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A scientific accident that could change the world

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Re: A scientific accident that could change the world

#41

Post by jaredmcateer »

gizmo686 wrote: post #32
jaredmcateer wrote: post #22

Earlier quoted context omitted.

In my inexpert knowledge I can see a few problems, while they have probably seen potential, they have yet to prove it can scale. Then there is getting manufacturers of devices to buy in to super capacitors and even worse getting battery life obsessed consumers to accept 1/4 the life as current Li Ion batteries is better because it has nearly instantaneous recharge times.

In my experience, the reason people are obssessed with battery life is that when it runs out (which it does), then you are pretty much screwed until you can plug it in for the night. I think that vendors could easily sell devices with a smaller capacity if they can charge in seconds. This seems like a benefit that is very clear, easy to explain, and understandable to a typical consumer, and it provides a near perfect…

Perhaps, I know I'd rather have a super fast charging phone that lasted a day than one that lasted 3 days and takes a long time to charge, but there are still people out there that seem to think the megapixels are the only thing that's important in a camera.

Re: A scientific accident that could change the world

#42

Post by warmwaffles »

clebio wrote: post #36
ratsbane wrote: post #7

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.

I wondered about the etching process too. It might not be at all like a normal R/W pattern for a DVD. They could conceivably be scanning radially, or using a very slow revolution, or (is this possible?) re-tuning the beam's frequency. Not insurmountable, but might require low-level re-writing of the driver, depending.

or just rig your own device and grab the high powered laser off of a blue ray player and slowly pull it to the outer edge. Seems a whole lot easier than having to deal with it messing up a drive within a computer.

Re: A scientific accident that could change the world

#43

Post by frankus »

gus_massa wrote: post #37
alexjeffrey wrote: post #3

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.

I searched a little, but the information is confusing. The superchargers (apparently) use 90kW/480V=~190A. I want to highlight this: 190A!!! A usual home connection can handle only up to ~10A, so 190A is a lot of current. To handle this you must use very thick wires. To charge faster you need move voltage or handle more current, probably you will need even thicker wires and to be careful with the safety measures. Add…

A typical new house in the US is wired for a 200A 240V circuit, or about 48kW.

By contrast the energy flux of a garden-variety gas pump is in the tens of megawatts.

Re: A scientific accident that could change the world

#44

Post by adestefan »

Fargren wrote: post #2

Well, the graphene seems easy enough to manufacture. What are the obstacles to start using this technology right now? What is still missing?

There's a lot of work to make sure this is actually a safe thing to use. I know lithium ion batteries are pretty dangerous, but you need to be damn sure this is as safe or safer. How does it hold up to heat, cold, punctures, short circuits, etc? What about degradation over time?

Also, there's a lot engineering that needs to happen about how to integrate the proper charging circuits. Plus all the work that needs to go into actual mass manufacturing.

In all there's a shit ton of work for any product to actually make it to a mass market.

Re: A scientific accident that could change the world

#46

Post by fus »

axelfreeman wrote: post #23

I'm not a scientist. I can't not say anything how this could be a revolution but if you want learn the basics about Graphene. Start with this video on youtube: http://www.youtube.com/watch?v=EX8ClPVkD1g and then to this http://www.youtube.com/watch?v=SXmVnHgwOZs or just search it on youtube. This helps me a lot to understand. Have fun.

Nice videos. Thank you sir.

Re: A scientific accident that could change the world

#47

Post by MichaelApproved »

Selfcommit wrote: post #45

Anyone else remember when this was posted a few months ago? (I wish my account was named pepperidge farm, just for occasions like this.)

This comment feels like its one step away from just being the word "repost". I really like browsing reddit but please leave these types of comments there. Hacker News is not reddit.

Re: A scientific accident that could change the world

#48

Post by revelation »

gizmo686 wrote: post #32
jaredmcateer wrote: post #22

Earlier quoted context omitted.

In my inexpert knowledge I can see a few problems, while they have probably seen potential, they have yet to prove it can scale. Then there is getting manufacturers of devices to buy in to super capacitors and even worse getting battery life obsessed consumers to accept 1/4 the life as current Li Ion batteries is better because it has nearly instantaneous recharge times.

In my experience, the reason people are obssessed with battery life is that when it runs out (which it does), then you are pretty much screwed until you can plug it in for the night. I think that vendors could easily sell devices with a smaller capacity if they can charge in seconds. This seems like a benefit that is very clear, easy to explain, and understandable to a typical consumer, and it provides a near perfect…

I think the vendors could already charge the batteries faster. A Tesla supercharger charges 40/85kWh in LiIon battery capacity in 30 minutes (from empty, it gets harder to push charge in as they get full). They use off the shelf batteries.

But the dirty little secret is of course that it's not necessary. You need one day of battery life, then people get home and charge it by their nightstand. Similar with the Tesla, it has enough range to get through five times the average American commute, and the majority of people just charge at home when they sleep.

Bandaging peoples irrational fears might simply not be a very viable business model.

Re: A scientific accident that could change the world

#49

Post by mbell »

dmethvin wrote: post #6
BenoitEssiambre wrote: post #4

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've heard this argument a few times: "It charges so fast that the density doesn't matter".

What often gets missed is that for it to charge fast, you need to provide a lot of power, a lot more than any current changer and laughably more than any inductive system can provide. Lithium Ion batteries can already max out the power offered by the 10W charger that comes with the iPad and charging off computer USB is often slow (USB is current limit). See Telsa's car charge times on normal wall outlets vs superchargers for another example.

To really reap the benefits of this quick charge technology you either need an infrastructure of ~1000W DC chargers throughout the world or carry something about the size of a desktop computer power supply with you at all times.

Re: A scientific accident that could change the world

#50

Post by Gravityloss »

bradleyjg wrote: post #29
brokenparser wrote: post #13

Earlier quoted context omitted.

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.

There isn't enough upward facing surface area on your body for solar cells to power anything non-trivial. Also floppy disks?!?

Power usage is going down with every generation. A few watts is quite a bit for a machine with an e-ink display.

For others, maybe nothing but charge sustaining purposes at first.

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