A general waste of time, making battery cells using conductive ink

Thread Starter

HugoMorris

Joined Nov 29, 2019
11
For some time now I've taken an interest is making battery cells using conductive ink on collecting plates with separator and liquid electrolyte.
After months of experimenting I have made 20 of them. Each cell is initially holding about 1.3V. Even though I connect several in series and parallel it's not enough to power anything. Not even a small light bulb.
Any advice or comments folks ?

I've followed Robert Murray-Smith's 'You Tube' tutorials on making these to the letter and have emailed him with no response.

I know lithium-ion is the way to go but these seemed interesting,were cheap to make and they charged really quickly
 

DickCappels

Joined Aug 21, 2008
6,388
To get 1.3 volts you must be using two different metals, or like a car battery, charging it. What is the chemistry of these cells?

Thoughts:
In general to increase current capacity you need to increase the area of the plates and not have them separated further than necessary. If conductive ink is one of the plates it might be that it is high resistance, in which case, you can try different conductive inks.
 

Thread Starter

HugoMorris

Joined Nov 29, 2019
11
Thanks for that Dick. Yes I am charging them with a bench power supply at 6V. I have been told that increasing the size of the plates won't work as 5.5-6V is the limit ,hence the series connection. The symmetrical collection plates are simply kitchen aluminium foil with Anode/Cathode tabs. The conductive ink is ground graphite and lampblack with a polyurethane binder soaked into a 'J' cloth with a paper separator and Sodium Sulphate electrolyte.
 

DickCappels

Joined Aug 21, 2008
6,388
The voltage out of a cell is determined by the cell chemistry and has little to do with the charge as long as current isn't being drawn.

Do you have any specific equivalent series resistance or current requirements?
 

Thread Starter

HugoMorris

Joined Nov 29, 2019
11
I guess I'm trying to achieve a high enough voltage through series connection to maybe power an electric bike. I know I'd need some type of battery management system but at the moment I feel I'm light years away.
 

jpanhalt

Joined Jan 18, 2008
9,426
Assuming the purpose of this thread is to search for causation or potential improvements, it will get nowhere until some basic answers are provided:
What chemistry are you using?
What conductive ink?
What is the design of your cells? That is, details of its construction.

Did you really think you would do better than Volta when mega companies have spent fortunes designing present day batteries? Yes, it is fun to experiment and you have done that.
 

MrAl

Joined Jun 17, 2014
7,594
If i remember right those cells are meant to supply small amounts of power to light duty circuits. I dont think you can expect to light up a 100 watt light bulb with just one cell.
What you need to do is study the relationship between the cell current and the surface area. You should find a relationship that will tell you how many cells you need to put in PARALLEL in order to get the current you need. If you study the relationship between the voltage and the current you can tell how many cells you need in SERIES. I have seen you had done the connecting in series/parallel, but you obviously have not yet studied the relationships yet. Try powering a small LED first.

So you need to increase the number of cells in parallel and probably the number in series too. That's how high power battery packs are made.

Also conductive ink is just conductive it does not store charge. Its main function is to act like a sort of "wire". I guess you are also using some sort of electrolyte too though that's good. The "plates" have to be two different metals too though i dont know if you have done that yet or not.


A friend of mine and me one day were fooling around with no much to do so we created a lemon battery and powered a small white LED with it, but i dont remember how many plates we used it was a long time ago.now.
 
Last edited:

Thread Starter

HugoMorris

Joined Nov 29, 2019
11
Assuming the purpose of this thread is to search for causation or potential improvements, it will get nowhere until some basic answers are provided:
What chemistry are you using?
What conductive ink?
What is the design of your cells? That is, details of its construction.

Did you really think you would do better than Volta when mega companies have spent fortunes designing present day batteries? Yes, it is fun to experiment and you have done that.
O.K. The answers to your comments have already been provided in the above posts. Volta and the rest have all piled into Lithium and we're heading for trouble with that one. Glass and sodium batteries are years away and why do you think Maxwell was bought out for $200,000,000 by Elon Musk?
 

Thread Starter

HugoMorris

Joined Nov 29, 2019
11
If i remember right those cells are meant to supply small amounts of power to light duty circuits. I dont think you can expect to light up a 100 watt light bulb with just one cell.
What you need to do is study the relationship between the cell current and the surface area. You should find a relationship that will tell you how many cells you need to put in PARALLEL in order to get the current you need. If you study the relationship between the voltage and the current you can tell how many cells you need in SERIES. I have seen you had done the connecting in series/parallel, but you obviously have not yet studied the relationships yet. Try powering a small LED first.

