Catalyzing the Intercalation Storage Capacity of Aqueous Zinc-Ion Battery Constructed with Zn(II) Preinserted Organo-Vanadyl Hybrid Cathode

Abstract

This article reports the first instance of exploring a chemically Zn(II) preinserted organic−inorganic hybrid material [vanadyl ethylene glycolate or VEG, (VO(CH 2 O) 2 )] as an efficient cathode for rechargeable zinc-ion batteries (ZIBs). The control VEG electrode synthesized by a glycothermal process showed a modest specific capacity of 157 mAh/g at 0.1 A/g current density, however, suffered from poor rate capability and cycle stability due to structural dissolution. Chemically Zn(II) preinsertion into VEG (Zn-VEG) catalyzed the Zn 2+ intercalation in the Zn-VEG cathode with a significantly decreased charge transfer resistance, resulting in high discharge capacity of 217 mAh/g (at 0.1 A/g) accompanied by excellent rate capability with ∼50% capacity retention on increasing the current by 50 times. A first-principles-based hybrid densityfunctional theory (DFT) study revealed that the electronic structure of the Zn-intercalated VEG is thermodynamically stable, indicating an energetically favorable Zn-ion intercalation process. The Zn(II) preinserted VEG cathode allowed faster ionic diffusion (D Zn 2+ in the order of 10 −9 cm 2 /s), and the diffusion controlled process was the major contributor (∼66.9%) to the overall capacity at low scan rate (0.1 mV/s) and remained significant (43.8%) even at high scan rate of 0.8 mV/s. Furthermore, the Zn(II) preinsertion in the VEG could act as a bridge to hold the VEG layers firmly. This provides the desired structural stability to the Zn-VEG cathode during a continuous Zn 2+ insertion/deinsertion process, resulting in excellent cycle stability with only ∼0.005% capacity loss per cycle over 2000 cycles (at 4 A/g) while maintaining a high columbic efficiency of 99.9% throughout the cycles. The high capacity accompanied by excellent rate capability and cycle stability supports the as-prepared Zn(II) preinserted organo-vanadyl hybrid electrode to be a potential cathode material for ZIBs.

Efficient electrocatalytic H2 evolution mediated by 2D Janus MoSSe transition metal dichalcogenide

“…36,37,41 It has been shown that the localized Gaussian basis set (GTO) codes are more intuitively appropriate for solving the Hartree-Fock (HF) part of the Schrödinger equations implemented in the hybrid density functionals menthods. 37,41,[51][52][53][54] The periodic HSE06 DFT method has been implemented in the ab initio-based CRYSTAL17 suite program, 48 which effectively executes hybrid functional methods and facilitates standard application of the new methods to large-scale calculations of such materials with excellent performance, even with small-scale computing resources. The HSE06 method provides a more accurate electronic band gap compared to the other DFT methods.…”

Aqueous Rechargeable Zn‐ion Batteries: Strategies for Improving the Energy Storage Performance

“…Pillaring of layer structured vanadium-and MnO 2 -based materials with metal ions, and structural water increase the interlayer spacing and favor the facile insertion/extraction of charge carrier. [71,112,[154][155][156][157][158][159][160][161]…”

“…It has also been demonstrated recently that the pre-insertion of Zn 2 + ion into the organic-inorganic hybrid material and VOPO 4 • 2 H 2 O favors faster ionic diffusion and enhances the overall performance of the device. [159,160] The alkali metal ion pillared vanadium oxides have been extensively studied for LIBs, and it has also been extended to ZIBs. [166,167] Theoretical studies showed that the K + intercalated V 2 O 5 (K 0.5 V 2 O 5 ) has metallic behavior.…”

Recent progress in quantum dots based nanocomposite electrodes for rechargeable monovalent metal-ion and lithium metal batteries

“…3,4 This has triggered a significant research interest in improving the electrochemical performance of the electrodes and electrolytes of the existing LIBs to meet the immediate demand, as well as in exploring other rechargeable battery chemistries beyond Li-ion for applications where the battery cost and maintenance are rather more important factors than the energy density. 5–10…”