A group of researchers is investigating innovative battery technologies for storing energy in the power grid. Their latest findings indicate that by adding silicate to iron, it could lead to the development of a highly efficient alkaline battery anode.
As the globe makes a swift shift to renewable energy, there are still challenges. Solar energy diminishes at night, and wind energy fluctuates without a consistent pattern. It’s essential to develop new technologies capable of storing excess energy from the electrical grid to use during periods of shortage.
Rechargeable lithium-ion batteries are integral to our daily lives, powering everything from smartphones to electric vehicles. However, these batteries depend on scarce resources like lithium, nickel, and cobalt, which raises concerns regarding their sustainability and cost-effectiveness.
Xiaowei Teng, who holds the James H. Manning Professorship in Chemical Engineering at WPI, is heading a team focused on discovering new battery technologies for grid energy storage. Their recent findings, published in the European scientific journal ChemSusChem, imply that by treating iron with silicate, a type of electrolyte additive, a high-performance alkaline battery anode can be achieved. Being the second most common metal on Earth after aluminum, iron is more sustainable compared to nickel and cobalt. Annually, the United States recycles over 40 million metric tons of iron and steel from scrap materials.
Teng points out that iron is already utilized as an anode in iron-nickel alkaline batteries, which were initially developed by Thomas Edison in the early 1900s. However, these batteries suffer from low energy efficiency and limited storage capacity due to the production of hydrogen gas while charging and the build-up of inert iron oxide when discharging.
“Hydrogen gas generation during the charging process is undesirable,” Teng explained. “It significantly reduces the battery system’s energy efficiency. Until these technical issues are resolved, iron alkaline batteries aren’t very appealing for modern energy storage solutions that connect with electric grids.”
In a cover article published on October 7 in ChemSusChem, the team revealed that introducing silicate into the electrolytes enables them to charge the battery without generating hydrogen gas.
Silicate, a chemical compound made up of silicon and oxygen, has been utilized for a long time as a cost-effective and straightforward material in products like glass, cement, insulation, and detergents, according to Sathya Jagadeesan, a PhD student at WPI and the lead author of the study. The team found that silicate interacts robustly with the battery electrodes, effectively reducing the generation of hydrogen gas. Teng mentioned that this novel approach could enhance the alkaline iron redox chemistry in iron-air and iron-nickel batteries, making them more suitable for energy storage uses in microgrids or individual solar or wind energy systems.
