Unraveling the effect of salt chemistry on long-durability high-phosphorus-concentration anode for potassium ion batteries
Journal
Nano Energy
Journal Volume
53
Pages
967-974
Date Issued
2018
Author(s)
Abstract
Phosphorus-based anode materials are of considerable interest for grid-scale energy storage systems due to their high theoretical capacity. Nevertheless, the low electrical conductivity of P, large volume changes during cycling, and highly-reactive phosphide surface are hindering their potential applications. Herein, outstanding long-term cycling stability with high retained potassium storage capacity (213.7 mA h g?1 over 2000 cycles) was achieved via the introduction of an alternative potassium bis(fluorosulfonyl)imide (KFSI) salt and by using a layered compound (GeP5) with a high phosphorus concentration as anode material. Fourier transform infrared spectroscopic mapping results suggest that KFSI salt helps to form an uniform solid electrolyte interphase (SEI) layer and reduces the side reactions at the electrode/electrolyte interface, thus enhancing the cycling performance. In-operando synchrotron X-ray diffraction analysis has revealed the synergistic reaction mechanisms of the K-P and K-Ge reactions. These findings indicate the enormous potential of phosphorus-based anodes for high-performance potassium ion batteries and can attract broad interest for regulating the SEI layer formation through manipulating the salt chemistry. ? 2018 Elsevier Ltd
Subjects
Durability; Germanium compounds; Ions; Phosphorus; Potassium; Secondary batteries; Solid electrolytes; X ray powder diffraction; Bis(fluorosulfonyl)imide; Electrode/electrolyte interfaces; Fourier transform infra reds; Phosphorus concentration; Potassium ions; Solid electrolyte interphase layer (SEI); Synchrotron x ray diffraction; Synergistic reactions; Anodes
SDGs
Type
journal article