But it didn’t immediately seem apparent to most observers that it would be useful because of rapid capacity fade – the battery would only last 150 cycles before it had only 50% of it’s original capacity, although that is still five times current battery capacity. Traditional lithium-ion batteries last 300 cycles to 80%, lithium-polymer (the battery in your iPhone and Mac laptop) last about 1000 cycles to 80%, and lithium-titanate batteries can last 5000+ cycles to 80%.

The difficulty with the Si-Graphene battery is managing the user experience. If a user were to go through their entire battery in a day, every day, in 5 months they’ll only have half the capacity. So the device developers have to oversize the batteries but artificially clamp the energy storage to keep heavy users from destroying the battery in a short time frame.

Consumer Electronics? Sure…

Putting this battery into a smartphone to replace the current lithium-polymer battery would let average users go 10 days between charges. However every 250 days (25-30 charges) the user would notice they’ve lost a day of use before it was time to recharge, so from 10 days to 9 days. Will users be upset that they lost a day? Will they even notice? Or will they beat down the door of the store where they bought it demanding an exchange on a perfectly good product? How can we avoid this? By artificially limiting battery capacity.

If we were to limit the battery capacity artificially to a value that the 80th percentile user will have after 2 years of usage, we can save the trouble of users noticing their battery doesn’t last as long as it once did. I’ll assume this number is 75% of capacity, that is the 80th percentile user will go through enough battery capacity in two years that will cause a 30% capacity fade (this also factors in an increase in usage due to the bigger battery). So the phone will be setup so the average user can go 7 days before hitting the 25% warning and then recharging. Using 4Wh/day the user will go through 36.5 full cycles per year, which represents a 12% capacity fade per year. After two years, the capacity fade will be 24%. So after two and a half years, the average user will start to experience the battery holding less energy, and probably notice it around the end of year three – about which time the user will need to buy a new phone anyways as this one will be long out of warranty. An 80th percentile use will probably start to experience capacity fade earlier, around 18-24 months. A 95th percentile user is likely to do crazy stuff with their phone like stream audio all day and go through one cycle per day, and run into capacity fade in 6 months. This last case could actually be accounted for in software – if the phone notices its being used heavily it could ask the user to plug it in while engaging in the heavy activity, or just nerf capacity in software in the name of getting out of the warranty period without having to replace the battery.

Below is a chart of a traditional Li-Polymer batter (5.3) and a new Si-Graphene battery (53). You can see that the new battery has much larger capacity, it also fades much quicker. If you were to limit the Si-Graphene battery at 40Wh (40) capacity, the battery would get to two and a half years of average use before the user experienced any capacity fade.

The downside to this approach over traditional batteries is that users might increase their phone use and suck down more battery power per day knowing they have a lot more energy available to them, which is all the more reason to artificially limit capacity in the name of having the battery last long enough to have a useful device for 2-3 years.

The same results from the smartphone situation above would also apply to tablets. Laptop computers would probably see more agressive artificial capacity restrictions, as users usually run out of battery on the laptop before they are done with whatever they were doing (like doing internet research and writing a blog post about batteries ಠ_ಠ), so the issue of using more energy per day and higher annual cycle counts would apply.

Electric Vehicles? Not so fast…

If the approach of limiting battery capacity in the name of extending its life sounds familiar, it should, as it is how the battery in the Chevy Volt is managed. So what would happen if you applied this to the battery in the Volt? Not much difference, and probably an increase in cost.

If you recharge the Chevy Volt once a day, 365 days per year, it is equivalent to 237 full battery cycles per year (10.4kWh used for 35 miles, 16kWh capacity), and the battery type they use is expected to have a life of 1500 cycles (without any depth of discharge reduction bonuses). But if you were to drop-in a replacement battery with this new technology (assuming same size, weight, etc), you’d have a 160kWh battery. Now that doesn’t mean you drive 10 times as far, rather you just use an increasingly small portion of the battery, specifically an initial depth of discharge of 6.5%, and a rate of 25 full cycles per year. By the end of year 10, or 250 cycles, the battery would have degraded enough where it will start to run into problems storing and producing enough energy (assuming they can last that long from a calendar standpoint). This doesn’t appear to be a significant change from the current battery regimen, where the battery is warrantied for 8 years or 100,000 miles (12,500 miles per year). The only benefit to using the Si-Graphene batteries would be the increased power output – a Volt’s 9-second 0-60mph times could improve dramatically, along with faster recharging times.

