Yesterday a battery recharge in a minute. Today a charge that lasts twice as long
via Flickr © scalespeeder (CC BY 2.0)
It's like waiting for a Number 9 bus into Central London. You hang around for ages and then a whole posse of them come along together. And it is the same it seems with new battery technology. Yesterday TelecomTV reported on a new system from Israeli start-up company StoreDot that will permit smartphones and other telecoms devices to be recharged in just a minute.
And now comes news that a Boston, US company (a start-up, spun-out in 2012 from the highly prestigious Massachusetts Institute of Technology) SolidEnergy Systems, has also made a breakthrough in battery technology. Their solution is a battery that, rather than re-charging within a few seconds, lasts twice as long between charges.
The prototype SolidEnergy Systems battery is very similar in size, weight and format to current lithium-ion batteries and they use good old tried-and-tested electrodes, anodes, cathodes and electrolytes to provide a regulated supply of ion energy. However, SolidEnergy Systems has added its own twist to the established recipe via the use of new materials.
In essence with the SolidEnergy system the conventional graphite anode is replaced by one comprising an amalgam of lithium and copper. The new anode is a thin film of metallic foil some 20 per cent of the thickness of today's common graphite anodes yet able to store ten times the number of ions.
The founder and CEO of SolidEnergy Systems, Qichao Hu, admits that the basic concept of what has been called "anode-less technology has been around for years now and many attempts have been made to produce a next generation battery by using the the concept. Mr. Hu says his company's approach is different to what has gone before because, from the outset, the new battery was designed for mass production rather than as a research-based, "pie-in-the-sky" laboratory prototype.
Hu says, “From day one, we wanted to make sure that we weren’t developing something that couldn’t easily be replicated on a production line. The battery we’re developing is something that can be put together using the same existing specialised equipment, techniques and criteria as what’s used for the ones being manufactured right now.”
SolidEnergy Systems new battery was built and tested at the manufacturing facility run by A123 Systems in Livonia, Michigan and the company has verified and certified the new battery's claimed capabilities.
At least this one shouldn't explode or burst into flames
Most of the earlier experiments into new battery technologies by other companies tended to have a major drawback. Prototypes either quickly stopped working or exploded and burst into flames after a few recharge cycles. SolidEnergy Systems seems successfully to have resolved these little difficulties that might have some effect on consumer confidence.
The trouble is that lithium metal can react badly with a battery cell’s electrolyte, and thus produce unwelcome compounds that hold on lithium ions and prevent them producing electrical current. This phenomenon significantly reduces the energy the battery can store whilst also forming 'dendrites', spikes of material that can cause short circuits that produce sufficient heat to set the battery on fire. Not good in a smartphone.
SolidEnergy Solutions seem to have obviated this problem by using both a solid and liquid electrolytes where the solid electrolyte is applied to the lithium-metal foil with the result that ions can easily and relatively slowly pass through the thin membrane.
Once through the solid electrolyte they make contact with the liquid electrolyte which provides a path into the opposite electrode. The solid electrolyte from SolidEnergy Solutions is not flammable (unlike today's conventional liquid electrolytes) and is doped with additives that stop lithium metal from reacting with it and so prohibit the formation of dendrites.
But not for electric cars - yet
SolidEnergy readily admits that its new battery technology will, for the time being, pertain only to the mobile technology devices market and not to battery-driven vehicles. That's because the new battery cannot be recharged many thousands of times. Indeed, the prototype certified by 123 Systems has a recharge lifetime of 300 cycles while retaining 80 per cent of its original storage capabilities.
Given such a limited lifespan compared to the number of times a conventional mobile device battery can be recharged the economics behind the development are particularly important. SolidEnergy estimates that an initial 12 million unit iteration of its battery would cost some US$400 per KWh which is about 80 percent of what lithium-ion batteries cost.
John Wozniak, a noted expert in battery technology and now an independent consultant after spending five years at Energiser and 12 years as a 'Distinguished Technologist' at HP says the big drawback to SolidEnergy's plans is that “big manufacturers prefer to do it all in house, so they’d rather figure out how a new technology works and tweak the formula to get around a patent,” he says adding, "Licensing deals are possible though".
And that is what is happening with SolidEnergy Systems. The company is in detailed negotiations with Google to provide a new custom-designed and built battery for Project Ara, which is a modular phone concept based on a structural exoskeleton within which various comms modules such a cameras and extra batteries can be mounted and demounted. Another potentially lucrative avenue is in manufacturing batteries for drones. Currently the flight time of drones is, at most, 30 minutes and often much less.
Qichao Hu is bullish about the prospects for the new battery. He says, “I know there are some people who may be sceptical of whether we will finally see these significant leaps in battery life because making it happen requires materials improvements and that usual takes quite some usually takes time. However, it took us only 12 months to make a good working prototype, and we expect to accomplish much more this year.