Enhanced electrochemical performance of a selectively formed V2O3/C composite structure for Li-ion batteries

In this study, V2O3@carbon nanofibers as flexible anode materials were synthesized via electrospinning. The electrode showed a specific discharge capacity with 495 mA h g–1 at 1000 mA g–1 after 1000 cycles. Surprisingly, the electrode fabricated from the V2O3@carbon nanofibers exhibited a specific capacity of 336 mA h g–1 at 5000 mA g–1. Even after 10,000 cycles, it still displayed a specific discharge capacity of 290 mA h g–1, indicating that it has outstanding capacity advantages and long-cycle lifespan. The large specific surface area and abundant active sites of urchinlike V2O3 were considered as the reasons for its outstanding electrochemical performance. The combination of V2O3 and the carbon nanofibers formed a complete conductive network that enhanced the conductivity of the sample, reduced the diffusion path of Li+, and eased the volume change during intercalation/deintercalation of Li+. These results not only demonstrated that the flexible V2O3@carbon nanofibers prepared herein have broad application prospects as an anode for LIBs but also offer a processing strategy for fabricating other state-of-the-art flexible electrode materials for energy storage systems.

“…Meanwhile, the peaks at 138, 280, 408, and 687 cm –1 correspond to the vibration modes associated with V–O bonds in vanadium oxides. Besides, the VO mode appeared at 987 cm –1 …”

Section: Resultsmentioning

confidence: 99%

Flexible and Self-Standing Urchinlike V₂O₃@Carbon Nanofibers toward Ultralong Cycle Lifespan Lithium-Ion Batteries

Liang

Zhu

Rao

et al. 2022

“…As shown in Figure S1a, the characteristic diffraction peaks located at 147, 284, 405, 525, 699, and 994 cm −1 further indicate that the V 2 O 3 has been successfully prepared. 13,24 The characteristic diffraction peaks located at 1357 and 1609 cm −1 can be attributed to the D band and G band (Figure 1b). The value of I D /I G can be calculated to be ∼1, demonstrating the low graphitization degree and the plentiful internal defects in amorphous carbon.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…V 2 O 3 has been applied to LIBs and achieved satisfactory results due to its special physicochemical properties. − On this basis, it is reasonable to believe that V 2 O 3 is also worth exploring as an anode for SIBs. − Nevertheless, there are still some difficulties for V 2 O 3 to achieve outstanding cycle stability and rate performance: (1) V 2 O 3 is accompanied by significant volume changes during the charge/discharge process, resulting in both shedding and crushing of the active material; (2) the low intrinsic conductivity of V 2 O 3 brings unsatisfactory rate performance; (3) the large atomic radius and mass of sodium lead to the torpid kinetic reaction. − Therefore, it is desirable to design an effective modification method to optimize the construction of V 2 O 3 and improve its Na-ion storage capacity. The acclaimed modified method is the nanostructure combined with conductive carbon, and the key step is the uniform distribution of conductive carbon. , Compared to other nanostructures, zero-dimensional (0D) nanounits can effectively accommodate volume changes during the continuous cycles. , Thus, the in situ carbon layer integrated with nanoparticles into a multidimensional structure can not only realize the uniform distribution of carbon layer and active material but also has the advantages of 0D and multidimensional structures, accordingly achieving the best modification effects in structure and composition. − …”

Section: Introductionmentioning

confidence: 99%

V₂O₃ Nanoparticles Anchored on an Interconnected Carbon Nanosheet Network Toward High-Performance Sodium-Ion Batteries

Liao

Dong

et al. 2022

Designing the multidimensional nanomaterial hybrid composite electrode is an effective approach to improve the electrochemical conductivity, structural stability, and Na-ion storage capacity of the anode for sodium-ion batteries. Herein, through solvothermal reaction and subsequent calcination, the V 2 O 3 /C nanocomposite is synthesized which served as a capable Na-ion host. Zero-dimensional V 2 O 3 nanoparticles are in situ generated on a two-dimensional carbon layer to constitute a firm structure with high electrical conductivity. The V 2 O 3 /C nanocomposite shows desirable cycle performance (216 mA h g −1 at 0.5 A g −1 after 1000 cycles) and remarkable rate ability (205 mA h g −1 at 2 A g −1 ). Meanwhile, the Na-ion storage mechanism indicates that the storage capacity is mainly dominated by the capacitance behavior, thus enhancing the rate ability and cycle performance. This work demonstrates the importance of constructing a nanocomposite on electrode materials and displays a viable approach to fabricate nanocomposite electrode materials for metal-ion batteries.

“…To tackle this problem, various materials engineering protocols have been proposed for V 2 O 3 . − Among them, structuring into a nanosized one and coating with a second phase (e.g., carbon) are popular tactics to accommodate the volume change and improve electrical connection and maintain structural integrity. Examples include diverse modalities of V 2 O 3 /C hybrids, such as ordered mesoporous carbon-supported V 2 O 3 , − carbon encapsulated peapod-like V 2 O 3 nanorods, carbon-encapsulated V 2 O 3 nanowires-constituted nanomeshes, porous V 2 O 3 /C hollow spheres, V 2 O 3 /C box-in-box structures, , and three-dimensional flower-like V 2 O 3 /C .…”

Section: Introductionmentioning

confidence: 99%

Scalable Fabrication of Carbon-Networked Size-Tunable V₂O₃ for Lithium Storage

Niu

Wang

et al. 2022

Vanadium sesquioxide (V2O3) is a promising electrode material for lithium-ion batteries and beyond, yet it encounters structural and cyclic instability issues. Although advances have been made with diverse material combination prototypes, the capacity or role of V2O3 is complicated, limiting rational design and performance enhancement. Herein, we demonstrate a simple, scalable intercalation and annealing strategy for synthesizing carbon-knitted V2O3, impressively in a V2O3 size-tunable manner. While holding similar morphology, composition, and pore structure, the hybrid with ∼3 nm V2O3 delivers stable cycling simultaneously with greatly improved capacity (∼450 mAh g–1) and initial Coulombic efficiency (∼87%) compared with its counterparts. This enhancement is verified by correlating it to the change in capacitive contribution. The study provides a smart and tailorable material model for understanding the lithium storage behavior of V2O3 and opens an avenue to combinedly improve stability, capacity, and initial Coulombic efficiency of V2O3 and other high-capacity intercalatable electrode materials.