NSF Award
2403874
Advanced batteries for vehicle transport and renewable electricity grid storage applications could improve domestic energy security but performance gaps and cost limit use. In addition, it is desirable to use earth abundant and domestically plentiful resources for these new battery chemistries. This CAREER project will conduct fundamental research on advanced battery chemistries and battery components that have the potential for greater energy density and cycling performance while operating safely. Among the considered options, rechargeable Aluminum batteries (Al-batteries) are appealing as aluminum is lightweight and abundant. Aluminum has low flammability and and can be easily handled in the air for simpler battery fabrication techniques. Furthermore, Al ions are trivalent, and this property can be potentially harnessed for higher energy density. The main technology challenge of Al-batteries is finding cathode materials that can reversibly store Al ions. This project addresses this crucial problem by providing a fundamental understanding of the properties of a new class of layered and two-dimensional (2D) materials, called MXenes, as cathode materials for Al-batteries. The research efforts in this project are focused on understanding factors that influence the kinetics and thermodynamics of Al ion intercalation into the structure of several MXene compositions. The fundamental knowledge gained through this project will enable the design of an entirely new family of cathode materials for Al-batteries. This project also includes outreach and educational activities that are designed for middle and high school students in Southeastern Alabama to succeed in science and engineering fair competitions. Educational modules focused on defining and performing science fair projects will be developed and disseminated to local schools through teacher training workshops. In addition, the educational plan utilizes "science and engineering as art" projects to foster creativity in science communication and dissemination of scientific concepts and discoveries among undergraduate and graduate students. <br/><br/>This CAREER project addresses the need for battery chemistries beyond Li-ion, and its expected outcomes will enable a rational design of cathode materials for Al-batteries. There are three research objectives in the project. Objective 1 involves elucidating the role of composition and surface chemistry on the charge transfer kinetics and Al ion transport properties of MXenes. M2CTx MXenes (where M is Ti, V, Cr, or Mo, C is carbon, and Tx represents surface functional groups O, F, or OH) will be synthesized and used to study the dependence of Al ions intercalation on the interfacial and structural properties of the cathode. Objective 2 involves studying the effects of nanoconfined interlayer water on the intercalation of Al ions into MXene structures. The main focus of research under this objective is to gain a mechanistic understanding of Al ion transport into MXenes with nanoconfined interlayer water and investigate the structural and electrochemical stability of hydrated cathode materials. The final Objective 3 involves understanding the effects of cation pre-intercalation on the properties of MXene cathodes and establishing the principles of designing multilayered and heterolayered MXene cathodes through a cation-induced assembly process. The research under this objective seeks transformative advances in designing aluminum battery cathode materials with controlled interlayer environments and efficient electronic and ionic transport pathways. The insight obtained through studying each factor will be connected into a cohesive picture of charge transfer and Al ion transport in the structure of MXenes.<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.
