Atomic EV batteries?

Here at Electric Vehicle News we try to report on the latest developments in EV battery technology from Zinc-Air and Lithium-Air research that promises 100 fold increase in energy density to the latest nano Lithium ion developments promising a 100 fold increase in power density. All these developments have one thing in common, they are all rechargeable batteries.

Atomic batteries that don't require recharging and last between 12 and 30 years are being developed for small scale applications that could potentially be scaled up for EV applications. There are quite a few variations on Nuclear batteries and just as many university labs working on them.

One of the most promising types, which is currently being developed for small scale applications such as tiny sensors and actuators, are classed as Betavoltaics and work a lot like a solar cell using a radioactive form of hydrogen, Tritium (the stuff used to illuminate watch faces) as the source of photons instead of the sun. Safety isn't an issue as only Beta particles are emitted (not Gamma) and these are unable to penetrate a piece of paper let alone a battery enclosure.

While an Atomic battery might last a decade without recharging and they do have a high energy density, equal to a lithium battery, they have until recently had a fairly low power density and have been too inefficient to be practical as most of the radiation in early models missed the silicon cell. More recent nano technology developments have allowed researchers at the University of Rochester to pit layers of silicon with micron sized 'wells' that increase the surface area 160 fold increasing the amount of radiation captured. Cells using this technology are now being commercialised by BetaBatt, Inc

More recent developments at the University of Missouri have been the replacement of solid semiconductor material with liquid semiconductor to reduce damage caused over the life of the battery. Still further research at the University of Houston is trying to combine Thermophotovoltaic cells which work the same as photo voltaic but in the infrared range, with thermocouples to provide a 3 to 4-fold improvement in system efficiency over current Radioisotope thermoelectric generator (RTG) that use only low efficiency thermocouples.

Even with a relatively low power density, Atomic batteries could be used in EVs in combination with a conventional chemical rechargeable battery pack. This would work much the same way a Fuel Cell recharges the traction battery in a FCV. While most vehicles spend 80% of their lives parked, an Atomic battery is 'always on' 24/7/365 so can be constantly recharging a vehicles traction battery at a steady rate non-stop for 10 - 100 years (depending on the energy source).

Atomic batteries are made using well known semiconductor techniques with cells up to 'D' size available. They can be stacked in series and parallel like conventional batteries so perhaps it may not be too long before we see a 1 kWh + Tritium battery suitable for EV use.

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