I'm a bit confused as to why there is work done against the electric field when charging a capacitor, as charge is moving from high potential to low potential.
For the sake of this question, I'll assume conventional current. Thus, there's an electric field flowing from the anode to what will become the positively charged conducting parallel plate. Let's say the battery is 12V. At first, when the battery is connected to the plates, the voltage of the plates would be zero. So positive charges would want to flow downstream the electric field. Then, the voltage difference between the battery and the positive plate decreases until it reaches zero. But I don't see how at any point the battery has to do any work against the electric field to push charges, as positive charges will naturally want to flow from high voltage to low voltage. I've seen the answer relate to force against the electric field between the plates, but I don't see how this is relevant as charges are not moving between the plates.