Rational Design of Preintercalated Electrodes for Rechargeable Batteries

Abstract

Rational design of the morphology and complementary compounding of electrode materials have contributed substantially to improving battery performance, yet the capabilities of conventional electrode materials have remained limited in some key parameters including energy and power density, cycling stability, etc. because of their intrinsic properties, especially the restricted thermodynamics of reactions and the inherent slow diffusion dynamics induced by the crystal structures. In contrast, preintercalation of ions or molecules into the crystal structure with/without further lattice reconstruction could provide fundamental optimizations to overcome these intrinsic limitations. In this Perspective, we discuss the essential optimization mechanisms of preintercalation in improving electronic conductivity and ionic diffusion, inhibiting “lattice breathing” and screening the carrier charge. We also summarize the current challenges in preintercalation and offer insights on future opportunities for the rational design of preintercalation electrodes in next-generation rechargeable batteries.

Multi‐Scale Investigations of δ‐Ni0.25V2O5·nH2O Cathode Materials in Aqueous Zinc‐Ion Batteries

“…The unsatisfactory performance could be regarded as fast deterioration of structure due to the strong electrostatic force, thus, introducing pre‐intercalated ions could be one of promising solution. [ 18–20 ] Moreover, it is inevitable to consider proton existing in adopted mild acidic electrolyte, which could possibly participate in intercalation in the cathode. In order to elucidate potential proton intercalation contributing to the electrochemical capacity, we conducted additional galvanostatic charge–discharge measurement through a three‐electrode configuration in dilute H 2 SO 4 (pH ≈ 4) electrolyte (Figure S12, Supporting Information).…”

“…The phenomenon is also reported in other AZIB electrodes, and is probably due to a displacement/intercalation reaction mechanism. [ 7,56–59 ] Figure 3c presents the XPS region of Zn 2p for the fully discharged and charged electrodes. An intense Zn 2+ 2p 3/2 peak at 1023.4 eV corresponds to the intercalated Zn 2+ in Ni 0.25 V 2 O 5 ·nH 2 O at the fully discharged state, while a lower intensity signal at 1022.1 eV in the fully charged electrode indicates some residual Zn 2+ remains in the structure upon cycling, consistent with previous studies.…”

“…An intense Zn 2+ 2p 3/2 peak at 1023.4 eV corresponds to the intercalated Zn 2+ in Ni 0.25 V 2 O 5 ·nH 2 O at the fully discharged state, while a lower intensity signal at 1022.1 eV in the fully charged electrode indicates some residual Zn 2+ remains in the structure upon cycling, consistent with previous studies. [ 16,17 ]…”

“…Modifications of behavior have been understood in terms of charge screening effects between the divalent Zn 2+ and the cathode by water molecules, structure stabilizing “pillars” arising from guest species, and shallow donor levels due to reduced framework V ions. [ 18–20 ] Although many pre‐intercalated metal ions in V 2 O 5 hosts have been investigated, such as Zn 0.25 V 2 O 5 , [ 17 ] Mg 0.34 V 2 O 5 , [ 16 ] Ca 0.25 V 2 O 5 , [ 21 ] Na 0.33 V 2 O 5 , [ 19 ] Mn x V 2 O 5 , [ 22 ] and Cu x V 2 O 5 , [ 23 ] the crystallographic complexity of the double‐layer V 2 O 5 host lattice and challenges associated with evaluating the precise role of different various pre‐intercalated ions has limited systematic improvements in the design of these cathode materials. In addition, there is limited discussion in previous literature in regard to the nature of the layers within the host V 2 O 5 framework, which can be classified as either a δ‐ or σ‐type, yet which display different vanadium coordination polyhedra and incorporate different guest ions.…”

Vanadium‐Based Nanomaterials: A Promising Family for Emerging Metal‐Ion Batteries

“…The optimization strategies of V 2 O 5 in LIBs, such as enlarging interlayer spacing, doping, and fabricating conductive nanocomposite, may be also useful in multivalent metal‐ion batteries. Among them, controllably adjusting the interlayer spacing to optimize the ion diffusion by certain strategies, such as metal‐ion preintercalation, organic molecules preintercalation and water content regulation, is expected to be the most effective way to improve the performance.…”