What would help

The problem with this is that batteries are predominately priced in $/kWh, which would make the above scenarios prohibitive. The fundamental question is would it be more appropriate to charge by mass and volume? Does it cost 10 times the amount of making traditional batteries to these batteries? I don’t think it will. They might be able to charge more than the highest end batteries, but the $/kWh would need to be discounted compared to other types of batteries that have higher cycle lives. The best figure to use when it comes to battery prices is $/lifetime kWh, or the amount of energy a given battery will output until its no longer usable for the specific application (e.g. smartphone, EV, etc). A battery might cost $700/1500 kWh lifetime, and it might not matter that its 1kWh of storage for 1500 cycles or 10kWh for 150 cycles for certain applications – assuming other factors are held constant (volume, weight, safety). In fact, the latter configuration helps in applications where power demand is high (e.g. a car).

So the most basic thing to help these batteries would be an increase in cycle life. Even a relatively small increase in cycle life would dramatically impact the usefulness and increase the impact these batteries can have.

But my question is more a question about innovation. If Li-Ion batteries improve 8-10% per year, do you want to invest anywhere between $8,000 and $15,000 for a battery in the first few years of this decade? Even after prices level out, will a 40% increase in range (or a similar decrease in cost) be enough to keep you from buying the battery outright? What about the residual value of the battery after 8-10 years of (ab)use in a vehicle.

The first premise is that batteries improve 8% per year. This appears to be close to constant (until major step-changes like changing chemistry from NiMH to Li-Ion), and has been noted by Elon Musk of Tesla Motors.

The next premise is that if batteries are constantly being improved, and will continue to improve until at least 2030 (around the time we hit the theoretical limits for Li-Ion), that constant innovation will push prices on older batteries down, in the same way when Intel produces their fastest chip and put it in the top of their price list, everything else gets knocked down a pricing level. Beyond that, as production ramps up, per unit costs will come down. This is a double whammy on battery prices – as such A123 representatives have speculated on end-of-2012 pricing of $400/kWh from about $750 in mid 2010 (a kWh will propel a Prius-like car approximately 4 miles, and a large Ford Explorer-like vehicle about 2.75 miles.

The argument to buy says its bad to lease anything because you don’t end up owning anything. At the end of the five year financing, you own the car and battery. But over time and with each recharge, batteries lose capacity, and that could be exacerbated depending on the climate you’re in, how you treated it (faster recharge = more degradation), if it is liquid or air cooled, etc. The return-on-investment calculations vary depending on your driving patterns, so you need to make sure that an electric car is right for you. If you lose your job or change jobs and your driving patterns change significantly, you might find yourself not having a positive return-on-investment compared to buying a traditional gasoline or regular hybrid car (you might end up not driving enough or driving too much per day).

The leasing argument is much more interesting (and complicated). The reason to lease is that the battery has a fairly fixed lifespan – 1,500 cycles or whatever the cell manufacturer promises. However, even after the batteries might no longer be suitable for driving (this would adversely affect the resale value of the car), they can still be used in applications like power grid storage and stabilization. This residual value of that battery could be 50-75% the price of a new battery. Returning the car after the lease and letting the dealer replace the battery, send it back to be remanufactured into something useful, and then installing a new (lighter, more powerful) battery and updating the car’s system for that battery is an easier course for the consumer instead of having to do that and pay for it before trying to sell it, or take a hit on trade-in value.

