) which is mainly generated from chemical reactions that occur inside the battery.
In general, all batteries operate with DC current and then inverters convert the current to AC which is then used by AC appliances.