As Toyota hesitates on lithium ion battery technology and General Motors races ahead, Canadian startup Zenn is trying to leapfrog them. We've talked about ZENN before and also their deal with EEStor to use their ultra-capacitor technology. EEStor has made some pretty amazing claims as has ZENN. ZENN is claiming that drivers will be able to charge up their cars in five minutes and get a five-hundred-mile range.
While this may indeed be possible it's still very much unproven. Capacitors are able to absorb energy much faster than batteries, which makes them desirable for EV applications where they can absorb the kinetic energy recovered during regenerative braking. However, their capacity is also much more limited. The current generation Honda FCX fuel cell car uses ultra-capacitors but only has a range of about one third of mile on the capacitors. High capacity ultra-capacitors are also very expensive.
Whether EEStor will be able to actually build an ultra-capacitor with a 500-mile range at an affordable price is still very much an open question. Another issue is the five minute charge time. Capacitors don't magically reduce the amount of energy it takes to move a car 500 miles. They just reduce the amount of time it takes to absorb that energy. Just like the Altairnano batteries that can reportedly be charged in ten minutes, you won't be able to get that five minute charge at home. You will need a very thick cable to transfer that much electricity in such a short time and a huge amount of stored energy. Special charging stations will be needed that will be very expensive at first. Charging at home on your 60-200A circuits will take almost as much time as a battery.
[Source: ABC News]