It looks like they do more than surf down in San Diego.

Folks at the UC San Diego's Jacobs School of Engineering say they've figured out a way to make batteries lighter and faster-charging by creating algorithms that simulate the physical activity inside a typical lithium-ion battery. Usually, just the battery's current and voltage is tracked.

UCSD, along with Bosch and battery maker Cobasys, received a grant worth almost $4 million from the U.S. Department of Energy's Advanced Research Projects Agency – Energy (ARPA-E) to study the process, and it looks like the university is making good use of the funds.

The process is a complicated one. Professor Miroslav Krstic and UC President's Postdoctoral Fellow Scott Moura used an analogy of a ticket taker who can track how a movie audience is choosing its seats based on the speed of the line into the theater. Think of the moviegoers as patrons and the seats are the particles. There are more details in the press release below.

We're not sure what that all means, exactly, but we do understand that the researchers say they may be able to reduce the cost of a battery by 25 percent and cut recharging times in half, which is pretty major considering that costs and charging times are two of the primary issues holding back broader adoption of electric vehicles.
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New Sophisticated Control Algorithms Poised to Revolutionize Electric Battery Technology

San Diego, Calif., Oct. 3, 2012 -- Engineers at the University of California, San Diego, have developed sophisticated estimation algorithms that allow lithium-ion batteries to run more efficiently, potentially reducing their cost by 25 percent and potentially allowing the batteries to charge twice as fast as is currently possible. In one instance, electric batteries could be charged in just 15 minutes.

The Department of Energy's Advanced Research Projects Agency - Energy (ARPA-E) has awarded researchers at the Jacobs School of Engineering at UC San Diego, automotive products supplier Bosch, and battery manufacturer Cobasys, just under $4 million to develop the estimation algorithms technology for electric vehicle batteries.UC San Diego's share of the grant is $415,000 for the research group of Professor Miroslav Krstic and UC President's Postdoctoral Fellow Scott Moura in the Department of Mechanical and Aerospace Engineering at the Jacobs School.

"This research is bringing the promise that, with advanced estimation algorithms that are based on mathematical models, batteries can be charged faster and can run more powerful electric motors," said Krstic, who is also associate vice chancellor for research at UC San Diego.

"This technology is going into products that people will actually use," said Moura, the co-lead researcher on the project.

Krstic and Moura are taking a unique approach to making lithium-ion batteries more effective. Instead of monitoring voltage and current, they have designed sophisticated algorithms that can estimate what is physically going on inside the lithium-ion battery.

"We have the unique ability to address the difficulties in estimating the battery's state of charge heads-on, at the electrochemical level," said Krstic.
Current technology

Manufacturers usually rely on voltage and current to monitor the battery's behavior and health. But those are very crude measures, said Krstic. Relying on these measures leads to over-designed, oversized batteries that weigh and cost more. They also take a long time to charge, compared with gas-powered vehicles. Toyota recently canceled mass production of its second all-electric car, the eQ, citing concerns over the viability of electric vehicle technology, including the amount of time vehicles take to charge.

Lithium-ion batteries are cylindrical and made of three sheets rolled together, very much like a jelly roll. One layer is the anode, another layer acts as a separator and yet another layer is the cathode. When the battery is fully charged, the lithium ions are stored at the anode. The battery is designed so that the ions want to move from the anode to the cathode, powering the device it's connected to in the process. To know whether the battery is functioning properly, it's important to know where the ions are in the anode. But that's very difficult to measure, even with sophisticated equipment. The ions are usually lodged deep inside irregularly-shaped particles within the anode.

Trying to estimate the particles' charge by measuring only the voltage on the battery is similar to having the person that collects tickets at the entrance to a movie theater try to estimate which of the seats the patrons are taking by watching the speed at which the line at the entrance is moving, Moura said. In this analogy, the ions are patrons making their way to seats within each row, which represent the particles.

