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View Diary: A Better Battery Changes The World, Crossing The Alt-E Threshold (175 comments)

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  •  why? maybe because (3+ / 0-)

    I've worked with reactive chemicals and seen what can happen when "high energy" chemical reactants are mixed (like they are in single-phase batteries).

    Fake Left, Drive Right . . . not my idea of a Democrat . . .

    by Deward Hastings on Mon Apr 28, 2014 at 07:37:10 AM PDT

    [ Parent ]

    •  Rate of reaction vs. energy density are different (12+ / 0-)

      things.  Seriously, the few megajoules in a car battery, if released all at once, would be a 'significant' threat.

      Also, from an engineering perspective, fewer moving parts is a good thing.

      If you're not part of the solution, you're part of the precipitate.

      Happy little moron, Lucky little man.
      I wish I was a moron, MY GOD, Perhaps I am!
      —Spike Milligan

      by polecat on Mon Apr 28, 2014 at 08:55:11 AM PDT

      [ Parent ]

    •  You mean like gasoline? (6+ / 0-)

      I seem to recall that's pretty explosive too yet no one bats an eye there

      •  without an oxidizer (0+ / 0-)

        gasoline is not "explosive" at all.  You have to add air to gasoline vapor even to get it to burn.  A battery, on the other hand, has all the necessary reactants together in one package, just like a (what was that word again?) bomb does.  As energy density rises so does the hazard, and the need to be able to withdraw energy means that many of the "normal" bomb stabilization techniques are not available.

        Granted we're not talking "excitement" on the level of Hexanitrohexaazaisowurtzitane, but when you start approaching the energy density of ANFO (which a "good" battery would have) you're not talking exactly benign either, and "stabilization" becomes a very real issue.

        Fake Left, Drive Right . . . not my idea of a Democrat . . .

        by Deward Hastings on Mon Apr 28, 2014 at 11:17:16 PM PDT

        [ Parent ]

        •  More nonsense (3+ / 0-)

          First off, ANFO is a low energy density combustible solid, at only 6.3MJ/kg, a mere seventh of gasoline's energy density. Nonetheless, it's still about 9 times more energy dense than the best lithium ions.

          You mention ANFO because it's explosive. There are no explosive lithium ion batteries. None. Some of the cobalt chemistries pose a fire risk if manufactured poorly or abused. Fire is not an explosion, and cobalt chemistries are not typically used in EVs. More to the point, the fastest charging chemistries are actually the most stable and non-combustible. They have to be in order to charge quickly - you can't charge quickly if you're heat-unstable. You have it all backwards.

          Batteries will likely never get to the point (at least during our lifetimes) where the amount of electricity stored by the battery is a large fraction of the energy in the chemical bonds, so the fact that it can "charge" is irrelevant. And nor do they need to get to that point. First off, electric drivetrains gain an automatic ~3x efficiency boost by bypassing Carnot losses. Secondly, batteries don't need to be comparable to the weight of gasoline, the drivetrains as a whole need to be comparable. You can't make a fair comparison just by taking one part in isolation. Yeah, batteries are heavier than gasoline. So? Electric drivetrains are lighter than gasoline drivetrains. The Tesla Roadster goes from 0-60 in 3.7 seconds using a motor the size of a watermelon. My favorite motor, the EMRAX 228, puts out 134 horsepower peak and 55 horsepower continuous... from a package 9 inches by 3.4 inches that weighs a mere 12kg. Its gross bias and an absurd comparison to only look at one part of each drivetrain (batteries vs. gasoline) rather than the whole.

          The day I'll consider justice blind is the day that a rape defendant's claim of "She consented to the sex" is treated by the same legal standards as a robbery defendant's claim of "He consented to give me the money": as an affirmative defense.

          by Rei on Tue Apr 29, 2014 at 03:07:00 AM PDT

          [ Parent ]

        •  Woot (0+ / 0-)

          Gasoline doesn't explode?   That's great news for all those not killed when tankers explode!  I am guessing oil trains don't explode either.  And natural gas?  Totally non reactive, amirite?

          Honestly, of the pro fossil fuel cover, this argument has to be the dumbest yet. The notion that batteries involve some massive new risk is rather overblown.   In either case, for transportation, it is traveling at speed that kills more than anything.  Nice theory, but rather irrelevant

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