Battery breakthroughs

"It doesn't prove that a true breakthru in li-ion batteries can be commercialized, but it does at least appear to prove it's possible -- which IMHO pretty sharply contradicts your claim that the tech is approaching its limits."

I have to disagree again I'm afraid. I'm quite sure that the performance envelope can be pushed out in many directions such as energy density, safety, temperature tolerance and so on. The HARD problem is finding a way of pushing out the envelope in ALL directions at once which is what you need. And it appears to be a very hard problem indeed as very little real progress appears to have been made despite billions of dollars having been thrown at it.

There is, of course, always the worrying possibility that a real improvement in one direction will result in an approach that fundamentally precludes any advances being made in some other directions.

We are already at the stage where the driver is having to tolerate long charging times, and to extend the life of his battery to give it an occasional long charge etc. I see this as highly undesirable and an indication that batteries are only marginally up to the job of running a car.

 

Yeah, but that was back when we and the Soviets were still doing atmospheric tests of nuclear weapons. Probably just a drop in the bucket compared to the fallout from just one of those!

As I understand it, the total emissions from the Three Mile Island incident were so tiny that no rational person would worry about that. Sadly, that happened in an age when mass media had brainwashed the public to be terrified at the slightest trace of "RADIATION!!", despite the reality that we get exposed to some amount of ionizing radiation (in the form of UV from sunlight, if nothing else) every day. Also despite the fact that far more radioactive material is pumped into the atmosphere by coal-fired power plant exhaust than comes from any operating commercial nuclear reactor, or even several of them together.

Even more sadly, we're still in the era of irrational fear of "RADIATION!!" from nuclear power, as demonstrated by the hysterical and amazingly long-lasting overreaction to the Fukushima power plant meltdown.

 

That is rather contrary to my view of reality, and contrary to the facts.

I don't understand your use of the word "already" in this context. That would imply things are getting worse instead of better!

In the few short years since the first mass-produced EV went on sale, charging has already gotten faster, both in terms of what cars are capable of and what chargers are capable of providing; EV ranges have gotten significantly longer, and -- as is normal with any tech revolution -- each new year brings new models with better capabilities and with increased ease of use.

I understand why you may think there is a need "to extend the life of his battery to give it an occasional long charge", but this is a misconception. NiMH battery packs did need to occasionally be completely discharged and then fully charged to prevent the "memory effect", which limited battery capacity. Li-ion batteries don't have that problem. Some BEV drivers say that they occasionally need to do the same to their cars to recalibrate the car's BMS so that it will correctly display remaining miles, but even if that's true, it doesn't actually extend battery life.

 

I notice you have omitted any reference to Chernobyl. Or the fire at Windscale.

I think any low-hanging fruit in battery development has now been picked. Doubling the energy density is nowhere near enough. And these figures are for individual battery chemistries. When assembled into large battery packs the energy density of the pack is significantly lower due to physical support, wiring, cooling fans, heating grids, thermocouples etc.

I will wait and see.

 

And in hundreds if not thousands of comments posted to this forum, despite all the discussion of batteries, not one has mentioned the 1984 Union Carbide factory disaster, for which the death toll estimates range from ~4000 - 16,000... the latter figure being far higher than the official death toll estimates for the Chernobyl and Windscale disasters combined.

Should we stop using batteries because of the danger of an industrial disaster?

If you consider the death toll due to the health hazards from coal-fired power plant emissions, estimated to be between 15,000 - 30,000 per year in the USA alone -- and obviously much greater worldwide -- then any person who is both scientifically literate and rational should be clamoring for every single coal-fired power plant to be shut down and replaced with a much, much safer nuclear power plant. Sadly, humans are not really rational animals.

Well, it certainly does appear that improvements in li-ion batteries of the type currently in use are being affected by the law of diminishing returns. That's why battery researchers are looking increasingly toward solid-state batteries and other fundamentally different types. They likely will still use lithium ions for energy storage, but will be significantly different in other aspects of their makeup.

I fail to see how this is significant. Very obviously current battery packs have sufficient energy density to make mass-produced BEVs practical, and the fact that the newest ones have better than double the range of the ones produced just a couple of years ago, is certainly sufficient proof that energy density isn't any limitation at all. It's primarily the cost which is the deciding factor on how much battery capacity to put into a BEV, these days.

As will we all! But it appears I'll enjoy the wait much more than you, since I'm very optimistic about the future of BEVs... and you apparently think fool cell cars are going to replace them. Prepare to be disappointed!
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Don't disagree with any of that. Merely an observation of how radiation dangers were so poorly understood. Deaths from civilian nuclear power are infinitessimal compared to fossil fuels- which FF advocates choose to ignore. I was surprised to learn than almost all Pu [plutonium, not you!] came from military reactors, only about 5% from civilian ones.