Using mathematics to estimate and control electrochemical phenomena

Schematic of a lithium-ion battery.

Enter the estimation and control algorithms Krstic and Moura developed. The algorithms allow researchers to estimate where the particles are. So the movie theater can now be filled to capacity safety and efficiently. The model can also estimate how the health of the battery evolves over time-the equivalent of which seats are breaking down in the theater and need to be fixed or replaced.

The grant will allow researchers to refine the algorithms and to test them on actual batteries on testbeds developed by Bosch and Cobasys. They will estimate the charge distribution within the battery. Then they will estimate its state of health. Finally researchers will devise a strategy to find optimal rates of charging and discharging batteries.

By testing their algorithms on electric vehicle batteries and comparing their performance to an electric battery run with existing technology, Krstic, Moura and colleagues plan to formulate a strategy to charge and use batteries to their maximum potential-safely.

"We monitor these crucial states directly," said Moura. "It allows us to operate right at the battery's limits without damaging it."


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    • 1 Second Ago
  • 9 Comments
      2 Wheeled Menace
      • 2 Years Ago
      Wow, there are numerous oddities in this article. What's a Toyota eQ? Are you sure that all lithium ion batteries are cylindrical? Who says electric car batteries are oversized? "Trying to estimate the particles' charge by measuring only the voltage on the battery is similar to having the person that collects tickets at the entrance to a movie theater try to estimate which of the seats the patrons are taking by watching the speed at which the line at the entrance is moving" No actually, that's tracking current, LOL. And voltage is absolutely the best way to track the progress of charge, though you can combine that with coloumb counting if you track the history of the battery, in order to get a better idea. What a joke. I thought they were going to talk about mapping internal resistance characteristics in order to optimize power output and charging rate current at given points in the SOC curve. Oh well, i will continue to bash my head on my desk when i read these battery articles.
        SVX pearlie
        • 2 Years Ago
        @2 Wheeled Menace
        Toyota "eQ" is an iQ EV. Or rather it's the (nick)name the car would have gotten, had Toyota not cancelled it.
          2 Wheeled Menace
          • 2 Years Ago
          @SVX pearlie
          Allright, i guess i've never heard it called that, so that's my bad.
      Sorten Borten
      • 2 Years Ago
      Wow, ABG, welcome to last month.
      Anderlan
      • 2 Years Ago
      "Think of the moviegoers as patrons and the seats are the particles. " Now that's a funny typo. Moviegoers ARE patrons. Maybe you meant moviegoers are electrons, and the seats are atoms that could hold them?
      JP
      • 2 Years Ago
      This press release sounds like a huge pile of BS. How are you going to use an algorithm during discharge when the motor and controller are simply going to demand current and voltage, period. I will say there is some research that suggests pulsing during charge may provide some benefit.
      SVX pearlie
      • 2 Years Ago
      If the notion is moving toward smaller batteries to supplement ICE, like strong PHEV / EREV systems, then reduction in cost would be the primary benefit - far more than reduced charge time. As it is, ~40-mile Volt charges fine on 110V, but being able to cut $3k from the pack cost would be awesome. Same with increasing the CMAX AER by 25% to reduce need for at-work charging.
        2 Wheeled Menace
        • 2 Years Ago
        @SVX pearlie
        Let's say you have this magic battery technology that allows you to magically get more output out of a battery with no downfalls. So you cut the pack size. The result is a larger cycle depth window which means that the battery does not last as long. For example, the Volt battery is cycled at something like 60-70% cycle depth. This means you can stretch out a battery that's designed for maybe 1000-2000 cycles at 80% cycle depth up to many thousands of cycles at say 65% SOC. Running shallow cycles can really extend the life of many battery chemistries. NiMH and cobalt/manganese/nickel type lithium batteries benefit from this greatly.
          SVX pearlie
          • 2 Years Ago
          @2 Wheeled Menace
          I'd rather have a magical technology which simply costs less to manufacture, package, and manage.
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