Mechanically Adaptive Polyrotaxane Interlayers for Low‐Pressure High Energy Density Sulfide‐Based All‐Solid‐State Batteries

Abstract

ABSTRACT 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 (InF 3 ), 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.