Graphene Oxide Wrapped CuV₂O₆ Nanobelts as High-Capacity and Long-Life Cathode Materials of Aqueous Zinc-Ion Batteries

Abstract

Rechargeable aqueous zinc-ion batteries are considered as a promising alternative of lithium-ion batteries for stationary energy storage because of their economical and high safety quality. However, their widespread application is still impeded by the development of cathode materials with poor energy density and limited long-term stability. Herein, we report a high-performance CuV 2 O 6 cathode material for aqueous zinc-ion batteries and elucidate the zinc-storage mechanism. The reversible phase transformation between CuV 2 O 6 and ZnV 2 O 6 , accompanied by zinc ion insertion/ extraction and the reduction/oxidation of metallic Cu nanoparticles, all contribute to excellent battery performance: an impressively high specific capacity of 427 mA h g −1 at current density of 0.1 A g −1 , long-term cycling stability with minor capacity loss (0.7%) after 3000 cycles at a high current density of 5 A g −1 , and a high energy density of 317 Wh kg −1 at a power density of 210 W kg −1 . Furthermore, graphene oxide wrapped CuV 2 O 6 nanocomposites are successfully fabricated, which demonstrates the significantly enhanced specific capacity (at least 30% improvement). This work provides an intriguing cathode material and expands available options of transition metal vanadate materials for zinc-ion batteries.

Binding Zinc Ions by Carboxyl Groups from Adjacent Molecules toward Long‐Life Aqueous Zinc–Organic Batteries

“…[ 2–7 ] Among them, aqueous zinc batteries have aroused extensive interest and attention, which benefits from many advantages of zinc anode, including high theoretical capacity (820 mAh g −1 ), appropriate redox potential (−0.762 V vs the standard hydrogen electrode (SHE)), and intrinsic safety in aqueous system. [ 8–20 ] Inspired by conventional Li + storage reaction, intercalation reaction of transition metal oxides are employed to storage Zn 2+ in the mild aqueous solution. For example, Zn 0.25 V 2 O 5 · n H 2 O, [ 9 ] Prussian blue analogue, [ 15 ] VO 2 , [ 17 ] MnO 2 , [ 18 ] Zn 3 V 2 O 7 (OH) 2 ·2H 2 O, [ 19 ] CuV 2 O 6 [ 20 ] have been used as cathodes for zinc batteries.…”

“…[ 8–20 ] Inspired by conventional Li + storage reaction, intercalation reaction of transition metal oxides are employed to storage Zn 2+ in the mild aqueous solution. For example, Zn 0.25 V 2 O 5 · n H 2 O, [ 9 ] Prussian blue analogue, [ 15 ] VO 2 , [ 17 ] MnO 2 , [ 18 ] Zn 3 V 2 O 7 (OH) 2 ·2H 2 O, [ 19 ] CuV 2 O 6 [ 20 ] have been used as cathodes for zinc batteries. However, the hydrated Zn 2+ and H + usually result in large volumetric change and serious structural collapse of these inorganic compounds with the insertion of a large amount of hydrated Zn 2+ , [ 21–25 ] showing significant capacity fading and limited cycle life.…”

Interlayer Doping in Layered Vanadium Oxides for Low‐cost Energy Storage: Sodium‐ion Batteries and Aqueous Zinc‐ion Batteries

“…More importantly, it is obvious that the excessive transition metal ions could precipitate and reduce to the high conductivity metal particles (such as Cu, Ag, etc.) during the process of discharge (Figure 2d) [12,50,51] . Although such effect of the conductive network constructed by this method is more significant and lasting, the intrinsic structure collapse of the electrode caused by cation precipitation is partially irreversible, ultimately reducing the comprehensive electrochemical performances.…”

“…On the other hand, the unique electronic characteristics endow them with considerable pseudocapacitance behaviour especially in aqueous systems (such as more than 400 mAh g −1 of V 6 O 13 in AZIBs) [7] . Furthermore, most vanadium‐based oxides, including the VO 2 , [8,9] V 2 O 5 , [10] V 3 O 7 , [11] MV 2 O 6 , [12] M 3 V 2 O 8 , [13] etc. with layered structure, could allow interlayered 2D diffusion owing to the open framework [14,15] .…”

Zinc–Organic Battery with a Wide Operation‐Temperature Window from −70 to 150 °C

“…Rechargeable zinc batteries using mild aqueous electrolytes are attracting extensive attention owing to the low cost, nontoxicity,high safety,high capacity,and low potential of the Zn anode. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Recently,v arious cathode materials,s uch as MnO 2 , [18][19][20][21][22][23] vanadium oxides, [24][25][26][27][28][29][30][31][32][33] and hexacyanoferrate, [34][35][36][37] have been coupled with aZ na node to build aqueous Zn batteries,w hich show promising electrochemical performance.U nfortunately,t he achieved performances are still far from those required for practical applications.Ithas been demonstrated that the cathodic reaction in arechargeable Zn battery is based on reversible Zn 2+ and/or H + insertion in the host materials (i.e., MnO 2 ,V O 5 ,o rhexacyanoferrate). However,t he insertion/extraction of the hydrated Zn 2+ (i.e., [Zn(H 2 O) 6 ] 2+ )a nd H + (i.e., H 3 O + )g enerally leads to the structure collapse of host materials in the cathode, [12,13,18] which greatly limits the cyclelife of rechargeable Zn batteries.…”