Metallic-State MoS Nanosheets with Atomic Modification for Sodium Ion Batteries with a High Rate Capability and Long Lifespan.

Exploring active materials with a high rate capability and long lifespan for sodium ion batteries attracts much more attention and plays an important role in realizing clean energy storage and conversion. The strategy of optimizing the electronic structure by atomic element substitution within MoS layers was employed to change the inherent physical property. The enhanced electronic conductivity from a decreased bandgap and increased surface Na adsorption energy can efficiently and dramatically optimize the electrochemical performance for sodium storage. Attempting to limit the large volume variation and avoid MoS nanosheet stacking and restacking, numerous nanosheets are grown into a designed hierarchical mesopore carbon matrix. This structure can tightly capture the nanosheets to prevent them from aggregating and offer a sufficient buffer zone for alleviating severe volume changes during the discharging/charging process, contributing remarkably to the structural integrity and superior rate performance of electrodes.