Flash Synthesis of Uniform Tin Modified Carbon Skeleton as Stable Anode for Sodium Metal Batteries

Abstract

Sodium metal, with abundance resources and high theoretical specific capacity of 1165 mAh g-1, is the significant anode for sodium metal batteries (SMBs). However, sodium anode still suffers from the inhomogeneous and dendritic sodium deposition during the plating/stripping. Here, a flash synthesis of uniform tin (Sn) nanocluster modified carbon skeleton (J800-Sn/C) are proposed as sodium host to inhibits the formation of dendrite and large volume change of sodium anode. The effect of the size and distribution of Sn particles on the sodium deposition behavior has been detail insight. The carbon skeleton with uniform distributed Sn nanocluster generates a positive effect on the homogeneous sodium deposition, which can provide wide distributed nucleation sites and promote the formation of granular sodium metal grown alone the film direction. On account of the abundant nucleation sites, the J800-Sn/C electrode reveals excellent cycling stability of more than 1000 h at a current density of 3 mA cm-2 with sodium capacity of 3 mAh cm-2. The full cell operates under the harsh condition (high mass loading of 1.5 mAh cm-2 cathode and low N/P ratio of 0.66) demonstrating specific capacity of 108 mAh g-1, with a high-capacity retention of 95% after 250 cycles, which enable dendrites-free SMBs and pave the way for designing higher sodiophilic sodium host.

Keywords: Tin, Carbon film, sodium metal batteries, dendrite free