Green Chemistry Challenge: 2019 Academic Award
Professor Sanjoy Banerjee, Distinguished Professor of Chemical Engineering at the City College of New York and Director of the City University of New York - Energy Institute
in partnership with Urban Electric Power, Inc., Sandia National Laboratories, Brookhaven National Laboratory, and the Energy Storage Research Program in the Department of Energy Office of Electricity
Rechargeable Alkaline Zn-MnO2 Batteries for Grid Storage Applications
Prof. Sanjoy Banerjee, City College of New York and City University of New York Energy Institute, in partnership with Urban Electric Power, Inc., Sandia National Laboratories, Brookhaven National Laboratory, and the Energy Storage Research Program in the Department of Energy Office of Electricity Urban Electric Power, Inc., is being recognized for creating large-scale zinc-manganese oxide batteries that can be recharged thousands of times without the typical decrease in the length of the battery’s life-time. These batteries do not have some of the limitations of lithium-ion and lead-acid batteries, and they use materials that are abundant and common in existing supply chains.
Summary of Technology:
Zinc (Zn) and manganese dioxide (MnO2) are electrochemical energy storage materials with high energy density, low cost, and established safety characteristics as demonstrated by the widespread use of alkaline primary batteries. Zn and MnO2 are readily available with an abundant domestic supply in the U.S. and Canada. These materials are key components of primary (non-rechargeable) alkaline batteries that presently dominate the disposable battery market. Transforming this technology into a grid-scale rechargeable system would enable a revolutionary, low cost, green technology able to meet critical U.S. electrical grid needs. But the traditional chemistries used in primary alkaline batteries lead to irreversible degradation of the electroactive components that has made them unsuitable for the thousands of charge/discharge cycles desired for rechargeable grid-scale energy storage systems.
The City University of New York - Energy Institute (CUNY-EI) has achieved a recent breakthrough utilizing chemical dopants, such as copper ions, to stabilize the MnO2 cathodes in these batteries by allowing them to be recharged thousands of times without degradation of capacity. In parallel, progress has been made in structuring and stabilizing Zn anodes with electrode and electrolyte additives that allow full utilization of the battery capacity while mitigating problems that degrade Zn-anode lifetime, such as dendrite formation, shape change and passivation. The resulting batteries feature energy densities approaching 200Wh/L and lifecycle CO2 emissions comparable to those of lead acid batteries. The batteries also do not have the temperature limitations of lithium-ion and lead-acid batteries. They do have an aqueous chemistry, are non-flammable, and use materials that are abundant and already in use in existing supply chains.
Urban Electric Power built a pilot scale manufacturing plant in Pearl River, NY, and is commercializing the battery technology developed at the CUNY-EI. When manufactured at high volume production, the batteries can be produced for <$50/kWh, enabling the expansion of renewable energy generation and significantly contributing to the reduction of CO2 generated. For example, storing 20% of the energy generated by renewables allows the plant to use those renewables for base load generation, typically the minimum power supplied at a continuous rate, further displacing traditional electricity generation. This translates to an additional reduction of 0.4 G Tons of CO2 per year.