SAFETY FIRST: This project is not for the timid. Wear goggles and gloves, seriously. see my previous
instructable for further details https://www.instructables.com/id/Create-a-recharga...
My goal, over the last four years, was to create a "good enough" battery for the billions who live in "light poverty" - 1.2-1.7 billion people who have no reliable source of light once the sun sets. Billions. So I decided that I can't help create a better LED, or necessarily in distribution, but I *COULD* help people build their own batteries for storage.
The first requirement was that the battery be cheap and easy to manufacture. It had to be an improvement over the toxicity of lead-acid, but could be as big and bulky as I might care to make it.
You can see some of my other instructables as steps toward this development.
What I've created is a wonderful 2.65v Aluminum-Ion battery due to an accidental discovery while exploring geopolymer-based electrodes for another cell. The aluminum silicates protect the aluminum from breaking down in the electrolyte, and allow the battery to work beautifully. I'm not 100% sure of the "final chemistry" of the cell, so I can't build one at 2.65 at the start, but the current cell (starting at 1.3-1.43 volts) can be conditioned to become the 2.65v cell over about 15 cycles. My "master" cell is still conditioning, so I'm not sure what the life cycle is at this point... but this is the best cell I've built in four years of working on it, and I want to make sure it's out there and ready.
0. Abundance - The battery should take advantage of abundant natural
resources, sticking within the top 10 or top 12 elements. (O, Si, Al, Fe, Ca, Na, K, Mg, Ti, H and possibly P, Mn)
1. A simple-to-make battery that could be constructed in primitive conditions
2. It should be easily constructed from recyclable/recycled materials "Junk"
3. It should provide enough power to light LED lighting systems through the night
4. It should be rechargeable
5. It should be easily deconstructed, "serviced", or recycled once it fails.
6. Open Source- the "recipe" will be freely available for anyone to use.
0. Carbon, because it's hard to make a cell without it, and is generally accessible. Sulfur as well, again, because it's generally accessible by consumers (battery acid is a common thing).
1. Size - I don't care if it takes up the size of a chair, up to 5 times equivalent size lead acid
2. Voltage - I'm not worried about a low voltage cell, if I can just stack several together
3. Graphite - While not ideal for primitive situations, it can be easily recycled from dead primary batteries
4. Time to condition - it might take a while to condition the battery to a useful state through repeated charge/discharge cycles
5. "Outgassing" - while a serious negative, it is understood that some outgassing may occur during conditioning. Gasses like Chlorine might require the battery to be stored outside.
6. Boost converter - Our goal is to create light, not worry about continuous voltage - so a pulsed boost converter is acceptable (a "Joule Thief") to get a lower voltage up to a pulsed signal capable of lighting an LED. I've driven "30 watt" LEDs on as little as 2 watts using this method.