News from AABC

[JackFlorey]

News from the Advanced Automotive Battery Conference in San Diego:

There was the usual "coming-soon" about silicon anode, lithium metal, sodium and sulfur, and solid state batteries. Silicon anode will be here Any Day Now, with several companies offering test cells (but with lifetimes in the 100-200 cycle range.) Still might be an option for racers. Enovix will have si-anode cells for portable devices by 2022 and for EV's by 2025 (they claim.) They are claiming >500 cycles but again no cells available yet.

I was excited about the GM Ultium battery system. Ultium is a skateboard type platform for GM's EV's. The (flat) battery box contains their modules. The reason it's exciting is that they are designing for second life use, which means that they will be usable for aftermarket applications like ebikes. Some details:

Ultium modules will have 12 (prismatic) or 24 (pouch) cells
Typical battery packs will have 8 to 24 modules - so doing a little guesswork each module will be about 6-8 kwhr
They developed a wireless BMS with ADI, and they are planning to document the interface
Modules are 2p12s or 3p8s - 48 or 32 volt - they are calling 12s "48V" but they are really 43V packs. Still a usable voltage.

Full battery packs will be switchable between 400 and 800 volt, to support both cars and trucks (currents for large trucks get unmanageable at 400 volts.) All likely NMC 8-1-1 lithium chemistries.

Several companies offer EIS (noninvasive electrical) inspection services for used cells, and two companies now offer ultrasonic inspections for used cells. Both will be useful for ebike pack integrators trying to use second life cells.

 

[Hillhater]

Was there any evidence to indicate future cost reduction in any of the battery technologies ?

 

[Pajda]

I was excited about the GM Ultium battery system. Ultium is a skateboard type platform for GM's EV's. The (flat) battery box contains their modules. The reason it's exciting is that they are designing for second life use, which means that they will be usable for aftermarket applications like ebikes.

Several companies offer EIS (noninvasive electrical) inspection services for used cells, and two companies now offer ultrasonic inspections for used cells. Both will be useful for ebike pack integrators trying to use second life cells.

I have been dealing with the issue of modern lithium batteries for some time, and unfortunately this has negative effects on my politically correct thinking. The second life for current lithium battery technology is technical and economic bullshit. In fact, we are talking about the further use of hazardous waste. Furthermore, if the battery still serves well and its original application was not intentionally totally messed up by design (eg, a BEV with a range of less than 200 miles EPA/WLTP), there is little reason to replace it from the original application. The main reason for replacement is a defect that must be solved before further use. If there is no problem in the electronics, then it means replacing the module. We know that it is not entirely easy just to produce new cells with the same parameters to avoid need of their balancing, but we have mysterious way how to make a worn out battery with a replaced module working better? There are already many examples where brand new batteries burn for often unexplained reasons, but we have mysterious way how to make a worn out battery safer? Another, but not the last, point is that the current generation of lithium cells contains an "unnecessarily" large amount of valuable materials like Co and Mn. So by recycling 1 kWh of the older generation of LIB we get valuable materials for >1 kWh of the new generation. In short, the second life of batteries is clearly counterproductive and the right way is to start their industrial mass recycling as soon as possible.

And the practical comment. I expect that GM Ultium modules will be too big to mechanicaly fit in ebikes and even emotorcycles. I suppose that they will use similar cells from LG as VW does and so Ultium modules will be close to VW MEB 590 modules with ca 590*221*110mm dimensions.

 

[JackFlorey]

Was there any evidence to indicate future cost reduction in any of the battery technologies ?

Quite a bit, although there was far more coverage of cost reduction for existing battery materials in the "materials" track. One interesting idea is extraction of lithium (and perhaps cobalt) from brines in the Salton Sea and coming from California geothermal energy plants.

 

[JackFlorey]

I have been dealing with the issue of modern lithium batteries for some time, and unfortunately this has negative effects on my politically correct thinking. The second life for current lithium battery technology is technical and economic bullshit.

Given that I am currently using a second life pack from a Smart ForTwo for a DR prototype, I will have to disagree there.

In fact, we are talking about the further use of hazardous waste.

Which cuts the problem caused by that hazardous waste in half.

Furthermore, if the battery still serves well and its original application was not intentionally totally messed up by design (eg, a BEV with a range of less than 200 miles EPA/WLTP), there is little reason to replace it from the original application.

People will still discard used EV's just as they discard old used cars now.

In short, the second life of batteries is clearly counterproductive and the right way is to start their industrial mass recycling as soon as possible.

Both are important. No current EV manufacturer is recycling their batteries now; until they do, interim measures like second life battery use will be important. It will also reduce the short term demand for batteries by getting twice the use out of the same batteries.