It feels like batteries are getting closer to a breakout, Wh/kg estimates each year recently keeps getting beat, we’re at 500 Wh/kg now, by mid 2030s we might reach 1000 Wh/kg,

https://www.pcmag.com/how-to/what-is-solid-state-battery-for-electric-vehicles

The future points towards 
Solid State Batteries

creating and destroying; built flying cars & autonomous vehicles, now building /faust, more here: /july, web: july.rocks

More battery bullishness: https://www.noahpinion.blog/p/decade-of-the-battery-334