One of the unfortunate aspects of lithium-ion batteries is that over time, their ability to retain and efficiently discharge energy deteriorates. At present, the industry seems to have settled on an eight year, 100,000 mile guarantee that batteries will still retain 70 per cent of their original charge after this time period.
But what if you more than doubled that timespan and multiplied that mileage by ten?
Battery research affiliated with Tesla, undertaken at Dalhouse University in Canada, and published in Journal of The Electrochemical Society suggests that not only is this lofty goal now achievable, Tesla might already have something even more impressive up its sleeve. We can imagine Elon Musk doing his best Dr. Evil impression, saying “One million miles” in a dastardly voice...
The prototype batteries' chemistry and physical form is published in detail within the journal, and in fact, the materials used are broadly the same as those already in widespread use. According to the research, where Tesla's prototype differs is in the size of the cathode. The structure of cathodes in regular EV batteries is susceptible to cracking which reduces charging performance. The experimental battery has a larger cathode structure, making it more resilient over repeated charging and discharging cycles.
In fact, it's so effective that over three years' testing and 4000 charging cycles at temperatures ranging from 20 to 55 degrees Celsius, the battery only lost 10 per cent of its original capacity. And what's particularly intriguing is that with the details available in the Electrochemical Society journal being easily accessible, it can be assumed that Tesla is well on its way to creating something better, albeit this isn't expected to be a solid-state battery.
This research and the technology it is developing has a variety of potential uses that marry closely with Tesla's ambitions – and also fulfils Musk's statement back in April that his company will develop a million mile battery.
For one thing, Tesla acquired battery development company, Maxwell Technologies, earlier this year. This supports the narrative that it will pursue its own battery-based avenues and eventually split from its long-term battery partner, Panasonic.
Another part of Tesla's development plans includes long-haul articulated lorries, which (given their mileage and battery size) would require regular charges and cover many more miles than an average family car. Similarly, the company's plans for autonomous taxis would also necessitate vehicles that are recharged often.
To make either of these plans truly viable, a resilient battery with a long lifespan would be needed. This might just be that battery.
Tesla's existing battery tech is still pretty impressive, and you can find out what we think of it in our Model S Long Range review.