F doped Li3VO4: An advanced anode material with optimized rate capability and durable lifetime

Ultrafast Knock-Off Li+ Diffusion and Subtle Structural Evolution of Li5V3O8 Anode in Lithium-Ion Batteries

Li5V3O8, a lithiation product derived from the LiV3O8 cathode, has emerged as a promising intercalation-type anode material, boasting a theoretical capacity of 256 mA h g-1. Through a comprehensive combination of experimental and theoretical approaches, we demonstrate its capability to intercalate a substantial amount of Li+ at extremely high rates. Experimental findings reveal that Li5V3O8 exhibits outstanding high-rate capability (with a specific capacity of 152 mA h g-1, 60% of the theoretical capacity at 40 C) and exceptional cyclability (with a capacity retention of 80% after 11,000 cycles at 20 C). The structural changes in Li5V3O8 during the lithiation/delithiation cycles are subtle and reversible. First-principles calculations highlight a knock-off mechanism in Li+ diffusion within Li5V3O8, with an estimated energy barrier ranging from 0.16 to 0.38 eV, considerably lower than that of a direct hopping mechanism (0.62-1.44 eV). These ultrafast ion diffusion properties are attributed to interlock interactions among interstitial tetrahedral Li+ and neighboring octahedral lattice Li+, facilitating long-distance and chain-like Li+ diffusion. This study not only introduces an influential vanadium-based anode material with practical implications for fast-charging lithium-ion batteries but also provides fundamental insights into solid state Li+ diffusion kinetics.

C-Doped LiVO3 Honeycombs Derived from the Biomass Template Strategy for Superior Lithium Storage

LiVO3 as a prospective anode for lithium-ion batteries has drawn considerable focus based on its superior ion transfer capability and relatively elevated specific capacity. Nevertheless, the inherent low electrical conductivity and sluggish reaction kinetics hindered its commercial application. Herein, C-doped LiVO3 honeycombs (C-doped LiVO3 HCs) are designed via introducing low-cost and scalable biomass carbon as a template, and the influence of the structure on the lithium storage property is systematically studied. The prepared C-doped LiVO3 HC electrode delivers a high reversible capacity of 743.7 mA h g-1 at 0.5 A g-1 after 400 cycles and superior high-rate performance with an average discharge capacity of 420.8 mA h g-1 even at 5.0 A g-1. The remarkable comprehensive electrochemical performance is attributed to the high electrical conductivity caused by carbon doping and rapid ion transport triggered by the honeycomb structure. This work may offer a rational design on both the hierarchical structure and doping engineering of future battery electrodes.

Synthesis of F-doped materials and applications in catalysis and rechargeable batteries

Elemental doping is one of the most essential techniques for material modification. It is well known that fluorine is considered to be a highly efficient and inexpensive dopant in the field of materials. Fluorine is one of the most reactive elements with the highest electronegativity (χ = 3.98). Compared to cationic doping, anionic doping is another valuable method for improving the properties of materials. Many materials have physicochemical limitations that affect their practical application in the field of catalysis and rechargeable ion batteries. Many researchers have demonstrated that F-doping can significantly improve the performance of materials for practical applications. This paper reviews the applications of various F-doped materials in photocatalysis, electrocatalysis, lithium-ion batteries, and sodium-ion batteries, as well as briefly introducing their preparation methods and mechanisms to provide researchers with more ideas and options for material modification.

Fabrication of VO Nanorings on a Porous Carbon Architecture for High-Performance Li-Ion Batteries

Vanadium monoxide (VO) is a promising candidate as an anode for lithium-ion batteries due to its high theoretical capacity, low cost, and considerable electronic conductivity. Unfortunately, a large volume change during electrochemical processes obstructs its practical application. In this work, a composite of VO nanorings grown on a porous carbon architecture is prepared via a topochemical self-reduction approach. When used as an anode for lithium-ion batteries, improved redox kinetics from enhanced electronic conduction and the corresponding fast lithium-ion diffusion is observed to greatly promote the electrochemical performance of lithium-ion batteries. The resulting composite delivered a reversible capacity of 336 mA h g^-1 after 400 cycles at 10 A g^-1 with a capacity retention of 85%, owing to the synergistic effect of VO nanorings and porous carbon in alleviating volume changes that result in a long-term cycling ability at a high current density. At 20 A g^-1, the composite anode exhibited a rate capability of 235 mA h g^-1, superior to all VO-based electrodes reported in the literature. Furthermore, a full cell was first fabricated by employing VO@C-2 as the anode and LiFePO₄ as the cathode, which exhibited a capacity of 213 mA h g^-1 after 100 cycles at 0.1 A g^-1, indicating the potential of VO as an anode for practical application.

In situ interfacial architecture of lithium vanadate-based cathode for printable lithium batteries

Most Li₃VO₄ anodes are obtained by pre-architecture methods in which Li₃VO₄ anode materials are prepared with more than six key processes including high-temperature annealing and long preparation time. Herein, we propose an in situ post-architecture strategy including Li₃VO₄-precursor solution (ink) preparation and then annealing at 250°C. The integrated Li₃VO₄ based electrode not only possesses good electrical conductivity and porous microstructure but also has superior stability because of Cu anchoring and inclusion by in situ catalysis. The integrated electrode demonstrates a high reversible capacity (865 mA h g^-1 at 0.2 A g^-1) and good cyclability (100% capacity retention after 200 cycles at 1 A g^-1). More importantly, the post-architecture electrode has a high energy density of 773.8 Wh kg^-1, much higher than reported Li₃VO₄-based materials, as well as most cathodes. Therefore, the electrode could be used to the printable cathode of low-voltage high-energy-density lithium batteries.