See safety notes below. This is not a build for the timid. Only build in a well ventilated area.
After several years of various experiments, I came upon a workable battery chemistry that is light, safer than Lead-Acid, and easy to make. My original intention was to create a battery that could be manufactured in low-tech environments with limited supplies, and I think I came very close to that ideal with this battery.
After searching the google patent database, I do not believe this idea to be patented. I decided that I could not ever stand to fight the big companies in court if anyone tried to challenge a patent on the material, and I couldn't defend the patent either - as that requires lots of legal representation and great expense. So, in the interest of having my little battery get in the hands of people who need it most - I decided to open source it. I decided to completely share how I built this little guy, and replicate it here with a fresh cell - proving that the technology works.
Composition: Aluminum/AlCl + Hcl + TiO2 + MgO2 + Graphite + Urea (+ mineral oil)
Voltage: 2.10v OCV, the body of work from 2.05v down to 1.80v very similar to lead acid
My current battery appears to still be conditioning, and seems to hold slightly higher voltages for longer each day. I don't know the eventual lifespan or final voltage of this battery, so this is still an unknown. But the behavior seems to reinforce a 2.1v resting voltage, which might eventually be as high as 2.25v.
NOTE: Danger. Be cautious, and wear protective eye wear and disposable gloves. While the battery is ultimately composed of chemicals that are far less nasty than Lead, they are still dangerous. Hydrochloric Acid can burn you, your children, pets, your clothing, the desk - just about anything around you.
Chlorine/Oxygen Gas Hazard: Charging this battery can cause a release of oxygen, which can cause fires. Over charging this battery can cause the release of Chlorine Gas (Cl2) which is nasty stuff. Only build in a well ventilated space, and do not leave an unattended battery charging.
Environmental Note: Do not dump out your battery outside or in the sink. Dispose of battery solutions at your local Hazardous materials collection times. Again, this battery is far less nasty than many, but there's no reason to pollute your local watershed. Be a good steward.
Why open source it?
Nickel-Iron batteries are very popular for solar projects. They were patented by Thomas Edison and Co around 1900. They hold a 1.2v charge, were nearly indestructible, able to be deep discharged and overcharged, and have lifespans in the range of 50-100 years. Drawbacks included a high rate of self discharge, weight, and electrolyte maintenance. The first electric cars at the time ran on these 1.2v batteries, and both fell out of favor with the introduction of internal combustion engines. Today, thanks to a resurgence in offgrid/microgrid ideas, these batteries are back in favor - being manufactured here in the US and in China. They are expensive, and made of plastic instead of all steel - and I doubt their 50 year lifespan.. but that aside, what's the interesting thing here? No patent. Who cares, people will buy them and the big companies don't care about appealing to offgrid types. Once I had a good long think about it, I didn't really see the need for a patent for a battery like this. I couldn't defend a patent in court against a mega-corporation if they wanted to steal the idea anyway, they'd bleed me dry in no time. The patent system as it exists today isn't for the small inventor, it's for corporations to wage battle against each other and maintain their competitive edge. This battery isn't super efficient, it's cheap, simple, lightweight and relatively benign. Which makes it perfect for someone in the middle of no-where to use to keep a light on.
I'm a software developer, and have been for nearly 20 years. I developed software for primarily windows-based systems for the first 8 or 10 or so, and then progressed into primarily web-based projects for the rest. Open source software has allowed me to focus on building the solution on powerful software stacks without having to worry about piracy, or licenses, or running out of money before the project even starts because we need the latest versions of the entire OS stack. Go find a community with similar needs and an existing stack, and start building. Give back to the community, and build open products and solutions for others to use. So, this is me giving back.
So go, build batteries, and make the world a better place. This is my gift to you.
This instructable is meant to be the springboard for other experimenters who might wish to help the community develop this battery, share in the general knowledge in its construction, and make the world a better place. My only request is that you share your construction techniques with the community the way I'm sharing now. Open source, but hardware/chemistry.