Calculation of Li metal - solvent interactions under an applied potential

Li metal anodes would be able to provide very high energy densities for Li-ion batteries, but poor Coulombic efficiency and dendrite growth limit their use in commercial applications. In order to overcome their limitations, recent work has explored modifying the battery electrolyte to give rise to a passivating SEI that limits dendrite growth while facilitating Li ion transfer. This work examines how an electrified Li anode interacts with an electrolyte solution as a means of understanding the interactions that take place before and during SEI formation. We use grand-canonical DFT calculations to study the behavior of biased Li anodes interacting with ethylene carbonate, a common solvent in Li-ion batteries, and Li cations discharging from solution. We study the system under potential biases within the ESM-RISM framework, and calculate the differential capacitance as a function of EC coverage, and in the presence of Li ions. We furthermore characterize the potential-dependent Li-ion discharge kinetics in a variety of local environments. This work establishes a computational framework for modeling battery electrochemistry with explicit voltage bias and reveals insight into the molecular-level effects of voltage on battery anodes.