Dense All‐Electrochem‐Active Electrodes for All‐Solid‐State Lithium Batteries

Abstract The energy density presents the core competitiveness of lithium (Li)‐ion batteries. In conventional Li‐ion batteries, the utilization of the gravimetric/volumetric energy density at the electrode level is unsatisfactory (<84 wt% and <62 vol%, respectively) due to the existence of non‐electrochemical active parts among the 3D porous electrodes, including electrolytes, binders, and carbon additives. These are regarded as indispensable and irreducible components of the electronic and ionic transport network. Here, a dense “all‐electrochem‐active” (AEA) electrode for all‐solid‐state Li batteries is proposed, which is entirely constructed from a family of superior mixed electronic–ionic‐conducting cathodes, to minimize the energy density gap between the accessible and theoretical energy density at the electrode level. Furthermore, with the ionic–electronic‐conductive network self‐supported from the AEA cathode, the dense hybrid sulfur (S)‐based AEA electrode exhibits a high compacted filling rate of 91.8%, which indicates a high energy density of 777 W h kg⁻¹ and 1945 W h L⁻¹ at the electrode level based on the total cathodes and anodes when at 70 °C.