No More Trial-And-Error Choosing Electrolyte for Metal-Air Batteries
July 17, 2019 | Washington University in St. LouisEstimated reading time: 2 minutes
Metal-air batteries have been pursued as a successor to lithium-ion batteries due to their exceptional gravimetric energy densities. They could potentially enable electric cars to travel a thousand miles or more on a single charge.
Image Caption: This graph shows the correlations between three parameters that lead to a single descriptor which provides a rational basis to design electrolyte compositions for high-power alkali metal-oxygen batteries, including potassium-air batteries. This research from the McKelvey School of Engineering will help engineers find the right electrolyte for new and improved batteries, including potassium-air batteries. (Credit: Ramani Lab)
A promising new member of the alkali-metal-air battery family is the potassium-air battery, which has more than three times the theoretical gravimetric energy density of lithium ion batteries. A key challenge in designing potassium-air batteries is choosing the right electrolyte, the liquid which facilitates the transfer of ions between the cathode and anode.
Typically, electrolytes are chosen using a trial-and-error approach based on rules of thumb correlating several electrolyte properties, followed by exhaustive (and time consuming) testing of several electrolyte candidates to see if the desired performance is achieved.
Researchers from Washington University in St. Louis, led by Vijay Ramani, the Roma B. and Raymond H. Wittcoff Distinguished Professor of Environment & Energy at the McKelvey School of Engineering, have now shown how electrolytes for alkali-metal air batteries can be chosen using a single, easy-to-measure parameter.
Ramani’s team studied the fundamental interactions between the salt and solvent in the electrolyte and show how these interactions can influence overall battery performance. They developed a novel parameter, namely the “Electrochemical” Thiele Modulus, a measure of the ease of ion transport to and reaction at an electrode surface.
This research documents the first time that the Nobel Prize-winning Marcus-Hush theory of electron transfer has been used to study the impact of electrolyte composition on the movement of ions through the electrolyte, and their reaction at the surface of the electrode.
This Thiele Modulus was shown to exponentially decrease with increasing solvent reorganization energy — a measure of the energy needed to modify the solvation sphere of a dissolved species. Thus, the solvent reorganization energy could be used to rationally select electrolytes for high performance metal-air batteries. No more trial-and-error.
“We started out trying to better understand the influence of the electrolyte on the oxygen reduction reaction in metal-air battery systems,” said Shrihari Sankarasubramanian, a research scientist on Ramani’s team and lead author of the study. “We ended up showing how the diffusion of ions in the electrolyte and the reaction of these ions on the electrode surface are both correlated to the energy needed to break the solvation shell around the dissolved ions.”
“Showing how a single parameter descriptor of the solvation energy correlates with both ion transport and surface reaction kinetics is a breakthrough advance,” Ramani said. “It will allow us to rationally develop new high-performance electrolytes for metal-air batteries.”
Joshua Kahky, a rising junior in the Department of Energy, Environmental and Chemical Engineering, is second author of the study. He helped carry out the study as an undergraduate summer intern in Ramani’s lab.
Suggested Items
Water Management in a Large Printed Circuit Board Manufacturer
04/15/2024 | Charles Nehrig, TTM TechnologiesTTM’s environmental management is grounded in its Environmental Statement and Environmental Policy, which promote measures that make for a more responsible environmental management process. Our management system helps TTM work toward minimizing its environmental footprint and increasing the sustainability of its operations. TTM monitors its environmental performance just as it monitors its operational performance, and provides the resources required to adhere to the Company’s environmental responsibilities.
Happy’s Tech Talk #27: Integrated Mesh Power System (IMPS) for PCBs
04/08/2024 | Happy Holden -- Column: Happy’s Tech TalkA significant decrease in HDI substrate production cost can be achieved by reducing the number of substrate layers from conventional through-hole multilayers and microvia multilayers of eight, 10, 12, and more to only two layers. Besides reducing direct processing steps, the yield will increase as defect-producing operations are eliminated. The integrated mesh power system (IMPS) was invented in the latter years of MCM-D use for thin-film fabrication. Those geometries fit today into our use of ultra HDI.
Trouble in Your Tank: Supporting IC Substrates and Advanced Packaging, Part 5
03/19/2024 | Michael Carano -- Column: Trouble in Your TankDirect metallization systems based on conductive graphite or carbon dispersion are quickly gaining acceptance worldwide. Indeed, the environmental and productivity gains one can achieve with these processes are outstanding. In today’s highly competitive and litigious environment, direct metallization reduces costs associated with compliance, waste treatment, and legal issues related to chemical exposure. What makes these processes leaders in the direct metallization space?
Indium Corporation Experts to Present at SEMI THERM
03/07/2024 | Indium CorporationIndium Corporation Global Account Manager and Senior Thermal Technologist Tim Jensen and Product Development Specialist for Thermal Interface Materials Miloš Lazić will present on thermal interface material (TIM) technology at SEMI-THERM, taking place March 25–28 in San Jose, California, U.S.
Indium Corporation to Showcase Proven EV Products and High-Reliability Alloys at Productronica China
02/28/2024 | Indium CorporationAs a materials pioneer and trusted partner in electric vehicle (EV) and e-Mobility manufacturing, Indium Corporation is proud to showcase its high-reliability alloys and soldering solutions at Productronica China, March 20-22, in Shanghai.