Measurement and modeling of the mechanical and electrochemical response of amorphous Si thin film electrodes during cyclic lithiation
Giovanna Bucci (Brown University), Siva Nadimpalli (Brown University), Vijay Sethuraman (Brown University), Allan Bower (Brown University), Pradeep Guduru (Brown University)
Lithium ion batteries: When Chemistry meets Mechanics
Wed 10:45 - 12:15
Salomon 003
A combination of experimental measurements and numerical simulations are used to characterize the mechanical and electrochemical response of thin film amorphous Si electrodes during cyclic lithiation. Parameters extracted from the experiment include the variation of elastic modulus and the flow stress with functions of Li concentration; the strain rate sensitivity; the diffusion coefficient for Li transport in the electrode; the free energy of mixing as a function of Li concentration in the electrode; the exchange current density for the Lithium insertion reaction; as well as reaction rates and diffusion coefficients characterizing the rate of formation of solid-electrolyte interphase layer at the electrode surface. Model predictions are compared with experimental measurements; and the implications for practical Si based electrodes are discussed.