Well, anyway. I don't know how realistic this is. Claims about various future breakthroughs often seem to fall into two camps: far too pessimistic or far too optimistic, and I'm not sure that there's always much in between really.
I'm reminded of a throwaway line in Apollo 13, for example, when Tom Hanks' character promises that NASA is working on such breakthroughs as "computers that can fit into a single room"; or that quote to Whittle about jet engines: "very interesting, my boy, but it will never work".
Who knows which one this is? But, as a general rule of thumb, if you throw enough resources at what is basically an engineering problem then you will usually end up solving it at some point. It wouldn't surprise me in the least if battery-powered planes, at least for short-haul flights, became a reality at some point.