The application of polymer electrolytes in Lithium Ion batteries (LIB), has been proposed as an effective method to alleviate the problems associated to the limited voltage window and safety issues associated to the traditional liquid organic electrolytes. However, polymer electrolytes studied so far based on poly (ethylene glycol) and its derivatives have been unable to reach the required Li⁺ ionic conductivity needed for a broader application for commercial devices. Common polymer electrolytes contain a polymer with specific chain length at a defined C:O ratio, the conducting salt is added either during the polymerization process or afterwards by a dissolution process; however, the salt is often not completely dissociated while the conduction mechanism has been described as hoping of Li⁺ (often Li⁺ and counter ions) between oxygen functional groups and between chains induced by its intrinsic mobility. In order to increase the polymer ionic conductivity, it has been recently proposed the modification of the polymer for the introduction of negatively charge moieties which allows the direct interaction of Li+ with the polymer having no free counter ions; these structures present two big advantages, the Li+ transport number is close to unity and the mobility of Li is not lowered by the presence of the counter Ion. In order to identify the possible modifications to the polymer which allows higher Li conductivity, a detailed study of sp³-Boron Poly (ethylene-glycol) is reported. In this work, by means of density functional theory simulations, different electron withdrawing/donating ligands have been included as modifiers of the Boron site electron density. It was found that the effect of the ligand on the electron density of the Boron site has a great influence on the Bader charge of the boron site and also in the interaction energy with Lithium Ions was. A further study by ab-initio molecular dynamics (AIMD) shows that the mobility of Lithium ion can be modified up to two-fold by the inclusion of withdrawing electron density ligands. This methodology might lead to the discovery of new polymer electrolytes with enhanced Li⁺ conductivity.