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How do Electric Double Layers Work?

  1. Oct 15, 2012 #1
    In an electric double layer, there are two types of ions. The first ion type is stuck to the surface and the second one is stuck to that ion layer. They are both of different charges, but are in close contact with each other. So what prevents this from discharging at the contact area?
  2. jcsd
  3. Oct 15, 2012 #2
    Discharging ions requires energy. For example if you stick two pieces of metal into water and apply a voltage you can only get electrolysis if the voltage is above a threshold. Otherwise you would violate conservation of energy. How many ions get neutralized depends on current times time i.e. charge. If a very tiny voltage was sufficient you could neutralize a huge amount of ions with a very small amount of energy.
  4. Oct 15, 2012 #3
    In the case of a capacitor, why is connecting the two sides with electrodes sufficient to discharge this instead of the two layers touching?

    The two layers being the capacitor that is and connecting this to a load.
  5. Oct 15, 2012 #4


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    If the two plates of a capacitor touch it will discharge, or not charge at all if touching when power is applied. Shorted plates are just that; a short. This is the key reason for the dialectic material it keeps the plates well separated both physically and electrically.
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