Li Battery Research

[EdEarl]

 

A team of researchers at MIT says it has carried out the most detailed analysis yet of exactly how Lithium deposits form during charging, and reports that there are two entirely different mechanisms at work. While both forms of deposits are composed of lithium filaments, the way they grow depends on the applied current. Clustered, "mossy" deposits, which form at low rates, turn out to grow from their roots and can be relatively easy to control. The much more sparse and rapidly advancing "dendritic" projections grow only at their tips. The dendritic type, the researchers say, are harder to deal with and are responsible for most of the problems.

 

This research shows that these growths can be effectively controlled at lower current levels, for a given cell capacity, and demonstrates what the upper limits on battery performance would need to be in order to prevent the truly damaging dendritic filaments.

My edits: Lithium and during charging.

 

If I understand this research correctly, the number of charges on lithium batteries can be increased and their volume and weight can be reduced by half, provided this research can be used in mass produced batteries.

 

Unfortunately, lithium is relative rare, and increased volume will probably result in higher bulk Li prices.

[timo]

I don't think your conclusion about reducing volume and weight by half is supported by what is said in the text you quoted. At best, there is the promise of extended lifetime (by avoiding damaging charging states) or improved charging performance (by knowing the damage limits more precisely).

 

I don't really know what you are trying to say with your last sentence. Some people (e.g. me) expect Lithium demand to greatly increase because of increased demand for battery production. That is because of renewable energies and their related technologies: electric cars and battery storage systems to compensate for the fluctuating power generation of wind-turbines and photovoltaic-plants. But that expectation is not influenced by a research team looking into the microscopic details of a battery but based purely on environmental, technical and economic expectations. The biggest potential influence of fundamental research onto technology that I currently expect is new types of Lithium batteries (namely Lithium-Sulfur). These do indeed promise higher energy densities. Especially for electric cars, which are often considered as having too little battery capacity, that could have a real impact (but still result in an increased demand in Lithium).

[John Cuthber]

Lead is relatively expensive and so the battery business got pretty good at recycling it.

I suspect they will do the same with lithium- which will help.

[EdEarl]

 

Wikipedia

According to the Handbook of Lithium and Natural Calcium, "Lithium is a comparatively rare element, although it is found in many rocks and some brines, but always in very low concentrations. There are a fairly large number of both lithium mineral and brine deposits but only comparatively few of them are of actual or potential commercial value. Many are very small, others are too low in grade."

The US and Europe have no useful reserves of lithium; we are at the mercy of other countries for our supplies. Bolivia may become the Saudi Arabia of Lithium.

 

 

Lead is relatively expensive and so the battery business got pretty good at recycling it.

I suspect they will do the same with lithium- which will help.

At this time the amount of Li in batteries is rather low; thus, recycling is good and will help. But, millions of batteries are required for transportation and storing energy from renewable sources such as PV, which require mining Lithium.

 

Seawater contains all we would ever need, but its concentration is less than 1 ppm.

[Sensei]

The US and Europe have no useful reserves of lithium; we are at the mercy of other countries for our supplies.

Lithium-7 can be made from Boron-10 after neutron capture.

 

B-10 + n0 -> Li-7 + He-4 + 2.795 MeV

 

Also it could be made by from Helium-4 after at least double neutron capture.

Edited September 2, 2016 by Sensei

[EdEarl]

Sodium battery technology is improving, but seems likely to be not quite as good as lithium. Nonetheless, it may improve enough to be viable, since sodium is abundant and inexpensive.

[EdEarl]

Lithium-7 can be made from Boron-10 after neutron capture.

 

B-10 + n0 -> Li-7 + He-4 + 2.795 MeV

 

Also it could be made by from Helium-4 after at least double neutron capture.

It might make a nice battery if we could easily change a neutron per atom into a proton, and reverse the process. If I did the math right, making a gram of protons from neutrons would cause 10KW flow of electrons.

[Sensei]

It might make a nice battery if we could easily change a neutron per atom into a proton, and reverse the process.

You don't need to do anything to make it happen.

Free neutron decays to proton, electron and antineutrino, releasing 0.782 MeV per reaction with ~10 minutes half-life (~15 minutes mean-life).

