INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Transport of Li+ and O2 in glymes in relation to lithium-air batteries
H. R. CORTI; H.A. CORTES PAEZ; G. HORWITZ; M. P. LONGINOTTI; M. FACTOROVICH
Congreso; 6th Symposium on Hydrogen, Fuel Cells and Advanced Batteries; 2017
Lithium air batteries (LAB) promiseshigher energy density than available commercial advanced batteries , buttheir development is hindered by the lack of a suitable electrolyte. Abraham and coworkers  emphasized the role of asolvent with high donor number (DN) on the stability of Li+-O2-ion-pairs. Thus, solvents like DMSO can support higher discharge/dischargecapacities, but it seems to be chemically unstable in the presence of Li2O2. Recent interest in glymes (glycol ethers) aselectrolytes for LAB is based in their relatively low volatility and the factthat the main discharge product is Li2O2 . Schwenke et al.  studied glymes of variouschain lengths, and concluded that pure mono-, di-, tri-, and tetra-glyme aresufficiently stable against superoxide attack. The dissociation level of the lithium salt used in aLAB plays a significant role in the oxygen reduction reaction (ORR) . Theion clustering of lithium salts in solvents of low dielectric constant, likeglymes, could be very large and have a huge influence on the ohmic overpotentials during charge/discharge of LABs . Moreover, the solubility and diffusivity of oxygen in the electrolyte determine the efficiency of thecathodic process in LABs . In this work we study theconductivity and speciation of lithiumtrifuorosulfonate (Li Triflate) and lithium bis(tri- fluoromethylsulfone)imide(LiTFSI) in two glymes: 1,2-di-methoxyethane (DME or monoglyme), and bis(2-methoxy-ethyl)ether (diglyme). We also analyze the diffusion of oxygen in glymes by resortingto semiempirical models.