I don't think there is any such thing as a 5V lithium ion battery.
Depending on the chemistry, battery cells have a characteristic voltage based on the chemistry, and multi-cell batteries are multiples of that voltage. For example, Lipo batteries have a nominal voltage of 3.7 volts, or 7.4 volts, or 11.1 volts ..... not 5V
Also, the capacity of a charger is determined by it's current supply ability, not the size of the battery. For a specified charger output current, bigger batteries just take longer to charge.