Leasing can also bring down the per-month costs – instead of paying for the entire car, and then getting a substantial bump in the trade-in value for the battery, the user (for the most part) only pays for the depreciation of the car during its use. As seen in both the Chevy Volt and the Nissan Leaf, the price for the lease (estimated $350/mo) is much less than what you would expect on cars costing between $27,000-33,000 after tax incentives.

Another non-conventional argument for leasing is the increasing rate of technology invading vehicles. From in-car entertainment, in-car communication (think: replying to text messages verbally), to safety features. While I don’t have a problem buying a new $300 iPhone every year, I certainly will not buy a new car with such frequency because its in-car entertainment is better than the car I currently have (software upgrades aren’t likely to help much in terms of adding new features – my 2009 Ford Escape hasn’t had any new features added to its in-car computer systems since I bought it). By 2015, most cars should have anti-collision systems to stop the car before it rear-ends the car in front of it (its already on some high-end cars today). By 2025 cars will be able to drive themselves down the highway and navigate to the exit, and even around some roads. It wont be fully autonomous but it will take care of 90% of your driving.

One of the ideas being tossed around is a hybrid – buying the car (shell, interior, electric motors, transmission, etc) and leasing the battery, often in conjunction with battery quick-swapping systems instead of dealing with lengthly recharge times – while battery technology might increase 8% a year, there is no way to increase recharging times for a given level of safety and source electrical systems: recharging a battery after 3-4 hours or 250 miles of all-electric highway driving will take 11 hours at 240V/30A (the most you’ll be able to get at home), and 5.5 hours at 240V/70A (the most you’ll be able to get in a commercial environment – e.g. an office building or parking lot). Even a 480V DC 50kW fast-charge circuit will still take 90 minutes. The only way to rapidly recharge the batteries is to have parallel 50kW fast charging systems hooked to one car, however fast-charging batteries can advance their degradation rate.

Its an interesting decision – there are clear pros to each choice, whether to buy, lease, or just buy the shell only and lease the battery. I would recommend that folks lease a first generation electric vehicle if they want to drive one, simply because of how much knowledge car companies and battery makers are going to learn the first few years about automotive batteries, and you don’t want to be stuck with an outmoded design or fatal flaw. By 2015 the prices of batteries will come down enough making the purchase of a second or third generation electric car reasonable if you carefully compare it to your driving habits compared to the vehicle’s EV characteristics.

So since 4.08kg of pure (elemental) lithium is equivalent to about 21.75kg of LCE (5.33kg of LCE is 1kg of Lithium). This means that the 24kWh battery contains 21.75kg of LCE, or about 0.9kg of LCE per kWh. This is 50% larger than the 0.6kg I had seen others cite as a figure for LCE per kWh, which would diminish the amount of batteries my in my estimates by 33%. But it seems there still will be plenty of LCE to go around since the numbers before were absurdly high.

WLC, in a recent press release, also stated that their target for their stage I lens production is 27,700 metric tonnes per year of Lithium Carbonate (LCE, or chemically Li2CO3). The math to turn that into the number of EVs is easy – 27,700 metric tonnes is 27,700,000 kg of LCE. In 1kWh of a Lithium-Ion battery there is 0.6kg 0.9kg of LCE (figures in this article have been updated). This means that 27.7M kg of LCE per year is about 30.8M kWh of batteries that can be produced. They have an expected 18 years at this rate of supply to mine (approximately 500,000 metric tonnes LCE total).

In a pure EV (like the Nissan Leaf) the battery is 24kWh, so from 27,700 tonnes of LCE comes 1.28M Nissan Leaf battery packs per year. In a EREV like the Chevy Volt, its battery pack is 16kWh, so 1.9M battery packs would be able to be manufactured for the Volt.

To put these numbers in perspective, in 2009 there were a total of 10.4M cars sold in the US, and in 2008 approximately 13M cars sold. So this single lithium mine could power up to 15% of all the US EVs and EREVs sold, if the automakers could build and sell that many (which they wont, at least initially).

