You will have to look up the motor specs and see if it is rated at 11.1V. Now the bad news, you will get more performance but I would expect the same flight duration. Adding an additional cell slightly increases the battery's internal resistance. The motor will pull more current at the higher rpm unless you drop down in prop size. You will also need to use more throttle with the increase in weight. Think of it like adding a supercharger to your car. It increases efficiency but adds power in the process. It requires fuel to produce power, in this case it is amps.