Introducing the potency of new boron-based heterocyclic anion receptor additives to regulate the solvation and transport properties of Li-ions in ethylene carbonate electrolyte of Li-Ion battery: An atomistic molecular dynamics study

Abstract

Development of new solvent/additive electrolyte is emerging field of research towards the improvement of ion transport and solid-electrolyte-interface formation in Li-ion battery (LIB). We perform extensive atomistic molecular dynamics simulations with LiPF6 in ethylene carbonate (EC) in presence of a new class of boron (B) based heterocyclic anion receptor additives; C2HBNO(NO2)2, and C2HBNS(NO2)2 and their trimers B[C2HBNO(NO2)2]3, and B[C2HBNS(NO2)2]3 to investigate the efficacy of this class of additives in regulating the solvation and transport properties of Li+ ions as compared to the reference LiPF6/EC solution that contained TPFPB, a commonly used B-based additive. Our designed additives in several aspects show their efficacy. Among all, C2HBNS(NO2)2 is found to be the most efficient PF6- trapper that reduces ion pair formation. It promotes diffusion of Li+ and EC, improves the transference number, and reduces viscosity of solution, as compared to TPFPB. Further, it improves the ionic conductivity and drift velocity under a wide range of temperatures and external electric fields, respectively. Some of the computed properties are in agreement with the available experimental results. Our study would facilitate the design and synthesis of this class of additives to open up new possibilities of accelerating the LIB power sources for portable appliances.