So the question is, how many tonnes of LCE would it take to make every car sold in America a plug-in? From a small two-mode system that would allow for 8-12kWh batteries for 10-15 miles at speeds below 60MPH, all the way up to pure EVs with 50kWh batteries. If we assume that 70% of cars sold are two-mode at 10kW, 20% are EREV (18kWh) and the last 10% are pure EVs (35kWh avg), the total kWh for a year of 14M cars is 197.4M kWh, or 177.3M kg of LCE. So in order to produce enough LCE, we would need to produce about 180,000 metric tonnes of LCE, or about 6.5x the amount of stage I.

The stage II lens has approximately 1.365M tonnes of LCE, and at 180,000 metric tonnes per year, it would be exhausted after 7.5 years, assuming the production rate could be sustained.

Seven and a half years might not be a long time, however there are still several other stages to this mine area (stages three and four), plus there are other lithium mines in the Nevada and the US. It appears that Lithium supplies wont be a blockade on the road to electric cars. While Li-Ion batteries can also contain other precious metals that might be scarce, Lithium shouldn’t be an issue.

[Update 5/27 - updated Lithium math based on Leaf's use of 0.9kg/kWh]

The raw numbers are very interesting – a theoretical maximum of over 2,000 Wh/kg, with initial numbers (though not available for many years) around 700Wh/kg. This figure is a huge leap above current technologies. Given “Musk’s Law” of 8% per year, we wouldn’t hit 700Wh/kg until about 2030. As long as they can deliver sometime in the next 5 years it would provide for a new level of energy storage capabilities. Batteries would reduce in volume by 50%. Size and weight would no longer be the issue (how to recharge such batteries quickly would still be).

The batteries also offer superior thermal behavior – down to -60C and up to +160C. This would be beneficial to the automotive applications where cold weather performance can be an issue.

The real question is how fast can they make a product and make it manufacturable. Contour hasn’t even bothered to announce any target dates for product delivery on their website or available documents. They have the talent and are attracting venture capital, so we’ll see how quickly they can turn their lab work into factories putting out large volumes of their unique chemistry.

A Japanese firm called Eamex has announced (Japanese translation via Google) that they have developed a new Li-Ion battery that is capable of withstanding 10,000 cycles and 10,000W/kg power. A huge achivement – considering most laptop batteries today can only hold up for 300 cycles, even the high-end batteries in the Apple MacBooks are only 1,000 cycles. Could this be the technology to finally lay to rest the issues of battery life in cars?

While I’m always skeptical of people touting new battery improvements due to the very high lead time between development, sampling, manufacturability and entrance to the market, these batteries could dramatically change the EV/E-REV world, as well as the power storage/back-up world.

The battery cycle life is a dramatic improvement. At 10,000 cycles, a plug-in vehicle could recharge twice a day for over 13 years. The battery not only eliminates the worry about having to replace it during the 10 year warranty. This also allows people not to worry about taking advantage of Vehicle-to-Grid technologies without excess wear on their battery; V2G during the summer months could take a tiny bit out of the battery at peak times and recharge it later.

The second improvement is the 10,000W/kg specific power. This is far and above what most Li-Ion batteries can provide today. Combined with the increased cycle life, you can build EVs and E-REVs with smaller battery packs; closer to the actual amount of energy that would be needed instead of having a limit on the depth of discharge like the Volt. This effectively reduces the cost of the battery by requiring less kWh of storage – batteries that might be $500/kWh to provide a 16kWh battery can be downsized to 10kWh and still provide the exact same performance in a smaller package (100kg instead of 160kg pack weight) while delivering more power than the engine will need. Hybrids will stand to gain from this as well, since a 2kWh battery could easily power the car entirely (200kW, or 266 HP) for a few miles.

From a grid-backup standpoint, the batteries could finally make practical and affordable to capturing cheap energy and selling it at peak demand times. The high cycle life will keep maintenance and replacement costs down, which is necessary when the difference between daytime and night time prices is only 10-15c/kWh.

