Zinc Pyrovanadate Nanoplates Embedded in Graphene Networks with Enhanced Electrochemical Performance

Abstract

Transition metal vanadates have gradually caputured reseachers' attention as anode materials for lithium ion batteries, because of their high specific capacity and relatively high chemical stability. However, they suffer from low rate performance and short cycling performance because of the intrinsic low electronic conductivity and large volume variation during lithiation and delithiation. Here we report a design of zinc pyrovanadate nanoplates embedded in graphene networks through a facile one-pot hydrothermal method. Benefiting from graphene and zinc pyrovanadate nanoplates, this nanocomposite possesses high specific capacity, excellent rate capability, and superior cycling stability. Particularly, it exhibits a high reversible capacity of 902 mA h g −1 at 500 mA g −1 , maintaining 854 mA h g −1 after 400 cycles. The impressive electrochemical performance makes it a promising anode material for lithium ion batteries.

Rechargeable Aqueous Zinc‐Ion Battery Based on Porous Framework Zinc Pyrovanadate Intercalation Cathode

“…It is clear that all the diffraction peaks can be indexed to Zn 3 V 2 O 7 (OH) 2 ·2H 2 O (JCPDS 50‐0570), indicating that single‐phase ZVO has been formed. It is interesting to note that the XRD intensity ratio I (001)/ I (012) of the ZVO prepared by our process shows a dramatic enhancement in comparison to hydrothermally synthesized ZVO nanosheets, nanoplates, and microflowers . Moreover, the preferential orientation of ZVO made by our process along the [001] direction ( c ‐axis) may provide better access for guest Zn 2+ ions into the available sites.…”

Lithium‐ion battery anode with high capacity retention derived from zinc vanadate and holey graphene

“…Table 1 summarizes literature values of S BET for a few already reported zinc vanadates used for LIBs application. 21,34,40,44,[47][48][49] Compared to most of the earlier reports, the S BET of Zn 3 V 2 O 8 /hGO is much higher with a sufficient amount of pores for mechanical stability, electrolyte infiltrations and provide an effective diffusion pathway for proper electrode performance.…”

“…9,21,47 A corresponding broad oxidation peak is consistently observed in every cycle at 1.25 V attributed to the oxidation of metallic Zn to Zn 2+ , V 3+ /V 4+ to V 5+ while an oxidation peak for a delithiation of Li-Zn alloy is noted at 0.76 V. 34,55 A weak reduction peak observed at 0.21 V is ascribed to the formation of Li-Zn alloy. 47 From the first cycle onwards, a pair of reduction peaks at 0.72 and 0.46 V correspond to the reduction of V and Zn, respectively. The area of curves for Zn 3 V 2 O 8 /hGO is much larger than that for Zn 3 V 2 O 8 , indicating a higher capacity of Zn 3 V 2 O 8 /hGO than that for Zn 3 V 2 O 8 .…”

“…(B), Impedance curves of as-synthesized materials (inset corresponds to the equivalent circuit) and (C), the corresponding linear fitting previous reports on similar metal vanadate electrodes. 8,9,47 Based on the ex situ XPS analysis the overall electrochemical reactions can be summarized as follows:…”

The kinetic investigation of Zn3(OH)2V2O7•2H2O nanosheets at various conditions by In-situ Electrochemical Impedance Spectroscopy

“…Mai' team prepared Zn3(OH)2V2O7•2H2O microflowers through liquid phase method, and achieved about 1287 mAh g -1 after 120 cycles at 200 mA g -1 (5) . With the further help of graphene networks, Zn3(OH)2V2O7•2H2O nanoplates delivered an enhanced reversible capacity of 854 mAh g -1 after 400 cycles at 500 mA g -1 (9) . Wang et al discussed the electrochemical reaction mechanism of Zn3(OH)2V2O7•2H2O nanosheets during the first cycle (10) .…”