No. The Airpod charging case uses a 3.81 V, 1.52 Wh lithium-ion cell battery.
"During the constant current phase, the charger applies a constant current to the battery at a steadily increasing voltage, until the voltage limit per cell is reached.
During the balance phase, the charger reduces the charging current (or cycles the charging on and off to reduce the average current) while the state of chargeof individual cells is brought to the same level by a balancing circuit, until the battery is balanced. Some fast chargers skip this stage. Some chargers accomplish the balance by charging each cell independently."