Comparing Electrochemical Properties of Amorphous and Crystalline Tantalum Pentoxide in Lithium Ion Batteries
Faculty Mentor Information
Dr. Claire Xiong (Mentor), Boise State University
Abstract
Lithium Ion Batteries (LIBs) have become dominant as an energy storage solution in many applications. Transition metal oxides exhibiting a disorder-order phase transition upon cycling have been investigated as a possible LIB anode technology. This project studies the existence of this phase transition in Tantalum Pentoxide (Ta2O5) as a battery anode material, and aims to compare the conductivity of Ta2O5 films before and after electrochemical-cycling-induced transformation to the rock salt structure. Multiple cells were assembled using a Ta2O5 anode created by anodization of Ta metal, and a Lithium cathode. One cell was cycled at a voltage range of 0.2-2 V to induce transformation from amorphous to rock salt phase another was cycled at 0.01-3 V in attempt to maintain an amorphous structure through cycling. From measurements obtained from cyclic voltammetry on the cells in later cycles, and 2-point conductivity performed afterwards, the properties of the amorphous vs. rock structure Ta2O5 anodes are compared. The phase transition is verified using X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) provides insight on the morphology of Ta2O5 films used in this project.
Comparing Electrochemical Properties of Amorphous and Crystalline Tantalum Pentoxide in Lithium Ion Batteries
Lithium Ion Batteries (LIBs) have become dominant as an energy storage solution in many applications. Transition metal oxides exhibiting a disorder-order phase transition upon cycling have been investigated as a possible LIB anode technology. This project studies the existence of this phase transition in Tantalum Pentoxide (Ta2O5) as a battery anode material, and aims to compare the conductivity of Ta2O5 films before and after electrochemical-cycling-induced transformation to the rock salt structure. Multiple cells were assembled using a Ta2O5 anode created by anodization of Ta metal, and a Lithium cathode. One cell was cycled at a voltage range of 0.2-2 V to induce transformation from amorphous to rock salt phase another was cycled at 0.01-3 V in attempt to maintain an amorphous structure through cycling. From measurements obtained from cyclic voltammetry on the cells in later cycles, and 2-point conductivity performed afterwards, the properties of the amorphous vs. rock structure Ta2O5 anodes are compared. The phase transition is verified using X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) provides insight on the morphology of Ta2O5 films used in this project.