Nano-Micro Letters (Dec 2021)

Fabricating Na/In/C Composite Anode with Natrophilic Na–In Alloy Enables Superior Na Ion Deposition in the EC/PC Electrolyte

  • Hui Wang,
  • Yan Wu,
  • Ye Wang,
  • Tingting Xu,
  • Dezhi Kong,
  • Yang Jiang,
  • Di Wu,
  • Yongbing Tang,
  • Xinjian Li,
  • Chun-Sing Lee

DOI
https://doi.org/10.1007/s40820-021-00756-7
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 15

Abstract

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Abstract In conventional ethylene carbonate (EC)/propylene carbonate (PC) electrolyte, sodium metal reacts spontaneously and deleteriously with solvent molecules. This significantly limits the practical feasibility of high-voltage sodium metal batteries based on Na metal chemistry. Herein, we present a sodium metal alloy strategy via introducing NaIn and Na2In phases in a Na/In/C composite, aiming at boosting Na ion deposition stability in the common EC/PC electrolyte. Symmetric cells with Na/In/C electrodes achieve an impressive long-term cycling capability at 1 mA cm−2 (> 870 h) and 5 mA cm−2 (> 560 h), respectively, with a capacity of 1 mAh cm−2. In situ optical microscopy clearly unravels a stable Na ion dynamic deposition process on the Na/In/C composite electrode surface, attributing to a dendrite-free and smooth morphology. Furthermore, theoretical simulations reveal intrinsic mechanism for the reversible Na ion deposition behavior with the composite Na/In/C electrode. Upon pairing with a high-voltage NaVPOF cathode, Na/In/C anode illustrates a better suitability in SMBs. This work promises an alternative alloying strategy for enhancing Na metal interfacial stability in the common EC/PC electrolyte for their future applications.

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