NiMH vs Li-Ion battery - what's the deal?

BMW 318i here has just lost a cylinder - now 3, and 1.5 litre. With turbo, and 100kw.

 

Don't see an answer yet. Does the battery range stay the same? Too many variables. Just assumed the Lithium was better.

 

TOYOTA says:
"The hybrid battery is an interesting example of how we have been able to improve performance. Like before, it uses nickel-metal hydride technology, which we know suits the Prius’ global market needs, but we’ve made it more compact, yet at the same time more powerful, faster charging and longer lasting." in their document "THE NEW TOYOTA PRIUS -THE REBIRTH OF THE PIONEER" dated 08 Feb 2016 on Toyota's EU website.

Interestingly enough, they don't mention Lithium Ion at all in the document - targeted publicity? I thought that NiMH has a higher energy density, at least in smaller scale domestic situations, and is more tolerant of deep discharge than Lithium Ion. Toyota must have a reason, though - it could purely marketing, that the 2 largest markets (Japan and USA) get the lighter weight battery?

 

That's interesting, in Australia as well, our Prius v has Li-Ion only on both models (Gen 3 and Gen 4 are NiMH only).

It would also be interesting to know the difference in price if either battery fails - anyone have any idea?

 

Nope...I've been asking here if anyone knows the price of a Prius +v Li batt in EU?
We know in the USA the Prius NiMH runs around $2250 without install.

I have also asked the question if we think Toyota would replace in kind (eg; for Gen4) or would they switch over to NiMH for replacement.

 

I'd be surprised if they were entirely compatible - seeing they have different energy densities and deep discharge profiles, and may therefore have differing software and even inverters, as well as different installations and cooling ducting.

 

I could be wrong, but there is no mention of Sunroof or Moonroof in Australian brochure either.

 

No moonroof or power seats in the UK. Think the Excel (top trim) has everything else tho' except LiPO HV battery, all models have NiMh chemistry. G...

 

Three trim levels/models available in Sweden: Life, Active and Executive.
No sun/moon roof.
Seven exterior colours and two interiors.
Only NiMh-battery.

 

I don't miss my sunroof in my solar four. The ceiling in the car is actually cooler in the 2016 plus it should never leak.

 

Interesting report on Lithium carbonate price:


Another source: Global Economy Making Clean Energy Transition From Fossil Fuels to Renewables | Gold Stock Trades


Source: Nickel Price Forecast 2016 - Investing News Network

NiMH batteries also need some rare earths but I don't have the quantities and list of elements.

Apparently lithium is not the price driver: 82. THE COST COMPONENTS OF A LITHIUM ION BATTERY - Qnovo

Bob Wilson

 

An interesting abstract: Metal hydride electrodes: The importance of surface area

Abstract

A large active specific surface area is a very efficient way to improve charge/discharge rate capabilities of metal hydride electrodes. This can be promoted by washing oxidized, pre-hydrided AB5 alloy particles in a hot KOH solution. This leads to magnetization of the alloy powder, making it possible to lift the powder with a simple permanent magnet, indicating that nickel liberated in the surface layer is essential for the improved kinetics.

The overpotential of each step in the discharge process is analysed in detail using both half cells and sealed cells. The electrode polarisation depends inversely on the current density per active area. Untreated and treated alloy powders have similar current densities per active area, but treated powder exhibits superior kinetics due to its larger surface area. A NiMH cell with a surface-treated alloy has very good rate capability, only limited by the kinetics of the Ni electrode.

At low overpotential, the electrochemical reaction gives the main contribution to the electrode polarisation. If the discharge current is increased to give an overpotential of more than 0.1 V, concentration polarisation will become important and a limiting factor at high current densities.​

Bob Wilson

​

 

I thought this related recent thread was quite interesting:
Who has got a Plug-in kit? Satisifed? | PriusChat

In Colorado you can convert a regular Prius into a plug-in with Li batts. But it'll cost you $10,000 for a 4 kWhr Li batt like PiP1 ($4000 after Colorado rebate which is not bad if you happen to live in CO).

 

A 23 page summary of how we got here from there. It is written in academic style which can be daunting. Regardless, there are gems in the paper: http://hsns.ucpress.edu/content/ucphsns/46/1/44.full.pdf

The protracted commercialization of battery electric passenger vehicles is often
ascribed to the failure of the automobile industry to embrace the latest power
sources. In this article, I argue that the pace of progress in this context was instead
dictated largely by the ways researchers constructed metrics of power source per-
formance. , , ,

Both popular and scholarly accounts tend to ascribe the long gestation of the
modern electric passenger vehicle to the dilatory tactics of auto manufacturers,
a sector often cast as a holdover from the golden age of heavy manufacturing. If
the conspiratorial predilections of automakers have perhaps been overstated,
this industry’s antipathy and coordinated resistance to technology-forcing
legislation, above all, the California Air Resources Board’s Zero Emission
Vehicle mandate, have been well documented.1 One industry tactic, theorized
the historian David A. Kirsch in 2000, was to conjure an imaginary super
battery as a way of indefinitely delaying commercial production of electric
vehicles.
. . .
an extended-range electric vehicle, the Volt was essentially a dual-mode hybrid
utilizing a large and powerful battery. Whereas Tesla Motors equipped its
Roadster with packs of lithium cobalt oxide electronics commodity cells, an
expensive and problematic application of this technology, GM wanted a lith-
ium battery pack designed expressly for electric traction.

Once again, the company had to rely on external expertise. The results fell
far short of expectations, in large measure due to the impulse to make perfec-
tion the enemy of the good.
. . .

Automakers had united in arguing for super batteries as the
necessary condition for super-electric vehicles, convincing CARB to roll back
the ZEV mandate in exchange for research and development commitments.
Unlike their American counterparts, however, Japanese automakers opened
a lucrative market for hybrids equipped with the less-than-super NiMH
battery, a system that combined reasonably high energy density and modest
lifespan with low cost and excellent safety.​

Bob Wilson