Constructing ultrastable electrode/electrolyte interface for rapid potassium ion storage capability via salt chemistry and interfacial engineering

Constructing ultrastable electrode/electrolyte interface for rapid potassium ion storage capability via salt chemistry and interfacial engineering

Graphene

Electrolytes

Tin compounds

Oxide minerals

Titanium dioxide

Anodes

Charge transfer

Potassium

Layered semiconductors

Diffusion coatings

IV-VI semiconductors

Conversion/alloying anode materials exhibiting high K storage capacities suffer from large volume variations and unstable electrode/electrolyte interfaces upon cycling. Herein, taking SnS/reduced graphene oxide (SnS/rGO) anodes as an example, the electrochemical performance of SnS/rGO could significantly be improved via employing potassium bis(fluorosulfonyl)imide (KFSI) salt in electrolytes and ultrathin TiO2 coating. KF-rich inorganic layer was demonstrated to help form robust SEI layer, which could suppress the side reactions to increase the Coulombic efficiency. The formed potassiated KxTiO2 coating layer was constructed to boost charge transfer capability and K-ion diffusion kinetics. The as-prepared SnS/rGO@TiO2-20 electrode in KFSI electrolyte delivers the high CE of 99.1% and 424 mAhg1 after 200 cycles with an ultrahigh capacity retention of 98.5%. [Figure not available: see fulltext.]. 2021, Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature.

3

15

Nano Research

2022

Wen, Sheng

Gu, Xin

Ding, Xiangwei

Zhang, Li

Dai, Pengcheng

Li, Liangjun

Liu, Dandan

Zhang, Wenchao

Zhao, Xuebo

Guo, Zaiping

2083-2091

journalArticle

19980124

10.1007/s12274-021-3830-0