According to foreign media reports, metal-air batteries have been considered the "successor" of lithium-ion batteries due to their excellent weight and energy density. Metal-air batteries have the potential to enable electric vehicles to have a cruising range of 1,000 miles or more. Potassium-air batteries are a very promising new member of the alkali metal-air battery family. In theory, their weight energy density is more than three times that of lithium-ion batteries. One of the key challenges in designing potassium-air batteries is choosing the right electrolyte, a liquid that facilitates the transfer of particles between the battery's anode and cathode to provide electricity.

　　Typically, an electrolyte is selected using a trial-and-error approach based on rules of thumb, relating several electrolyte properties, followed by exhaustive (and time-consuming) testing of several candidate electrolytes to determine whether they perform as expected. performance.

　　Researchers at Washington University (St. Louis), led by Vijay Ramani, have demonstrated how to select electrolytes for alkali metal air batteries through a simple, easily measurable parameter. Vijay Ramani is the Roma B. and Raymond H. Wittcoff Distinguished Professor of Environment & Energy in the McKelvey School of Engineering.

　　Ramani's team studies the fundamental interactions between salts and solvents in electrolytes and shows how such interactions affect the overall performance of the battery. They developed a new parameter, the "electrochemical" Thiele modulus (a measure of how easily ions transport and react at the electrode surface). In addition, this research also applied the electron transfer theory of Nobel Prize winner Marcus-Hush for the first time to study the movement of ions in the electrolyte and the impact of their reactions on the electrode surface.

　　As the solvent reorganization energy continues to increase, the Thiele modulus decreases exponentially. Reorganization energy is a measure of the energy required to correct a solvated sphere. Solvent recombination energy can therefore be used to select suitable electrolytes for high-performance metal-air batteries without the need for additional trial-and-error efforts.

　　"Initially, we sought to better understand the impact of electrolytes on redox reactions in metal-air battery systems, ultimately showing how ions diffuse in the electrolyte and how such ions react on the electrode surface," said Shrihari Sankarasubramanian, a research scientist in Ramani's group. How, and such information relates to the energy required to break the solvation shell around a dissolved ion. Having a single parameter describing the relationship of solvation energy to ion transport and surface reaction kinetics is a breakthrough that allows us to reasonably to develop new high-performance electrolytes for metal-air batteries."

Read recommendations:

801752 720mAh 3.7V

The release of the "Plan" is expected to change the world's lithium battery landscape

Lithium phosphate iron and lithium battery principle.Column rechargeable battery

603450 battery

703048 lipo battery