Highly concentrated nitrile functionalized disiloxane - LiFSI based non-flammable electrolyte for high energy density Li metal battery

Abstract

High energy density and safety are key issues of Li metal battery (LMB). A thin Li anode coupling with high voltage/ high capacity cathode (NCM811) can increase the energy density of Lithium batteries. We have developed a fire retar dant disiloxane based highly concentrated electrolyte which makes a coordinated Li+-FSI--Solvent cluster to produce stable interphase on electrodes. This electrolyte shows reduced reactivity towards Li metal anode. The oxidation stability of electrolyte is high (5 V) and also shows less Al corrosion. The synergistic effect of additive makes inorganic 'LiF'-rich dendrite free interphase. SEM analysis confirms dendrite free surface morphology. A Li metal full cell is fabricated with thin Li anode (20 mu m, 4.12 mAh/cm(2)) and NCM811 cathode with moderate active material loading (1.1 mAh/cm(2)), providing a high energy density of 614 Wh kg(-1) (based on total weight of anode and cathode excluding current collectors).