Organic Molecular Intercalated V₃O₇·H₂O with High Operating Voltage for Long Cycle Life Aqueous Zn‐Ion Batteries

Abstract

V 3 O 7 •H 2 O (VO) is an attractive cathode material for high-capacity aqueous Zn-ion batteries (AZIBs), but it is limited by slow ion mobility and low working platform voltage. Here, a 1,3-propane diamine (DP)-intercalated VO with nanoribbon-assembled thorn flower-like structure is fabricated by a facile hydrothermal method, noted as VO-DP. The study shows that the zinc ion diffusion coefficient in VO-DP (3.1 × 10 −8 cm −2 s −1 ) is five orders of magnitude higher than that of a pure VO counterpart. Auxiliary density functional theory simulation shows that the embedded energy of zinc ions in VO-DP significantly decreases from 0.24 to −2.5 eV, thus leading to excellent diffusion kinetics and superior rate performance. Benefiting from these unique properties, AZIBs composed of VO-DP cathodes exhibit high operating voltage (0.89 V), remarkable capacities of 473 mA h g −1 at 0.05 A g −1 , excellent rate capability (144 mA h g −1 at 10 A g −1 ) and long-term cycling performance (73% capacity retention over 15 000 cycles at 10 A g −1 ).

Electrochemical Performance and Mechanism of Bimetallic Organic Framework for Advanced Aqueous Zn Ion Batteries

“…The redox peaks of the second circles are located at 1.19, 1.38, and 1.58 V, assigning to the H + and Zn 2+ insertion and extraction of the compound. ,, In addition, the area of CV from the second to the fifth increases, indicating an activation process accompanied by increased capacity. During the cycles at 0.2 A g –1 (Figure b and Figures S7 and S8), there is a significant capacity rise stage up to 20 cycles, and the capacity of ZnMn-SQ can be reached to 502.3 mA h g –1 , which accounted for the activation of the samples (e.g., the electrolyte sufficiently infiltrates the inside of the material) and the degree of Mn 2+ stripping (Figure b) Figure c shows the excellent rate performance at different current densities.…”

“…During the cycles at 0.2 A g −1 (Figure 3b and Figures S7 and S8), there is a significant capacity rise stage up to 20 cycles, and the capacity of ZnMn-SQ can be reached to 502.3 mA h g −1 , which accounted for the activation of the samples (e.g., the electrolyte sufficiently infiltrates the inside of the material) and the degree of Mn 2+ stripping (Figure 2b). 45 Figure 3c shows the excellent rate performance at different current densities. The capacities are 504.4, 481.13, 353.5, 251.3, and 143.8 mA h g −1 for current densities increasing from 0.2 to 1 A g −1 .…”

Enhancing Interplanar Spacing in V2O3/V3O7 Heterostructures to Optimize Cathode Efficiency for Zn-Ion Batteries

“…To investigate the alterations in valence states during the insertion and extraction of Zn 2+ ions, the valence states of V must undergo corresponding changes to uphold charge equilibrium throughout the discharge and charge processes in the layered H-VHN cathode. This phenomenon is scrutinized using ex situ XPS. , In Figure S14a of the Supporting Information, the comprehensive survey spectrum of the layered H-VHN cathode post-1000 cycles is presented, revealing an additional Zn 2p peak, thereby confirming the Zn 2+ ion intercalation into the cathode material. − Furthermore, when XPS of the pristine state and the state after cycling is compared, an additional peak is identified in the V 2p 3/2 region at 516.4 eV. This observation is associated with the existence of the V 3+ valence state, as illustrated in Figure d.…”

Foldable chromium vanadate cathodes for high-performance aqueous zinc ion batteries

“…However, the low electronic conductivity, vanadium dissolution, and slow diffusion kinetics still limit the development of vanadium-based materials. 19 Many attempts have been made to solve the above problems, and one basic strategy is to introduce water molecules and/or pre-intercalated ions, including alkali metal ions (Li + , Na + , and K + ), alkaline earth metal ions (Ca 2+ and Mg 2+ ), rare earth metal ions (La 3+ ), and other species (Al 3+ ). 20–26 For example, MnV 12 O 31 ·10H 2 O (MNVO) nanoflowers obtained via a one-step hydrothermal method to introduce Mn 2+ into the vanadium–oxygen skeleton have a high capacity of 433 mA h g −1 at 0.1 A g −1 , of which 81.5% is retained after 5000 cycles.…”