Mechanically Adaptive Polyrotaxane Interlayers for Low-Pressure High Energy Density Sulfide-Based All-Solid-State...

All-solid-state batteries (ASSBs) employing lithium (Li) metal anodes or an anode-less configuration, despite their superior energy density, suffer from performance degradation under low stack pressure, hindering their practical application. To address this, we design a mechanically adaptive anode interface that leverages an elastic polymer incorporating mechanically interlocked polyrotaxane (PR). This interface synergistically combines the elastic resilience-derived from the unique ring-sliding motion of PR-with indium fluoride (InF₃), which undergoes spontaneous conversion to form a chemically stable interface. This approach enables robust cycling stability and reliable operation under commercially relevant conditions (25°C, 0.8 MPa), even in an anode-less configuration (N/P = 0), thus demonstrating the potential of mechanically interlocked molecular architectures for maintaining void-free interfaces in low-pressure ASSBs with high energy densities.