Recent Progress on Zinc-Ion Rechargeable Batteries

Abstract

The increasing demands for environmentally friendly grid-scale electric energy storage devices with high energy density and low cost have stimulated the rapid development of various energy storage systems, due to the environmental pollution and energy crisis caused by traditional energy storage technologies. As one of the new and most promising alternative energy storage technologies, zinc-ion rechargeable batteries have recently received much attention owing to their high abundance of zinc in natural resources, intrinsic safety, and cost effectiveness, when compared with the popular, but unsafe and expensive lithium-ion batteries. In particular, the use of mild aqueous electrolytes in zinc-ion batteries (ZIBs) demonstrates high potential for portable electronic applications and large-scale energy storage systems. Moreover, the development of superior electrolyte operating at either high temperature or subzero condition is crucial for practical applications of ZIBs in harsh environments, such as aerospace, airplanes, or submarines. However, there are still many existing challenges that need to be resolved. This paper presents a timely review on recent progresses and challenges in various cathode materials and electrolytes (aqueous, organic, and solid-state electrolytes) in ZIBs. Design and synthesis of zinc-based anode materials and separators are also briefly discussed.

Keywords: Cathode; Electrolyte; Flexible device; Zinc anode; Zinc-ion batteries.

Fig. 1

Schematic illustration of the transformation process of γ-MnO₂ cathode with Zn²⁺ ion insertion [58]. With permission from American Chemical Society

Fig. 2. a

Schematic of aqueous ZIBs based on Zn_0.25V₂O₅ cathode. Due to the water molecules between the V₂O₅ layers, the interlayer space expands. b The related HRTEM image of the Zn_0.25V₂O₅·nH₂O nanobelts. c Schematics showing the co-intercalation of water molecules accompanying Zn²⁺ in/out of the interlayer space of V₂O₅ layers during charging and discharging process [67]. With permission from Springer Nature

Fig. 3. a

Schematic illustration of Zn²⁺ intercalation/deintercalation in VO₂ crystals. b HRTEM and SEM images of RGO-VO₂; schematic view of the pathways for electron transportation in different samples (RGO-VO₂ and VO₂-super P). c Electrochemical performance of RGO-VO₂ composite film, including charge/discharge profiles, rate capability, and long-term cycling test at 4 A g⁻¹ [67]. With permission from Elsevier and Wiley

Fig. 4

a SEM image of V₆O₁₃·nH₂O (insert: the corresponding atomic structure). b Rate capabilities of V₆O₁₃·nH₂O and V₆O₁₃ electrodes. c Long-term cycling performances of V₆O₁₃·nH₂O and V₆O₁₃ cathodes at 5 A g⁻¹ [70]. With permission from American Chemical Society

Fig. 5

a Schematic view of single-nanowire ZIB, b the transport property, c the CV curves tested at different scan rates ranging from 50 to 500 mV s⁻¹, d the specific capacitances at different scan rates [80], e the SAED pattern; the inset shows the TEM image and f HRTEM image of Na_0.33V₂O₅ electrode after 100 cycles [78]. With permission from American Chemical Society and Wiley

Fig. 6

Comprehensive electrochemical performance for LiV₂(PO₄)₃. a Comparison of LiV₂(PO₄)₃ cathode with other researched cathode materials for ZIBs. b Gravimetric (Wh kg⁻¹) and volumetric (Wh L⁻¹) energy densities for different battery systems. c The spider chart for the itemized comparison of Zn/LiV₂(PO₄)₃ cell with other commercial systems [90]. With permission from The Royal Society of Chemistry

Fig. 7

a Schematic of formation of MoO₂/Mo₂N composite materials during the electrochemical activation process. b The capacity during the electrochemical activation cycling process. c The Nyquist plots at different cycling times [95]. With permission from Elsevier

Fig. 8

Specific capacity versus discharge potential of various cathode materials for ZIBs

Fig. 9

a Schematic showing the flexible quasi-solid-state Zn-MnO₂@PEDOT batteries. b HRTEM images of MnO₂@PEDOT sample [107]. c Schematic illustration of the structure of the solid-state ZIB and d the hammering test [108]. e Schematic illustration of the structure of the wire battery, inset showing the charging–discharging curves corresponding to the wire batteries bending at different angles [109]. f Galvanostatic discharge curves of Zn–MnO₂ batteries bending at different curvatures [110]. With permission from The Royal Society of Chemistry

Fig. 10

a Schematic diagram of a quasi-solid-state Zn/NVO battery [50], b LED array with 52 bulbs powered by two quasi-solid-state Zn/NVO battery under bending condition, c cycling performance under various bending states at 0.5 A g⁻¹ of the flexible quasi-solid-state Zn/NVO battery. d cycling performance of soft-packaged and cable-type quasi-solid-state batteries under various bending states at 0.5 A g⁻¹. e A wrist strap powered by two soft-packaged quasi-solid-state batteries in series, f an LED array powered by two cable-type quasi-solid-state batteries in series [52]. With permission from Elsevier and The Royal Society of Chemistry

Fig. 11. a

Comparisons of the adhesion force of the PAM gel and AF gel at − 20 °C. b Bending test of the PAM battery and AF battery at − 20 °C. c Charge–discharge profile of the AF battery under bending test at 0.2 A g⁻¹. d PAM battery and AF battery holding an ice block; the AF battery can still power an electrical watch at − 20 °C. e Cycling test of the AF battery under various heavy loads at − 20 °C. f Hammering tests of the PAM battery and AF battery after 1 day of cooling at − 20 °C. g Discharge curves and h cycling test of the AF battery under hammering tests. i Capacity retention of the AF battery washing in an ice bath [113]. With permission from The Royal Society of Chemistry

Fig. 12

Schematic illustration of the zinc metal anode with stable coating layer. a Plating and stripping of zinc ions lead to unstable surface. Side reaction during continuous cycling can lead to passivation and dendrite growth. b A thin coating layer leads to a stable deposition/stripping process, hindering dendrite growth, and by-product formation. Schematic of morphological changes about c the formation of ZnO passivation layer on Zn anode during charging and discharging. d GO on Zn surface can suppress the formation of ZnO passivation and slow down the dissolution of Zn metal [124]. With permission from Elsevier