General Construction of Ultrathick Sulfur Cathode for High‐Energy‐Density Lithium–Sulfur Battery

Abstract

Lithium–sulfur battery has high theoretical energy density (2600 Wh kg−1) and specific capacity (1675 mAh g−1), which is the research hotspot of next‐generation high‐energy‐density energy storage systems. In order to make the actual energy density of the battery closer to the theoretical value, it is necessary to increase the proportion of active substances as much as possible, but this will lead to the increase of the thickness of the electrode and affect the transport of ions inside the electrode. A new NH4HCO3 template to help solve the above problem is proposed. A large number of efficient ion transport channels are generated in ultrathick cathodes. The discharge capacity of the primary button battery reaches 1500 mAh g−1 at the rate of 0.005C. Meanwhile, the actual gravimetric and volumetric energy density of the primary pouch cell are 645 Wh kg−1 and 952 Wh L−1. The special cathode structure makes it easier for the electrolyte to penetrate the thick cathode, and makes the ion transport faster, which is the reason for the excellent performance of the battery. The work provides an effective way to improve the performance of high‐loaded sulfur cathode, enabling the commercialization of high‐specific energy Li–S batteries.