Volkner is one of Sinnoh's Gym Leaders, specializing in the Electric Type. He runs the Sunyshore Gym. His rival and childhood friend is the Elite Four member
Flint, and the two are seen hanging out a lot. Volkner may be the descendant of
Ginter, but this has not been confirmed.
Pokémon the Series
Ash arrived at the Sunyshore Gym gym to have a battle with Volkner but he was depressed and did not want to battle trainers anymore. He left a box of gym badges at the entrance to the gym but Ash wasn't satisfied with receiving a badge without battling.
After encountering Flint outside the Sunyshore Gym, Flint took Ash and his friends to the Sunyshore Tower where they met Volkner. After Ash had a battle with Flint, Volkner agreed to have a battle with Ash.