Energy Institute Unveils Prototype Alternative Battery

Sanjoy Banerjee (CUNY Energy Institute)

The CUNY Energy Institute, part of City University of New York, has built an operating prototype zinc anode battery system, as an alternative to traditional nickel-cadmium batteries. The institute plans to start a company to commercialize the technology later in the year.

The battery project is led by engineering professor and institute director Sanjoy Banerjee (pictured right), who says zinc anode batteries  are an environmentally friendlier and less costly alternative to nickel cadmium batteries, and could eventually replace lower-priced lead-acid batteries used in today’s gasoline-powered cars. “This is affordable, rechargeable electricity storage,” says Banerjee, “made from cheap, non-toxic materials that are inherently safe.”

The problem with zinc-based batteries up to now has been the build up of crystalline formations called dendrites that can cause a short circuit. To prevent dendrite build-up, the CUNY team developed a flow-assisted zinc anode battery with a management system to control the charge/discharge protocol.

The researchers have devised a prototype 36 kilowatt-hour (kWh) rechargeable battery system, installed in the university’s Steinman Hall, to demonstrate its capabilities. The prototype battery has 36 individual one-kWh nickel-zinc flow-assisted cells strung together and operated by a management system. The overall system is engineered to charge during low-usage periods and discharge during peak demand periods, when utilities often impose price surcharges.

The team is expanding the demonstration system  to 100 kWh, with another 200 kWh planned for later this year. At that point, the system is expected to be capable of meeting more than 30 percent of Steinman Hall’s peak-demand power needs, with savings of $6,000 or more per month.

The batteries are designed for more than 5,000 to 10,000 charge cycles and a useful life exceeding 10 years. Banerjee anticipates the system to be used first as an alternative to nickel-cadmium batteries in industrial facilities and commercial properties. Examples include backup power for computer server farms and large starter motors, as well as for electric power grids. A nickel-cadmium system now provides back-up service in the Alaska power grid.

The CUNY team plans to start a company to commercialize the zinc anode battery system by the Fall of 2012, with a pilot manufacturing facility likely in the vicinity of the campus. They believe they can produce the system initially for $300 to $500 per kWh, which would provide customers with a three to five-year payback.

Read more: Energy Department Seeking New Power Storage Technologies

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