Synthesis and electrochemical performance of xLiV₃O₈·yLi₃V₂(PO₄)₃/rGO composite cathode materials for lithium ion batteries

Abstract

A series of xLiV 3 O 8 $yLi 3 V 2 (PO 4 ) 3 /rGO (x : y ¼ 2 : 1, 3 : 1, 1 : 1, 1 : 2, and 1 : 3) composites are synthesized by simple mechanical mixing of LiV 3 O 8 and Li 3 V 2 (PO 4 )/rGO, which are prepared by the hydrothermal method and the sol-gel route, respectively. From scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs, the composites are found to be a mixture of rod-like LiV 3 O 8 particles and flower-shaped Li 3 V 2 (PO 4 )/rGO. Among these composites, the 2LiV 3 O 8 $Li 3 V 2 (PO 4 )/rGO electrode delivers an initial discharge capacity of 197 mA h g À1 at a current density of 100 mA g À1 between 2.0 V and 4.3 V, and shows the best comprehensive electrochemical property. The diffusion coefficients of Li ions in the 2LiV 3 O 8 $Li 3 V 2 (PO 4 )/rGO electrode are in the range of 10 À11.5 to 10 À9.5 cm 2 s À1 obtained using the galvanostatic intermittent titration technique (GITT).

Hollow Porous VOx/C Nanoscrolls as High-Performance Anodes for Lithium-Ion Batteries

“…Figure d shows the XPS spectrum, where the peaks are indexed to C, N, O, and V elements. The V 2p 3/2 peaks of the nanoscrolls in Figure e present the mixed vanadium valence of V 4+ (516.4 eV) and V 3+ (515.4 eV). − Additionally, the vanadium valence can also be determined by the difference ( D ) between V 2p 3/2 and O 1s level binding energies . In the present work, the D values for the deconvoluted V 4+ and V 3+ are 13.6 and 14.6 eV, respectively, which are very consistent with the reported ones in the literature. , The XPS result of NH 4 VO 3 is also given in Figure f, demonstrating that the V 5+ in the raw material was reduced to V 3+ and V 4+ after the reaction.…”

High-energy cathode materials for Li-ion batteries: A review of recent developments

“…It is known that the capacity fading of lithium trivanadate can be ascribed to the local damage of the crystal structure, which is caused by the great change in the cell lattice and the partial dissolution of the active material in the liquid electrolyte during cycling [256][257][258]. To deal with these tough problems, exotic atom doping is believed to be an effective method.…”

Nanorod-Nanoflake Interconnected LiMnPO4·Li3V2(PO4)3/C Composite for High-Rate and Long-Life Lithium-Ion Batteries

“…Rechargeable lithium-ion batteries (LIBs), with their high energy density and durable cycle life, are currently being utilized in portable electronic devices, electric vehicles, and larger scale energy storage applications, but further improvements are needed. , The breakthrough in electrode materials is the key to improve the capacity, rate performance, and cycling stability of LIBs. − Among the candidate materials, lithium transition metal phosphates, such as LiMPO 4 (M = Fe, Mn, Co, Ni), , Li 3 V 2 (PO 4 ) 3 , and LiVOPO 4 , have been investigated as promising cathode materials for LIBs owing to their high energy density, long lifespan, good safety, and low cost. Among these phosphates, a cathode material of nanometer-sized LiFePO 4 (LFP) particles with a coating of conductive carbon has been commercialized successfully .…”