Vanadium Pentoxide Nanosheets in-Situ Spaced with Acetylene Black as Cathodes for High-Performance Zinc-Ion Batteries

Abstract

The 2D materials of ultrathin nanosheets possess plentiful active sites, effectively enhancing the electrochemical kinetics of various electrode materials. However, 2D materials usually suffer from the aggregation issue due to the strong van der Waals force of the individual nanosheets, leading to irreversible stacking and decreasing capacity. In this work, we develop a universal method to in-situ space the nanosheet cathodes for the electrodes of ZIBs. As a proof of concept, the V 2 O 5 nanosheets with in-situ AB spacer were obtained, which were used as the cathode of aqueous ZIBs. Owing to plentiful active sites usable for electrolyte/electrode interfaces of the spaced V 2 O 5 , the ion diffusion kinetics of the electrodes would be enhanced. In contrast with the stacked V 2 O 5 , the spaced V 2 O 5 delivers an exceptional specific capacity (452 mAh g −1 ), superior rate capability, and stable cycle life (the capacity retention of 92% after 5000 cycles). Moreover, the resultant ZIBs assembled with spaced V 2 O 5 show an impressive energy/power density (158 Wh kg −1 at 19.3 kW kg −1 ). These superior electrochemical properties make the method of in-situ adding AB spacer hold promising potential to obtain advanced nanosheet electrodes for energy storage systems.

Understanding the Design Principles of Advanced Aqueous Zinc‐Ion Battery Cathodes: From Transport Kinetics to Structural Engineering, and Future Perspectives

“…For cathode materials applied for AZIBs, the dissolution in the aqueous electrolyte, low electronic conductivity, and structural degradation during cycling have become serious drawbacks that greatly weaken their electrochemical performance. [204] In this case, metal ion doping seems to be the promising strategy to address those facing issues. Currently, many types of metal ion such as Ni 2+ , Ti 4+ , Al 3+ , and Ag + have been applied for doping modification, forming…”

Cathodes for Aqueous Zn‐Ion Batteries: Materials, Mechanisms, and Kinetics

“…The V coordination polyhedral can be divided into five forms, tetrahedron, square pyramid, trigonal bipyramid, and distorted and regular octahedral, with the V oxidation state changing (Figure 9). [98] More than 60 V‐based oxide materials with different open structures have been established from these five kinds of coordination polyhedral and such open framework structures can provide convenience for investigating the storage mechanism of Zn 2+ in vanadium oxide materials [99–105] …”

Vanadium‐Based Materials as Positive Electrode for Aqueous Zinc‐Ion Batteries

“…Later, Wang et al prepared an ultrathin V 2 O 5 •1.6H 2 O nanosheet, which tremendously reduces the diffusion length of Zn 2+ ions and improves the ion diffusion kinetics of the electrode. [86] To further improve battery performance, a new strategy of providing a large mass of active sites on the surface of the electrode was proposed by Wang et al [87] They adopted a general method for the formation of advanced 2D electrodes. At the electrolyte/electrode interface, V 2 O 5 provides abundant active sites that promote ion diffusion kinetics.…”