This NAISS Medium Compute proposal covers all computing activities within Johansson Research group - that can be summarized as being part of the PI's Distinguished Professor grant from VR (47.5 MSEK, 2022-2031) The main goal of the project is to employ computational studies to rationalize the development of rechargeable batteries. The specific goals for us at Chalmers are: 1. To apply several modeling approaches based on ab initio, DFT and COSMO-RS to rationalize the development of electrolytes. This will then be connected both to high-throughput screening and to large-scale facility experiments, for the best candidates. 2. To proceed with a detailed investigation of the proposed electrolytes by also understanding the underlying mechanisms of ion transport etc.. The initial stage of this project will investigate the structure and dynamics of small local models and then stretch to solubility calculations of salts in organic solvents. This will all be performed by employing the framework of DFT to predict Gibbs free energies together with the COSMO-RS approach to evaluate the solvation energy of the ions in a number of different organic solvents. This procedure will indicate, together with the computation of properties such as viscosity and flash point, attractive electrolyte compositions. Molecular dynamics (MD) simulations will be performed to gain deep understanding of the formation of decomposition products and the stability of the anion and solvent molecules on the interface surface. Moreover, important information regarding the kinetics of the electrolyte decomposition can be revealed from analysis of the MD trajectories. One particular goal for the DP grant is to in some way model electrolytes with a clear focus on the role of entropy. This is done by focusing on multicompent eutectic electrolytes, deep eutectic solvent based electrolytes, liquid-solid gel electrolytes.