Water-in-Salt Electrolyte Promotes High-Capacity FeFe(CN)6 Cathode for Aqueous Al-Ion Battery

Anxing Zhou; Liwei Jiang; Jinming Yue; Yuxin Tong; Qiangqiang Zhang; Zejing Lin; Binghang Liu; Chuan Wu; Liumin Suo; Yong-Sheng Hu; Hong Li; Liquan Chen

doi:10.1021/acsami.9b14149

Water-in-Salt Electrolyte Promotes High-Capacity FeFe(CN)₆ Cathode for Aqueous Al-Ion Battery

ACS Appl Mater Interfaces. 2019 Nov 6;11(44):41356-41362. doi: 10.1021/acsami.9b14149. Epub 2019 Oct 23.

Authors

Anxing Zhou^{1

2}, Liwei Jiang^{1

2}, Jinming Yue^{1

2}, Yuxin Tong^{1

2}, Qiangqiang Zhang^{1

2}, Zejing Lin^{1

2}, Binghang Liu^{1

2}, Chuan Wu³, Liumin Suo^{1

2}, Yong-Sheng Hu¹, Hong Li¹, Liquan Chen¹

Affiliations

¹ Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Devices, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China.
² Center of Materials Science and Optoelectronics Engineering , University of Chinese Academy of Sciences , Beijing 100049 , China.
³ School of Materials Science and Engineering , Beijing Institute of Technology , Beijing 100081 China.

PMID: 31603299
DOI: 10.1021/acsami.9b14149

Abstract

Prussian blue analogues (PBAs) are considered to be ideal multivalent cation host materials due to their unique open-framework structure. In aqueous solution, however, the PBAs' cathodes have a low reversible capacity limited by the single electrochemical group Fe(CN)₆^3- and high crystal water content. They also suffer from fast cycle fading, resulting from significant oxygen/hydrogen evolution and cathode dissolution. In this work, a high-capacity PBA-type FeFe(CN)₆ cathode with double transition metal redox sites is successfully demonstrated in 5 m Al(CF₃SO₃)₃ Water-in-Salt electrolyte (Al-WISE). Due to Al-WISE having a wide electrochemical window (2.65 V) and low dissolution of the cathode, our PBA cathode exhibits a high discharge capacity of 116 mAh/g and the superior cycle stability >100 cycles with capacity fading of 0.39% per cycle.

Keywords: Al-ion battery; Al-ion cathode; Prussian blue analogues; Water-in-Salt; aqueous battery; aqueous electrolyte; concentrated electrolyte.