N‐Doped Carbon Modifying MoSSe Nanosheets on Hollow Cubic Carbon for High‐Performance Anodes of Sodium‐Based Dual‐Ion Batteries

The preparation and electrochemical storage behavior of MoS2 nanodots--more precisely single-layered ultrasmall nanoplates--embedded in carbon nanowires has been studied. The preparation is achieved by an electrospinning process that can be easily scaled up. The rate performance and cycling stability of both lithium and sodium storage were found to be outstanding. The storage behavior is, moreover, highly exciting from a fundamental point of view, as the differences between the usual storage modes--insertion, conversion, interfacial storage--are beneficially blurred. The restriction to ultrasmall reaction domains allows for an almost diffusion-less and nucleation-free "conversion", thereby resulting in a high capacity and a remarkable cycling performance.

Molybdenum disulfide (MoS2) has received considerable interest for electrochemical energy storage and conversion. In this work, we have designed and synthesized a unique hybrid hollow structure by growing ultrathin MoS2 nanosheets on N-doped carbon shells (denoted as C@MoS2 nanoboxes). The N-doped carbon shells can greatly improve the conductivity of the hybrid structure and effectively prevent the aggregation of MoS2 nanosheets. The ultrathin MoS2 nanosheets could provide more active sites for electrochemical reactions. When evaluated as an anode material for lithium-ion batteries, these C@MoS2 nanoboxes show high specific capacity of around 1000 mAh g(-1), excellent cycling stability up to 200 cycles, and superior rate performance. Moreover, they also show enhanced electrocatalytic activity for the electrochemical hydrogen evolution.

Onion-like NiCo2 S4 particles with unique hollow structured shells are synthesized by a sequential ion-exchange strategy. With the structural and compositional advantages, these unique onion-like NiCo2 S4 particles exhibit enhanced electrochemical performance as an electrode material for hybrid supercapacitors.