Boeing 737: A historical reference for range improvements

[RegGuheert]

Capacity of Li-ion batteries has been improving at a historical rate of 8%/year.

What's your source for this data?

Carlos Ghosn has been quoted as saying that is the rate of capacity improvement they are seeing, but I cannot find the reference.

Here is another report which shows 7%/year: Comments on the History of Li-ion BatteriesSee Figure 3 about 18650 cell capacity. 1991: 1 Ah, 2001: 2 Ah

2009: Panasonic Develops New Higher-Capacity 18650 Li-Ion Cells; Application of Silicon-based Alloy in Anode: 4 Ah

I guess that last data point is a bit over 8%/year from 2001.

So, how are BEVs doing in terms of specific capacity of batteries?

2011 Nissan LEAF: 24 kWh battery weighing 650 lbs. (295 kg) = 81 Wh/kg
2017 Chevy Bolt: 60 kWh battery weighing 960 lbs. (435 kg) = 138 Wh/kg

That's a 70% improvement in specific capacity in 6 years. That is a battery capacity growth rate of 9.3%/year, which exceeds both Ghosn's prediction and the historical rate of Li-ion capacity improvement seen in cylindrical cells.

More importantly, the range of BEVs has improved by 200 miles/84 miles = 2.4 times over the same period, which is a 15.6%/year rate of range improvement.

It seems that the range of BEVs is increasing more rapidly than the range of the 737, though I doubt this rate of improvement will continue into the future. Only time will tell.

 

[TomT]

Maybe GM is simply better at it...

That's a 70% improvement in specific capacity in 6 years. That is a battery capacity growth rate of 9.3%/year, which exceeds both Ghosn's prediction and the historical rate of Li-ion capacity improvement seen in cylindrical cells.

 

[RegGuheert]

Maybe GM is simply better at it...

Perhaps. It will be interesting to see the numbers when LEAF 2 is revealed.

 

[TonyWilliams]

GM / Chevrolet
Spark EV - 5 miles per kWh (200 wattHours per mile) (111 Wh/km) * 19kWh = 95miles / EPA 82

Spark: 95 miles/19000Wh = 200 Wh/mi = 125 Wh/km.
(Chevrolet appear to claim the 82 mile range, though = 19000Wh/132km = 144 Wh/km)
(ref http://www.chevrolet.com/spark-ev-electric-vehicle.html" onclick="window.open(this.href);return false; )

There are 1.61 km in a mile - even an Amurcan' mile!

Merc appear to claim 185km from a 28kWh battery. (Is that all useable battery, though, or is that the useable capacity?) = 151Wh/km
(ref: http://www.emercedesbenz.com/autos/mercedes-benz/b-class/2014-mercedes-b-class-electric-drive-coming-to-america/" onclick="window.open(this.href);return false

(Side note: There was a mediaeval Arabic mile of ~1.8km length, which is what someone appears to have chosen to use in the last post. Just to mention... they didn't have EV's in mediaeval Caliphates. :lol: )


I don't regard the Rav 4 as a passenger car of the same class. Of course larger vehicles will take more energy. I'm talking about a regular 2-5 seater 2WD passenger car, around whom a body design of some moderately optimised aerodynamics can be designed. That is, Euro passenger class Segments A to F (also as defined by NCAP as 'passenger cars').

Again, the parameters for my MEASURED data was identified.

I don't work off of "claimed" data.

 

[Nubo]

[2011 Nissan LEAF: 24 kWh battery weighing 650 lbs. (295 kg) = 81 Wh/kg
2017 Chevy Bolt: 60 kWh battery weighing 960 lbs. (435 kg) = 138 Wh/kg

That's a 70% improvement in specific capacity in 6 years.

Or rather, it will be, if and when Chevy starts selling Bolts with those specifications...

 

[RegGuheert]

More importantly, the range of BEVs has improved by 200 miles/84 miles = 2.4 times over the same period, which is a 15.6%/year rate of range improvement.

Let's redo that calculation with the real numbers for the Bolt:

The range of BEVs has improved by 238 miles/84 miles = 2.83 times over the same period, which is a 19%/year rate of range improvement.