Toyota Pushing Move To lithium-Ion Batteries

I am glad to see Toyota using what works, instead of what is trendy.
I bet several manufacturers plagued by fires with they had chosen what works.

 

Obviously as battery technology improves and changes, and also as production methods improve and are streamlined, the batteries used in hybrids are going to change in kind.

It's arguable that nickel metal isn't the state of the art today, but given the 5 million hybrids Toyota has sold, it's the most commonly used battery in service.

My not so speculative guess is Lithium-Ion is not only "today" for many hybrids but simply becomes the standard very shortly for all Hybrids.

It's interesting that Toyota admits to looking into the "wrong" type of Lithium Ion chemistry in 2010.

I don't pretend to be an expert, but I do think battery technology is exciting to hear about. It will be interesting to see what type of battery is in the next generation Prius.

 

Toyota was not 'left behind,' it built a patent garden and technology advantage that forced other car manufacturers to pick Li-X. Funny how that gets spun

This isn't to say that some variations of Li-X do not have advantages, particularly with power density and volume or weight per capacity. If Toyota has ironed out reliability, cost and safety problems then by all means lets transition to Li-X.

 

well, its blog adding their own words to short Reuters story on Toyota and Panasonic increasing lithium battery production to 200,000/year. What Toyota has "admitted" for lion is that it is not solution.

And based on this, Prius is not moving to lion certainly... as they sell 3x more Prii than 200k/yr lion plant can produce.

So this could be for upcoming RX for instance, and other more expensive Toyota/Lexus vehicles.

 

LiIon would be the way to go for plug-in hybrids and full electric cars.

For a regular hybrid like the Prius, the weight savings in not that great due to the capacity and output of the battery needed. As the battery capacity gets higher, the weight savings becomes greater.

It's like the structure of an airplane. 4 to 5 ounces of extra weight in one component out of 5000 matters little. 4 to 5 ounces of weight added to 5000 components make a lot of difference.

 

they didn't even mention pip.

 

Ken@Japan had posted a chart showing both energy and power density of various battery chemistries:

• Energy density - how much power per unit weight, extra power for passing or hill climbs
• Power density - how fast the power can be added or removed, how fast it accelerates or hill grade

I remember Ken's chart showed energy density and power density were at odds. For the Toyota hybrid systems, power density is very important, both in discharge but especially charge. This was where the Lithium chemistries were weak. But this chart was several years ago.

My studies show our current traction battery has frequent, short, high current draws and during braking, significant charging currents. Regenerative charging appears to be the lithium technical challenge. But they may have a technical solution.

Bob Wilson

 

Bob, most lithium chemistries have higher energy density and power density than nimh chemistries. The Sanyo designed battery in the plug in though, was designed for large usable state of charge, and longevity. The battery in the alpha is designed for hybrid operation, and should have higher power density to the prius.s nimh.

Toyota mentioned that lithium is harder to control, I believe that means that the lithium requires more complicated control electronics. They may want to develop that outside of the US market.

 

Didn't Chevron-Texaco build the "patent garden" with regard to NiMH (especially large-format/plug-in)

 

For plug-in applications, yes.

I was referring to hybrids.
It wasn't just patents by the way. Toyota also cornered the market on supplies and production. For years Ford whined that their hybrid production (using NiMH) was constrained by purchase agreements Toyota had with suppliers.

 

GM bought the company with the patent, then sold it, which became controlled by Chevron. This really is not a guarded patent now, it is owned by IIRC a Samsung-Bosch joint venture now. That likely would prevent Panasonic from building the batteries as inexpensively as the LIon they are now, but nothing prevents toyota from buying batteries from that joint venture.

Lithium Ion and lithium polymer are simply better technologies for both plug-ins and hybrids. They have better power to weight, energy to weight, and energy to volume than nimh. Panasonic/Toyota's joint venture to build hybrid nimh batteries was quite a high investment, so Toyota may have a cost reason to stick with nimh for a while longer. In the long run LIon and lithium polymer prices are dropping, and in the long run should be lower than Toyota's cost for nimh.

 

I'm not so sure that Li-X to date is superior to NiMH. IIRC (although I do not have a reference,) Toyota reckoned that NiMH outperforms Li-X in long term reliability for straight hybrid applications. The future of course may be different.

While Li-X may in the future be cheaper than NiMH, the point was that competing manufacturers were forced to use the more expensive battery, and have not been able to make a hybrid superior to Toyota's NiMH Prius.

The only daily performance advantage Li-X has over NiMH in hybrid applications is higher power density, which might translate into more efficient regen. So far though, no proof of concept has emerged. That is really the bottom line here: NiMH is the superior battery chemistry for the Prius, per the Prius performance characteristics as defined.

Likely not the best platform for a hybrid Porsche

 

you mean when Ford purchased directly from Toyota owned companies? Toyota didnt have enough production for themselves.

 

Did Toyota Buy Panasonic?

 

The "dendrite" crystalline formation is the major problem with Li-Ion technology.

The future of the current installed base of Li-Ion batteries has to be seen. The "track record" of Ni-MH technology has bee secured.

I'll wait until Li-Ion establishes an equivalent record, before I "dive in."

 

You mean Toyota Panasonic JV that supplied these batteries (actually didnt they buy it off 3-4 years ago as part of requirement for Sanyo bid?). Or Aisin who supplied PSD? Or Denso who supplied rest of the stuff?

Yes, they are all Toyota owned.

 

Umm, say what?
Panasonic makes LIon cells based on sanyo technology. Panasonic bought Sanyo. They sell these cells to whoever they want, which includes Ford and PEV. Ford used to buy whole batteries from Sanyo, and was forced to buy from PEV for a short time after the takeover. Now they assemble panasonic cells into batteries at their own plant. This is similar to Tesla assembling panasonic cells at their plant. PEV is a joint venture between Toyota and Panasonic. The Chinese government required Panasonic divest some of its stake in PEV, IIRC to prevent it from having an monopoly in NIMH batteries when it bought Sanyo. Toyota bought that stake. So if Toyota owns Panasonic now, which seems like a false rumor on your part, why doesn't the Chinese have an anti-trust lawsuit against them?

PEV is heavily invested in Nimh, which likely gives them cost advantages. I suspect at sometime in the future when Nimh is at a cost disadvantage to LIon or lithium polymer, PEV will switch completely to the technology.

I also have no idea what you are rattling around about denso or aisin, they have nothing to do with lithium batteries. aisin also no longer supplies Ford or Toyota with psd parts. Toyota is a large intertwined enties that owns parts of many companies, but only their joint venture in PEV matters to this discussion.

 

Prime Earth EV is licensing the fundamental NiMh patents because the got sued. That ends in 2014 because those patents will expire.

PEVE have their own high power cell patents perfected for hybrids.

Sure, they invested in it out of the need to meet HV battery requirements. Heavily invested? I think that's stretching it.

I bet PEVE would have probably invested in more in Lithium than NiMH.

 

I don't follow battery chemistry closely but one article I read suggested that one lithium chemistry generates a small but increasing percentage of non-reactive, lithium compounds. In effect the charge/discharge cycles slowly convert the active compounds into unusable.

My studies of NiMH suggests that does not happen. I've taken nearly dead NiMH modules and with water rehydration and charge/discharge cycling returned them to 'like new' capacity. But you have to add water to rehydrate the electrolyte.

Would anyone have a summary of the different lithium chemistries and perhaps post a synopsis?

Bob Wilson