Resolving anodic and cathodic interface-incompatibility in solid-state lithium metal battery via interface infiltration of designed liquid electrolytes

Owing to their interfacial wettability, liquid electrolytes (LEs) are widely used in all-solid-state lithium metal batteries (ASSLMBs) as interface infiltrators. Nevertheless, no single LE compatible with both anode and cathode impedes its practical applications. To alleviate the issue, ethylene carbonate-based reduction-resistant LEs (RRLEs) and acetonitrile-based oxidation-resistant LEs (ORLEs) are designed as anolyte and catholyte infiltrators to meet the different compatibility requirements of the anode and the cathode with Li1.6Al0.4Mg0.1Ge1.5(PO4)3 (LAMGP), respectively. Electrochemical instability of the LAMGP toward Li metal has been improved by infiltrating the interface using the designed anolyte RRLE. A concentrated LiFSI LE dissolved in EC, a reduction resistant solvent that solidifies at 25 degrees C produces an ultra-thin in-situ solidified layer that presents superb interface compatibility between Li metal and LAMGP effectively impedes Li dendrite penetration into the solidstate electrolyte (SSE). Furthermore, the layer raises the critical current density to 2.2 mA cm-2 at 25 degrees C. On the other hand, the incompatibility between the cathode and the SSE is mitigated by infiltrating the interface using designed acetonitrile-based ORLE catholyte. Finally, the Li|LAMGP|LiNi0.33Co0.33Mn0.33O2 based battery infiltrated by the designed anolyte and catholyte LEs at its corresponding interface achieves a remarkable reversible capacity of 131.3 mA h g-1 and 88.4% capacity retention after 300 cycles.

Automated summary

To address the compatibility issues in all-solid-state lithium metal batteries, reduction-resistant and oxidation-resistant liquid electrolytes are designed as infiltrators for the anode and cathode, improving battery performance and cycling stability.