Video Shows Why Recharging Kills Batteries

sciencehabit writes with this except from Science: "You may not give a lot of thought to what happens inside the battery of your laptop or cell phone, but to judge from this video, it's not a dull place. The battery in question is a miniature rechargeable lithium-ion device, and the clip shows what happens when it is charged. As lithium ions flow from the positively charged cathode into the 200-nanometre diameter wires of tin oxide that make up the negatively charged anode, the nanowires writhe and bulge, causing them to expand up to 2.5 fold. The wires also change structure from a neatly ordered crystal to a disordered glassy material. These distortions may explain why such batteries ultimately wear down. Knowing more about the process may help researchers develop longer lasting, and perhaps much smaller, batteries in the future."

Comments

For my fellow noscript and requestpolicy users...

[TheCarp]

The sight has a boatload of requests going all over the place... the video is hosted on "brightcove"

It's an engineering trade-off

[Anonymous Coward]

You can have a battery which has almost infinite charge-discharge cycles. (iron-nickel) It will be very large and heavy for the energy it stores and also has quite a large self-discharge.

If you want a small light battery that stores a large amount of energy, something has to give. In this case battery life suffers. You can make batteries that last a lot longer, they will just be big.

Re:It's an engineering trade-off

[jeff4747]

Because no one has found a material for batteries without trade-offs. All currently known chemistries maximize at best two of weight, power density and cell life.

When someone finds a material that maximizes all 3, then we get that whole 'world-changing-invention' situation.

Direct link

[qwertyatwork]

http://bcove.me/581iaz9a

Re:Positive and negative?

[cdrudge]

It depends on if the battery is charging or discharging as to if the anode or cathode is the positive or negative terminal. Read the top of the wiki page for cathod or anode for more info.

Re:What we don't know why or how?

[Twinbee]

The CRT is a mature technology too. Doesn't mean it's ideal, or nearly ideal. Anyway, see:

http://en.wikipedia.org/wiki/Transmission_electron_microscopy#Limitations

Yes a lot of the problem is holes in our knowledge of the presumably complicated battery physics, but I bet we'd have a lot more insight if these things could be analyzed and seen in realtime without any of the tedious preparation and other obstacles. Ideally, we'd even have the battery running as normal the whole time, though that may be almost impossible.