Atomistic design of stable lithium anode for high energy density battery
This project aims at developing computational materials design approaches to speed-up the design of anode materials with high specific capacity and electrochemical stability for the next-generation of electric-vehicle’s batteries. The strategy is to target stable electrochemical interfaces made of lithium metal protected by polymer membranes. The specific goals are: (i) To achieve fundamental understanding on the underlying mechanisms of the reactivity on the lithium metal-electrolyte interfaces, unveiling the atomic-level properties that govern the electrochemical stability. (ii) To develop a novel high-throughput computational materials design (HCMD) approach, incorporating ionic conductivity in the materials screening step to search for stable electrochemical interfaces. Li-ion batteries have provided a lot of advancement to the mobile devices since its first commercialization in 1990 . Now, new Li-battery concepts are emerging with the potential to meet the high-energy storage requirements (250 Wh/Kg and 800 Wh/l) of electric vehicle . The popularization of such technology is a route to enable a sustainable world growth with reduced impact on the environment. However, there are many challenges facing these technologies, and in particular they still depend on the development of stable Li-metal anode for successful commercialization. In this project, we will investigate the electronic structure, electrochemical properties and ionic conductivity mechanism in some target polymer compounds and lithium metal-polymer interfaces, from density functional theory (DFT). The ultimate goal is to establish the compostion-structure-properties relationships unveiling fundamental descriptors for the high-throughput (HT) screening. As a second step, we will build a wide library of co-polymer candidates (including existing and hypothetical compounds) adding key properties that will be calculated from accurate DFT. We will start by calculating the key properties of template polymers like poly(4-bromostyren) and polyethylene oxide and then compose a large amount of co-polymers playing with three different heteroatoms (viz. N, O and S) and many functional groups. Different copolymer arrangements will be evaluated for a given A and B building blocks. The HT screening will follow the hierarchy of stability –> suitable level potentials –> appropriate ionic conductivity –> surface attachment energy. After selecting the potential candidates we will proceed with an in-depth study of the surface interactions. A feedback loop will be established with experimental collaborators to calibrate this machinery. A sequential MD/DFT scheme will be used to determine the electronic structure at a given temperature. In this approach, snapshots of the MD simulations are selected to carry out high-accurate single point DFT calculations. Reference: 1. Tarascon, J.-M. & Armand, M. Nature 414, 359–367 (2001). 2. Bruce, P. G. et al. Nature Materials 11, 19–29 (2012).