Flexible graphite sheets for batteries
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- Опубліковано 21 лип 2024
- This video describes a method for making conductive graphite sheets, these sheets can be used for many applications, including electrodes for batteries. At the end the construction details of the carbon electrode used in the aluminum, sodium hypochlorite battery.
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00:00 Introduction
00:35 Materials
00:53 Screen printing
01:22 Preparation of graphite ink
04:30 Graphite sheet printing
08:34 Resistance measurement
10:29 Construction of an electrode
Other web pages of the author:
claudiohomelab.altervista.org/
#graphite, #carbonblack, #electrodes - Наука та технологія
Thank you very much. Your video is highly educational.
Thank u Sir for sharing valuable information blended with your experience.
Thank you for sharing useful information and the efforts taken to take the video. From Jawaharlal Bharat INDIA 🙏
Thank you for your understanding, it is a pleasure for me to share this information, from Claudio Cervellin, Italy
Very nice. Thank you for sharing
thanks a lot sir for sharing this invaluable treasure....because the net of life starts from a super energy source...in the future I'll wait for it to be made...warm greetings from me always healthy and ever more successful...tanks very much
Thank you for appreciating my work
@@claudiohomelab8181 you are well come
Thank you very much!
great video
pls anyone could tell me how to increase the sheet flexibility
Dip coating could b helpful
What kind of binder can i use?
Polyvinyl acetate (PVAc). other types of binders can also be used, such as polyvinyl alcohol (PVA) or carboxymethylcellulose (CMC).
But PVAc is the easiest to use
is that any journal that lead you to make this carbon graphite sheet,if you could kindly provide the title and link for my research journal, thank you
no magazine, it was just my idea, I had a few kilos of graphite powder and I thought I'd use some of it in the making of these sheets
Very nice but grafit or grafin ???
Graphite
It is not possible to obtain carbon black in my country. What can I use instead?
You can not use it. However, remember that carbon black with its nanometric particles helps to lower the resistance of the electrodes.
However, carbon black is also used as a pigment to make colors used in graphic arts, so you should find it in your country as well.
Check it out here:
www.jacksonsart.com/blog/2021/11/17/pigment-colour-index-black-pigments/
What additives can be added to the slurry to obtain a lower resistance?
Acetylene black
@@claudiohomelab8181 It seems you didn't add this additive. Where can I obtain this additive?
Acetylene black is an expensive product, that's why I didn't use it.
Now I'm preparing low-resistance carbon electrodes for supercapacitors, without using acetylene black,
so far I have managed to have electrodes with R < 1ohm @@kazeem-mustapha
@@claudiohomelab8181 I'm looking forward to this video
@@kazeem-mustapha OK
This looks really awesome. How about durability?
As for the durability of these graphite electrodes, there are no problems in contact with salt electrolytes,
I have some cells with LiClO4 and LiCl electrolyte, and electrodes aluminum - graphite sheet still working after 2 years.
They cannot be used with strong acids because they are slowly dissolved,
with concentrated NaOH KOH they are slowly consumed, if the solutions are diluted they resist enough.
@@claudiohomelab8181 I thaught that they may react with the glue. Anyway awesome work.
Using nickel current collectors instead of aluminum. and a sodium sulfate or potassium carbonate electrolyte. and graphite and activated charcoal mixed 50/50 I was able to achieve a conductivity of 10 to 30 ohms directly measuring with the probe of multimeter anywhere across the surface of the active material on resistance scale setting
I also tried a sample with pure graphite only and achieved 0.5 to 2 ohms.
Nickel works much better than aluminum foil. more durable. more resistance to electrolyte and very high performance. I achieved over 500mA of current maximum charging current from a 0.57 farad test sample being able to charge and discharge instantly in less than one second. Very low internal resistance. and much more powerful.
Size was only 0.4 inch by 1.25 inch and active material thickness only 0.3mm
And a sheet of angel soft brand toilet paper tissue. Or a sheet of coffee filter paper (Coffee filter paper better durability more porous and consistent thickness) cut to size
It works up to about 1 to 1.2 volts with very high performance.
I used 10 to 20% polyvinyl acetate by weight to dry active material powder mix as the binder.
no graphite sheet. no stainless steel mesh. nothing extra.
Just be sure to roughen up the surface of the nickel sheets or foil before applying the active material layer to get it to stick better. Paint and spread a thin layer and let it dry overnight.
Thanks for sharing news about your trial, it's useful news!
I use aluminum foil as a collector which then undergoes corrosion. In my last video I made a supercapacitor with
protected aluminum that should solve the corrosion problem. For now, it works, but we will have to wait to see the final results.
If it goes wrong I will use other metals, such as nickel foil, an alternative could be stainless steel foil
@@claudiohomelab8181 Yes stainless could also be used. Nickel might be slightly easier to work shape cut or handle. sand or roughen the surface etc.
I recommend if your using flat sheets to highly roughen the surfaces thoroughly with sandpaper or similar roughening options before applying the active material coating. Makes it stick a lot better and you get a much better easier wetting of the active material and better bond. more conductivity. Sodium sulfate will give highest performance but too much will cause crystal precipitation to form. At room temperature probably 50% to 75% of the maximum solubility will be a good target. Too close to 100% will form precipitation and reduce performance.
Nickel works extremely well much better than aluminum No oxide layer formation and high resistance to corrosion in neutral or strong alkaline electrolytes.
This is not correct way how to make flexible graphite foil for battery
It's interesting what you say.
Can you tell me where to find information about these graphite foils to be used directly as a current collector?
The electrodes that I prepare with these foils have a stainless steel mesh manifold, so in effect they are cathode material
There are so many ways of doing anything!!! I think we should learn to appreciate what people offer to us for information. If you know any other ways, then it would be better that you share the information rather than seek for non existing mistakes from people who are taking their time to inform people like us. I am an electrochemist and I deeply appreciate the efforts and work of our dear claudiohomelab!!! Let's encourage him and let's share the little or the much he offers. It's a gift!!!
@@claudiohomelab8181 Sorry for those unscientific words from our friend! Keep your head high and just keep on keeping on with your great work! We need you! There will be distractions all over but the world needs you - remember that! We need people like you ready to share the little precious experiments with the rest of the world. Congratulations!
Thank you very much for what you have said
@@claudiohomelab8181 You're welcome!