Chlorine-rich argyrodite electrolytes, despite their exceptional ionic conductivity, face critical challenges in industrial utilization of all-solid-state lithium batteries (ASSLBs) due to inherent air instability and unsatisfactory compatibility with lithium metal anodes.
To solve this problem, this work doped PO 4 3- unit in Li 5.5 PS 4.5 Cl 1.5 , yielding a modified electrolyte LPSC-5%Li 3 PO 4 with significantly enhanced chemical/ electrochemical stability. The integration of PO 4 3⁻ units within the bulk structure reinforces lattice stability through robust P-O bonding while inhibiting reactive sulfur species responsible for moisture-triggered H 2 S generation, resulting in enhanced air/ moisture stability. Moreover, the electrolyte demonstrates an ionic conductivity of 5.71 mS cm −1 coupled with an exceptional critical current density reaching 2.9 mA cm -2 , indicating robust dendrite suppression capability. Notably, the PO 4 3⁻ doped into the LPSC electrolyte induces multifaceted interfacial enhancements: a composite interphase layer consisting of LiCl and Li 3 OCl phases is spontaneously formed at the lithium/electrolyte interface. Physical field simulations demonstrate that the electrolyte exhibits excellent mechanical stability, effectively suppressing the penetration of lithium dendrites. Chemically, Density functional theory calculations reveal that the electrolyte possesses a high lowest unoccupied molecular orbital potential, demonstrating good compatibility with lithium metal. This multifaced mechanism synergistically inhibits dendritic lithium growth by simultaneously passivating reactive interfaces and homogenizing ion transport dynamics. The assembled ASSLBS enables stable cycling performance, delivering an initial discharge capacity of 146.7 mAh g −1 and a capacity retention of 80.0% after 1000 cycles at 0.5C.
This work establishes a straightforward and effective doping paradigm that simultaneously addresses ionic transport efficiency, air stability, and interfacial compatibility in sulfide-based electrolytes. The proposed strategy provides critical insights into the rational design of high-energy-density ASSLBs with superior cyclability.
Science China Chemistry
Experimental study