by Texas A&M University College of Engineering’s Raven Wuebker
Significant storage capacity in water-based batteries has been found by Dr. Daniel Tabor, an assistant professor of chemistry, and Dr. Jodie Lutkenhaus, a professor of chemical engineering. Texas A&M Engineering is credited.
Texas A&M University researchers have found that the storage capacity of water-based, metal-free battery electrodes differs by 1,000%.
These batteries are not the same as cobalt-containing lithium-ion batteries. Since cobalt and lithium are outsourced, the organization wants to have more control over the domestic supply chain, which is why they are investigating metal-free batteries. Battery fires would also be avoided with this safer chemical.
Dr. Daniel Tabor, an assistant professor of chemistry, and Dr. Jodie Lutkenhaus, a professor of chemical engineering, have published their research on lithium-free batteries in Nature Materials.
“There would be no battery fires anymore because it’s water-based,” stated Lutkenhaus. “If future material shortages are anticipated, lithium-ion battery costs will skyrocket. If we have this other battery, we can switch to this chemistry, where the supply is considerably more steady since the raw materials are available and we can produce them right here in the United States.”
Aqueous batteries, according to Lutkenhaus, are made up of an anode, an electrolyte, and a cathode. Polymers with the ability to store energy serve as the cathodes and anodes, while water combined with organic salts serves as the electrolyte. Through its interactions with the electrode, the electrolyte plays a crucial role in both energy storage and ion conduction.
“If an electrode swells too much during cycling, then it can’t conduct electrons very well, and you lose all the performance,” she stated. “I believe that there is a 1,000% difference in energy storage capacity, depending on the electrolyte choice because of swelling effects.”
Their study states that due to their high discharge voltage and quick redox kinetics, redox-active, non-conjugated radical polymers (electrodes) are viable options for metal-free water batteries. Because electrons, ions, and water molecules are all being transferred at the same time, the reaction is complicated and challenging to understand.
“We demonstrate the nature of the redox reaction by examining aqueous electrolytes of varying chao-/kosmotropic character using electrochemical quartz crystal microbalance with dissipation monitoring at a range of timescales,” according to the article’s authors.
Tabor’s study team used computer simulation and analysis to supplement the experimental work. The simulations provided information about the structure and behavior at the microscopic molecule scale.
Understanding these materials frequently requires close collaboration between theory and experiment. In this research, we really charge the electrode to many levels of charge and see how the environment responds to this charging, which is one of the new computational things we perform,” Tabor added.
By precisely measuring the amount of water and salt that enters the battery while it is operating, researchers were able to macroscopically examine whether the battery cathode performed better in the presence of specific types of salts.
“We did that to explain what has been observed experimentally,” he stated. “At this point, we want to include more systems in our simulations. We required confirmation of our theory regarding the forces underlying that type of water and solvent injection.
“This is a step toward lithium-free batteries with this novel energy storage technology. Our understanding of the molecular mechanisms underlying the superior performance of some battery electrodes over others is improving, and this provides compelling evidence for future directions in materials science,” stated Tabor.