I am not sure this is true as volts=amps x resistance and therefore amps=volts / resistance....volts and resistance are both the same as with a smaller battery so should give exactly the same ampage but last longer!
Your referring to ohms law and ohms law has to do with circuits not batteries. Ohms law states the voltage drop over a circuit is equal to the circuits resistance multiplied by the current. The resistance of the circuit is always the same(as long as the circuit elements don't change) the current depends on the voltage drop applied over the circuit. The larger the voltage the greater the current that can be pushed thru the circuit's resistance.
Batteries are EMF piles that generate a voltage and current by using a the chemical energy of a redux(reduction/oxidation reaction). By oxidizing one metal at the positive end(the anode) and reducing another metal/substance at the negative end(the cathode) the batterties create a voltage potential. The Batteries total Voltage depends upon the relative oxidation/reduction potentials of the respective metals involved as well as the concentrations of the ionic solutions the metals are associated with. The batteries total current(amperage) depends on the quantity of the metals involved.
The maximum discharge rate of a battery is a function of the battery's total available charge(in mAh) multiplied by it's maximum discharge rate(measured in C). So, for example a 3.7V 2400mAh battery with a C rating of 1 can provide an average voltage of 3.7V with a maximum discharge current of 2.4Amps for 1 hour) 2400mAh*1C= 2400mA or 2.4 amps for 1hour. The higher the C rating the higher the maximum discharge current, but the shorter amopunt of time that current can be maintained.
Lets contrast this with a standard Joye 510 battery with a 180mAh rating at 1C. 180mAh*1C= 180mA or .18A for 1 hour. That's a much , much lower possible maximum current that the Joye battery can provide as compared to the 18650 3.7V 2400mAh battery.
Seeing that the Joye 510 atomizer has a resistance of about 2.4ohms and operates at 3.7V, using ohms law it would run optimally at Current=voltage/resistance:::Current=3.7V/2.4ohms= 1.5Amps. Since the JOye 510 battery can only provide a maximum of 0.18Amps at 1C, the atty will be underpowered. The 18650 battery can provide 2.4Amps, so the atty will have all the current it needs(plus more, which it won't use according to ohms law) to run at optimal power.
This is why higher rated batteries outperform lower rated batteries.