Interesting article and I wish Formula E luck and success !

BUT:
" ...  so the only noise they produce is a persistent whine from the lithium-ion battery packs ...." 
News flash  .-)
Lithium ion batteries don't "whine" - they discharge their energy quietly without the racked of exploding gasoline fumes ! What you may be hearing is elecftric motor and drive train whine, air flow, tires ....