Abstract
Research solutions that improve the performance of Li-ion batteries are essential to meet the future needs of the electric grid and transportation industries. Increasing costs associated with sourcing Cobalt has spurred demand for new cathode materials that are inexpensive and environmentally-friendly. Manganese oxides (MnO2) are an important class of electrochemically active transition metal oxides, which have been extensively studied as a potential candidate for replacing cobalt.[1] Alpha-MnO2 is an MnO2 polymorph, which contains structurally stable and porous 2x2 tunnels with tunnel widths in the range of ~5Â. These tunnels, which are formed by edge and corner sharing MnO6 octahedra, provide low-energy sites for ionic insertion and offer suitable diffusion pathways for intercalating ions.[2] Cationic species such as Na+, K+, and Li2O reduce the lithiation-induced structural distortion in these tunnels and offer a pathway for stabilizing the tunnels during electrochemical cycling.[3,4] This poster presents results from ab-initio Density Functional Theory (DFT) based computational studies to reveal new insights into the impact of cationic stabilization on the intercalation dynamics of these materials, which are otherwise difficult to obtain directly from spectroscopic or electron microscopy techniques. Using alpha-MnO2 as a model material, we present the correlation between the concentration of cationic species and its resulting impact on lithium diffusion in the following aspects: (i) energetic barriers for Li diffusion, and (ii) structural distortions induced within the tunnels.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call