I am using a 12V,600 rpm PMDC motor. When I start the motor, it takes a little bit of time to reach its max speed due its inertia. My requirement for a specific task is that the motor should reach the max speed as early as possible. I am using 11.1V,30C ,8000 mAh Li-Po battery. Is there any way to achieve it without changing the motor. Can I use capacitor bank to supply the transient currents for overcoming inertia quickly. Please don't downvote.
If the battery is not delivering as much initial current as the motor can tolerate, a capacitor will help. A different battery might also help. If the motor only needs to overcome its own inertia, changing the motor will only help if you can find a motor with a higher ratio of torque to inertia. With a speed of 600 RPM, I suspect the motor includes a speed reduction gear. A gear that is more efficient would help.
To get the maximum rate of acceleration from a given motor, the only answer is the one given by Eugene Sh. "...you will need a controller that has a current controlling loop, providing as much voltage as needed to maintain the maximum allowed current."