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Battery researchers claim lithium metal breakthrough to triple electric car range

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Battery researchers claim lithium metal breakthrough to triple electric car range

In the latest battery breakthrough claim of the week, researchers from the University of Waterloo released a new paper claiming a breakthrough involving the use of negative electrodes made of lithium metal.

They claim that it has the potential to “dramatically increase battery storage capacity,” which could triple the range of electric vehicles.

The main issue with Li-metal batteries is the quick degradation due to dendrites forming in the cells.

Quanquan Pang, who led the research while he was a PhD candidate at Waterloo (now a post-doctoral fellow at MIT), claims to have solve the issue by “adding a chemical compound made of phosphorus and sulfur elements to the electrolyte liquid that carries electrical charge within batteries.”

They claim that the compound reacts with the lithium metal electrode in an already assembled battery to “spontaneously coat it with an extremely thin protective layer.”

It enables them to use lithium metal electrodes in battery cells and take advantage of their greater storage capacity without the safety risks and faster degradation.

Pang commented:

“This will mean cheap, safe, long-lasting batteries that give people much more range in their electric vehicles,”

He and his team published their findings in the journal Joule this week.

In the paper, they claim to have completed “over 400 cycles at 5-C rate” in prototype cells and that they have achieved a “close to 100% coulombic efficiency.”
 
First, this thread should be moved to the battery tech section, mods?

Second, did you guys read the paper published in Joule? It is well written. Among other things, it shows a new avenue for battery research in that they coat the lithium metal electrode during conditioning of the cell after the cell has been assembled, as opposed to during the manufacturing process. That’s new and their particular, rationally designed electrolyte additive (ie. They created this particular electrolyte additive based on a model of cell function rather than semi randomly trying different things, which is what most other battery research is), does something new too - creates a thin ionically conductive electrode coating which prevents dendrite growth, the bane of lithium metal electrodes.

Now all that said, their results are: “The LSPS cell exhibits very stable capacity retention (89%) over 400 cycles and high coulombic efficiency averaging 99.99%”. The coulombic efficiency is awesome, the 10% loss after 400 cycles, not so much (correct me if I’m wrong, current EV cells typically show 10% loss after a longer cycle count?). What these guys didn’t appear to do is to measure capacity loss under different charge/discharge scenarios. This is possibility due to their specialization. It would be interesting to get Jeffrey Dahn’s lab at Tesla to look at this cell in more detail to see if they can coax more cycle life out of the cell.

So, my take is that this is at the very least a very promising step in the direction (with a lot more research) towards higher density cells, and might possibly even be a relatively near term (2-3 year) breakthrough if what they have now shows promise under different testing conditions.
 
One wonders if Dr. Dahn might have already achieved something like this, and that Tesla is using/will use it as the foundation for the super-dense battery pack in the new Roadster. They have something way up their sleeve, I am sure of it!

Yes, it does appear that way based on Dr. Dahn’s statement about how quickly they’ve been making progress.

While battery improvements DO NOT in any way shape or form adhere to Moore’s law, it is very possible they adhere to Elon’s law (or was it JB’s law?) of 7% improvement per year.

Which means that a company that rides this continuous improvement wave, like, oh say Tesla, is going to do as well as other companies who have ridden such waves in the past. Like Microsoft.
 
glanced their PDF:
~140 mAh/g at ~1,5V avg test at 1C gives 210Wh/kg, don't know if its active material or cell, Tesla uses cells that are about 270Wh/kg at 0,2C rate and should be about 240 at 1C.
Maybe this cell can be cycled at faster C rates like other LTO, usual LTO are at about 70-100 Wh/kg...
 
glanced their PDF:
~140 mAh/g at ~1,5V avg test at 1C gives 210Wh/kg, don't know if its active material or cell, Tesla uses cells that are about 270Wh/kg at 0,2C rate and should be about 240 at 1C.
Maybe this cell can be cycled at faster C rates like other LTO, usual LTO are at about 70-100 Wh/kg...

In other words, not better than what Tesla currently uses...
 
sorry if this is not new news - quick scan of this thread and I didn't see.

Lithium Battery Research, Jeff Dahn, Dalhousie/Tesla Motors

This talk is from March 2017. The title is "Surprising Chemistry in Li-Ion Cells" and Dahn talks about gas formation and cycle life in lithium nickel manganese cobalt oxide (NMC), and related types.