Ultralong cycle stability of aqueous zinc-ion batteries with zinc vanadium oxide cathodes

Abstract

Rechargeable aqueous zinc-ion batteries are promising candidates for large-scale energy storage but are plagued by the lack of cathode materials with both excellent rate capability and adequate cycle life span. We overcome this barrier by designing a novel hierarchically porous structure of Zn-vanadium oxide material. This Zn0.3V2O5·1.5H2O cathode delivers a high specific capacity of 426 mA·h g−1 at 0.2 A g−1 and exhibits an unprecedented superlong-term cyclic stability with a capacity retention of 96% over 20,000 cycles at 10 A g−1. Its electrochemical mechanism is elucidated. The lattice contraction induced by zinc intercalation and the expansion caused by hydronium intercalation cancel each other and allow the lattice to remain constant during charge/discharge, favoring cyclic stability. The hierarchically porous structure provides abundant contact with electrolyte, shortens ion diffusion path, and provides cushion for relieving strain generated during electrochemical processes, facilitating both fast kinetics and long-term stability.

Layered Ca0.28MnO2·0.5H2O as a High Performance Cathode for Aqueous Zinc‐Ion Battery

“…According to the literature, the Zn 2+ ions insertion will cause a lattice contraction due to the effect of interlayer electrostatic attraction and the expulsion of water from the interlayer, while the hydrated H + ions insertion will result in lattice expansion owing to the large hydration radius. [ 22 ] The two opposite effects cancel each other out, and maintain constant layer spacing during the charge/discharge cycles. There are other two types of lattice fringes in the discharge products, corresponding to (150) d = 0.26 nm plane of ZnSO 4 ·3Zn(OH) 2 ·H 2 O and (−1−12) d = 0.28 nm plane of CaSO 4 ·2H 2 O, respectively.…”

Toward a Reversible Mn4+/Mn2+ Redox Reaction and Dendrite‐Free Zn Anode in Near‐Neutral Aqueous Zn/MnO2 Batteries via Salt Anion Chemistry

“…Aqueous batteries are favorable candidates owing to their intrinsic safety and environmental friendliness. [5][6][7] Among them, rechargeable Zn/MnO 2 batteries employing a mild aqueous electrolyte have attracted extensive attention, due to the high abundance and environmental compatibility of manganese dioxide, as well as the low cost, low redox potential (−0.76 V vs standard hydrogen electrode), and high capacity (820 mA h g −1 ) of Zn anode. [8,9] Several key challenges, however, have limited the practical application of rechargeable aqueous Zn/MnO 2 batteries.…”

Binder-Free Centimeter-Long V2O5 Nanofibers on Carbon Cloth as Cathode Material for Zinc-Ion Batteries

“…Several cathodes have been utilized for AZBs e.g., Prussian blue analogues [18][19][20], metal oxides (manganese and vanadium) [21][22][23], and zinc salts (Zn x M y O z ) where M is manganese (Mn) or vanadium (V) [24,25], and where the storage mechanism of Zn 2+ can either be conversion or intercalation mechanism. Intercalation compound provides the benefits of topotactic reaction that minimizes the changes in the structure and hence the large volumetric change [26].…”