Revealing the Impact of Oxygen Dissolved in Electrolytes on Aqueous Zinc-Ion Batteries.

Lijun Su,Bao Liu,Xingbin Yan,Jianing Meng,Lingyang Liu

doi:10.1016/j.isci.2020.100995

Abstract

SummaryAqueous zinc-ion batteries (ZIBs) are promising low-cost and high-safety energy storage devices. However, their capacity decay especially at the initial cyclic stage is a serious issue. Herein, we reveal that the dissolved oxygen in aqueous electrolyte has significant impact on the electrochemistry of Zn anode and ZIBs. After removing oxygen, the symmetrical set-up of Zn/Zn is capable of reversible plating/stripping with a 20-fold lifetime enhancement compared with that in oxygen enrichment condition. Taking aqueous Zn-MnO2 battery as an example, although the presence of oxygen can contribute an extra capacity over 20% at the initial cycles due to the electrocatalytic activity of MnO2 with oxygen, the corrosion of Zn anode can be eliminated in the oxygen-free circumstance and thus offering a better reversible energy storage system. The impact of the dissolved oxygen on the cycling stability also exists in other ZIBs using vanadium-based compounds, Birnessite and Prussian blue analog cathodes.

Highlights

Aqueous zinc-ion batteries (ZIBs) have gained more and more attention mainly due to their low cost as well as high safety (Parker et al, 2017; Zheng et al, 2019), and significant research progress has been achieved in designing aqueous ZIBs with Zn anode and various cathode materials (Trocoliand La Mantia, 2015; Sun et al, 2017; Pan et al, 2018; Wan et al, 2019)
We reveal that the dissolved oxygen in aqueous electrolyte has significant impact on the electrochemistry of Zn anode and ZIBs
The symmetrical set-up of Zn/Zn is capable of reversible plating/stripping with a 20-fold lifetime enhancement compared with that in oxygen enrichment condition

Summary

Introduction

Aqueous zinc-ion batteries (ZIBs) have gained more and more attention mainly due to their low cost as well as high safety (Parker et al, 2017; Zheng et al, 2019), and significant research progress has been achieved in designing aqueous ZIBs with Zn anode and various cathode materials (Trocoliand La Mantia, 2015; Sun et al, 2017; Pan et al, 2018; Wan et al, 2019). Taking the reported ZIBs using the most typical ZnSO4 aqueous electrolytes as examples, whether the cathode material is vanadium oxides (Wan et al, 2018; Yang et al, 2018), manganese oxides (Mondoloni et al, 1992; Xu et al, 2012; Alfaruqi et al, 2015a, 2015b), Prussian blue analog materials (Zhang et al, 2015), and so on, all suffer significant capacity decay in the initial cycling stage (Table S1) (Fang et al, 2018; Song et al, 2018) Such decay was mainly explained because of the dissolution of cathode materials into the bulk electrolytes as well as the formation of Zn dendrite (Lee et al, 2014, 2016; Boeun et al, 2015; Mainar et al, 2018; Yi et al, 2018; Zhao et al, 2019a, 2019b). The study on the influence of the dissolved oxygen in electrolytes on the electrochemical properties of aqueous ZIBs is rare to date

Results

Discussion

Conclusion