 

They certainly were. I had a radium dial "glow in the dark" watch when I was a kid. My aunt, who had a PhD in (if I I recall correctly) radiology and radio-biology from the University of Colorado, and who was involved in post-graduate research using radioactive materials, warned me that my radium watch was a health hazard, and said I should minimize the hours per day that I wore it. Sadly, she later died of leukemia, and I've always suspected her exposure to radioactive materials during her research was the cause of that. Of course there is only a statistical correlation; it's difficult or impossible to prove any individual case of cancer, leukemia, etc. is caused by exposure to ionizing radiation.
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I'll wait and see.

As will we all! But it appears I'll enjoy the wait much more than you, since I'm very optimistic about the future of BEVs... and you apparently think fool cell cars are going to replace them. Prepare to be disappointed!
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I have no financial or emotional investment in either technology so whatever happens, I will only be mildly surprised. I merely note hydrogen involves less hassle, and can be used by the 50% or more folk who cannot charge their battery cars even if they are prepared to, and also that they are currently growing in popularity significantly faster than plug-in.

 

Reality check: They can be used only by those within easy driving distance of a public H2 fueling station. That's what? Maybe 5% of the U.S. population, at most? And not likely to increase significantly! The pace at which new H2 fueling stations are getting opened keeps dropping further and further behind the announced plans of the California Fuel Cell Partnership and other promoters of the "hydrogen economy" hoax.
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Google 'radium girls', or just hit this link--https://www.buzzfeed.com/authorkatemoore/the-light-that-does-not-lie?utm_term=.eybaAY4lD#.be8XDNdlE
This is a horror story of epic proportions- not just the poor girls but the inevitable corporate/political lies and cover-ups we are now accustomed to.
Oh dear, we are now miles off topic!

 

I am not concerned with the USA. I see Europe, where home charging is impossible for more than half the population. A technology which can only be used by 40% of the population doesn't seem to me to be a very good starting point for a business model. Hydrogen is used already for buses in various cities and it seems to work well. Most people are unaware of what drives their bus, and if it turned out to be pixie dust they would be only politely interested.

There are a lot fewer public hydrogen filling stations in the UK than in the USA, but |I imagine they will come in time. You don't need to have hydrogen filling stations everywhere like charging points because the range of the cars is greater and will probably be extended by the simple expedient of fitting bigger tanks. I imagine a single filling station would be adequate for a small town of up to a few hundred thousand souls.

There is one hydrogen filling station I know of that produces its own hydrogen by electrolysis using electricity from its own small wind turbine (About 250 kW). By my rough mental calculation, this corresponds to filling half a dozen cars a day, but I suppose if business picks up for them they can always import it by tanker. Or given that 10MW turbines are now being installed offshore, I guess they could simply install a bigger windmill and increase their output by a factor of 40.

One interesting fact that surprised me when I looked at it, is to do with the relative efficiency of moving energy about the country in the form of electricity and doing so by tanker. Tankers are MUCH more efficient. Transmission systems are not terribly efficient, suffering from transformer losses, resistance losses, corona losses capacitive losses etc and if you can get power to your house from the power station with only 5% losses, you have done well! A tanker carrying Diesel will do about 2 miles per litre so in a hundred mile journey will use 50 litres of fuel. It carries some 40,000 litres however, so it's losses are only 0.125%. I suppose it's pretty obvious in retrospect, but I had assumed electrical transmission systems were much better!

 

Hi,

This just a nit, a minor even gentle correction:

• NiCAD - the Cadnium versions had the memory effect that NASA had to deal with in the early satellites.
• NiMH - they don't really have a memory effect as much as during charging, the incremental electrolysis generates hydrogen and oxygen gas at high pressure. Properly sealed, the gasses will recombine but if one of the gasses, H{2}, leaks out, it dries out the electrolyte and eventually leads to a local hot spot that melts a hole, a short, in the plastic separator. That short can not be repaired except by recycling. Rehydrating before the melt corrects the problem and then there is the 'conditioning' problem. The NiMH battery effect is a surface function so multiple charge-discharge cycles are needed to recondition the surfaces.

Here is some of my work with Prius NiMH:
http://hiwaay.net/~bzwilson/prius/pri_batt.html

The NiMH has no memory effect that I can detect but the NiCAD "memory effect" is well documented. NiCAD batteries were used in 1960s era, Naval aircraft also had a dendrite formation problem that required periodic 'burn out.'

Bob Wilson

 

Clearly you know much more about this subject than I do, so I certainly don't want to suggest anything you've said here is less than fully correct. However, that said, perhaps the subject is worth exploring a bit more.

Do NiMH batteries have memory effect?

