Boosting the Performance of Sb₂Se₃ Cathode‐Based All‐Solid‐State Batteries by Carbon Coating

All‐solid‐state battery (ASSB) is a potential future energy storage technology to power the future world. However, the solid–solid contacts among the various components in ASSB often require a high stack pressure which is unrealistic in practical applications. Here it is shown that by carbon‐coating Sb 2 Se 3 (Sb 2 Se 3 @C) nanorods, a record low stack pressure is attained, and the Sb 2 Se 3 @C electrode exhibits outstanding performance of 862 mAh g −1 over 50 cycles at 0.1 A g −1 when it is operated at 5 MPa stack pressure in an ASSB using LiIn anode and Li 10 Si 0.3 PS 6.7 Cl 1.8 solid‐state electrolytes. Furthermore, a record high active material loading (the mass fraction of Sb 2 Se 3 @C being 0.7 in composite cathode) is achieved, and the Sb 2 Se 3 @C based ASSB delivers a reversible capacity of 2.6 mAh cm −2 at 0.1 A g −1 after 100 cycles. This work provides a strategy to significantly increase the cathode active material loading and dramatically reduce the stack pressure of ASSBs, which brings it one step closer toward the practical implementation of ASSBs for energy storage applications.