Introduction: Making Instant Batteries
Survive usually means to succeed in keeping alive against odds, to live after some event that has threatened one. In our daily lives survival is not apparent,we may not even think about survival because we are surrounded by the comfort of technology. Food, water, Shelter are readily available. But in a country that is usually battered by typhoon and other calamities survival is a paramount. We know it very well in Philippines because we are visited every year with not less than 10 typhoon. Our country is also situated in the Ring of Fire https://en.wikipedia.org/wiki/Ring_of_Fire.
In order to survive in adverse condition we must have set of knowledge at our disposal anytime when such condition arise. In this instructables I am going to share how to make instant batteries using materials easily available and can be found in our homes. It should also be easy to make. It would be valuable in case of blackout in the aftermath of typhoon. We can power LED torch out of this batteries.
We're making an instant battery which is called aluminum-air batteries it uses aluminum for more info you can read https://en.wikipedia.org/wiki/Aluminium%E2%80%93a... This type of batteries work by electro-chemical reaction of aluminum and air.
The anode oxidation half-reaction is
Al + 3OH−→ Al(OH) 3 + 3e− +2.31 V.
The cathode reduction half-reaction is
O 2 + 2H 2O + 4e− → 4OH− +0.40 V.
The total reaction is
4Al + 3O 2 + 6H 2O → 4Al(OH) 3 + 2.71 V.
About 1.2 volts potential difference is created by these reactions, and is achievable in practice when potassium hydroxide is used as the electrolyte. Saltwater electrolyte achieves approximately 0.7 volts per cell. I also tried Sodium Hydroxide as electrolyte which gives 1.25 volts. Pond water gives 0.4 volts. You can try urine when situation arise that its difficult to find any liquid for electrolyte which can give approximately 0.8 volts.
Step 1: What We Need?
1. aluminum as anode
any form of pure aluminum(foil, bar, cans, truss) I use aluminum from the cover of easy to open milk can
any of the following sodium hydroxide (lye) or potassium hydroxide (caustic potash) or sodium chloride (salt)
WARNING CORROSIVE be careful when you choose to use lye or caustic potash
4.Paper as separator
I use tissue paper, table napkin or any paper that is not glossy will also work
5.charcoal as cathode, together with
6. wire screen
the following can also be used carbon black, activated carbon and soil which I already tested
7. connecting wires
aside from our materials, please also prepare multi-tester for checking continuity of the battery, sandpaper, scissors, disposable syringe, disposable spoon, pliers, plastic container for charcoal, glass for water, for easy and fast construction of battery.
Step 2: Let's Do It!
Prepare the aluminum by sanding it to increase surface area. Sand it specially when the aluminum is shiny. It is necessary to increase surface area to increase the area for chemical reaction. Prepare the wire screen by cutting small pieces using scissors. Make sure that the wire screen is smaller than the tissue paper. Aluminum and wire screen should not touch each other that is why there is a paper separator to prevent short circuit. fold 4 ply of tissue paper as separator, make the tissue thicker so it can hold more of our electrolyte solution and prevent short circuit. if your battery is short circuited, it will not produce voltage, it gets hot, and produces hydrogen.
Cut connecting wires of your desired length. connect the black wire to aluminum, aluminum is our anode and will be the negative terminal. Make a secure connection of wire to aluminum. What I did was I cut on the edge of aluminum (check the picture) and attached wire on it then fold the aluminum together with the connecting wire to create sturdy connection. Connect the red wire to wire screen. Wire screen and charcoal forms the cathode and this will be the positive terminal of the battery. Place a tissue paper in between the aluminum and wire screen. add 4 sheet of tissue paper. make it like sandwich, aluminum then paper and then wire screen. aluminum and screen should not touched each other and fold more tissue paper so that it wont tear apart as we add electrolyte solution.
WARNING CORROSIVE. If you'll be using salt or tap water or pond water it is alright because its not corrosive.If you will use lye please be careful. you can clearly see on it label. keep away from children, dispose it properly.When you accidentally spill it in your skin wash immediately with running water to minimize skin burn. My electrolyte solution is compose of 10% sodium hydroxide. 9 part water and 1 part sodium hydroxide. put 10 ml to syringe first then next is 90 ml water as you put water into syringe it automatically mixed and forms the solution. use gloves for added protection.
I tried different electrolyte solution using salted water, pond water, it all works but lye works best.
when you have made sandwich of aluminum paper and wire screen its time to add electrolyte solution make sure to wet 90% area of tissue paper. use multi-tester and watch as you pour the solution you can have a voltage reading as soon as the paper is wet. then finally add the powdered charcoal, it acts as oxygen absorber that helps speed up the reaction. Add solution to the paper first before charcoal. Adding charcoal first and then pouring the solution will flood the charcoal minimizing the contact area of air to the charcoal. It is fine if your tissue paper is soaking wet with the solution just be careful not to add to much charcoal to the point that the charcoal touches your aluminum. If it happens it is shorted. Just throw the charcoal and paper then wash the aluminum together with wire screen and start over.
Step 6: We're Done. We Have Now a Working Battery :)
I made 5 cells to create more power enough to lit LED torch,digital watch,small DC motor and boost converter but using boost converter circuit as load on my battery didn't turn out well, my batt couldn't sustain long enough to charge a phone. The total voltage produced is 6 volts mean to say that all the cells has an average of 1.2 volts. If you want to pile your cells to make it more battery looking (picture from the start of instructables) use Popsicle stick. Maybe in the future I could charge my phone with it if I can make a better battery that produces stronger current OR its you who can do it. :) For now I am satisfied with the result because it is working, my batteries are able to power some useful electronics and made from recycled materials.
Step 7: Testing With Other Materials
I tried to use different solutions and materials to check its versatility. I tried salted tap water and got 0.7 volts, I tried to use soil/mud instead of charcoal and it also work giving 0.75 volts. Tried pond water and soil, tried salt water and mud, salt water and activated carbon, tried lye solution and activated carbon. the later produces highest voltage and current. That is why I said you can use urine at the beginning of this instructables as an alternative electrolyte because this battery is not that sensitive you can try experimenting on different materials. Feel free to explore. Thank you for reading this instructables. Hope you'll also make one.