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Old Battery Type Gets an Energy Boost

Discussion in 'Battery Discussion' started by Tharo, Feb 23, 2015.

  1. Tharo

    Tharo Member

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    The chemical company BASF says the basic type of battery used now in hybrids could be improved tenfold, leading to cheaper electric cars.


    By Kevin Bullis on February 19, 2015
    WHY IT MATTERS


    Nickel-metal hydride batteries wouldn’t require the heavy, expensive safety systems needed by the lithium-ion batteries used in electric cars now.


    Almost every automaker interested in producing electric cars is betting on improvements to lithium-ion batteries to make the cars cheaper and extend their driving range.


    But scientists at BASF are exploring the possibilities of an older type of battery, nickel-metal hydride, now used in hybrids. They recently doubled the amount of energy that these batteries can store, making them comparable to lithium-ion batteries. And they have a plan to improve them far more, potentially increasing energy storage by an additional eight times.


    The BASF researchers are aiming for batteries that cost $146 per kilowatt-hour, roughly half as much as the cheapest lithium-ion electric car batteries.


    Lithium-ion batteries have been preferred in many applications because they’re lighter and more compact—that’s why they’ve superseded nickel-metal hydride batteries in most portable electronics.


    But nickel-metal hydride batteries have some significant advantages in cars, which is why they’ve been used in hybrids for decades. They’re durable, and inherently safer than lithium-ion batteries, partly because they don’t use flammable liquids, as lithium-ion batteries do—they don’t catch fire if they overheat or are overcharged so their cooling systems and electronic controls are far simpler. Safety systems can add about 25 percent to the cost of a lithium-ion battery pack, and increase their weight by 50 percent, based on data from the industry group U.S. Advanced Battery Consortium.


    To these inherent advantages, the BASF scientists added improvements to the nickel-based materials used in the batteries. Changing the microstructure helped make them more durable, which in turn allowed changes to the cell design that saved considerable weight, enabling storage of 140 watt-hours per kilogram.


    Lithium-ion battery cells can store far more—230 watt-hours per kilogram in some cases. But when you factor in the added weight of the safety systems, and the fact that much of the energy is held in reserve to reduce wear and tear and allow for energy storage capacity fade over time, that advantage can disappear.


    One recent analysis found that the total usable amount of energy storage in lithium-ion electric car batteries is between 60 and 120 watt-hours per kilogram. Researchers still need to test whether BASF’s cells can last as long as conventional nickel-metal hydride batteries.


    The next step for BASF is to introduce more radical changes to nickel-metal hydride batteries, swapping out the materials used now for ones that can store more energy and withstand higher voltages.



    BASF Doubles Nickel-Metal Hydride Energy Storage | MIT Technology Review
     
  2. deckofficer

    deckofficer Member

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    It is my belief that after the GM EV1 switched to NiMH, its range went from 60 miles with lead to 180 miles. After the oil companies brought suit against California for the zero emission mandate, and it was repealed, GM crushed them and Chevron Oil purchased the patents to NiMH above 10 ahr to insure no further threat from BEVs.

    Has that patent run out? In my projects the only NiMH cells I can get are D cells at 10 ahr.
     
  3. JohnSnowNW

    JohnSnowNW Active Member

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    That article seems a bit...optimistic.
     
  4. liuping

    liuping Active Member

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    Every few weeks there is a "battery breakthrough" article published. I no longer get excited about them, as they never seem to pan out.

    I'm still hopeful though. It will happen eventually. In the mean time, I'll enjoy the power from our actually-existing-and-working-in-the-real-world lithium-ion batteries.
     
  5. dpeilow

    dpeilow Moderator

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    I guess the original patents are running out an there are no longer restrictions on plug-ins.
     
  6. rolosrevenge

    rolosrevenge Dr. EVS

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    As Elon would say, show me the cells.
     
  7. AWDtsla

    AWDtsla Active Member

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    S85 pack is 85000/(1323/2.2) = 140.8 Wh/kg.

    But yes, Chevron/Texaco NiMH patents supposedly expired at the end of 2014. It's likely to see improvement of NiMH, if nothing else because they are in the consumer space.
     
  8. David99

    David99 Active Member

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    I didn't know they bought patents only to stop the development. How messed up is that! I always wondered why NiMH cells stalled in development. They are very robust and have excellent cycle life. They can also handle high power well.
     
  9. deckofficer

    deckofficer Member

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    Your surprised an oil company would do that? I worked in that industry and believe me Big Oil is no angel.
     
  10. Moonwick

    Moonwick Member

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    http://www.batteryspace.com/nimhrechargeablecellm-size12v26ah52arate.aspx

    1.2v 26Ah NiMH cells. I came across those recently, but haven't gotten around to buying any to experiment with. Unfortunately the price per amp-hour doesn't compare all that favorably with typical AA cells (1x26Ah for $40 vs. 10x2.5Ah for ~$2/cell working out to roughly $20.)
     
  11. David99

    David99 Active Member

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    From the specs:


    • Energy Density: 78.98 wh/kg
    • Can be rapidly charged at 0.2 C

    Half of what Lithium cells are in energy density and 0.2C is anything but 'rapid' :/

    cycle life is 500 which is a showstopper for EVs as well. It would mean within 2 years it would have lost 20% of it's capacity.
     
  12. Moonwick

    Moonwick Member

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    Oh, yeah, these definitely wouldn't be useful for an EV, but they might be for other projects. I was mainly pointing them out as an example of generally-available cells > 10 Ah.
     
  13. David99

    David99 Active Member

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    They are definitely better than any lead acid battery in electric scooters or electric kids cars and such. Sanyo has done some excellent work with NiMHD batteries with their Eneloop batteries. Battery management and safety is definitely better that Lithium. If they can improve them, it could become an realistic alternative where a simpler and safer setup is of advantage.
     
  14. 30seconds

    30seconds Active Member

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    You can use someone else's patents in development - you just can't sell anything. In other words if these patents were the essential blocking patents the companies interested in marketing improved cells could have them ready to go upon patent expiration.
     
  15. neroden

    neroden Happy Model S Owner

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    I believe it has, or if not, it's about to run out. Patents only last 20 years.
     

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