Gan Chen

SLAM Talk Title: "Flow Batteries that Shine our Future"

How did you originally get interested in science?

I was fascinated by the magic-like demo experiments in my first chemistry class. And since then, I gradually built a passion for chemistry and materials.

What is your favorite place at the Lab?

The couch in front of the window wall on the 6th floor of the Foundry. You can enjoy the great view of the bay and San Francisco skyline while figuring out research puzzles.

Most memorable moment at the Lab?

One day this past January, I was ready to go home after a day’s lab work, feeling exhausted. When I looked out through the window wall, the San Francisco skyline was totally red because of the sunset glow. It was just gorgeous and refreshing!

What are your hobbies or interests outside the Lab?

Basketball, poker games, billiards, hiking, ping-pong, badminton, fishing.

Gan's Script - "Flow Batteries that Shine our Future"

Can you imagine power outage after sunset every day? No TV shows, no internet and you have to stay in complete darkness. Sounds horrible, right? US has set the goal to reach 100 percent carbon free electricity by 2035, at least 50% of which is estimated to come from solar energy. But the sun is not always shining.

The solution is that we must generate extra electricity when the sun is shining, temporarily store it and release the stored electricity when needed. The most well-established technology for grid-scale energy storage is pumped hydropower. For this system, two reservoirs at different elevations are needed. The system stores energy as water is pumped to the upper reservoir and generates electricity as water flow back to the lower reservoir through turbines that rotate generators. This technology has an 80% efficiency; yet wide applications are limited by geographic constraints.

My research is to address this need by building a battery system that pumps electrons instead of water. The two water reservoirs are replaced with two gigantic tanks. The tanks are filled with liquids that carry electrons at different energy levels. This system stores electricity as electrons are pumped to the high energy tank and releases electricity as electrons flow back to the low energy tank. In operation, the liquids are pumped to flow through the porous electrodes to enable continuous electron exchange, which is why this system is called flow battery. Flow batteries can deliver energy over 10 hrs and don’t require precious metals like Li and Co, which is great for grid scale energy storage. To further improve this technology, we are adding solids that can carry much more electrons within unit volume to the tanks. The solids are now the real electron hosts, and the liquids flowing through the solids and the porous electrodes are shuttling electrons between them. With this new design, at least10 times more energy can be stored within the same tanks.

Hopefully with technologies like this new flow battery that we’re working one, you can still enjoy our favorite TV shows after dinner in the clean electricity era.