Potential breakthrough in Lithium-Sulfer batteries

[Martinet]

https://www.scientificamerican.com/...e-critical-flaw-in-lithium-sulfur-batteries/#

 

[JRA]

To me batteries are arguably the most important component of the e bike equation. The fact that battery chemistry is on the verge of changing radically in the near future is my main reason for sticking with a non-proprietary motor/controller system so that going forward I will be able to take advantage of new developments as they come along by just plugging in the new technology.

Here is another one with potential: https://www.extremetech.com/extreme...ctrolyte-same-guy-pioneered-lithium-ion-cells

Also the larger cells being developed that promise higher c rates and charge cycles have promise. http://www.bike-eu.com/home/nieuws/...ry-innovations-presented-at-eurobike-10127504

Luckily I have over a thousand plus cycles between my two batteries because it seems that these still may be awhile before they hit the market.

 

[tomjasz]

Sadly todays science is usually at least 3 years away...

 

[Toynut]

Panasonic new 20700 cells
Also Panasonic presented bigger battery cells at last week’s Eurobike. Their newly developed 20700 cell (20mm diameter and 70mm high) is in particular targeting e-MTBs that have downtube mounted batteries. By the way, Eurobike indicated that integrating the battery in the downtube is currently the general trend among electric Mountainbikes. Panasonic says on its 20700 cell, “This battery call has been developed for compact and integrated designs.” Panasonic offers two 36V integrated battery versions with 8 and 12Ah allowing for 288 and 432Wh.

Panasonic is on the right track as far as downtube mounted batteries, but, the capacity of the 36 volt battery design does not appear to be much of a game changer ,

 

[tomjasz]

Panasonic new 20700 cells
Also Panasonic presented bigger battery cells at last week’s Eurobike. Their newly developed 20700 cell (20mm diameter and 70mm high) is in particular targeting e-MTBs that have downtube mounted batteries. By the way, Eurobike indicated that integrating the battery in the downtube is currently the general trend among electric Mountainbikes. Panasonic says on its 20700 cell, “This battery call has been developed for compact and integrated designs.” Panasonic offers two 36V integrated battery versions with 8 and 12Ah allowing for 288 and 432Wh.

Panasonic is on the right track as far as downtube mounted batteries, but, the capacity of the 36 volt battery design does not appear to be much of a game changer ,

Interesting, Tesla is introducing 21700. That's their replacement for the venerable 18650.

One review, making me wonder what will be the new standard?

"
20700 battery VS 21700 battery, who will be the winner?

Tesla's Gigafactory, under construction in Sparks, Nevada will be the biggest lithium ion battery factory in the world. “If you add up all the lithium factories in China, Korea, Japan, elsewhere in the world, and you sum them all up, on all the production capabilities last year, the Giga factory is actually bigger than that. “ Tesla CEO Elon Musk said.

Panasonic and Tesla will produce millions of 21700 batteries for the upcoming Model 3 car. Musk said that after Tesla gets the Model 3 out the door it will revisit whether or not it wants to make new Model S and Model X cars with the 21-70 batteries. By that time, 21700 might be produced in the largest number.

- See more at: (Link Removed - No Longer Exists)

 

[Toynut]

The article indicates a 40-60% increase in battery capacity. Assuming that Panasonic is pretty much in line with their battery design and chemistry, why such a low expectation for their new 36 volt battery packs (288-432 WH)?

 

[tomjasz]

The article indicates a 40-60% increase in battery capacity. Assuming that Panasonic is pretty much in line with their battery design and chemistry, why such a low expectation for their new 36 volt battery packs (288-432 WH)?

Perhaps the focus is making a smaller battery in physical size? I've done that with the newer cells. Rather than more amp hours or watt hours chose a smaller size.

 

[Toynut]

The battery case will probably be physically taller or wider than one using 18650 cells. I don't see any benefit in shrinking the battery pack and the capacity, particularly on a 50 pound e bike. The trend and goal of adding additional range is the driving factor to battery cell innovation. I don't expect trimming a pound or two off of a cell pack in lieu of extended range is the right trade off, marketing-wise.

 

[tomjasz]

I guess we all have differing wants. Personally I'm moving towards more stealthy builds. I like battery packs hidden in seat packs, as an example. And hub motors as small as dynamo hubs. If I get 15-20 miles with assist I'm happy. That's enough for a days recreational riding in the park or a few days of errands. And the less I look electric the happier I am. There's a market there as well. I see your point and market as well. But more energy density in the packaging mean it can be smaller and the Ah of the batteries is increased over 18650 batts. We'll have to see what they hit the eBike market at. I suspect we'll be able to reduce sizes. As we did when we went from 2000Mah to 3500Mah. OR give you you extended range in the same size pack, by volume. By design a pack would be taller, but with less cells narrower.