Graphdiyne oxide for aqueous zinc ion full battery with ultra-long cycling stability

Abstract

Zn metal has been regarded as an ideal anode material for rechargeable aqueous Zn ion batteries (ZIBs) due to its high specific capacity, abundance, safety, and low cost. However, the application of ZIBs is being seriously hindered by the uneven plating/stripping of Zn on the anodes. Such serious issues are leading to enlarged polarization or even cell failure. Herein, we develop a new strategy to alleviate these issues, in which the hydrophilic and porous graphdiyne oxide (GDYO) is used for modifying Zn anode (Zn-GDYO) to fabricate a Zn-GDYO//ZnVO full cell with ultra-long cycling stability. The functional GDYO layer displays a significant synergy effect, which not only results in relatively uniform electrolyte flux but also increases the nucleation sites, thereby promotes uniform planar Zn deposition. The Zn-GDYO//Zn-GDYO symmetrical cell shows reduced overpotential from 75 mV to 106 mV and dendrite-free plating/stripping with a 10-fold enhancement in running ultra-long lifetime over 3000 h, compared to the bare Zn at 0.1 mA cm−2. Furthermore, as the anode of the Zn-GDYO//ZnVO full cell, the cycling performance of Zn-GDYO electrode is up to 1200 cycles with the capacity retention of 94.5% (267.3 vs 252.5 mA h g−1) and Coulombic efficiency (CE) is above 99% at 1 A g−1.