Multifunctional α-MoO3 Nanobelt Interlayer with the Capacity Compensation Effect for High-Energy Lithium–Sulfur Batteries

Spatial hindrance of lithium polysulfide (LiPS) diffusion by inserting a barrier interlayer has been deemed as an effective strategy to restrict the shuttle effect in lithium–sulfur batteries (LSBs). However, the extra interlayer without reversible capacity production inevitably reduces the actual energy density of the battery. Herein, a freestanding α-MoO3 nanobelt interlayer with the decoration of TiN nanoparticles and carbon nanotubes (denoted as MCT) is established. To investigate the capacity compensation effect of the MCT during cell operations, X-ray absorption near-edge spectrometry is conducted. It is revealed that MoO3 can sustain a reversible Li intercalation/deintercalation in a voltage range of 1.8–2.8 V, providing 180 mAh g–1 of extra capacity for compensating sulfur cathode. In addition, the adsorption of the lithiated α-MoO3 toward LiPSs is further evaluated. By matching a high-loading sulfur cathode (3.0 mg cm–2), a superior capacity of 713.3 mAh g–1 can be retained after 100 cycles under the MCT assistance.