There are still many questions left to ask – how does the power output of the battery vary with the depth of discharge, how is the charge and discharge and cycle life affected by temperature. They expect to start producing this battery at the end of the year, but who knows in what quantities and if it will live up to the performance above.

via Electronista

I missed on a lot of the renewable energy stuff – wind is definitely getting going with lots of agreements and more work being done on transmission infrastructure, and solar is hurting and didn’t get any sort of comeback this year. Large deals have been made but there isn’t a whole lot of upwards movement in the market.

Apple

• Apple does, along with a few other companies, releases various 7-10″ tablets. (OK, at the time of publication this is a foregone conclusion, but when I wrote this in the middle of December it wasn’t). Apple’s cost the most, but you get the most (e.g. the App Store). Other tablets don’t have the battery life or applications to match up.
• Apple continues to see growth of 20-30% year over year in computer sales (this number will vary depending on how they categorize the “iSlate” – as a computer or a iPhone-ish device, or its own category).
• The iPhone does go Verizon in July (probably announced earlier), AT&T counter by offering tiered monthly data plans – $20 for 250MB or less, $30 for 1GB or less, $45 for anything over 1GB. They do the rate structure in such a way that there aren’t really overage charges, you just get moved into the next tier (if you use 1.01GB of data, its $45).
• AT&T’s network continues to suck and iPhone users continue to complain. Verizon’s iPhone helps but AT&T doesn’t seem to care too much about network performance.
• The iPhone does not go 4G (LTE or WiMax) in 2010. Its expected to go LTE in 2011 as Verizon gets 50 markets online and AT&T still sucks with HSPA 7.2Mb/s network.
• The iPhone does get bumped to 64GB/32GB/16GB for the same prices ($299/199/99). The 3G iPhone goes away and all phones are 3GS. It doesn’t look like a processor or RAM speed bump is in the cards, but there are some new (risky?) features that get added.

Tech

• LED LCDs dominate 2010. Internet connectivity becomes prominent as TV manufacturers push streaming video on demand services like Netflix and YouTube.
• 3D TVs are introduced but don’t get adopted. Avatar gets released in September as the first true 3D Blu-Ray disk, but since BR hasn’t taken off it doesn’t go anywhere.
• 2010 still isn’t the year of Blu-Ray. Its getting close though! Players are available at $99 by Black Friday and things start to pick up for the holidays. I’m still not sure if broadband speeds will increase fast enough to take Blu-Ray out completely.

Green

• Wind continues to dominate the green generation sector. Transmission projects also start to get under construction in the second half.
• Solar recovers a little. But the problem is that the people wanting to middle-scale solar (between 1MW and 10MW and not utilities) don’t have the money and cant get loans to do it. Where available, PACE (property assessed financing) helps individual home owners defray the cost of putting solar power on their own homes by adding the price into their annual property tax assessment for a low interest rate (4-5%), so even if they move the next owner is paying for it through property tax.
• Geothermal still gets little love. 20MW here and 10MW there. No magic increase that gets geothermal to be some huge part of generation.
• Biofuels and biomass start to transition into more mainstream. You see a lot of coal plants augmenting their coal-fired boilers with wood, trying to reduce net CO2 output.
• EVs (Volt, Leaf, etc.) don’t make that big of a splash in the personal transport market because they cant get out that many units because of battery production issues (producing the number of cells and modules necessary). The tech turns out to be solid, but its the cost and production issues. Its somewhat disappointing that the cars have so much promise and they have trouble making them in volume.

Other

• I figure out some way to get a girlfriend this year. No idea how long I manage to keep her, but I do manage to get one. I had one date in 2009, but 2010 is better.
• I don’t do all that well in the stock market.
• I manage to write an iPhone app for myself. Don’t know whether I publish it – if its the one I think I’m writing it wont get published because it uses private APIs.

And thats it. See you next year!

There are a few interesting points that are made in the presentations..

