Insights on lithium plating behavior in graphite-based all-solid-state lithium-ion batteries

Graphite with high reversibility of the lithium ion (Li+) intercalation/de-intercalation endows all-solid-state batteries (ASSBs) with excellent cycling stability. However, the fast-charging of high areal capacity ASSBs is impeded by Li plating on graphite. Herein, we proposed a core-shell microstructural graphite@Li6PS5Cl with fast Li+ kinetics to address this issue. Three-electrode systems, galvanostatic intermittent titration techniques, and operando Raman measurements are conducted to verify the inhibition of Li plating, the reducing of anodic voltage hysteresis, and the faster stage transition of graphite, respectively. Under 0.3 C and 2.4 mAh cm−2, ASSB coupling with LiCoO2 cathode and graphite@Li6PS5Cl anode shows a high average Coulombic efficiency over 99.95% and good capacity retention of 72.5% after 650 cycles at 30 °C. Moreover, ASSBs under high charging current densities (4.8 mA cm−2), or high areal capacity (12.5 mAh cm−2), even in pouch cells (61.6 mAh, 2.6 mAh cm−2) are also demonstrated, highlighting the effectivity of our strategy towards fast-charging ASSBs.