Ion Channel Engineering in Super Thick Cathodes toward High-Energy-Density Li-S Batteries

The lithium-sulfur (Li-S) battery has been expected to be the most promising next-generation energy storage device. Aiming to fabricate a high-energy-density Li-S battery, numerous approaches have been devoted to primarily increase the sulfur loading of cathodes. However, it is unavoidable that the cathode with an increasing sulfur loading will be increasingly thicker, causing severe electrolyte transportation problems that compromise the advantages of thick cathodes. Herein, we propose a novel NaCl template-assisted pore generation strategy to solve the above problem within thick cathodes. The pathway of electrolyte transportation in thick cathodes with a superhigh sulfur loading of more than 20 mg/cm(2) is effectively generated, and the resultant Li-S primary battery delivers an unexpectedly high specific capacity of 1346 mA h/g. The overall mass and volume energy densities of the pouch cell are 614.96 W h/kg and 923.00 W h/L, respectively, outdoing the values of its counterparts. The high performance of our advanced Li-S primary battery is well attributed to the favorable microarchitecture of thick cathodes with abundant pores, which act as ion channels and allow electrolytes to penetrate through easily, assuring the fast Li ion transfer. Our findings provide an outstanding avenue for the high-mass-loading cathode design of Li-S batteries to remarkably enhance their practicable energy density.