NSF Award
1809306
NON-TECHNICAL SUMMARY:<br/><br/>High cost of rechargeable batteries is a problem for the widespread adoption of electrical vehicles and grid-scale energy storage systems. The type of electrodes currently used, intercalation cathodes, are expensive and have low energy densities. This leads to the high price of batteries. This project, funded by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, explores a new strategy for the design of transition-metal-free intercalation cathodes with high energy density by utilizing redox active anions charge compensation mechanism. A crystal structure type with covalent anion framework allows designing new cathodes for Na-ion, and Mg-ion battery chemistries. Additionally, the project includes comprehensive training of graduate and undergraduate students in the areas of inorganic materials synthesis and characterization; the High School Science Teachers Club for the teachers from the Greater New Orleans area has been formed. The Teachers Club is designed to involve teachers in sharing effective teaching strategies and to educate the teachers on current research topics. With the goal of improving the science education, an Educational Equipment Lending Library has also been established, and now enables demonstrations which reach many high school students and to increase their interest in science.<br/><br/>TECHNICAL SUMMARY:<br/>Design of cathode materials with a redox active anions (RAA) charge compensation mechanism is a new and attractive possibility for increasing cathode energy density. The researchers at the University of New Orleans study transition metal and oxygen-free compounds with covalent anionic networks as candidates for cathodes with RAA. This project, funded by the Solid State and Materials Chemistry program in the Division of Materials Research at NSF, provides new and important fundamental insights into possible redox active anions cathodes through experimental proof-of-concept of RAA cathodes with extended covalent anionic networks. The strong covalent boron-boron bonds in the selected borides preserve a covalent boron framework during electrochemical cycling. Density functional theory (DFT) calculations indicate high energy density and ionic conductivity for the Mg-ion cathode material studied. The research focuses on syntheses, structural and electrochemical properties investigations of several borides, which are potential Na-ion, and Mg-ion cathodes. Utilization of soft chemistry approaches extends the accessible compositions to new compounds. DFT determination of average voltages and volume changes on cation deintercalation as well as activation energies of the cation diffusion and ionic conductivities are performed. Additionally, the project includes comprehensive training of graduate and undergraduate students in the areas of inorganic materials synthesis and characterization; the High School Science Teachers Club for the teachers from the Greater New Orleans area has been formed. The Teachers Club is designed to involve teachers in sharing effective teaching strategies and to educate the teachers on current research topics. With the goal of improving the science education, an Educational Equipment Lending Library has also been established, and now enables demonstrations which reach many high school students and to increase their interest in science.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
