Bi-Cation Electrolyte for a 1.7 V Aqueous Zn Ion Battery

Na Li; Guoqing Li; Changji Li; Huicong Yang; Gaowu Qin; Xudong Sun; Feng Li; Hui-Ming Cheng

doi:10.1021/acsami.9b20531

Bi-Cation Electrolyte for a 1.7 V Aqueous Zn Ion Battery

ACS Appl Mater Interfaces. 2020 Mar 25;12(12):13790-13796. doi: 10.1021/acsami.9b20531. Epub 2020 Mar 10.

Authors

Na Li¹, Guoqing Li¹, Changji Li², Huicong Yang², Gaowu Qin¹, Xudong Sun¹, Feng Li², Hui-Ming Cheng^{2

3}

Affiliations

¹ State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China.
² Shenyang National Laboratory for Materials Science, Institute of Metal Research Chinese Academy of Sciences, Shenyang 110016, China.
³ Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.

PMID: 32108465
DOI: 10.1021/acsami.9b20531

Abstract

Rechargeable aqueous zinc-ion batteries (ZIBs) are receiving increased attention because of their high safety and low cost. However, their practical application is plagued by their low energy density as a result of low output voltage and a narrow voltage window of aqueous electrolytes. Here, we explored a ZIB with a wider potential window using bication (1 M Al(CF₃SO₃)₃/1 M Zn(CF₃SO₃)₂) as the electrolyte and α-MnO₂ as the cathode, obtaining a discharge voltage of 1.7 V, ∼0.3 V higher than the value reported earlier. The resultant cell delivers a record high energy density of 448 W h kg^-1 (based on MnO₂ mass) and retains 100% capacity over 1000 cycles. The ion-storage mechanism and the role of Al³⁺ in enlarging the output voltage were elucidated. This research indicates the important role of using bications in improving the electrochemical performance of aqueous ZIBs, opening a new way to increase the energy density of aqueous energy storage devices.

Keywords: Al(CF3SO3)3; Zn−MnO2 battery; bication electrolyte; high energy density; high voltage.