A Texas company called EEStor has announced a type of battery it calls an Electrical Energy Storage Unit, or EESU. It uses barium-nitrate powder and stores 10 times as much energy as a lead-acid battery, by weight. It also recharges much more quickly than lead-acid or lithium-ion batteries.
EEStor claims that, using an automated production line and existing power electronics, it will initially build a 15-kilowatt-hour energy-storage system for a small electric car weighing less than 100 pounds, and with a 200-mile driving range. The vehicle, the company says, will be able to recharge in less than 10 minutes. The company announced this week that this year it plans to begin shipping such a product to Toronto-based ZENN Motor, a maker of low-speed electric vehicles that has an exclusive license to use the EESU for small- and medium-size electric vehicles.
By some estimates, it would only require $9 worth of electricity for an EESU-powered vehicle to travel 500 miles, versus $60 worth of gasoline for a combustion-engine car.
Reader comment:
Dan says:
The EEStor ultra capacitors will certainly be an awesome technology if they work out, but it’s important to note that these are not batteries. Batteries store energy by electrochemically converting ions to neutral species at electrodes, supercapacitors work by building up a densely charged surface that actually violates electronuetrality, called the “double layer”. Because the creation of this double layer is an absorption/adhesion phenomenon and not a chemical reaction it is much faster (hence why typical capacitors have at least 10X the power density of the best battery) and there is little degradation over time and use (thus the capacitors can be cycled almost endlessly while the best lithium-ion batteries have cycle lives of 10 K at best).
The classic trade-off, however, is that because this double layer is such an affront to nature, the amount of charge it can store per unit mass of the cell is a small fraction of what a battery can store per unit mass. In the past ten years tricks using extremely high surface area electrodes for capacitors have narrowed the gap, but currently the best ultracaps still only have 5% to 10% the energy storage capability per unit mass. The EEstor folks are claiming a 2X improvement over Li-Ion in energy density while maintaining the 10x improvement in power density. If this pans out it will be a truly amazing feat, but because it’s such a massive improvement in an area that many folks have been plowing at for a while, these initial blurbs should be taken with a pretty coarse grain of salt.
Mike “the lapsed electrochemist in the SFO Bay Area” says:
I did my grad work on electrochemistry of systems similar to these.
FYI/FWIW – the chemical compound of interest is not Barium Nitrate. It’s
Barium Titanate.BIG difference!
As has already been noted, these systems are electrochemical capacitors, and
not batteries per se.Although, Dan’s comment is not strictly correct either.
Batteries chemically store energy which can be released via reduction and
oxidation of chemicals at their respective electrodes.Electrochemical capacitors create charged double layers of ions (BTW, ions
are molecules/atoms that carry a net positive/negative charge). The
separation of charge that occurs in this double layer is stable and
reversible.Classical capacitors accumulate a charge via a plate-dielectric structure.
You COULD think of the electrochemical capacitor as the molecular equivalent
of a capacitor. Although, the analogy is very simplistic.Yup,
The devil is in the details…
It’s all vaporware until I see it on the shelf…
But it’s still good fun.