Direct Calculation of Li-Ion Transport in the Solid Electrolyte Interphase

The mechanism of Li(+) transport through the solid electrolyte interphase (SEI), a passivating film on electrode surfaces, has never been clearly elucidated despite its overwhelming importance to Li-ion battery operation and lifetime. The present paper develops a multiscale theoretical methodology to reveal the mechanism of Li(+) transport in a SEI film. The methodology incorporates the boundary conditions of the first direct diffusion measurements on a model SEI consisting of porous (outer) organic and dense (inner) inorganic layers (similar to typical SEI films). New experimental evidence confirms that the inner layer in the ∼20 nm thick model SEI is primarily crystalline Li(2)CO(3). Using density functional…