Monday, 20 June 2016
Riverside Center (Hyatt Regency)
With higher theoretical lithium ion capacity of 670 mAh g–1 comparing with commercial graphite electrodes, molybdenum disulfide (MoS2) may be a promising alternative for lithium ion batteries (LIBs) because it offers unique layered crystal structure with Mo atoms sandwiched between two layers of closely packed S atoms and the MoS2 layers are linked by weak van der Waals interaction. Either bulk or nanoscale MoS2 delivers poor conductivity for the electron/ion transfer, thus leading to obvious capacity loss after several cycles. To overcome these barriers, numerous efforts have been devoted into the engineering of MoS2 nanostructures with optimized electrochemical performances. Herein, we prepared hierarchical MoS2-carbon microspheres via continuous and scalable ultrasonic nebulization route. The structure, composition, electrochemical properties are investigated in detail. The MoS2-carbon microspheres consist of MoS2 nanosheets with a few layers bridged by carbon (15 wt%), which separates the exfoliated MoS2 layers and prevents their aggregation and restacking. The novel architecture offers additional merits such as overall large size, high packing density, which promote their practical applications. The MoS2-carbon microspheres have been demonstrated to deliver excellent electrochemical performances in terms of low resistance, high capacity even at large current density, ultrastable cycling over hundreds of cycles, etc. Specifically, the electrodes exhibited over 900, 800 mAh g–1 at 200, 1600 mA g–1 over 500 cycles, respectively. At higher current density of 3200 mA g–1, a capacity of 730 mAh g–1 can be also maintained. The MoS2-carbon microspheres are practically applicable not only because of the continuous and large scale synthesis via current strategy, but also the robust and integrated architecture which ensures the excellent electrochemical properties.