Date/Time: 04-24-2019 - Wednesday - 05:00 PM - 07:00 PM
Zeeshan Ali1 2 Yanglong Hou1 2 3

1, Peking University, Beijing, , China
2, Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKLMMD), Beijing, , China
3, Beijing Innovation Centre for Engineering Science and Advanced Technology (BIC-ESAT), Beijing, , China

Binary transition metal chalcogenides have recently drawn boosted attraction as anodes for sodium ion batteries (SIBs) owing to their greatly enhanced electrochemical performances. Superior intrinsic conductivity and richer redox reactions, as compared to monometal chalcogenides, are the main origins of improved performances of these binary transition metal chalcogenides. In pursuit of employing various binary transition metal selenides (B-TMSs) for energy storage, a simplistic and universal synthesis approach is highly desirable. Here, we present a facile and comprehensive strategy to produce various combinations of nanostructured B-TMSs by the use of either nitrates or sulfates of corresponding metals in a high yield room temperature solution reaction. Furthermore, the structure evolution mechanism of nano rods from precursor nanosheets was investigated through the study of products obtained after various reaction durations. As proof of concept, high surface area and hierarchical nanosheets of Fe2NiSe4, Fe2CoSe4 and NiCoSe4 (termed as FNSe, FCSe and NCSe respectively), were manufactured and employed as anodes for sodium ion batteries. These as prepared anodes of B-TMSs exhibited adequately high energy capacities (e.g. 755, 660 and 397 mA h g-1 after 100 cycles at 1 A g-1 for FNSe, FCSe and NCSe, respectively) and excellent rate capabilities (e.g. 776 mA h g-1 at 0.5 A g-1 and 432 mA h g-1 at 20 A g-1 for FNSe, 655 mA h g-1 at 0.5 A g-1 and 466 mA h g-1 at 20 A g-1 for FCSe and then 660 mA h g-1 at 0.5 A g-1 and 366 mA h g-1 at 20 A g-1 for NCSe). In addition to this, FNSe and FCSe also presented extraordinary stable life of 2500 cycles (with reversible capacities of 554.2 and 554.6 mA h g-1 at 4 A g-1, respectively). In situ X-ray diffraction analysis combined with ex situ X-ray and selected area diffraction analysis revealed that the electrodes of FNSe, reversibly transform into the discharge product (Na2Se) through multistep reactions with sodium ions. When employed in sodium full batteries with lab-made Na3V2(PO4)3/C cathode, as prepared B-TMSs anodes presented reasonably high reversible specific capacities (228.5, 216.5 and 100.2 mA h g-1 at 0.1 A g-1 after 100 cycles for FNSe, FCSe and NCSe, respectively). Overall, the presented strategy will pave the way for the development of numerous binary transition metal chalcogenides which are the potential materials for energy storage and conversion systems.

Meeting Program

Symposium Sessions

5:00 PM–7:00 PM Apr 24, 2019 (US - Arizona)

PCC North, 300 Level, Exhibit Hall C-E