HN Gopher Feed (2017-08-14) - page 1 of 10
'Instantly rechargeable' battery could change the future of
39 points by taconhttps://www.purdue.edu/newsroom/releases/2017/Q2/instantly-recha...
mjevans - 56 minutes ago
The problems that I see with this:* Refueling requires hooking up
and exchanging hazardous materials (fluids).* This assumes that
there's a single universal electrolyte fluid.* Variability in fluid
quality / consistency (across areas and batches) / return materials
fraud are problems.* The less sealed nature of the batteries is
probably a safety hazard (increased crash/fire risk, etc).I think
that the public would be better served by standardizing on a few
/types/ of battery packs as physical interfaces, and having rapid
'tank replacement' stations (robots) and leased battery
packs.Innovation in storage tech and/or picking a pack sized for
the expected use would allow for improvements and competition as
well as changes in technology.
ethagknight - 49 minutes ago
For 3/4 of your concerns, kinda like gasoline?
colordrops - 21 minutes ago
Which of the 4 is not like gasoline? Seems like 4/4 to me.
TallGuyShort - 34 minutes ago
Still has a point regarding the potential superiority of
battery exchange programs. Gasoline isn't exactly the holy
grail of fuels :)
mjevans - 31 minutes ago
Gasoline is mostly just flammable (and the vapor /slightly/
explosive).We'd need to know more about what type of chemicals
are used in this battery, but glancing at what's involved for
'flow batteries' I'd make a /slightly/ educated guess that
these would all be considered 'industrial' materials. You
might see a public bus using them, but I doubt it would be safe
to allow the average driver to self-refuel.
undersuit - 9 minutes ago
The average driver refills their vehicle using decades old
technology which would probably be unsuited for exchanging
the fluid these batteries would need. Any kind of system for
exchanging the fluid in a flow battery would probably be self
contained and would be better designed than holding a lever
on a nozzle dumping a flammable liquid into an empty vessel.
maxerickson - 7 minutes ago
The article mentions the chemicals. Light alcohols and water.
maxerickson - 7 minutes ago
The never-wind people in an area I lived in shouted about rogue
electricity killing cows.Worrying about quality control of the
fluids is similar. The global energy industry is up to the
challenge of reliably producing batches of chemicals that
narrowly match a particular specification.
danans - 15 minutes ago
> The greatest hurdle for drivers is the time commitment to keeping
their cars fully charged.For a large percentage of common use
cases this is not an issue. EV drivers by and large do other
valuable things while their vehicles charge, like work and sleep.>
Current electric cars need convenient locations built for charging
ports.This is only true for apartment dwellers (for now). People
who live in houses typically charge at home.> Designing and
building enough of these recharging stations requires massive
infrastructure development, which means the energy distribution and
storage system is being rebuilt at tremendous cost to accommodate
the need for continual local battery recharge> Users would be able
to drop off the spent electrolytes at gas stations, which would
then be sent in bulk to solar farms, wind turbine installations or
hydroelectric plants for reconstitution or re-charging into the
viable electrolyte and reused many times.How is this fueling and
distribution system cheaper or more efficient than the grid plus a
bunch of 240v/60a outlets, most of which are already available in
home garages. If instant refueling is a really a dire need for
someone, they can just get a plugin hybrid (i.e. Chevy Volt) and no
new infrastructure needed at all.Edit: removed snarky words
StavrosK - 1 hours ago
Oh look, another revolutionary battery technology.
Animats - 1 hours ago
Right. This is a flow battery/fuel cell; you change the liquids
rather than recharging it in place. The new feature is that this
doesn't use a membrane to separate the two liquids. They're
immiscible and one is denser, so they stay separate, in layers.
Why this doesn't short out at the liquid interface isn't
clear.There are commercial flow batteries that use membranes.
One uses zinc-iron. The energy storage capacity is limited only
by tank capacity, so you can fill big tanks using solar power or
wind and draw it out later. Typical system is 288 kW/960 kWh,
and occupies 6 shipping containers. https://www.viznenergy.com
ars - 32 minutes ago
> Why this doesn't short out at the liquid interface isn't
clear.The same reason metal does not rust without water (the
metal/oxygen is touching after all without a membrane) - you
need a second path for the electricity, which is what the water
does. (The water does not chemically do anything - it simply
acts as a wire.)
deegles - 1 hours ago
Just once I wish one of these headlines would end with " and is
coming to market soon!"
gordon_freeman - 1 hours ago
I feel your anticipation. But I think the more such experiments
happen, the more we as consumers would accelerate towards zero
emission transportation future. As it stands, time to charge
battery (especially on long road trips)is one of the factors
discouraging consumers to adopt electric vehicles.
hinkley - 41 minutes ago
A revolutionary battery technology involving vodka.
gist - 1 hours ago
Hard to believe that Tesla isn't working on something like this.
aeleos - 1 hours ago
This is pretty cool. The general idea is that a gas station
dispenses a water and ethanol solution that acts as the electrolyte
and provides energy for the battery. And then recharging is done by
reprocessing the electrolyte with renewable energies. If this turns
out to be a technology that can work well on large scales, it could
really be a game changer.
jonshariat - 1 hours ago
Trying to understand this from a customer's point of view:1.
would this be dispensed just gas? Pull up, pay, and pump it in?2.
