3D Sodiophilic Ti3C2MXene@g-C3N4Hetero-Interphase Raises the Stability of Sodium Metal Anodes
Publication Name
ACS Nano
Abstract
Owing to several advantages of metallic sodium (Na), such as a relatively high theoretical capacity, low redox potential, wide availability, and low cost, Na metal batteries are being extensively studied, which are expected to play a major role in the fields of electric vehicles and grid-scale energy storage. Although considerable efforts have been devoted to utilizing MXene-based materials for suppressing Na dendrites, achieving a stable cycling of Na metal anodes remains extremely challenging due to, for example, the low Coulombic efficiency (CE) caused by the severe side reactions. Herein, a g-C3N4layer was attached in situ on the Ti3C2MXene surface, inducing a surface state reconstruction and thus forming a stable hetero-interphase with excellent sodiophilicity between the MXene and g-C3N4to inhibit side reactions and guide uniform Na ion flux. The 3D construction can not only lower the local current density to facilitate uniform Na plating/stripping but also mitigate volume change to stabilize the electrolyte/electrode interphase. Thus, the 3D Ti3C2MXene@g-C3N4nanocomposite enables much enhanced average CEs (99.9% at 1 mA h cm-2, 0.5 mA cm-2) in asymmetric half cells, long-term stability (up to 700 h) for symmetric cells, and stable cycling (up to 800 cycles at 2 C), together with outstanding rate capability (up to 20 C), of full cells. The present study demonstrates an approach in developing practically high performance for Na metal anodes.
Open Access Status
This publication is not available as open access
Volume
16
Issue
10
First Page
17197
Last Page
17209
Funding Number
MOE2018-T2-2-095
Funding Sponsor
Ministry of Education - Singapore