The primary battery can only be discharged once, and the secondary battery can be repeatedly charged and discharged for recycling. The rechargeable battery has a reversible change between the electrode volume and the structure during discharge. Therefore, these changes must be adjusted during design, and the interior of the primary battery is much simpler. Because it does not need to adjust these reversible changes, the mass ratio capacity and volume specific capacity of the primary battery are larger than that of the general rechargeable battery, but the internal resistance is much larger than that of the secondary battery, so the load capacity is low, and the self-discharge of the primary battery is far. Less than the secondary battery.