At its heart, this is a power bank with a 5,300mAh battery inside of it, meaning that it should be good enough to charge your phone at least once over. Its creator also claims that the Pokeball is hand-painted, meaning that this is definitely not one of your mass produced solutions. It also comes with built-in LED indicators to show its status.
According to its creator, “The interior of the plastic shell is hand-painted, carved with a Dremel, and the battery fits securely inside in a vinyl-sealed Pokeball. I made one after Pokémon Go kept draining my battery and I wanted a cool way to keep my phone charged. I love that people immediately know that I’m playing the game too. Each one is crafted to order in my studio in San Francisco. They are fragile and should not be dropped or thrown.”
Note that this is obviously not a Nintendo-approved/licensed accessory, meaning that Nintendo could very well come along and clamp down on its sales, but if you like what you and wouldn’t mind getting your hands on it, it is priced at $40 and is available for purchase via Etsy.