Designing Intrinsically Fast-Amorphizing Solid Electrolytes with Low Processing Cost

Abstract The processing cost of solid electrolytes (SEs) is a critical yet underexplored barrier to the commercialization of all-solid-state Li batteries, and this issue is a chemical challenge. Some SEs such as Zr-based (oxy)chlorides have commercially feasible raw material cost. However, to reach the highly amorphous state needed for optimal performance, prolonged ball milling of 20−80 h is often needed, incurring prohibitive processing cost. Here, we propose a strategy for designing SEs with intrinsically fast amorphization kinetics: changing the lithium source from the typically employed LiCl to an easily amorphized compound. Using Li3PO4 as the proof-of-concept, the resulting Li3PO4-ZrCl4 achieves nearly full amorphization within 3 h of ball milling, lowering the processing cost by ∼90%. Meanwhile, effective amorphization endows the material with an ionic conductivity of 2.23 mS cm−1 and exceptional mechanical compliance, enabling stable all-solid-state cell cycling with an areal capacity of 9.89 mAh cm−2. This strategy opens a new avenue to SEs with intrinsically low processing cost.