But in this case you would also pump the old stuff out?3. Is
there any "prep" time needed for the solution? aka charging
aeleos - 28 minutes ago
1 and 2 I think so, 3. The stuff that comes out of the pump is
ready to use, the old stuff needs to be "recharged" to be
mikeash - 1 hours ago
Can you also recharge it in the battery with electricity, or do
you have to go to a special station? The ability to "fill up" at
home is one of the great advantages of EVs, although I realize a
lot of people can't do that.
daotoad - 1 hours ago
Too bad the nifty techno-in-a-can synth diddling in the video
drowns out the inventor talking about his technology.
ars - 1 hours ago
Quick summary: It's a flow battery. Replace the liquid with
fresh liquid and you are recharged.This one is different by not
having a membrane. https://en.wikipedia.org/wiki/Flow_battery
tedsanders - 1 hours ago
Question: Why is this a flow battery and not a fuel cell?My
impression is that the difference between flow batteries and fuel
cells is that flow batteries are closed systems whereas fuel
cells are open systems. Since this can be refueled, it sounds
like an open system.Edit: Your linked Wikipedia article answers
my question. "A flow battery is a rechargeable fuel cell." I
guess the distinction is not closed vs open, but rechargeable vs
ars - 38 minutes ago
I think a fuel cell is distinct by having the oxidizer be from
the environment, and not within it.A flow battery is completely
self contained.Getting your oxidizer from the environment
obviously helps with weight, but it comes with its own set of
problems since it's hard to control purity.The wikipedia
definition kinda touches on this. Since everything is contained
in the battery you can recharge it with just electricity.In
contrast a fuel cell will emit the waste (water usually), so
you no longer have the raw material to recharge it anymore.
(Although obviously you can just make more by collecting it
from the environment - think emit the water, then electrolyze
other water to recharge the battery.)
calebsurfs - 38 minutes ago
What is the energy density of a flow battery like this? It's hard
to imagine it is anywhere near gasoline or a lithium ion battery.
mjevans - 23 minutes ago
Read the (currently) top post by Ars linking to the Wikipedia
page.There's a table of the currently known public chemistries
near the bottom.There are applications with better power density
than Lithium based batteries (at the electrodes), but I don't
know about how an overall solution would compare to a gasoline
setup.I think the only fair comparison in such a case would be to
have a roughly standard car design and compare complete solutions
(currently common petrol / diesel depending on vehicle size,
hybrid (electric), full electric (batteries / 'flow batteries' of
nathan_f77 - 30 minutes ago
This sounds interesting. It got me thinking about some other
ideas.What about solar panels on the roof? I found this article
, and Elon Musk has said they'll "probably offer it as an
option" .I wonder how many extra miles you could get with that.
If nothing else, it would be nice to know that you could slowly
recharge your battery if you get stuck in the middle of
nowhere.Another idea - highways where you could drive while
recharging. Maybe something similar to train tracks, or an overhead
wire. Or wireless power transfer through the wheels, if that would
be possible? (I don't think it is.) https://thinkprogress.org
Xeoncross - 24 minutes ago
Solar panels charge really slowly compared to how much energy is
needed to move a car.I'm probably totally wrong here, but if the
whole car was solar panels I would expect 600 watt to be
generated. An electric car would need that for 0.8hrs or so to
move one mile (0.44 kWh/mile?) plus acceleration.
dangero - 20 minutes ago
Still seems worth it for a slight efficiency gain plus the
ability to gain charge just by waiting if you run out of juice
in the middle of nowhere.
tempestn - 1 minutes ago
Another issue is that most people prefer to have a sunroof on
their car. (Ideally a large, panoramic one, as Teslas have.)
Can't really do that with solar panels.
maxerickson - 22 minutes ago
The sun is ~1 kw/square meter and solar panels are 15-20%
efficient.So for every square meter of roof space covered in
panels you can get a max of about 200 watts of power.This is a
lazy, handwavy characterization of the situation, but it paints
the picture, it isn't much of a contribution as batteries head
north of 50 kw-h.