What has a small Canadian low-speed vehicle firm and Tesla CEO Elon Musk got in common? 


Just like Zenn and the troubled EEstor supercapacitor firm,  Tesla CEO Elon Musk thinks that batteries are so last century. 

Talking at the Cleantech Forum in San Francisco on Wednesday this week, the 39 year old entrepreneur told the assembled audience that he’d bet on supercapacitors, not batteries, to deliver an important breakthrough in electric vehicle range. 

Unlike batteries, supercapacitors do not lose the ability to store charge with age. As a consequence they could potentially offer future where electric car owners are not faced with the worry of battery packs wearing out before the car does. 

Supercapacitors also have a much higher power density than batteries, meaning they can provide power far more quickly than existing battery technology. 



With extremely high efficiency capable of supplying up to 95% of the energy used to charge it on discharging, a supercapacitor isn’t carrying around a dead weight of unusable capacity.

But there are significant problems with supercapacitors too. At the moment supercapacitors have a very low energy density, meaning they cannot store as much energy per lb of weight as a conventional lead acid or lithium-ion battery. In addition, supercapacitors discharge more rapidly in storage than batteries, meaning a stored electric car with a super-capacitor pack could run out of charge while in storage. 

Also, the voltage of a supercapacitor behaves much more linearly than a battery when discharged, meaning that a fully charged supercapacitor pack will suffer voltage drop more quickly than an identically sized battery pack. In order to make use of such a pack, complex power circuitry and management would be needed.

Even with these disadvantages, supercapacitors could very well cut our dependence on the humble battery pack. Simpler and faster to charge, longer-living and in some ways more versatile, supercapacitors are the holy grail of energy storage.

And Elon Musk Knows it. After studying high-energy capacitors as part of Ph.D work at Stanford University before co-founding Internet payment portal PayPal, his desire to include supercapacitors in a future Tesla electric car is obvious.