Kyoto University and Toyota test 1,000 km per-charge EV battery

Posted: August 15, 2020 by oldbrew in Batteries, research

Toyota’s Prius model

They say solid-state batteries – unlike lithium-ion ones – can’t catch fire, but on the other hand the electrolyte needs to be warmed up. Years of technical challenges still lie ahead, it seems.
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A team of researchers from Kyoto University and Toyota Motor is making solid progress developing next-generation battery technology that has the potential to cram far more energy into a small, lightweight package than today’s standard lithium-ion, or li-ion, batteries, says Nikkei Asian Review.

The new fluoride-ion battery the researchers are working on, which would hold about seven times as much energy per unit of weight as conventional li-ion batteries, could allow electric vehicles to run 1,000 km on a single charge.

The team has developed a prototype rechargeable battery based on fluoride, the anion — the negatively charged ion — of elemental fluorine.

A fluoride-ion battery, or FIB, generates electricity by shuttling fluoride ions from one electrode to the other through a fluoride-ion-conducting electrolyte.

The prototype was created by a team of researchers led by Yoshiharu Uchimoto, a professor at Kyoto University. It uses an anode, or negatively charged electrode, composed of fluorine, copper and cobalt, and a cathode, or positively charged electrode, made mainly of lanthanum.

The researchers have confirmed that the prototype has a higher theoretical energy density, potentially giving it a range up to seven times longer than today’s li-ion batteries.

The ranges of electric vehicles have increased significantly over the years, due to improvements in li-ion battery performance and deceleration energy recovery systems, which recharge the battery using electricity generated by braking.

Some of the latest EV models from Tesla and Nissan Motor, for instance, can run up to 600 km per charge under ideal conditions. But experts say there is a theoretical limit to the energy density of li-ion batteries, which means their range cannot be extended much further.

The researchers at Kyoto University and Toyota have turned to the FIB because of its theoretically higher energy density. This translates to smaller, lighter batteries with same performance as li-ion cells, or, if they were made the same size and weight as today’s li-ion batteries, could put out juice for longer between charges.

The researchers have gone for a solid electrolyte in place of the liquid ones typically used in li-ion batteries. One key advantage of such solid-state batteries is that they cannot catch fire, which means engineers do not have to worry about creating systems to prevent overheating.

The researchers are betting that a solid-state FIB battery can solve the puzzle of building an EV that can run 1,000 km on a single charge. Many experts remain skeptical, however.

Full report here.

  1. oldbrew says:

    would hold about seven times as much energy per unit of weight as conventional li-ion batteries

    Reviving electric plane dreams?

  2. Bloke back down the pub says:

    If they need to heat the electrolyte, maybe they’ll consider using these.

  3. Gamecock says:

    Cheerleading for EVs.

    They built a prototype. It’s too early for a press release. The message is that technological advancements will cure the problems with EVs.

    They won’t.

    ‘The researchers have confirmed that the prototype has a higher theoretical energy density’

    This makes no sense.

  4. Graeme No.3 says:

    “building an EV that can run 1,000 km on a single charge”, of course you can if you have greater energy density it means more range for the same weight, or less weight for the same range.
    But what is the recharging time? Not much point if you have to charge it overnight (assuming the renewables are delivering and the grid isn’t draining the battery instead).

    “Many experts remain skeptical”, however. Surprise! Surprise! Probably those who wonder about the supply of cobalt and lanthanum.

  5. Gamecock says:

    Yes, Graeme. A range of 600 miles is worthless if you then have to charge the car for 24 hours.

    ICE, you just fill it up at any number of stations. Five minutes, and you are on your way again.

    Improving range doesn’t solve the charging problem. And it IS a problem.

  6. oldbrew says:

    Another report — Toyota’s Quick-Charging Solid-State Battery Coming in 2025 — says:
    Solid-state batteries charge quicker, last longer, and have a larger energy density.

    But then:
    One of the biggest issues with solid-state batteries is their short life span: they tend to fail after repeated charging.

    So which is it: ‘last longer’ or ‘short life span’? Maybe ‘last longer’ refers to how long a single charge lasts — not clear.

  7. cognog2 says:

    I didn’t think experts were allowed to be sceptical.

  8. Tim Spence says:

    Probably takes 7 days to charge.

  9. stpaulchuck says:

    might not work for cars but maybe for stationary systems as backup power?

    Then again, what is the cost per mile driven? If equal to or less than gas and diesel then it will be nice for large cities to reduce exhaust gas pollution of various kinds. Conventional engine designers are continually moving those goal posts though as they make engines cleaner.

  10. “New battery technology will allow us to “realize a new society without making massive infrastructure investments,” says Akira Yoshino, a fellow at chemical maker Asahi Kasei who shared the Nobel Prize in chemistry in 2019″.
    So no investment in a massive grid upgrade then!

    Not much knowledge of electrical supply or business then!

  11. konradwp1 says:

    1000 km range has already been demonstrated by an entirely different technology: the aluminum/air “Battery”. It’s not so much a conventional battery as a chemical reactor.

    The advantages of the aluminum/air power source for EVs is high power density, refueling times as fast as petrol, entirely crash safe and no exotic materials needed for manufacture.

    At a service station you drain the slurry for recycling, top up the electrolyte (which can be salt water) and replace the consumable aluminum.

    Why did people bother with the dead end of lithium? Because “charge at home” was low hanging fruit. You could build EVs for virtue signallers without planned Infrastructure changes to petrol stations and smelters.

    Rechargeable EVs are an engineering dead end.

  12. dennisambler says:

    A fluoride-ion battery. Great potential for electric toothbrushes?

  13. JB says:

    Lanthanum: difficult to mine, time consuming, expensive. Then cobalt, same problem as Li Ion, and copper already up there with aluminum in cost.

    Heavier than iron, copper, cobalt, nickel, zinc.

    Just great for EVs and landfills.

  14. Dodgy Geezer says:

    I just do not think it is safe to store that much energy as electrical charge …

  15. Adam Gallon says:

    No cobalt in these batteries.

  16. Impressive (potentially) but requires cobalt and other exotic elements. So it would be a battery for the elites only. Prohibited by resource limitation from general public use. Like all exotic metal batteries.

  17. Bill Treuren says:

    without nuclear power this is valueless.

    gas coal and hydro pivot around 6C/Kwh Nuclear has the capability of getting there also and lets not discuss the dispatchability because all else simply fail there.

  18. oldbrew says:

    Hunterson – is fluorine just for the prototype? Not clear from the article.

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