This is not a great cell, and our cars and homes will likely never employ the design, but it is curious that ~2000 years ago people may have been experimenting with electricity. What they were using this electricity for is subject to as much speculation as the actual construction of the "battery" (Perhaps it was not a battery, that is for you to decide).
To keep the interest of the reader and focus on the construction aspects of the replica I will try not to write too much about the history and interpretation by others of the artifacts. Several of the sources listed in Step 10 have already done a wonderful job discussing these details.
A few notes:
>Several of the listed artifact photos were found on Wikipedia or widely used on the web, so I am assuming there are no copyright infringements.
>Since this is my first instructable, and it has been a while since I've had to explain anything to someone through writing, I welcome all criticism and suggestions for improvement.
>I would like to reference photos and figures inline with the text since I presume it would be easier for the reader to follow, but I am unsure if there is a way to do this through the instructable editor interface and wiki markup (?) - so for now I am just listing relevant images at the bottom of a step. Also, I'm unsure how to apply subscripts in the editor to write chemical formulas, I'd like to include the half cell reactions - otherwise I can take a screenshot and post it as an image.
Step 1: Construction Overview an Materials
I did not create a true replica, since I could not find a porous jar with the correct geometry. However, jar geometry should not have much effect on the battery performance. Also, a clear vessel - such as the mason jar I used - is helpful for observing the chemistry. If you want a replica that is similar in form to the artifacts, use an unglazed jar with the geometry seen in the photos, and substitute asphalt for the rubber tape I used as a sealant.
Nothing is precise here, so feel free to substitute similar materials. For example, I used bundles of nails before I could find a large iron nail. Just be careful what you use is uncoated iron, many iron objects in the hardware store will be coated with a polymer or zinc (galvanized). Regardless of where you find the metals, ensure your copper and iron have the oxidation layers cleaned off - I used Al2O3 abrasive to clean the copper, and HCL acid for the iron.
- sheet of copper, it can be found in craft stores -copper pipe found in the hardware store will work too, but the slit seen in the side of the copper tube (in photos) does improve performance, so try to emulate this construction detail (use a saw or mill)
- piece of iron with an Fe3O4 coating - I used a large iron nail and created my own Fe3O4 coating, see step 2 for details on creating Fe3O4
- mason jar or similar non reactive container for holding the electrolyte and electrodes - if you have a porous clay jar, try this instead
- stranded and solid wire
- rubber stopper
- rubber mastic tape, or if more adventurous, try asphalt
- rubber gloves
- an alkaline electrolyte - Potassium Hydroxide (KOH), also known as Potash, or an alkaline urine should work. Note: Be careful with retailers of KOH, since there is some paranoia of KOH in certain areas. My first attempt at purchase was a bad experience and waste of time. I believe the first company I contacted was under investigation for supplying methamphetamine manufacture - I'm not quite sure who the owner thought I was. Anyway, stay away from any companies that rhyme with "Spinner Chemical" and are based in Michigan. I won't advertise the company I did have success with, but if you can read the label in one of the photos, my experience was completely painless with this company.