MIT "Yolk and Shell" Nanoparticle Promises Longer-Lived Rechargeable Batteries

jan_jes writes: A new "yolk-and-shell" nanoparticle created by researchers at MIT and Tsinghua University in China could boost the capacity and power of lithium-ion batteries. The researchers have created an electrode made of nanoparticles with a solid shell, and a "yolk" inside that can change size again and again without affecting the shell. The new findings, which use aluminum as the key material for the lithium-ion battery's negative electrode, or anode, are reported in the journal Nature Communications. The use of nanoparticles with an aluminum yolk and a titanium dioxide shell has proven to be "the high-rate champion among high-capacity anodes." The linked article goes into much more detail about the (serendipitous) discovery.

Comments

Wow...

[Dr_Barnowl]

TLDR?

• * > 3 x the charge density of carbon cathodes
• * Still has nearly double the charge density of carbon after 500 balls-to-the-wall rapid charge cycles (6 minutes)
• * Made of very cheap stuff - we package soda in aluminium and slather titanium dioxide on our bodies and then wash it away, ferchissakes

Very, very exiting. I imagine they'll be getting a call from Elon Musk in their near future.

Re:Wow...

[Rei]

Indeed, aluminum is the 3rd most common element in Earth's crust (more common than iron), oxygen is the most common, and titanium the 9th most common (more common than hydrogen). Now, of course, it's not elemental abundances that matter but raw feedstock prices. Their feedstocks are 50nm aluminum powder, sulfuric acid, and titanium oxysulfate. Concentrated sulfuric acid is one of the most widely used industrial chemicals on the market, cheap at about $700 a tonne. Even high purity sulfuric acid isn't particularly expensive. Titanium oxysulfate is about $5000 a tonne - still really trivial compared to the value of the anode material you're getting. However: 80nm aluminum nanopowder (in the same size ballpark) costs $1109 per kilogram, and that's the cheapest I've found online that has a price quote. And this here is a big problem, that's just way too expensive, your finished batteries will be selling for something in the ballpark of $100/kg. But, this is small scale. If anyone here has any idea how cheaply 50nm aluminum powder could be made if desired in quantities of hundreds of tonnes a year, I'd be quite curious.

Of course, as pointed out below, the sort of news we really want to see is about significant cathode improvements...

Re:Wow...

[Rei]

Wait a minute.... it says mean size 30 *micron*, not 30 *nanometers*. Sorry - the particles are 600 times too large :(

Great news

[Anonymous Coward]

I'll add it to my ever growing list entitled "Technologies promising to double battery capacity that have yet to come to market"

Re:Great news

[Rei]

No, that's just the issue - all hell doesn't break loose. Peoples' electronic devices just keep consuming more power and/or manufacturers keep shrinking the size of the battery pack. We keep reading about new battery capacity techs, and while most of them don't make it to market, some of them actually do. For example, on Slashdot 5-ish years ago we were at several points reading about silicon anodes for li-ion batteries. Guess what? Some manufacturers today now use them. But we just don't notice these things because there's no "hell breaks loose" moment.

Re:Great news

[Dr_Barnowl]

It's not personal devices that will benefit the most. As you point out, there is a stalemate between the twin goals of more power, and less power consumption, in the IC market.

It's devices with relatively fixed power consumption that will benefit, like electric cars. Even if this only adds 50% capacity to batteries, that will push electric cars over the threshold of viability for a LOT more people. Anything that does stuff in the real world rather than the virtual world.

Great, but...

[Rei]

... there's many alternative, highly improved anode types. There's much more room for improvement on cathodes. There's diminishing returns focusing so much on the anodes. Don't get me wrong, this really does sound like a very good anode material - in particular, both the raw materials and the manufacturing process should be cheap and with good throughput. But we need cathode improvements more.

Re:Great, but...

[Rei]

For those interested in the current state of cathodes in li-ion batteries and the research underway to improve them, there's a good paper here. The short of it is that they do keep making incremental improvements, and might continue that way for a long time, but they don't seem to be as subject to the "big leaps" that people are working towards on the anode side. There's been some interesting work since then, though - for example they don't mention anything about the recent work on vanadium/boron glasses (~300Mah/g initial capacity (twice that of LFP), without as much degradation as with forms of crystalline vanadium oxide)

Honestly, I don't expect any "big leaps" overall in battery tech. But based on everything I've seen that's already "in the pipeline", incremental improvements in li-ion battery capacity should be expected to continue to improve for at least 5 years, and probably much longer. There are a number of proposed techs for what will come after li-ion. I personally wouldn't be surprised if lithium-sulfur becomes the next usurper - it has huge capacity, generally common materials, there's been a lot of work towards overcoming its main downside (short lifespan), and there's already a low-volume manufacturer out there PolyPlus with limited use in special applications.