Bivalence Mn5O8 with hydroxylated interphase for high-voltage aqueous sodium-ion storage.

Academic Article

Abstract

  • Aqueous electrochemical energy storage devices have attracted significant attention owing to their high safety, low cost and environmental friendliness. However, their applications have been limited by a narrow potential window (∼1.23 V), beyond which the hydrogen and oxygen evolution reactions occur. Here we report the formation of layered Mn5O8 pseudocapacitor electrode material with a well-ordered hydroxylated interphase. A symmetric full cell using such electrodes demonstrates a stable potential window of 3.0 V in an aqueous electrolyte, as well as high energy and power performance, nearly 100% coulombic efficiency and 85% energy efficiency after 25,000 charge-discharge cycles. The interplay between hydroxylated interphase on the surface and the unique bivalence structure of Mn5O8 suppresses the gas evolution reactions, offers a two-electron charge transfer via Mn2+/Mn4+ redox couple, and provides facile pathway for Na-ion transport via intra-/inter-layer defects of Mn5O8.
  • Authors

  • Shan, Xiaoqiang
  • Charles, Daniel S
  • Lei, Yinkai
  • Qiao, Ruimin
  • Wang, Guofeng
  • Yang, Wanli
  • Feygenson, Mikhail
  • Su, Dong
  • Teng, Xiaowei
  • Publication Date

  • November 15, 2016
  • Published In

    Digital Object Identifier (doi)

    Start Page

  • 13370
  • Volume

  • 7
  • Issue

  • 1