Interfacial Stabilization by Prelithiated Trithiocyanuric Acid as an Organic Additive in Sulfide‐Based All‐Solid‐State Lithium Metal Batteries

Abstract Sulfide‐based all‐solid‐state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li‐ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid‐electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetri…