What is a Lithium-ion capacitor?

(jtekt.co.jp)

36 points | by ksec 4 hours ago

5 comments

  • rpaddock 49 minutes ago
    For anyone that wants to see a real data sheet:

    Nominal Voltage: 4.0V High Power and Energy Densities Cycle Life > 50K Cycles Capacitance Range: 10F-1200Farads

    https://abracon.com/product-lineup/frequency-control-timing-...

    Note that the original data sheets said that these could be wave soldered. ABSOLETLY NOT. Even hand soldering they must be treated with respect, a lot of respect.

    One of the major problems with these is there a minimal voltage that they must not go below. Their life gets shortened. I've never seen data on how much.

    To my knowledge Li-Ion Capacitors were first introduced to the market by Taiyo-Yuden in 2010. They are no longer in this market. I wrote a blog about it back then:

    http://blog.softwaresafety.net/2010/11/introducing-lithium-i...

  • supertroop 43 minutes ago
    Dumb question but I though capacitors store energy and not power?
    • azornathogron 38 minutes ago
      They store energy but there's a limit to how quickly you can get that energy out, hence a limit to power. And I suppose you can kinda talk about them "storing power" in the sense that power is what you might be interested in getting out of them.

      At least, that's my understanding of it.

    • martinbfine 0 minutes ago
      [dead]
  • mrDmrTmrJ 1 hour ago
    Let's say you want to make a hybrid car lighter-weight. Where is this useful?

    Power density and cycle life are truly impressive. Energy density is super low

    • ricardobeat 1 hour ago
      Interestingly it seems to have some applications for high peak power and regen, they had a car in the Dakar rally:

      https://www.jtekt.co.jp/e/products/capacitor/capacitor_mobil...

      https://www.jtekt.co.jp/e/engineering-journal/assets/1019/10...

    • colechristensen 1 hour ago
      You would use these to provide peak power in a system that had short term power needs that were high above the average power needs AND had that power requirement as a bottleneck. Energy is the bottleneck for cars though, not power. unless you're wanting your prius to accelerate like a ferrari

      Maybe it would be useful for less losses with regenerative braking? These would presumably be able to charge much faster and then trickle that power out to the normal battery. You'd need actual power numbers for a car to determine if it would be useful or not.

      In other words this is for "boy I wish I didn't have to have so much extra battery capacity in order to get the power I need" situation which... cars don't have. Maybe in F1?

      • marcosdumay 32 minutes ago
        > unless you're wanting your prius to accelerate like a ferrari

        That's the point of a hybrid.

    • traverseda 1 hour ago
      Regen braking,
  • LorenPechtel 2 hours ago
    And no mention of the self discharge rate.
    • rpaddock 36 minutes ago
      For a similar part in this class:

      Low Leakage Current as small as 1µA Low Self-discharge rate, 72 hours @ discharge <5%

      https://abracon.com/datasheets/AHCR-S04R0S.pdf

      The more the Farads the higher the leakage. The higher the tempature the higher the leakage.