Degraded Electrodes Observed In Aging Batteries 108
schliz writes "Scientists have identified nanoscale changes in aging lithium-ion batteries that could be responsible for their degradation over time. By dissecting and examining dead batteries, they found that some lithium was irreversibly lost from the positive to negative electrode of dead batteries, and no longer participated in charging and discharging. They discovered that finely-structured nanomaterials on dead batteries' electrodes had coarsened in size, and theorise that the coarsening of the cathode may be responsible for the loss of lithium."
Re:Keyword slapping strategy. (Score:5, Informative)
Really? You're complaining about using the term "nano" to refer to structures bigger than molecules but smaller than the wavelength of light?
By the same token, everything that goes on in your body is based on bio-chemistry, and therefore "nanoscale by definition". But it's still useful to distinguish (for example) biochemical changes in bone digestion due to biphosphonates from microscopic changes in bone structure associated with osteoporosis from large-scale changes associated with being run over by a truck.
The nanoscale structure of battery electrodes, larger than individual molecules but smaller than the wavelength of visible light, is absolutely critical to optimizing battery performance. It's distinct from the battery's basic chemistry, it's distinct from gross electrode shape and size, and it's certainly distinct from the macroscopic and chemical changes "studied for ages" in association with corrosion.
Re:Planned obsolescence (Score:4, Informative)
Modern lithium polymer batteries survive best if you keep cycling them regularly, but *not* deep cycling them. Regularly discharging to 30-70%, and then charging again keeps them nice and healthy. Running them down to 0% all the time drives charge backwards through some cells, and helps cause early death.
Re:Solar backup (Score:1, Informative)
I woudn't google SlaveryExtreme if I were you.
If people don't know what DealExtreme is, or if people don't know that all this $2.99 shit coming out of China is built with slave labor, or can't put these two facts together, then they probably don't need to be buying any cheap chinese shit anyway.
Re:Planned obsolescence (Score:3, Informative)
I just found a power setting on my new Ideapad that keeps the maximum charge at %80. You lose 1/5th of the runtime in the short term, but you should be able to get a much longer total runtime over time out of it, especially if you keep it plugged in. Thank you, Lenovo.
Which brings to my next point: DON"T KEEP YOUR LAPTOP PLUGGED IN. Charge it, then unplug. The battery will last much longer if you continually cycle it, rather than if you try to keep it topped off all of the time. I've toasted batteries in 6 months by keeping them plugged in for too long. Use them like batteries, or they will die.
Re:Planned obsolescence (Score:1, Informative)
If you want to keep your laptop plugged in (say if you use it as a desktop replacement), take out the battery.
I am using the first (original) battery that came with it, it's still good enough to give me about 20 minutes worth of power so in case of a power outage there's enough time to finish what I am doing, saving my work, and gracefully power down the system (unless the power came back up, of course).
I bought an aftermarket regular and an extended capacity battery for less than an original Sony battery would have cost me (disclaimer: I bought the laptop used).
Re:Planned obsolescence (Score:2, Informative)
>>>Regularly discharging to 30-70%, and then charging again keeps them nice and healthy.
I like to use a dog analogy. If you feed your dog until he's overweight, then don't feed him until he's skeletal, and then feed him again til he's overweight, then don't feed until he's skeletal... your dog won't live long. The stress will shorten his life. ----- The same is true for batteries. Overcharging and then draining them to empty stresses the cell. The ideal is to hold the battery between 60% and 90%, avoid stressing it, and thereby extend its life. That's what Toyota and Honda do to extend their hybrid battery life longer than the gasoline engine.
On another note:
I like NiMH (nickle-metal hydride) better than Lithium. They only hold 75% as much energy but have a very long lifetime (over ten years if not abused), and when they do start showing age, and dying after just a few hours, a "refresh" cycle in a charger will restore them to like new condition again. Plus they can be tossed into landfills because they are environmentally neutral (no mercury, no cadmium, nothing hazardous).