We have reached a point in our story where a battery has cycled most of its electrons to the cathode. It has provided useful service to a device, but now it is flat, run out of steam if you like. We move on to the miracle of recharging a battery so it can start performing its duties all over again. However, not all batteries are smart enough to recharge.
The Principles of Recharging a Battery
A battery runs flat when the majority of the electrons have traveled across to the cathode. Sometimes this is permanent, because the design allows for an accumulation of reaction products on the electrodes.
However, some more expensive batteries (including our lead-acid ones) delay this accumulation. And so we can return the electrons to the anode from whence they came. Engineers call this process recharging a battery, or recycling the electrons.
This remarkable phenomenon saves a considerable sum of money over time. It makes our devices more affordable. It also makes an indispensable contribution to transportable energy. Another small miracle we take for granted, like so much of our other technology.
The Science Behind Electron Recycling
Electrons travel across from the anode to the cathode when we draw electricity from a battery. In a similar way, they shuttle back where they came from, when we recharge a battery with electricity from an external source. At the same time, the balancing ions return to the anode. Our battery is reborn, well almost.
That because nothing we create seems to last forever, and even the best human inventions eventually wear out. In the case of a rechargeable battery, the electrodes gradually degrade. Finally, they reach a point where it is time to recycle their materials into new batteries, so their value may continue.
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