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MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

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Re: MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

#71

Post by blacksmith_tb »

science4sail wrote: post #62
rdudek wrote: post #59

Earlier quoted context omitted.

But a -70C superconductor could theoretically be used in space environment where the temperatures are even colder, no?

Space is "cold", but the problem is that it's hard to get rid of waste heat in space since you aren't surrounding by a heat-carrying fluid (air). Therefore a -70c superconductor would still require a large cooling apparatus to function properly.

But waste heat is a valuable resource, thermoelectric generators could turn it into electricity, for example.

Re: MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

#72

Post by logfromblammo »

dghughes wrote: post #69
science4sail wrote: post #62

Earlier quoted context omitted.

Space is "cold", but the problem is that it's hard to get rid of waste heat in space since you aren't surrounding by a heat-carrying fluid (air). Therefore a -70c superconductor would still require a large cooling apparatus to function properly.

Yeah that threw me too when I thought the same thing I never thought about how difficult it would be to get rid of heat in space I figured just let it go out into space not thinking there isn't anything to send the heat into; no medium. NASA has a nice info page about it: http://science.nasa.gov/science-news/science-at-nasa/2001/as...

Basically, there's no convection, so the only way to dump heat is by radiation.

And since a radiator absorbs as well as it emits, you need to create a shade with reflective material and point a directional radiator in its shadow at the emptiest space you can see.

So sure, superconductors could be really cold in space, but if their solar shade or thermal control system fails, they are suddenly really hot.

Re: MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

#73

Post by piotrkaminski »

henry_vonfire wrote: post #42
piotrkaminski wrote: post #21

Earlier quoted context omitted.

FYI, waiting until a Li-ion battery is nearly fully discharged before recharging will actually shorten its life by 3-4x compared to recharging when it hits 50%. See: http://batteryuniversity.com/learn/article/how_to_prolong_li...

Really? I've heard that by doing that what you are doing is reducing the time the battery will be charged (it's like instead of using 100% of your battery, it set its limit at 50%). I don't have the source where I saw this, sorry.

You may be thinking of the "memory effect" of old NiCad batteries, which indeed needed to be thoroughly discharged before recharging otherwise they'd lose capacity. However, LiIon is a different chemistry, and different rules apply. I don't know of any modern device that still uses NiCad, though I'm sure there's still some legacy niche where they're useful...

Re: MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

#74

Post by mkr-hn »

science4sail wrote: post #62
rdudek wrote: post #59

Earlier quoted context omitted.

But a -70C superconductor could theoretically be used in space environment where the temperatures are even colder, no?

Space is "cold", but the problem is that it's hard to get rid of waste heat in space since you aren't surrounding by a heat-carrying fluid (air). Therefore a -70c superconductor would still require a large cooling apparatus to function properly.

That still sounds useful for something like a moon-based spaceport where they can drill heat sinks into the ground. Maglev catapults would help cut the amount of fuel they need to transport or produce.

Re: MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

#75

Post by tsotha »

ChuckMcM wrote: post #47

I have "battery breakthrough fatigue" so announcing a lab result isn't really going to get me excited. A licensing deal and a factory being built, much more exciting. Interesting challenge of the terms indefinite and infinite. I read it as batteries that may die may not after every action (which would actually be indeterminate batteries :-)) rather than an infinite number of cycles.

They're not even announcing batteries. They're announcing the theoretical possibility of a type of battery.

Re: MIT discovers batteries with indefinite lifetimes using solid-state-electrolytes

#76

Post by science4sail »

blacksmith_tb wrote: post #71
science4sail wrote: post #62

Earlier quoted context omitted.

Space is "cold", but the problem is that it's hard to get rid of waste heat in space since you aren't surrounding by a heat-carrying fluid (air). Therefore a -70c superconductor would still require a large cooling apparatus to function properly.

But waste heat is a valuable resource, thermoelectric generators could turn it into electricity, for example.

Yeah, you still need to get rid of the heat eventually. For example, thermoelectric generators depend on a temperature gradient to function, but you can't maintain a gradient without some kind of heat sink that draws heat away from the "cold" side.
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