# Explain how carbon-nano tube batteries work

**URL:** <https://boards.straightdope.com/t/explain-how-carbon-nano-tube-batteries-work/525008>\
**Category:** Factual Questions\
**Created:** [January 14, 2010, 11:48pm UTC](https://boards.straightdope.com/t/explain-how-carbon-nano-tube-batteries-work/525008 "2010-01-14T23:48:25Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\
**Post date:** [January 14, 2010, 11:48pm UTC](https://boards.straightdope.com/t/explain-how-carbon-nano-tube-batteries-work/525008/1 "2010-01-14T23:48:25Z")

</div>

Was watching an episode of Sci-Fi Science, and Dr. Michio Kaku was speculating on how to build a real light saber. Anyway, the power source he mentioned was a carbon-nano tube battery. Could anyone explain in simple terms how it would work and what the potential energy we could (theoretically) get out of something like that? I realize that the technology is purely speculative at this point, but he used it in his design so it must be at least theoretically possible.

-XT

---

<div class="post-metadata">

**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [January 15, 2010, 12:13am UTC](https://boards.straightdope.com/t/explain-how-carbon-nano-tube-batteries-work/525008/2 "2010-01-15T00:13:34Z")

</div>

I’d WAG that the ‘carbon-nano tube’ bit is a futuristic way of saying ‘electrodes with a very large surface area’.  
You can get more current out of a large surface area than you can out of a small one.  
Here’s a [recent patent application in the area:](http://www.faqs.org/patents/app/20090042101)

> [@](#):
>
> Abstract:  
> A method of forming battery electrodes with high specific surface and thin layers of active material is disclosed. The method enables low series resistance and high battery power.  
> Claims:
> 
> 1. A battery electrode made from open-porous metal of at least 1000 square centimeters surface area per cubic centimeter volume with the surface layer chemically converted into a film or layer of active material prior to incorporation in a battery; the active material is an oxide, hydroxide, or a salt of the electrode metal
> 
> 2. A battery electrode comprising open-porous metal sponge or open-porous metal structure comprising one or more elements in the active material of a battery and the metal surface layer being chemically converted to form an adherent film of active material…

Neatly arrayed and hooked up nano tubes could give a higher surface to volume ratio than a metallic sponge.