News of new battery technologies breaks regularly, most researchers claiming to have devised a system promising greater range, better stability, lighter weight, lower cost--all characteristics desirable in electric vehicles.
All require a caveat though: This technology may never get beyond the research stage. And that's exactly what has happened with one technology developed by Dalhousie University and at Argonne National Laboratory.
The cathode design was actually patented as far back as 2000, but recent developments in electric vehicles finally brought the technology to the fore.
Promising twice the capacity of a traditional lithuim-ion battery, the NMC cathode relied on a jolt of extra voltage in order to unlock its potential--the battery would operate at about 4.7 volts, rather than the 3.7 volts of a regular lithium-ion battery.
However, researchers realized that during charge and discharge cycles, the battery would suffer a steep loss of energy. They called this 'voltage fade', and while startup Envia Systems had an attempt at fixing this issue, the company soon had bigger issues.
Essentially, the mixture of elements in the cathode was breaking down under high voltage. Tony Burrell, director of the battery department at Argonne, described it as a "fundamental property" of the material--"like being surprised that wood combusts with oxygen".
Jeff Dahn, the man who originally pioneered the design, believes it's not as big an issue as some are making out, and that the difficulties NMC experiences at higher voltage don't necessarily make it useless.
However, it's clearly a setback for companies like General Motors, which had put faith (and money) into the technology with the aim to use it in their next generation of electric vehicles--a way of extending range and reducing the cost of future batteries.
NMC still has potential, but its benefits now look much smaller than they did originally, and one of the benefits, that of cost, still applies regardless of the cathode's effectiveness. Nickel, cobalt and aluminum (NCA) cathodes used by Tesla cost $60 per kWh according to Argonne--NMC costs $45 per kilowatt-hour.
NMC isn't dead yet then, but it certainly isn't the breakthrough the battery world was predicting. Consider it therefore a lesson for future battery technologies, too.