11–20 of 109 posts
I'd love to see this technology being incorporated into Tesla's batteries. With super-fast and long lasting charges their cars might become viable in countries where charging stations are either incredibly rare or nonexistent.
Conspicuously missing is any mention of energy density. Who cares about power density. That's juste how fast it can discharge. We don't need capacitors that can discharge faster. All capacitors are already much better than batteries with respect to power. We need capacitors that can store more energy. Capacitors typically suck at that and this article doesn't give any indication that these new ones are better.
Here's a page which provides a bit more information than the OP: http://www.engineer.ucla.edu/newsroom/more-news/archive/2012... And here's a paper on the subject: http://evmc2.files.wordpress.com/2013/02/laser-scribing-of-h...
"The LSG-EC can exhibit energy densities of up to 1.36 mWh/cm3 , a value that is approximately two times higher than that of the AC-EC"
1.36 mWh/cm3 = 1.36 Wh/L
If we assume that 1 L of it weights very roughly 1kg. We get 1.36 Wh/kg.
From wikipedia:
"The amount of energy stored per unit weight [in ultracapacitors] is generally lower than that of electrochemical batteries (3 to 5 W·h/kg, although 85 W·h/kg has been achieved in the lab[12] as of 2010 compared to 30 to 40 W·h/kg for a lead acid battery, 100 to 250 W·h/kg for a lithium-ion battery and about 0.1% of the volumetric energy density of gasoline."
This is still less than 1% of the energy density of lithium ion batteries.
Conspicuously missing is any mention of energy density. Who cares about power density. That's juste how fast it can discharge. We don't need capacitors that can discharge faster. All capacitors are already much better than batteries with respect to power. We need capacitors that can store more energy. Capacitors typically suck at that and this article doesn't give any indication that these new ones are better.
In the comments they mention about 1/4 the energy density of a lithium ion battery, so yes they don't compete on that measure. But full charging can happen in a minute or two, and you could top up a charge in seconds. Perhaps public areas would have inductive chargers on the wall; you'd just walk over and hold your phone or tablet up to it for a few seconds. Airline tray tables could have an inductive charger built i…
I'd love to see this technology being incorporated into Tesla's batteries. With super-fast and long lasting charges their cars might become viable in countries where charging stations are either incredibly rare or nonexistent.
Countries with poor infrastructure and handy sources of insanely high wattage power who can afford $50,000 sedans? Which countries would those be?
note, I didn't downvote your comment.
Am I the only one to think "hey, I could try this at home?" 1) prepare carbon slurry 2) pour on dvd 3) etch with LightScribe DVD drive... 4) Peel of graphene layer ...? I wonder what, exactly, goes into the carbon slurry and if it's necessary to etch a particular pattern with the LightScribe.
A headline like "DVD Graphene sheets store charge super fast in lab" would have helped me shift the various articles into my own working memory whilst the page loaded.
Downvote with comments please
(And I seem to get the general idea that Graphene will be big, but this is unlikely to be the killer app)
Earlier quoted context omitted.
In the comments they mention about 1/4 the energy density of a lithium ion battery, so yes they don't compete on that measure. But full charging can happen in a minute or two, and you could top up a charge in seconds. Perhaps public areas would have inductive chargers on the wall; you'd just walk over and hold your phone or tablet up to it for a few seconds. Airline tray tables could have an inductive charger built i…
Your inductive charging tray tables are terrible for my magnetic tapes and floppy disks. Also, where does it get its energy from? It's much more efficient to walk around with wearable solar panels or to embed them directly into the devices. It may not work well on the north pole half the time but batteries aren't very conductive in those environments, anyway.
Now - what happens if you put your wallet full of credit cards on it?
Earlier quoted context omitted.
Here's a page which provides a bit more information than the OP: http://www.engineer.ucla.edu/newsroom/more-news/archive/2012... And here's a paper on the subject: http://evmc2.files.wordpress.com/2013/02/laser-scribing-of-h...
ok so here is the only real data I could find. At the end of the paper: "The LSG-EC can exhibit energy densities of up to 1.36 mWh/cm3 , a value that is approximately two times higher than that of the AC-EC" 1.36 mWh/cm3 = 1.36 Wh/L If we assume that 1 L of it weights very roughly 1kg. We get 1.36 Wh/kg. From wikipedia: "The amount of energy stored per unit weight [in ultracapacitors] is generally lower than that of…
Earlier quoted context omitted.
ok so here is the only real data I could find. At the end of the paper: "The LSG-EC can exhibit energy densities of up to 1.36 mWh/cm3 , a value that is approximately two times higher than that of the AC-EC" 1.36 mWh/cm3 = 1.36 Wh/L If we assume that 1 L of it weights very roughly 1kg. We get 1.36 Wh/kg. From wikipedia: "The amount of energy stored per unit weight [in ultracapacitors] is generally lower than that of…
There is a big miscalculation: Graphene seems to be extremely light weight. 1 liter of graphene will definitely not weight 1kg. Wikipedia [1] only gives measures for m²: Graphene is very light, weighing only about 0.77 milligrams per square meter. [1] https://en.wikipedia.org/wiki/Graphene