Energy Storage for Portable and Stationary Application: Materials Limitations

4,794 Views

Stan On January 8, I spoke at Applied Materials headquarters in Santa Clara, California to a packed room about the status of electrical energy storage. Energy storage is the limiting technology for renewable energy, such as wind and solar, and particularly for the next generation of hybrid electric vehicles, the plug-in hybrid electric vehicle (PHEV). If long-lived, low cost and safe batteries or capacitors are to be developed, a range of materials limitations must be overcome. The presentation discussed the present status of materials, both bulk and nano, for the next generation of batteries, with an emphasis on the anodes and cathodes for lithium-ion batteries.

The challenge facing the United States (U.S.) is how to become competitive in the energy storage area, when presently essentially all advanced batteries are made in Asia. This is despite the fact that the original IP is essentially all U.S. or the United Kingdom in origin. The answer might lie in advances in new materials and new battery systems that will leap-frog the capabilities of the present high-cost lithium-ion cells. Then, of course, retain the technology in the U.S. through appropriate carrots and sticks.

The materials challenges that need addressing are new anodes and cathodes that will store about double the energy of today’s carbon anodes and oxide cathodes. But beyond the materials themselves, lower cost manufacturing methods need to be developed not only in the synthesis of the raw materials but also in the assembly of the cells and batteries. These will be major challenges as the materials go nano, with their low densities, and lifetimes of 10 years are demanded at costs of no more than $250/kWh. There may be special market niches, where the cost curve can be lowered before the mass production scale is attained. Such niches include buses (which run around $500,000 each), and short-term load leveling. For the latter to be successful, it will need U.S. Federal incentives to get the utilities to work together and jump start the Smart Grid.

Bookmark/search this post with:

Keywords:

Comments

The Public Transport System.

Submitted by LPG Gas Suppliers on Tue, 09/28/2010 - 02:11.

I too have grave concerns, as the energy consumption increases with the use of rechargeable batteries and electric vehicles. There has been many papers written in recent months outlining proposals to limit times when vehicle can be recharged from the grid. By restricting recharge to specific hours we will see greater emphasis and cost to law enforcement and increase in frustration by electric vehicle owners and basically an unsustainable situation will emerge. Solution to our energy crisis must include alternative methods of transport that decreases our reliance on the PMV and increased flexibility and costs through the public transport system.

Great potential achievements, yet lots of risks and hypes

Submitted by Anonymous on Fri, 01/29/2010 - 15:28.

It is very encouraging to see a 68 year young Professor still dedicated to educate the American people about the importance of renewable energy. I am in the battery profession and have great enthusiasm toward a cleaner, greener future less dependent on Mideast oil, but I do see some trouble down the road, which potentially hands the opportunity to the Japanese once again, just like the digital camera (based on CCD), LCD TV, etc.

Both the anode and cathode require further improvement. Often the cathode determined the energy density while the anode dictated the longevity. Most fundamental research focuses on a new cathode beyond NCA compound; while it is not realistic to expect 100% improvement in Kwg/Kg, some improvement is still possible. On the other hand, a newer anode with operating voltage (vs. Li) around 0.5V needs to be discovered, potentially eliminating the SEI layer (forget the voltage for that) and simplifying the manufacturing process, [because the formation of a fresh battery is a manufacturing bottleneck and incurs high cost,] thus lower cost, at the same time, higher anode vs. Li voltage also helps to improve the charge rate by reducing/eliminating Li dendrite; this somehow will ameliorate EV range anxiety and make EV more realistic for short range commuting. I notice that there has been little material innovation after Dr. Goodenough's retirement and most in academics lack industry expertise, so they are eager to hype their latest virus battery, paper battery or other things that are totally useless. This is mainly due to funding pressure and quick-turn-around mentality which permeates throughout modern society, and is highly toxic.

HEV, PHEV, and EV: GM is the only company openly to "bet" their future on PHEV while abandoning HEV, Nissan bets on EV while Honda, Ford, and Toyota are proceeding cautiously. The price of a 16Kwh battery is unlikely to be under $10K for any foreseeable future due to high material cost, stringent quality control, warranty and expensive BMS/TMS. At the same time, the longevity has not been proven and accelerated lab tests can't simulate 10 years of actual driving due to different corrosion mechanisms. GM's much hyped Chevy Volt claimed to have 230 mpg. So in order to have 150,000 miles, the electric driving needs to be about 125,000 miles, equivalent to 3300 cycles with 20% degradation thereafter. The ironic thing is that GM can't test their Volt for that mileage before Nov. With normal charging, one can get about 160 miles EV range per day and 125,000 miles requires over two years of day and night testing. GM is aware of the risk by reducing DOD swing to 50%, it is still difficult to ensure 3300 cycles for 99.99% vehicles. So either the project will flop and bring down GM, or the regulators have to allow the auto company to sell something considered defective by current NTFSA standard; the current regulation will certainly ask GM to recall the vehicles when just a few fail and consumers will rebel in droves. There are some discussions on using the used PHEV battery for a Smart Grid, Solar station to reduce cost, it is not known if the Utility company will be willing to pay a reasonable price high enough to compensate the high PHEV battery price tag. On the economic side, it will NOT pay off for the average customer, even the gas is over $6/gal, and that is based on the assumption of a never-changing electricity rate, which surely will go higher. So the main risk in PHEV is battery longevity and cost. No wonder the internal battery group in GM opposes the Chevy Volt as a PR stunt. The main reason that Toyota and Ford followed is to ensure they are NOT behind GM technically and to have GM carry the business risk. Also the Tesla EV is another hype that sooner or later some vehicle will fail prematurely and cause sensation on the News coverage. Toyota is a company with such a long vision, they are right to concentrate on HEV, which is only a transition technology; hopefully Fuel Cell vehicles will catch on in 2020. There are reports that Toyota already shifted their basic research budget away from Li battery research, for good reasons.

Overall business environment in the U.S. is harmful, the VC model is largely built upon starting a company and getting a quick 2000% return. Companies such as A123 and Boston-Power have done a wonderful job, but they will have a tough time to compete against Panasonic-EV, LG. Those Japanese/Korean companies have close relations with their auto companies and share the risks, while U.S. counterparts are orphans with no one to share huge risks. That leaves A123, Boston-Power pursuing other battery opportunities; they are surely less focused on automotive and can't get into the auto parts supply chain easily. It is hard to believe they can dominate this industry. Johnson Control might be an exception.

Obama is regarded by many as a talented President and he is absolutely right to point his fingers toward Wall Street, and rightful to use the stimulus money to sponsor domestic battery manufacturing. He also needs to reign in the oil speculation, which is very harmful for the HEV/PHEV market because the hugely fluctuating gas price is a major impediment to mass adoption of HEV/PHEV.

I think lots of hype will end up with small achievements only, if any at all, while others may bring big benefits. It will also face strong competition from Asia, there is little hope that the short-term focused mentality will change, and the U.S. might follow U.K. to decline, few people in the U.S. will like the way the ridicules Britain is getting those days: a sick man, America lackey and bluffing bozos. Obama must use his presidential power to maximize the benefits of green evolution and reduce the chance of another bubble.

Once the dust settles down, the little guy like me or average American worker will bare most of the blunt, just like the fallout of the sub-prime mortgage mess.