Scientific Challenges for the Implementation of Zn-Ion Batteries

Abstract

The safety, affordability, and impressive electrochemical performance of many Zn-ion batteries (ZIBs) has recently triggered an overwhelming literature surge. As is typical for a new area, initial enthusiasm and high expectations have now been replaced by a more measured period of research that reaches deep into the underlying factors controlling electrochemical properties. Rather than battery metrics, this review focuses on fundamental aspects of the chemistry of ZIBs that are the least understood and on which there has been progress over the last few years. We provide guidance for future research regarding (1) the significant challenge of proton/Zn 2+ co-intercalation in aqueous media, (2) limitations to conversion chemistry that often accompanies ZIB electrochemistry, (3) positive aspects of facile Zn 2+ (de)intercalation in nonaqueous electrolytes and organic cathode materials, (4) the desolvation penalty at electrode-electrolyte interfaces, (5) solutions for controlling Zn dendritic growth, and (6) suggested electrochemistry protocols for the field.

An Interface‐Bridged Organic–Inorganic Layer that Suppresses Dendrite Formation and Side Reactions for Ultra‐Long‐Life Aqueous Zinc Metal Anodes

“…Recently,N azar proposed desolvation of Zn 2+ should be consideration. [57] Here the desolvation energy barriers of Zn 2+ are studied by density functional theory (DFT) calculations (Figure 3a-c). In ZnSO 4 electrolyte,each Zn 2+ is coordinated with six H 2 Om olecules,w hich delivers ah igh desolvation energy of Zn 2+ (À14.9 eV/atom, Figure 3c).…”

Mass‐Producible, Quasi‐Zero‐Strain, Lattice‐Water‐Rich Inorganic Open‐Frameworks for Ultrafast‐Charging and Long‐Cycling Zinc‐Ion Batteries

“…[ 1–3 ] As alternatives, rechargeable aqueous zinc‐ion batteries (ZIBs) have been recognized as an exceptionally promising solution because of high theoretical capacity (820 mAh g Zn −1 or 5851 mAh cm Zn −3 ), compatibility with aqueous electrolytes, low cost and low toxicity of Zn anodes as well as intrinsic safety from the aqueous nature. [ 4–11 ] Despite the multiple advantages, the divalent nature of Zn 2+ has set up formidable obstacles to the implementation of ZIBs. Zn 2+ ions have strong electrostatic interactions (ionic bonding) with host lattice, hence, their repeating (de)insertion typically initiates substantial lattice strain, structural degradation, and inferior cyclability to cathode hosts.…”

“…Zn 2+ ions have strong electrostatic interactions (ionic bonding) with host lattice, hence, their repeating (de)insertion typically initiates substantial lattice strain, structural degradation, and inferior cyclability to cathode hosts. [ 5–9 ] On the other hand, the strong electrostatic interactions cause sluggish solid‐state Zn 2+ migration within cathodes and thus, voltage polarization and depressed energy efficiency. [ 5–9 ] Therefore, the key challenge facing ZIBs is exploring low‐cost cathodes that store as many Zn 2+ as possible while exhibiting low lattice strain and fast kinetics.…”

Defect Engineering in Manganese‐Based Oxides for Aqueous Rechargeable Zinc‐Ion Batteries: A Review

“…[ 15–19 ] While much can be celebrated due to these attractive properties, ZIB research is still severely plagued with the limited selection of materials that can demonstrate reversible Zn 2+ storage after prolonged cycling. [ 20–22 ] This is especially crucial as the cathode is arguably one of the most important components in the ZIB, which can significantly influence the overall electrochemical performance of the ZIB. As such, in the recent years, researchers have been exploring various materials that can potentially work as the ZIB cathodes.…”