Synergistic Construction of Efficient Heterostructure Electrocatalysis for High-Performance Lithium–Sulfur Batteries

Since a sluggish conversion reaction and shuttling of polysulfides have been barriers to high-performance Li–S batteries, it is particularly critical to establish nanostructured electrocatalysts with high specific surface area and electron conductivity, an excellent anchoring capability, and long-term durability. Herein, a robust binary synergistic MoS 2 /MXene heterostructure is proposed by the homogeneous growth of MoS 2 on an MXene substrate. Due to the hierarchical structure and strong interfacial coupling effect, the binary synergistic MoS 2 /MXene heterostructure not only suppresses the restacking of MoS 2 and MXene nanosheets but also provides abundant active sites to capture polysulfides and catalyze its conversion reaction. Typically, polysulfides are immobilized by MoS 2 nanosheets; then, the anchored polysulfides are rapidly transferred from MoS 2 to MXene via heterointerfaces. The MXene surface is endowed with abundant oxygen terminations, which accelerates the polysulfide conversion kinetics to a great extent. Therefore, the assembled Li–S battery delivers a reversible capacity of 981 mA h g –1 at 0.5 C after 300 cycles. Even at high rate of 5 C, capacity is still maintained at an excellent level of 408 mA h g –1 after 500 cycles with a Coulombic efficiency of 96.5%. Even more fascinating, at 0.2 C, the MoS 2 /MXene cathode can realize a high sulfur loading of 4.0 mg cm –2 and with capacities of 608 mA h g –1 over 500 cycles, which will promote the practical applications of Li–S batteries.