Hexagonal WO₃/3D Porous Graphene as a Novel Zinc Intercalation Anode for Aqueous Zinc-Ion Batteries

Abstract

Aqueous Zn-ion batteries (ZIBs) have acquired great attention because of their high safety and environmentally friendly properties. However, the uncontrollable Zn dendrites and the irreversibility of electrodes seriously affect their practical application. Herein, hexagonal WO3/three-dimensional porous graphene (h-WO3/3DG) is investigated as an intercalation anode for ZIBs. As a result, the h-WO3/3DG//Zn half-battery shows excellent electrochemical performance with a high capacity of 115.6 mAh g–1 at 0.1 A g–1 and 89% capacity retention at 2.0 A g–1 after 10 000 cycles. The reason could be that the crystalline structure of WO3, which has hexagonal channels, with a diameter of 5.36 Å, much higher than the diameter of Zn2+ (0.73 Å), accelerating the insertion/extraction of Zn ions. A zinc metal-free full battery using h-WO3/3DG as the anode and ZnMn2O4/carbon black (ZnMn2O4/CB) as the cathode is constructed, exhibiting an initial capacity of 66.8 mAh g–1 at 0.1 A g–1 corresponding to an energy density of 73.5 W h kg–1 (based on the total mass of anode and cathode-active materials) and a capacity retention of 76.6% after 1000 cycles at 0.5 A g–1. This work demonstrates the high potential of hexagonal WO3 as an advanced intercalation anode material for Zn metal-free batteries and may inspire new ideas for the development of other intercalation anode hosts for ZIBs.

Few‐Atomic‐Layered Co‐Doped BiOBr Nanosheet: Free‐Standing Anode with Ultrahigh Mass Loading for “Rocking Chair” Zinc‐Ion Battery

“…High capacity (126 mAh g −1 after 100 cycles) and coulombic efficiencies (≥ 97%) are obtained, reflecting the excellent cycle stability of Co‐UTBiOBr//MnO 2 . Significantly, the specific capacity of Co‐UTBiOBr//MnO 2 (based on the mass of anode) is superior to the most reported “rocking‐chair” zinc ion batteries such as Na 0.14 TiS 2 //ZnMn 2 O 4 (105 mAh g −1 @0.05 A g −1 ), [ 28 ] h‐WO 3 /3DG//ZnMn 2 O 4 /CB (62 mAh g −1 @0.1 A g −1 ), [ 24 ] h‐MoO 3 //Zn 0.2 MnO 2 (85 mAh g −1 @0.15 A g −1 ), [ 30 ] WO 3 /WC//MnO 2 /graphite (118 mAh g −1 @0.17 A g −1 ), [ 46 ] Zn x MnO 2 //H 2 Ti 3 O 7 ∙xH 2 O (67 mAh g −1 @0.2 A g −1 ), [ 31 ] MoO 2 @NC//Na 3 V 2 (PO 4 ) 2 O 2 F (102 mAh g −1 @0.1 A g −1 ), [ 33 ] TiSe 2 //VO 2 (44 mAh g −1 @0.2 A g −1 ), [ 26 ] and Zn 2 Mo 6 S 8 //K 0.02 (H 2 O) 0.22 Zn 2.94 [Fe(CN) 6 ] 2 (62 mAh g −1 @0.064 A g −1 ). [ 47 ] Co‐UTBiOBr//MnO 2 quasi‐solid‐state flexible battery is also designed.…”

“…[ 20–23 ] On the other hand, more and more insertion host materials are used as anodes of “rocking chair” ZIBs due to their high capacities, low discharge platforms, and dendrite‐free operation. [ 24–27 ]…”

“…[20][21][22][23] On the other hand, more and more insertion host materials are used as anodes of "rocking chair" ZIBs due to their high capacities, low discharge platforms, and dendrite-free operation. [24][25][26][27] Among the reported metal compound anodes, Ti/Cu/Mobased materials exhibit good electrochemical properties. [28][29][30][31][32][33] Li and coworkers reported a presodiated TiS 2 and it showed a capacity of 140 mAh g −1 with a suitable potential of 0.3 V (vs Zn 2+ /Zn) at 0.05 A g −1 and a good cyclability of 77% retention over 5000 cycles at 0.5 A g −1 .…”

A strategy for anode modification for future zinc-based battery application

“…117 Equally, h-WO 3 /3DG, where 3DG stands for three-dimensional porous graphene, in the half batteries also showed excellent electrochemical performance with a high capacity of 115.6 mA h g À1 at 0.1 A g À1 and 89% capacity retention at 2.0 A g À1 after 10 000 cycles. As alternatives to Zn anodes, there is no doubt that they are suitable 127 (Fig. 16d).…”

Constructing Three-Dimensional Topological Zn Deposition for Long-Life Aqueous Zn-Ion Batteries

“…Zn metal is the most ideal anode for Zn batteries because of its high capacity and relevant stability in aqueous electrolytes. , However, the prominent problems of Zn dendrites, large volume change, corrosion, and hydrogen generation have hindered the practical applications of Zn metal anodes. Extensive efforts have been made to address the above issues, such as introducing advanced electrolytes, − developing alloyed anodes, − designing protective coating layers, − and structural optimization for Zn anodes. − …”