Tesla battery research partner releases paper to enable higher voltage and longer lasting LiIon cell

[Morgen]

[QUOTE]The paper states that ethylene carbonate (EC), an organic compound until now thought to be an essential electrolyte component for Li-ion cells, is “actually detrimental for cells at high voltages” – 4.5 V and above. Tesla/Panasonic’s current cells are believed to be around 4.2 V, but the upcoming cells to be produced at the Gigafactory are expected to have a higher voltage.
...
In order to replace EC in the electrolytes, the group developed “EC-free linear alkyl carbonate electrolytes” and tested them in pouch cells. They report “excellent charge-discharge cycling and storage properties” and better cyclability of cells than cells with EC.
[/QUOTE]
[URL="https://electrek.co/2016/08/17/tesla-battery-research-partner-jeff-dahn-cells-longer-range-life-cycle/"]Source[/URL]

Higher voltage generally means higher energy density. If they didn't increase the voltage then using this at 4.2V would give you a battery with a substantially higher cycle count apparently. This is more relevant to Tesla's stationary battery products than the cars due to the paper being about the type of cells that Tesla use in the stationary products. Maybe this will allow them to switch to NMC cells in the cars as well.

[ironman17]

Certainly an electrifying discovery! Again, batteries march forward thanks to Tesla.

[Van-man]

I'd say higher cycle count is actually more attractive for 'portable' use (automotive and generally powered gadgets) than stationary, given the space & weight constraint means that a more durable as a whole battery will mean the car can be made lighter, smaller and also require far longer time before the pack will have to be replaced due to insufficient range.

[Morgen]

[QUOTE=Van-man;50907919]I'd say higher cycle count is actually more attractive for 'portable' use (automotive and generally powered gadgets) than stationary, given the space & weight constraint means that a more durable as a whole battery will mean the car can be made lighter, smaller and also require far longer time before the pack will have to be replaced due to insufficient range.[/QUOTE]

I'm not sure how a higher cycle count leads to the car being lighter? You would still have the same amount of cells, and if you removed some then you would have lower capacity which would mean you would go through more cycles. If you went with the high voltage cell though then you could remove some cells and maintain the same capacity.

The obvious benefit stationary storage gets from a higher cycle count is that it lasts longer, which increases its financial viability.

[ithon]

trickle down battlebot economics

[OvB]

Stuff like this goes to show that were better off using the tech we got rather than waiting for "battery breakthroughs". Those breakthroughs only come when you have an economic reason to research it. As Elon said about the Gigafactory "nobody else is going to build the fucking thing." Previous EV components were basically off-the-shelf hardware, and people wondered why we had no breakthroughs, why EVs were so crappy. That's because progress requires true dedication.

[Van-man]

[QUOTE=Morgen;50908543]I'm not sure how a higher cycle count leads to the car being lighter?[/QUOTE]

Because then you can spec the battery pack so you can still promise the car will have a specific range at certain age after driven a set distance driven with a slightly smaller battery.

Otherwise you'd have to slap in a higher capacity battery to compensate for the drop in capacity.

And with how heavy EV's tend to be compared to combustion cars of same size and range, then every gram counts.