Generally, column-shaped power banks are made of lithium ions, while laminated batteries are made of lithium polymer. They are nominally 3.6V, fully charged at 4.2 or 4.3V, and the discharge cutoff voltage is typically 2.8 to. 3v.
At present, mobile power banks mainly use lithium polymer batteries as energy storage units. It itself is a lithium polymer battery storage device that replenishes and stores electrical energy through its own AC outlet, regulates the voltage through the IC chip, then charges or stores the electricity by connecting to the power cord, then releases the stored electricity. banks are still relatively rare in today's market, and mobile power banks are more commonly called mobile power banks.