So you need to increase the number of cells in parallel and probably the number in series too. That's how high power battery packs are made.

Also conductive ink is just conductive it does not store charge. Its main function is to act like a sort of "wire". I guess you are also using some sort of electrolyte too though that's good. The "plates" have to be two different metals too though i dont know if you have done that yet or not.


A friend of mine and me one day were fooling around with no much to do so we created a lemon battery and powered a small white LED with it, but i dont remember how many plates we used it was a long time ago.now.
Hi. I already understand parallel/series ratios as I have built many ebike batteries. The plates are ok, I've checked. Thanks for your comments guys but I think I know where I'm going with this project.
 

jpanhalt

Joined Jan 18, 2008
9,426
Sorry, I missed your detailed description in post #3. Not much to go on. For example, what concentrations did you use? What was the electrical resistance of your carbon/graphite filled fabric? Have you also tried copper sulfate as the electrolyte? It might work a little better.

Had a bit of time to waste, so looked up Robert Murray-Smith's YouTube. He has a lot of them. One is titled, "How to Build a better Battery."

1) Comment:
Very inspiring as always. I need batteries for my solar system and love the idea of making my own.
Reply(Robert Murray-Smith):
easy to do mate - give it a go

2) Comment:
Could you make a hemp based plastic substitute for the HDPE you're using?
Reply (Robert Murray-Smith):
you probably could mate - I would say give it a go and let me know how you get on - cheers

3) He also offers to sell carbon filled HDPE.

My impression is snake oil. With enough work, you may improve your results, but you still will not get anything nearly as good as you can buy.
 

Thread Starter

HugoMorris

Joined Nov 29, 2019
11
Sorry, I missed your detailed description in post #3. Not much to go on. For example, what concentrations did you use? What was the electrical resistance of your carbon/graphite filled fabric? Have you also tried copper sulfate as the electrolyte? It might work a little better.

Had a bit of time to waste, so looked up Robert Murray-Smith's YouTube. He has a lot of them. One is titled, "How to Build a better Battery."

1) Comment:
Very inspiring as always. I need batteries for my solar system and love the idea of making my own.
Reply(Robert Murray-Smith):
easy to do mate - give it a go

2) Comment:
Could you make a hemp based plastic substitute for the HDPE you're using?
Reply (Robert Murray-Smith):
you probably could mate - I would say give it a go and let me know how you get on - cheers

3) He also offers to sell carbon filled HDPE.

My impression is snake oil. With enough work, you may improve your results, but you still will not get anything nearly as good as you can buy.
I'm very familiar with Robert Murray-Smith videos. It's where I found the inspiration to experiment with battery making in the first place.However like many others I'm realising the guy is making spurious claims on what's achievable with effectively paper batteries. Take a look at the electric scooter video, supposedly powered by five hundred of them. He's also pulled a number of videos for obvious reasons. FWG were taken over by EESTOR last year, I researched their history and it makes for interesting reading.
 

jpanhalt

Joined Jan 18, 2008
9,426
I am not about to waste more time listing to a salesman mumble gibberish.

Since you have been inspired, consider this:

Batteries are not magic. Basically,you have something that is oxidized and something that is reduced, and the power provided is the arbitrage (to use a financial term) between the two. Those processes can be written as half-equations (https://www.bbc.co.uk/bitesize/guides/zpxn82p/revision/4 ).

In simple batteries, the oxidized something is a metal or similar and the reduced something is a non-metal. In an alkaline battery, the material being oxidized is zinc; the reducing material is manganese dioxide. Wikipedia shows the half-equations for that battery. There is no requirement that metals be involved, but they are convenient. The project outlined in this thread is presumably rechargeable, which means the reaction is reversible upon charging.

Back to the premise of this thread, the constituents you describe are carbon/graphite and sodium sulfate. What are the half-equations for charging and subsequent discharging? Try writing them out. I will help you understand the problems with a sodium sulfate and carbon battery in water.

That is why, I suggested the you might have better luck with copper sulfate. It will still be an inefficient battery, but you might be able to light an led after charging.
 
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