A 3D Hydroxylated MXene/Carbon Nanotubes Composite as a Scaffold for Dendrite-Free Sodium-Metal Electrodes |
| |
Authors: | Xin He Dr. Song Jin Licheng Miao Yichao Cai Yunpeng Hou Haixia Li Prof. Kai Zhang Dr. Zhenhua Yan Prof. Jun Chen |
| |
Affiliation: | Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin, 300071 China |
| |
Abstract: | Sodium metal is a promising anode, but uneven Na deposition with a dendrite growth seriously impedes its application. Herein, a fibrous hydroxylated MXene/carbon nanotubes (h-Ti3C2/CNTs) composite is designed as a scaffold for dendrite-free Na metal electrodes. This composite displays fast Na+/electron transport kinetics and good thermal conductivity and mechanical properties. The h-Ti3C2 contains abundant sodiophilic functional groups, which play a significant role in inducing homogeneous nucleation of Na. Meanwhile, CNTs provide high tensile strength and ease of film-forming. As a result, h-Ti3C2/CNTs exhibit a high average Coulombic efficiency of 99.2 % and no dendrite after 1000 cycles. The h-Ti3C2/CNTs/Na based symmetric cells show a long lifespan over 4000 h at 1.0 mA cm−2 with a capacity of 1.0 mAh cm−2. Furthermore, Na-O2 batteries with a h-Ti3C2/CNTs/Na anode exhibit a low potential gap of 0.11 V after an initial 70 cycles. |
| |
Keywords: | 3D composite scaffold sodiophilicity hydroxylated MXene long cycling life thermal conductivity |
|
|