 

If I did the math right, making a gram of protons from neutrons would cause 10KW flow of electrons.

Mass-energy of neutron is 939.565 MeV/c^2

multiply it by 1e6 * 1.602176565*10^-19 to convert to Joules,

divide by c^2, to have mass in kg:

~1.67492667626123E-027

 

1 g = 0.001 kg

divide by 1.67492667626123E-027

gives 5.97e23 neutrons per gram

 

Each one can release 0.782 MeV (782000 eV) per reaction.

* 1.602e-19 (eV->J), * 5.97e23 neutrons = 74803398357 J

Half on it will be taken by electrons, because antineutrino takes some energy.

 

Alternatively you can subtract sum of mass of proton and electron from mass of neutron, in kg, multiply by c^2, and multiply by quantity of reactions.

Edited September 3, 2016 by Sensei

[John Cuthber]

It might make a nice battery if we could easily change a neutron per atom into a proton, and reverse the process. If I did the math right, making a gram of protons from neutrons would cause 10KW flow of electrons.

You can't have got the maths right; the units are wrong.

Lithium-7 can be made from Boron-10 after neutron capture.

 

B-10 + n0 -> Li-7 + He-4 + 2.795 MeV

 

Also it could be made by from Helium-4 after at least double neutron capture.

There's only about 10 times more B10 in the crust than there is Li.

The neutron capture cross section fo 4He is pretty close to zero.

The only way to get enough of it to react would be to put (already scarce) He in lots of huge nuclear reactors.

Those rectors would produce enough power to pretty much make the Li cells redundant.

 

The Li cell is great if you are concerned about energy stored per unit volume, or unit weigh.

But for load levelling storage you don't need to worry so much about those.

Something like this might work better.

https://en.wikipedia.org/wiki/Vanadium_redox_battery

[EdEarl]

The idea of making lithium was unrealistic, as the idea of generating electricity using neutrons decaying into protons. We couldn't mine a neutron star, nor carry even a bit the size of a grain of sand.

 

I like the idea of redox batteries or super capacitors, because recharging is fast. Super capacitors are also very light weight. Lithium batteries are best at this time, but another technology may be developed to replace them, especially if lithium prices soar.

[Sensei]

Why unrealistic?

Tritium is produced from Lithium..

Building fusion reactors will increase demand for Lithium even more.

Neutrons are for free in currently existing nuclear plants..

So better to use them cleverly.

Edited September 3, 2016 by Sensei

[EdEarl]

How much could be produced in a year? Would there be residual radioactivity? Are there legal hurdles to resolve? It's not being done now, why not?

Edited September 3, 2016 by EdEarl

[Ken Fabian]

I think we are better positioned to invent, improve and produce better batteries than ever and the motivation to do so has never been stronger. Stationary storage and transport suitable storage are different enough that they may be done by very different means, however any EV suitable battery that is low cost enough will - as Lithium in several forms is already doing - be potentially able to compete as stationary storage.

 

I think flow batteries - still have a lot of potential in stationary applications, with it's expandability of storage capacity independent from charge and discharge capacities. Vanadium redox, for example, can offer endless re-use of it's electrolytes. True recycling at as good a quality as the first time use, rather than the 'down-cycling' that we are more familiar with - that puts a few steps at best between first use and becoming waste that is degraded beyond all re-use - is an important consideration. I think the capability for true recycling is important for everything we produce and use - but that kind of technological optimisation may take far greater community awareness and concern as well as far more political maturity than we currently have and perhaps only after squandering what appears plentiful and facing the costs of scarcity will that become a routine design consideration.

 

Demand for Lithium may well prove a significant barrier but it is not the only chemistry that will be used and I think there is still room for some big surprises. Certainly if there isn't enough of it - sending lithium prices soaring - that may drive the market towards alternatives. I don't expect transmutation of elements to ever become a source for battery materials.

[John Cuthber]

Why unrealistic?

Tritium is produced from Lithium..

Building fusion reactors will increase demand for Lithium even more.

Neutrons are for free in currently existing nuclear plants..

