Fundamental Chemistry Behind Rechargeable Li-Based Batteries and Beyond: Theoretical and Computational Chemistry Approach

Abstract

: Motivated by energy security and environmental concerns, policymakers around the world are directing attention to electrified vehicles as a partial solution to reducing fossil fuel consumption and carbon emissions. In recent years, rechargeable Li-ion batteries emerge as an important power source, and their performance highlights the adoption into the automobile electrical vehicles (EV) sector as viable alternatives to combustion engines. The success of market penetration of these environmental-friendly vehicles strongly depends on the industrialization of new energy-storage technologies that must meet at the same time, performances, security, durability and cost requirements. However, the performance of today's battery chemistries relative to the battery weight is a limiting factor – there is a gap to close between today's technology and the requirements of future battery vehicles. The next-generation energy storage systems may be based on novel chemistries, such as all-solid-state, Li-ion, Li-S, and metal-oxygen, to achieve significantly higher energy density. Materials and their interfaces in these batteries are often the key limiting factors and origins of failures. For example, the degradation at the electrolyte-electrode interfaces causes poor cyclability, low capacitance, and premature failure in these new battery systems. It is crucial to focus on research which aligned towards, robust reaction kinetics modelling and its possible validation through experiments and discovering future advanced (Li, Si, Na-ion) batteries based on material chemistry and electrolyte design. To reveal such details, a fuller understanding of how the materials composition interact at the molecular level, which is not investigated in great detail so far is highly recommended by considering cost-effective computational chemistry tools (DFT, MD). Interaction of decomposed electrolyte/salt components with Li-ion is the key source of formation of SEI layer at the anode surfac such as LiF, Li2CO3, LiO, etc. To understand the stability and chemistry of SEI layer which is in general very complex, atomic level molecular chemistry simulation were performed. The perfect SEI would be a fast forming, flexible, stable and insoluble species with minimum electronic and maximum ionic conductivity. We use computational techniques to understand the limiting factors- such as reaction kinetics and chemistry involved for solid electrolyte interphase (SEI) growth and failure mechanisms at the interfaces, for the improvement of capacity and power fade to the new energy-storage technologies Fig. 1 [1]. [1] M. Datt Bhatt and C. O’Dwyer, “Recent progress in theoretical and computational investigations of Li-ion battery materials and electrolytes,” Phys. Chem. Chem. Phys., vol. 17, no. 7, pp. 4799–4844, 2015. Figure 1