The Yellow Jacket Black Shock iPhone Cover is a handy self defense accessory for your phone. It enables you to convert your phone into a stun gun. It offers a rechargeable battery that provides the punch and can also charge your phone. It features durable PC and ABS hard plastic construction that pr... Read more
This stun gun looks like a smartphone!
It exists!
This portable solar charger for devices looks like a nice alternative
I found this company that makes solar-charging phone cases.
They are pretty common. You can buy them on Amazon.