A Comparative Computational Study of Li, Na, and Mg Insertion in α-Sn
Published online by Cambridge University Press: 30 July 2014
We present a comparative density functional theory study of Li, Na, and Mg storage energetics and diffusion in α-Sn, including the effects of temperature (vibrations). We study several concentrations corresponding to initial stages of insertion (number densities x= 1/64, 1/32, 1/16, and 1/8) as well as the final state of charge (Li17Sn4, Na15Sn4, and Mg2Sn). While final states of charge correspond to positive anode voltages for all three types of metal, insertion energetics is favorable for insertion for Li at all concentrations studied, for Na up to the concentration of x = 3/64, and Mg insertion is thermodynamically disfavored at all x. Diffusion barriers at dilute concentrations are computed to be 0.23, 0.51, and 0.44 eV for Li, Na, and Mg, respectively. Vibrations have a noticeable and temperature-, concentration-, and dopant-type dependent effect on voltages, of the order of 0.1 eV at room temperature.
- MRS Online Proceedings Library (OPL) , Volume 1678: Symposium N – Research Frontiers on Electrochemical Energy Storage Materials— Design, Synthesis, Characterization and Modeling , 2014 , mrss14-1678-n09-06
- Copyright © Materials Research Society 2014