Quicker and More Zn²⁺ Storage Predominantly from the Interface

Abstract

Aqueous zinc‐ion batteries are highly desirable for large‐scale energy storage because of their low cost and high‐level safety. However, achieving high energy and high power densities simultaneously is challenging. Herein, a VOx sub‐nanometer cluster/reduced graphene oxide (rGO) cathode material composed of interfacial VOC bonds is artificially constructed. Therein, a new mechanism is revealed, where Zn2+ ions are predominantly stored at the interface between VOx and rGO, which causes anomalous valence changes compared to conventional mechanisms and exploits the storage ability of non‐energy‐storing active yet highly conductive rGO. Further, this interface‐dominated storage triggers decoupled transport of electrons/Zn2+ ions, and the reversible destruction/reconstruction allows the interface to store more ions than the bulk. Finally, an ultrahigh rate capability (174.4 mAh g−1 at 100 A g−1, i.e., capacity retention of 39.4% for a 1000‐fold increase in current density) and a high capacity (443 mAh g−1 at 100 mA g−1, exceeding the theoretical capacities of each interfacial component) are achieved. Such interface‐dominated storage is an exciting way to build high‐energy‐ and high‐power‐density devices.

A Composite Material with Internal Hydrophilicity and External Stability as the Cathode of Aqueous Zinc-Ion Batteries Exhibiting Excellent Rate Performance and Energy Density at High Power Density

“…From 0.5 to 32 A g –1 , the capacity retention rate of the VO 2 -SDBS@rGO electrode is 77.6%, showing its excellent rate performance. The quicker and more Zn 2+ storage may be triggered by interface-dominated electrons and Zn 2+ ion storage between VO 2 and rGO . We also juxtapose the energy density and power density with some recently reported studies in Figure e.…”

“…For example, Lan et al studied the reduced graphene oxide (rGO)-modified FeVO 4 · n H 2 O@rGO cathode material, which has a fast electron transfer rate and excellent zinc ion storage performance. Moreover, the latest research has revealed an interface storage mechanism between VO x and rGO, which enables the interface to store more Zn 2+ . Therefore, improving the hydrophilicity internally and coating with rGO externally are predominant ideas to enhance the performance of ZIB electrodes.…”

“…Moreover, the latest research has revealed an interface storage mechanism between VO x and rGO, which enables the interface to store more Zn 2+ . 18 Therefore, improving the hydrophilicity internally and coating with rGO externally are predominant ideas to enhance the performance of ZIB electrodes.…”

A binder‐free bivalent manganese oxide cathode elective structure with high activity in aqueous zinc ion batteries

“…To date, various cathode materials, such as MnS, 8 VS 2 , 9 Na 3 V 2 (PO 4 ) 3 , 10 LiV 3 O 8 , 11 Zn 0.25 V 2 O 5. nH 2 O, 12 V 2 O 5 , 13,14 VO 2 , 15 VO x @rGO, 16,17 Mg x MnO 2 , 18 MnO 2 , 19,20 and Mn 3 O 4 , 21 have been explored for AZIBs. Among them, manganese oxides are highly attractive cathode candidates for AZIBs because they can be easily prepared using affordable Mn resources and oxygen from the atmosphere.…”

Fe‐Ion Bolted VOPO4∙2H2O as an Aqueous Fe‐Ion Battery Electrode

“…Global prosperity demands energy security that entails reliable energy storage systems with inerrable safety. [1][2][3][4] Recently, aqueous batteries that employ metal anodes have attracted much attention. [5][6][7][8] The emerging aqueous batteries differ from the well-established alkaline metal batteries, many of which are primary batteries; [1] new aqueous batteries often employ neutral or mildly acidic electrolytes that exhibit a wider electrochemical stability window.…”