Conductivity improving grease project

I have managed to get in contact with folks at OCSiAl, and today three gentlemen from the company came to Livonia to make a presentation and discuss possible applications. These guys have been quite helpful, and even mixed up some grease for us to experiment with here. They used Loctite 8104 mixed with 0.1% SWCNT's by weight. They used a high speed ball mixer to combine the materials and were very clear that this is the proper way to mix these types of materials together. More conventional/manual mixing methods result in agglomeration of the carbon, and performance apparently suffers for it. I will be trying some high current tests in the next week or so using both the grease they prepared, and what I have prepared previously. I'm curious how much difference the mixing method really makes. They showed us results where they stuffed a plastic tube with the grease and measured resistance through 1 cm of material. It was about 10 Ohms/cm in that arrangement. They're shopping this stuff pretty hard as a cathode powder additive as well.
 
wb9k said:
I have managed to get in contact with folks at OCSiAl, and today three gentlemen from the company came to Livonia to make a presentation and discuss possible applications. These guys have been quite helpful, and even mixed up some grease for us to experiment with here. They used Loctite 8104 mixed with 0.1% SWCNT's by weight. They used a high speed ball mixer to combine the materials and were very clear that this is the proper way to mix these types of materials together. More conventional/manual mixing methods result in agglomeration of the carbon, and performance apparently suffers for it. I will be trying some high current tests in the next week or so using both the grease they prepared, and what I have prepared previously. I'm curious how much difference the mixing method really makes. They showed us results where they stuffed a plastic tube with the grease and measured resistance through 1 cm of material. It was about 10 Ohms/cm in that arrangement. They're shopping this stuff pretty hard as a cathode powder additive as well.
Click to expand...


Exciting to hear! I have heard many good things about that material in Anodes and Cathodes both. :)
 
cycleops612 said:
IF, the rim of a hub motor is a hotspot, methinks thermal grease may may help in the spoke holes during tightening?
Click to expand...

Would be a VERY marginal difference. Im confident to say it would make no valuable difference.
Firstly, the shell of a hubbie generally isnt a hotspot, the issue lies in transfering the heat from the stator to the rotor.
The rotor sees some more heat transfered if something like statorade is used inside the motor.
Secondly the spokes are often stainless steel and that material transfers heat very bad in comparision to aluminum.
Thirdly, I have no clue about how well conductivitygrease would transfer heat.
 
I have only spotted one oblique reference to conductivity of heat, yet surely this is an issue too for many.

Conductive grease on the bolts attaching an overly warm running mid drive motor to the bike frame e.g., or on the spokes connecting a hub motor to the rim.
 
Wheazel said:
cycleops612 said:
IF, the rim of a hub motor is a hotspot, methinks thermal grease may may help in the spoke holes during tightening?
Click to expand...

Would be a VERY marginal difference. Im confident to say it would make no valuable difference.
Firstly, the shell of a hubbie generally isnt a hotspot, the issue lies in transfering the heat from the stator to the rotor.
The rotor sees some more heat transfered if something like statorade is used inside the motor.
Secondly the spokes are often stainless steel and that material transfers heat very bad in comparision to aluminum.
Thirdly, I have no clue about how well conductivitygrease would transfer heat.
Click to expand...

I had forgotten I made this post. It was only an eg. w/ the spokes, still...

I have a mid drive motor where the housing sure gets hot. If so, it sure cant hurt the core to have a cooler housing. Yes, I was aware the stator is the main heat source.

The spokes may not be great conductors, but you couldnt ask for better heat dissipators, cutting thru the air as they do. The junction would flex a lot tho.

Whatever, mainstream thermal pastes certainly exist, e.g. CPUs.
 
I'm too lazy to go through all the posts, so I don't know if it was mentioned already. But the company MG Chemicals makes 2 electrically conductive pastes. One is silicone based, and contains silver, not great for making batteries because there will be slip due to the silicone.

The 2nd paste they make uses carbon, I don't know what the base is, but they say silicone free, and won't slip, perfect for making battery packs I think.

http://www.mgchemicals.com/products/greases-and-lubricants/conductive-greases/carbon-conductive-assembly-paste-847

For us Canadians, you can get it from Mouser, 25mL (1oz) is CAD$23, and 454mL (1pt) is CAD$103.

I think this, in combination with bus bars that have detents like in snaths design, would be great for battery builders that can't spot weld. It'd be interesting to see how well the paste holds, and if there are any resistance issues.
 
I don't get what's bad about the silver based conductive greases, what do you mean slippage?
That " 847 MG Chemicals Carbon Conductive Assembly Paste" has a resistivity of 82 Ω·cm as listed on their website data. http://www.mgchemicals.com/products/greases-and-lubricants/conductive-greases/carbon-conductive-assembly-paste-847

But this silver based conductive CW7100 grease claims it has "resistivity <0.01 ohm-cm" while also claiming it protection from moisture, oxidation etc.
https://www.chemtronics.com/p-715-circuitworks-silver-conductive-grease.aspx
https://www.chemtronics.com/descriptions/document/Cw7100tds.pdf
If CW7100 grease has 100+ times more conductive with all the other protection features why wouldn't I want to use this?

Wish I lived in the USA, looks like it's just $25 from their website, local sites want $100.
https://www.walmart.com/ip/Electrical-and-Thermal-Silver-Conductive-Grease-6.5-g.-Syringe-Dispensing/40720271

Hoping it will show up at my local electronics retailer soon..
http://www.jaycar.com.au/search?text=CW7100+Chemtools+Silver+Conductive+Grease
 
SUBSCRIBE =)

(better be ready just incase I am not happy with the conductive/protective grease I am trying out for my project)
 
I was recently a bit surprised to hear solder is a considerably worse conductor than copper.

If so, it would seem a well clamped together pair of wire ends, hermetically sealed and protected from corrosion has its good points.

OTH, if the soldered wires overlap some, the junction is theoretically twice as conductive as the wire.
 
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