So better to use them cleverly.

It's unrealistic for essentially the same reason that it's uneconomic to make gold in a nuclear reactor. It's possible- but the yield is so poor it doesn't cover the cost.

 

 

This statement

"Neutrons are for free in currently existing nuclear plants.."

simply isn't true.

If you take out too many neutrons you shut down the reactor.

You get about 2.5 neutrons per fission, and you need at least one of them to start the next fission reaction.

So, at best you can take about 60 % or so of them- call it near 50% to allow for an improbably high efficiency- just to give us a number to play with. It's about 1 "spare" neutron per atom.

 

According to this

https://www.physicsforums.com/threads/how-much-uranium-235-does-a-nuclear-power-generator-consume-to-generate-1-5-gw.360052/

a reactor converts something like half a ton of Uranium a year.

Each uranium fusion could set free enough neutrons to make about 1 atoms of lithium.

And each Li atom weighs about 1/24 as much as the uranium.

So at best you could get something like 1/24 times the half a ton or so i.e. about 20 Kg a year of lithium from your reactor (blanketed and moderated entirely with boron).

That's a mighty expensive by-product you have, especially once you have to extract it from the boron.

There's another simpler argument for why it's clearly impractical.

As you say

B-10 + n0 -> Li-7 + He-4 + 2.795 MeV

So each atom of Li you make produces about 3MeV of energy.

If you take that atom of Li and put it in a battery you can use it to store about 3 eV of energy.

And the best Li cells have lifespans of something like 10,000 cycles (it's typically a tenth of that).

So in it's life time the battery will never store more than 1% (more likely 0.1%) of the energy that was set free by creating its lithium in the first place.

Once you run the reactors to make the Li, you don't need the batteries any more- you can just use the energy from the reactors.

[Ken Fabian]

Tritium is produced from Lithium..

Building fusion reactors will increase demand for Lithium even more.

 

 

The combined resources of the most technologically advanced nations hasn't built a single working fusion power plant. Being optimistic is okay with me but improving energy storage looks far more likely to have significant and tangible impacts on our energy systems. Whilst I would not like to see such efforts to develop working fusion cease I would like to see advanced energy storage research - which looks to have enormous potential for viable results on shorter time scales - get more support.

Edited September 5, 2016 by Ken Fabian

[StringJunky]

 

The combined resources of the most technologically advanced nations hasn't built a single working fusion power plant. Being optimistic is okay with me but improving energy storage looks far more likely to have significant and tangible impacts on our energy systems. Whilst I would not like to see such efforts to develop working fusion cease I would like to see advanced energy storage research - which looks to have enormous potential for viable results on shorter time scales - get more support.

Firms like Tesla are constantly working on increasing energy-density of storage systems; there's plenty of attention and money being thrown at it. It's commercial priority is very high, especially given that electric cars are emerging beyond the novel.

[EdEarl]

Automatic autos (AA) will reduce the price of Taxi service, according to some reports, to the point that automobile ownership is unnecessary for most people. Thus, car companies expect reduced sales, and perhaps the total number of AA will be only 10% of the number currently on roads, because robo taxis would be driving 90% of the time instead of parked 90% of the time as privately owned cars are. This means the demand for batteries will be lower than a fleet of privately owned cars.

 

Wikipedia

Two US researchers estimate that the world's fleet will reach 2 billion motor vehicles by 2020, with cars representing at least 50% of all vehicles.

I don't know, but believe, this estimate does not include the expectation of fewer cars due to robo taxis, because 2020 is too soon for electric AA to replace more than half the existing fleet of cars. Thus, if robo taxis become the primary means of personal transport, the fleet may be fewer than a half a billion cars.

 

The following analysis of lithium reserves and electric car production does not account for lower car fleet numbers.

 

greentechmedia.com

 

The U.S. Geological Survey produced a reserves estimate of lithium in early 2015, concluding that the world has enough known reserves for about 365 years of current global production of about 37,000 tons per year.