Technically, NiMH batteries do not have a "memory effect", but strictly speaking neither do NiCds. However NiMH batteries can experience voltage depletion, also called voltage depression, similar to that of NiCd batteries, but the effect is normally less noticeable. To completely eliminate the possibility of NiMH batteries suffering any voltage depletion effect manufacturers recommend an occasional, complete discharge of NiMH batteries followed by a full recharge. NiMH batteries can also be damaged by overcharge and improper storage... Most users of NiMH batteries don't have to be concerned with this voltage depletion effect. But if you use a device say a flashlight, radio, or digital camera for only a short time every day and then charge the batteries every night, you will need to let the NiMH (or NiCd) batteries run down occasionally.
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Source: Green Batteries.com: "NiMH Battery FAQ"

I've never owned a car with NiMH batteries. I did drive one a few times, but it was a mild hybrid (first generation Honda Insight), so there was no need for the driver to worry about charging the battery pack.

So I can't speak from personal experience on this, bwilson4web; pretty obviously you can. I will say that I've seen on many EV forums, many times, the advice to occasionally completely discharge batteries and then charge to 100% to prevent the "memory effect", even for modern BEVs using li-ion batteries. I know enough about li-ion batteries to know that this simply isn't true for them, but this is the first time I've seen anyone say it's also not true for NiMH batteries either.

But perhaps this is just a problem with semantics. If it's not a "memory" problem with NiMH batteries, then why do manufacturers recommend occasionally fully discharging and then fully charging them? Is there a more correct term to refer to the problem... assuming there really is such a problem?

At any rate, I apologize to my Gentle Readers for any misinformation I've given here. Bwilson4web, I appreciate your correction / input. I learned something today!
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You're just repeating yourself. Claiming that running an electric power line for the last 50 feet or so from the house to the driveway or curb is, somehow, an "impossible" barrier which will forever prevent mass adoption of BEVs, is self-evidently wrong. It's like a flat-earther continuing to insist the Earth is flat even when shown photos of the Earth taken from space.

You are, in fact, claiming this is impossible:

You don't even have plausibility on your side here, Martin. Nobody is going to put up with driving long distances to refuel his car, when he could have the convenience of plugging it in at home or at work, or just stick to driving a gasmobile.

It does not at all surprise me that public H2 fueling stations are rare in the UK, with the number significantly lower than it is in the USA. What is surprising is that you seem to think this will change in the future.
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Domenick, I certainly do appreciate your efforts here, but speaking as someone who is a moderator on some other low-volume forums, asking people to stick to the topic is fruitless. Topic drift happens. You're the moderator, so moderate! It wouldn't be the first time you've moved off-topic posts to a different or new thread, and I certainly encourage you to do so when you think it's appropriate.

Just my opinion, of course.

 

The Prius control laws keep the traction battery SOC 40-80% and works hard to keep it close to 60%. In this sweet range, the battery never gets fully charged or discharged. It needs 'head room' to handle regeneration and enough depth to handle hill climbs.

Heat is the only enemy because it increases the internal pressure and weakens the terminal seals. Then gas can leak out and dehydrate the electrolyte.

Bob Wilson

 

It seems to me that a battery should work over the temperature range of the car without the need to keep it at room temperature with heaters or refrigeration. It is obviously possible to provide these measures but they are undesirable from cost, reliability, power consumption and bulk. A battery technology which requires external measures to prevent it from destroying itself is a distinctly sub-optimal solution.

Battery 'breakthroughs' are probably best ignored until a safe, intrinsically temperature-robust, inexpensive, energy-dense, fast charging, long-lasting product can actually be bought and used. I suspect we will have quite a wait!

 

Well, if they are, I think they must be a lot smaller, but yes they probably are a nuisance there too if they need to be kept at room temp.

I don't know how it's done but the Mirai is claimed to reach full operating power in 70 seconds after 17 hours parked in sub-zero temperatures. Perhaps the small size makes the batteries easier to heat quickly? (Perhaps in 70 seconds??) They are used to make up power when demand exceeds the FC output I expect, so one could simply not allow them to be used - at the cost of initially possible sluggish performance - running on teh fuel cell alone until they are warmed up. I suggest few people want a car to accelerate at maximum power immediately on starting it in freezing temperatures after being parked for long periods.

But I imagine the battery in these cars will be replaced by supercapacitors eventually. They are capable of operation from -40C to +55C with hardly any degradation in performance and no long-term damage. No good for traction batteries, they are well adapted to relatively short bursts of high power and high current regenerative braking as is needed in a FCEV.

My post was a comment on battery breakthroughs and what is required. Comparison with FCEVs has been done and will, no doubt, continue to be done elsewhere.

I think if you take a sheet of paper and write down all you want of a 'perfect' battery for an EV - high energy density, low cost, accurate indicator of energy it contains etc etc - a sort of informal requirement specifications - you will find you have listed all the features of a gas tank for an ICE! I have never been an advocate of ICE vehicle and would be delighted to see the end of them, but you have to admit the gas tank seen as a 'chemical battery' is an almost impossibly good act to better.