New generation battery engineer takes lithium ion technology to the next level

By Cindy Atoji Keene

Creating efficient battery technology has been an ongoing challenge for developers. There are no real moving parts in a battery, but simply put, it is difficult to build a battery that holds a charge for long periods – and especially hard when materials are potentially volatile and unstable. With today’s announcement of a new type of lithium ion battery capable of operating in extreme heat or cold, Greg Tremelling, electrical engineering manager at A123 Systems Inc, said that although he has not been involved with any R&D with this new technology, he’ll be leveraging it for new customers, especially for use on electrical power grids run by renewable energy sources.

Lithium-ion battery maker A123 Systems is best known for making batteries for electric cars but has seen increased demand for its commercial transportation and grid operations systems. In its Westborough facility, Tremelling, 31, is leading a team focused on “big batteries,” energy storage for applications such as smoothing out the irregular power output for wind farms. “I like the ability to create a design out of passive components that can end up performing a function, and almost think on its own,” said Tremelling. He is helping to create battery configurations that can be used in hybrid buses as well as scaled upwards to operate a controller that uses up to 90,000 individual battery cells to allow operators to pull more energy out of wind and solar plants.

Q: How do lithium batteries work?
A: Most people think of lithium batteries as the type of batteries that power laptops and cell phones, and not a commercial grade workhorse. A123’s lithium batteries are based on nanostructured electrodes, where chemistry of the cells has been configured to allow a lot of electrical charges without wearing out. There are many reasons batteries age, with heat being one of the main reasons. With our latest battery, improved chemistry offers more power even under extremely high temperatures, without sacrificing storage or energy capabilities.


Q: How did you develop the batteries for use in wind farms or solar that help cope with fluctuations in supply of energy?
A: A grid system uses a very high DC voltage to deliver a megawatt power rating, so designing and working with this type of voltage was a new development. We outfitted our facility with a multi-megawatt power system and brainstormed about what sort of containers could hold over 80 thousand cells for the battery. The answer was a 53-foot shipping container that we outfitted with insulation, wiring, electrical panels, and cooling pipes, which became the perfect package to hold the battery. A West Virginia wind farm today has 16 of these trailers, all outfitted as batteries, and they respond autonomously to the output from the wind farm and help make variations in wind production less jarring.

Q: How did you get started in battery technology?
A: After graduating from Worcester Polytechnic Institute, I went to work at American Power Conversion, where I worked on power suppliers and inverters, then someone invited me to check out this tiny startup in Hopkinton, which A123 was at the time. One of my first assignments was a hybrid bus program in upstate New York, and we drove up there and took a look, and as a result, later that spring, the public transportation system started rolling out energy-efficient hybrid buses. I’ve been with the company now since the end of 2006 in various positions from design engineer to grid system integration.

Q: What have been some new battery developments at A123 systems?
A: One of the technologies was done on the Formula One circuit, integrating a hybrid power boost system into a race car. Using batteries at certain points around the track, the driver was able to hit a button and add a large boost to the horsepower of the car. This was an exciting development because the battery was operating at high power levels and high temperatures.


Q: Have you visited the factories where the lithium ion batteries are manufactured?
A: I’ve been to China and gone through factories, seeing the clean room areas, visiting suppliers and trying to improve battery manufacturing process. The technology starts with the basic elements, and of course, at the end of the line, finished batteries come out.

Q: And have you ever driven a Tesla?
A: I’ve never driven a Tesla, but I did sit test an electric drive car made by the Norwegian electric carmaker Think.

Q: Do you tinker in your spare time?
A: I do. I’m always looking for a project or something to build. Most recently, I converted an old snowmobile into what looks like a chopper motorcycle. It has a single ski in front but a snowmobile drive train in the back. It was something silly I played with for a while and it did actually work.

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