 

Even though 365 years of reserve supply sounds very comforting, the point of the EV and stationary storage revolutions is that current demand will shoot up, way up, if these revolutions do happen. The 100 (Tesla battery) Gigafactories scenario could come true. And if that happens, the 365-year supply would be less than a 17-year supply (13.5 million tons of reserves divided by 800,000 = 16.9 years).

Thus, lithium reserves are adequate for a while, but may be used up with continued use. Changing to another technology, such as graphene supercapacitors or sodium batteries, seems to be inevitable.

 

Notes:

 

Wikipedia

 

To clarify the legal status of and otherwise regulate such vehicles, several states have enacted or are considering specific laws. In 2016, 7 states (Nevada, California, Florida, Michigan, Hawaii, Washington, and Tennessee), along with the District of Columbia, have enacted laws for autonomous vehicles.

 

 

insurancejournal.com

 

Developer nuTonomy invited a select group of people to download their app and ride for free in its “robo-taxi” in a western Singapore hi-tech business district, hoping to get feedback ahead of a planned full launch of the service in 2018.

Edited September 5, 2016 by EdEarl

[Ken Fabian]

Firms like Tesla are constantly working on increasing energy-density of storage systems; there's plenty of attention and money being thrown at it. It's commercial priority is very high, especially given that electric cars are emerging beyond the novel.

 

I suppose that is true - and the willingness of commercial enterprises to invest in battery development suggests results are seen as achievable. Interestingly most of Tesla's batteries appear to be based on a type of Li-Ion that isn't cutting edge; it sounds like economies of scale and optimising the production of them has been how they've reduced costs.

 

Still, I think the fundamental research that tends to be more reliant upon taxpayer funds is probably still crucial to making the big leaps possible and I'm not convinced energy storage has been strongly supported - not relative to the scale and importance of the climate/emissions/energy problem.

[EdEarl]

Ken, you aren't alone in your frustration at the slow progress of battery improvement.

Spectrum.IEEE.org: The Search for a Better Battery

The classic combination of government research funding and entrepreneurial gumption won’t take energy storage to the next level anytime soon

Despite the appearance of rapid technological advances, the specter of stagnation looms over the world’s innovators. Low-hanging fruit is nowhere to be seen in fields as crucial as digital electronics, biomedical devices, or space technology. Nothing illustrates the looming problem of stagnation more dramatically than the quest for a superbattery.

This article says that the Tesla super battery factory is located near a lithium mine, which is news to me. That mine isn't mentioned in the Wikipedia article Lithium.

 

A Google of "US lithium" does get hits, including this one in Wyoming, which may have enough lithium to satisfy the US needs. I added a note in Wikipedia:Lithium:Talk about lithium in the US.

[Ken Fabian]

EdEarl; actually I've been impressed by how many new battery options are becoming available, the rate of improvements and price improvements. Still a long way to go but compare to even a decade ago, when a home PV solar installation had the option of Lead-Acid or none - and those were almost exclusively for remote area off-grid applications. Hybrid grid connected systems that included storage were not even on offer, whilst now almost every installer offers it - I think we have come a long way quite quickly.

[EdEarl]

I was watching a youtube, "Science of SLAC | Batteries for the Future: What's Possible?" when the speaker showed a frame with the following:

 

Nissan Leaf has batteries with 24kWh drives 84 miles using 4kg lithium, which is enough for 10 billion Leafs.

The Tesla S model has 85 kWh drives 265 miles using 14kg lithium, which is enough for 3 billion Teslas.

 

There are about 1 billion cars in the world.

[koti]

I'd like to share what I know about this subject as I've been a "flashaholic" for many years and batteries are the key part of flashlight building & modding.
LiOn IMR (safe chemistry) is the "best" we have right now as far as delivering most current in the shortest time. Sony VTC5 18650 cells are capable of delivering 60 ampers in short bursts and 20 ampers constant. These 18650 cells are the size of cells that laptop batteries are built of. They are rechargable cells, 4.2V fully charged/3.7V discharge voltage. The "IMR" chemistry is safe as opposed to regular LiOn cells which can explode or burn with lithium fire when missused (when voltage goes lower than about 2.5V)
The Sony and Panasonic LiOn IMR cells are the best we have right now and they are used in Teslas and Koenigsegg hyper cars.