Synthesis Process of CoSeO3 Microspheres for Unordinary Li‐ion Storage Performances and Mechanism of Their Conversion Reaction with Li ions. Issue 24 (6th May 2019)

• Record Type: Journal Article
• Authors: Park, Gi Dae; Hong, Jeong Hoo; Choi, Jae Hun; Lee, Jong‐Heun; Kim, Yang Soo; Kang, Yun Chan
• Is Part Of: Small. Volume 15:Issue 24(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-06
• Subjects: anode materials -- conversion reaction -- Li‐ion batteries -- metal selenite -- spray pyrolysis; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201901320
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Multicomponent materials with various double cations have been studied as anode materials of lithium‐ion batteries (LIBs). Heterostructures formed by coupling different‐bandgap nanocrystals enhance the surface reaction kinetics and facilitate charge transport because of the internal electric field at the heterointerface. Accordingly, metal selenites can be considered efficient anode materials of LIBs because they transform into metal selenide and oxide nanocrystals in the first cycle. However, few studies have reported synthesis of uniquely structured metal selenite microspheres. Herein, synthesis of high‐porosity CoSeO3 microspheres is reported. Through one‐pot oxidation at 400 °C, CoSe x –C microspheres formed by spray pyrolysis transform into CoSeO3 microspheres showing unordinary cycling and rate performances. The conversion mechanism of CoSeO3 microspheres for lithium‐ion storage is systematically studied by cyclic voltammetry, in situ X‐ray diffraction and electrochemical impedance spectroscopy, and transmission electron microscopy. The reversible reaction mechanism of the CoSeO3 phase from the second cycle onward is evaluated as CoO + x SeO2 + (1 − x )Se + 4( x + 1)Li + + 4( x + 1)e − ↔ Co + (2 x + 1)Li2 O + Li2 Se. The CoSeO3 microspheres show a high reversible capacity of 709 mA h g −1 for the 1400th cycle at a current density of 3 A g −1 and a high reversible capacity of 526 mA h g −1 even at an extremely high current density of 30 A g −1 . Abstract : Herein, a synthesis process of phase‐pure CoSeO3 microspheres with high porosity through the use of cobalt selenide is introduced. Then, the Li‐ion storage mechanism of the CoSeO3 microspheres is systematically studied. CoSeO3 microspheres with heterostructures via coupling of nanocrystals of cobalt oxide and selenide show unordinary Li‐ion storage performances as anode materials of lithium‐ion batteries.