WPI researchers unlock the silicate magic for safer, cheaper, and more efficient iron alkaline batteries
The world is transitioning rapidly to renewable power. As solar power falls at night and wind Apower recedes and ascends irregularly, new technologies are needed to store power for the electric grid when too much electrical energy is produced for later energy consumption. Rechargeable lithium-ion batteries have played a crucial role in everyday life, powering devices from smartphones to electric vehicles. However, the large-scale implementation of lithium-ion batteries in the electric grid has raised concerns over sustainability and cost due to their reliance on limited resources like lithium, nickel, and cobalt. Researchers continue searching for battery systems better suited for electric grids.
Xiaowei Teng, the James H Manning Professor in Chemical Engineering, is leading a team to explore new battery technologies for grid energy storage: their recent results suggest that iron could create a high-performance alkaline battery anode. Iron is the second most abundant metal in the Earth’s crust after aluminum and is far more sustainable than nickel and cobalt. The United States alone recycles approximately over 40 million metric tons of iron and steel from scrap each year.
Iron is already used as an alkaline battery anode in iron-nickel alkaline batteries invented by Thomas Edison in the 1900s, but it has low energy efficiency and storage capacity due to the formation of hydrogen gas during charge and inert iron oxide species during discharge. “You don’t want hydrogen gas formation when charging a battery,” said Teng. “It impairs the energy efficiency of the battery system considerably because the electrical energy should be used to electrochemically reduce iron electrode materials instead of water in the electrolyte. Without addressing these technical challenges, iron alkaline batteries are less competitive for modern energy storage systems to be coupled with electric grids.”
“We are developing a new strategy to revitalize iron battery chemistry,” said Teng, the corresponding author of a study detailing this work in ChemSusChem with a journal cover highlight. Sathya Jagadeesan, the lead author of this study who recently completed his PhD in Chemical Engineering from WPI, identified a new redox pathway involving one-charge transfer between Fe(OH)2 and FeOOH without generating hydrogen gas.
The key to success was the silicate, an electrolyte additive. Silicate, a chemical compound of silicon and oxygen, has long been used as an inexpensive and simple agent in glass, cement, insulation, and detergents. The team found silicate is also efficient as a battery electrolyte additive, strongly interacts with electrodes, and strengthens hydrogen-bond networks in electrolytes, eventually suppressing hydrogen gas generation and promoting iron redox.
As this work evolves, the hope is that this new iron anode chemistry could improve the alkaline iron-air batteries for stationary energy storage applications, such as microgrids or individual solar or wind farms.
This work is funded by the National Science Foundation.
Reference: “Unlocking High Capacity and Reversible Alkaline Iron Redox Using Silicate-Sodium Hydroxide Hybrid Electrolytes” by Sathya Narayanan Jagadeesan, Fenghua Guo, Ranga Teja Pidathala, A. M. Milinda Abeykoon, Gihan Kwon, Daniel Olds, Badri Narayanan, and Xiaowei Teng, October 7 2024, ChemSusChem
https://doi.org/10.1002/cssc.202400050