# 20,000 milliamp-hours from a 'AA' battery? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [January 20, 2008, 7:19pm UTC](https://boards.straightdope.com/t/20-000-milliamp-hours-from-a-aa-battery/434285 "2008-01-20T19:19:09Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 20, 2008, 7:19pm UTC](https://boards.straightdope.com/t/20-000-milliamp-hours-from-a-aa-battery/434285/1 "2008-01-20T19:19:09Z")
I want some! [High-performance lithium battery anodes using silicon nanowires](http://www.nature.com/nnano/journal/v3/n1/full/nnano.2007.411.html) > [@](#): > > Silicon is an attractive anode material for lithium batteries because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g-1; ref. 2). Although this is more than ten times higher than existing graphite anodes and much larger than various nitride and oxide materials silicon anodes have limited applications because silicon’s volume changes by 400% upon insertion and extraction of lithium which results in pulverization and capacity fading. Here, we show that silicon nanowire battery electrodes circumvent these issues as they can accommodate large strain without pulverization, provide good electronic contact and conduction, and display short lithium insertion distances. We achieved the theoretical charge capacity for silicon anodes and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling. This beats the heck out of those [ultracapacitors](http://en.wikipedia.org/wiki/Supercapacitor) that somehow never seem to make it into the marketplace. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [January 20, 2008, 8:02pm UTC](https://boards.straightdope.com/t/20-000-milliamp-hours-from-a-aa-battery/434285/2 "2008-01-20T20:02:00Z")
Damn. Sign me up. I use a surveying instrument that takes a while to set up accurately and can only get 2 to 4 hours on a set of AA’s. I can get better results if I can maintain a single setup for a bigger dataset, but having the batteries die requires repeating the setup and breaks the dataset. This would fix everyting. ---
**Author:** ![hekk](https://avatars.discourse-cdn.com/v4/letter/h/50afbb/32.png) [@hekk](https://boards.straightdope.com/u/hekk)\ **Post date:** [January 20, 2008, 8:05pm UTC](https://boards.straightdope.com/t/20-000-milliamp-hours-from-a-aa-battery/434285/3 "2008-01-20T20:05:44Z")
**Napier** , are you using regular alkaline AA batteries? The reason I ask is because you might benefit from using Lithium batteries or rechargeable Nickel-MH batteries, which have a much higher energy density. It’s the same way with digital cameras and other high-drain devices, in which conventional AA batteries last only an hour or so. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [January 23, 2008, 11:15am UTC](https://boards.straightdope.com/t/20-000-milliamp-hours-from-a-aa-battery/434285/4 "2008-01-23T11:15:01Z")
I heard an interview with the inventor on BBC’s Digital Planet, and you might want to dial back the excitement a bit. He wasn’t really clear about the performance, but from the way it sounded, they needed to do some more work on it before it reached it’s described value. He said they had yet to figure out a way to do the cathodes. Also, there’s not been any stress testing on the batteries and I’m sure I don’t have to remind everyone about the ol’ exploding laptop batteries. The inventor was saying it would be at least 3 - 5 years before they hit the market. ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [January 23, 2008, 7:19pm UTC](https://boards.straightdope.com/t/20-000-milliamp-hours-from-a-aa-battery/434285/5 "2008-01-23T19:19:17Z")
[QUOTE=hekk] […] you might benefit from using Lithium batteries or rechargeable Nickel-MH batteries […] [/QUOTE] (A bit OT. Sry) Rechargables are pretty good; lithiums are very pricy though. My older digicam doesn’t like anything but super-charged NiMH, and even with those took only a few dozen photos. On a long trip I discovered Nickle metal oxide batteries (similar to [these](http://www.duracell.com/gna/powerpix/faq.htm), if not those exact ones) that let it take about a hundred photos.