Co3V2O8 Nanoparticles Supported on Reduced Graphene Oxide for Efficient Lithium Storage

Abstract

Co3V2O8 (CVO) with high theoretical specific capacity derived from the multiple oxidation states of V and Co is regarded as a potential electrode material for lithium-ion batteries (LIBs). Herein, reduced graphene oxide (rGO)-supported ultrafine CVO (rGO@CVO) nanoparticles are successfully prepared via the hydrothermal and subsequent annealing processes. The CVO supported on 2D rGO nanosheets possess excellent structural compatibility for the accommodation of volume variation to maintain the structural integrity of an electrode during the repeated lithiation/delithiation process. On the other hand, the rGO, as a highly-conductive network in the rGO@CVO composite, facilitates rapid charge transfer to ensure fast reaction kinetics. Moreover, the CV kinetic analysis indicates that the capacity of rGO@CVO is mainly dominated by a pseudocapacitive process with favorable rate capability. As a result, the rGO@CVO composite exhibits improved specific capacity (1132 mAh g−1, 0.1 A g−1) and promising rate capability (482 mAh g−1, 10 A g−1).

Bifunctional mesoporous CoO/nitrogen‐incorporated graphene electrocatalysts for high‐power and long‐term stability of rechargeable zinc‐air batteries

“…It indicates that the growth of CoO nanocrystals was affected onto the N-rGO surface in a different manner to the bulk CoO. 18 The d-spacings of N-rGO and rGO by estimated by Bragg's law are 0.34 and 0.36 nm, respectively ( Figure S5), implying the effect of N atoms on the interlayer distance. 19 In Figure 2B Bulk CoO.…”

Lithium Storage Performance and Investigation of Electrochemical Mechanism of Cobalt Vanadate Nanowires Assembled by Nanosheets

“…Among them, the first discharge capacity of the as-prepared CVO electrode is higher than other annealed CVO, possibly due to the formation of SEI film and the decomposition of electrolyte. 11 CVO-300 and CVO-400 electrodes exhibit an increased capacity before about 15th cycles, but their capacity gradually decreases during the following cycles. For the CVO-500 sample, its capacity keeps dropping during the whole cycling process.…”

“…Figure a reveals the cycling performances of different CVO electrodes evaluated at 200 mA g –1 . Among them, the first discharge capacity of the as-prepared CVO electrode is higher than other annealed CVO, possibly due to the formation of SEI film and the decomposition of electrolyte . CVO-300 and CVO-400 electrodes exhibit an increased capacity before about 15th cycles, but their capacity gradually decreases during the following cycles.…”

“…At the same time, the valence state of vanadium also decreases from V 5+ /V 4+ to V 3+ . 11,12 To further understand the detailed reaction kinetics behavior of the CVO electrode, the EIS plots of as-prepared CVO at the fresh (blue) and 50th (yellow) states were analyzed (Figure 8a). Both plots display a semicircle at high frequency and a diagonal line at low frequency (Figure 8a).…”

“…Currently, as a candidate material for Li-ion storage, vanadates (M x V y O z (M: Na, Li, Co, Fe, Zn and so on)) have received considerable attention due to their outstanding properties. , A wide variety of vanadates, such as Co 2 V 2 O 7 , Zn 32 V 2 O 8 , LiNiVO 4 , and RVO 4 (R = In, Ce, Bi) were proved to display good electrochemical property. Researchers also founded that cobalt vanadate (Co 3 V 2 O 8 , CVO) has a multiple morphology and interesting storage behavior. − For instance, Soundharrajan et al demonstrated that a CVO metal organic framework possesses an excellent lithium storage property (∼1000 mAh g –1 at 200 mA g –1 ). Wu and co-workers reported that CVO microspheres were obtained via a controllable assembly process, which exhibited a superior storage property for lithium (about 780 mAh g –1 at 1 A g –1 after 250 cycles) .…”