Influence of lithium metal anode coated with a composite quasi-solid electrolyte on stabilizing the interface of all-solid-state battery

Solid-state lithium batteries (SSLBs) are perceived as cutting-edge technology and have garnered considerable interest due to the high energy density and safety they could offer. However, the poor interfacial contact between the solid electrolyte and the electrodes limits its immediate commercial application. In this paper, a composite quasi-solid electrolyte (CQE) comprising Li6.6La3Zr1.6Sb0.4O12 (LLZO-Sb) garnet oxide, 1-Butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI), and poly(ethylene oxide) (PEO) is investigated for Li-ion battery application. The primary aspiration of this work is to reduce the interfacial resistance between electrode/electrolyte by making a composite electrolyte that establishes a stable, conformal contact with Li metal and cathode film. The direct coating of electrolyte paste onto the lithium metal eradicates the need for an interface layer and assists in reducing the dendrite formation. The symmetric cell Li ||CQE|| Li displays a low interfacial resistance as small as 75 omega. Furthermore, the symmetric cell demonstrates steady lithium stripping/platting behavior with less voltage hysteresis and manifests good stability up to a current density of 500 mu A cm(-2). The fabricated cell with Li||CQE||LFP configuration shows the first discharge capacity of 148 mAh g(-1) at 0.1 C rate, and at the end of 100 discharge cycles, 125 mAh g(-1) capacity is observed. The excellent performance displayed by the direct coating of composite quasi-solid electrolyte over lithium metal anode provides an alternate route for the practical development of high-energy-density lithium batteries.