Well-to-wheel Efficiency: They peg electricity generation at only 30% efficient. If you combine the generation efficiencies, transmission efficiency and the energy spent to get the fuel, electricity generation is surprisingly inefficient. However the highly efficient transfer of that electric energy from the car’s battery to the wheels makes up for it. I’m interested in seeing how renewable energy can make the generation of energy more efficient – wind specifically.

CO2 Output: Depending on generation source, a hybrid electric car (like the Prius) can release less CO2 (~90g/km) than a pure EV when powered by coal generation (170g/km). However a traditional gasoline car is about 160g/km.

Cycle Life: Battery cycle life is largely impacted by depth of discharge (DoD)- limiting pack DoD to 50% more doubles cycle life.

Different Types of Hybrids: Outlines the many types of hybrids available – from weak to plug-in.

Payback Times: A comprehensive list of different types of alternate energy transportation vehicles and their estimated payback time.

The estimated battery capacity would be around 250Wh/kg. This is about double of the current batteries (100-140Wh/kg), and assuming a commensurate increase in Wh/L, the batteries would get lighter and smaller for the same energy storage capacity. If we were to drop this battery in a hypothetical generation two LEAF, we could increase range to 130 miles city, 100 miles highway, and still reduce batter weight (and probably volume) by 25-30%. This would cut a 100-150lbs off the weight of the car (roughly 3-4% of curb weight), and would in turn extend the range of the battery another 3-4%.

The batteries are estimated to get 1000 cycles, presumably at 100% depth of discharge (DoD), which would provide 1500 cycles at an 80% maximum DoD, likely for pure EV applications like the LEAF. This would be suitable to deliver at least 150,000 miles of driving on the battery pack before it degraded to 80%, likely far more due to the relationship between average DoD, cycle life and maximum storage capacity – that is, the lower the average DoD, the more full cycles the battery can withstand before equivalent degradation.

Finally, this advancement pushes ahead the development curve of Lithium Ion batteries. For years, the average increase in capacity was 5-8%, but as more companies throw their hat into the ring of battery research and development, we’re starting to see batteries advance faster. We’ll likely never see batteries advancing as fast as microchips, but it is satisfying to see the rate of innovation ramp up. The electric car future might be here a little bit sooner than expected.

via Green Car Congress

The Tata EV is scheduled for Europe in 2010 or 2011. But the battery performance is what I’m interested in – just like the Panasonic battery from last month, this battery has outstanding energy storage and power delivery characteristics. These are Nickel-Cobalt-Manganese li-ion cells, and the one mentioned is their largest capacity prismatic cell, rated at 3.65V/20Ah (73Wh).

The specification sheet is here (warning: one big image), and the specifications are impressive. 175Wh/kg means that you can put together a 25kWh pack at only 143kg. Adding 20% of that weight for cables, electronics, packaging and safety you’ll get a final pack weight of 171kg, and an approximate volume of 81L. These figures aren’t far off from what is estimated for the Volt, but with a 50% larger gross storage capacity and a much larger net storage capacity. A Volt-spec battery pack, being constrained on volume and power, weights 69kg, produces 130kW at maximum discharge, stores its 8kWh usable in 12kWh (75% DoD), and should last between 1500- 6000 cycles (this range is so large because while the data sheet says 1000 cycles to 80% at 100% D0D, the chart below that shows 1000 cycles to 95%, plus the 50% cycle count boost by using only 75% DoD).

I’ve asked myself if we’re headed towards a leap in technology. Even after factoring packaging weight, the batteries still exceed the rumored pack figures for the upcoming battery packs (Volt, Leaf), factoring in three years for mass manufacturing,is this the leading edge for 2012-2015? The performance aspects about double what is rumored to be in existing EVs in the early part of the decade, and could provide for a new wave of larger, heavier EVs (small SUV or Crossover) that can be driven for 50-100 miles (EREV or BEV) that are more in line with whats popular in terms of car size.

[via Green Car Congress]