Template directed hydrothermal synthesis of flowerlike NiSex/C composites as lithium/sodium ion battery anodes

• Published in: Journal of materials science Vol. 55; no. 8; pp. 3495 - 3506
• Main Authors: Zhao, Chenhao, Shen, Zhen, Tu, Fengzhang, Hu, Zhibiao
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-03-2020
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Energy Materials; Materials Science; Polymer Sciences; Solid Mechanics
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-019-04200-5

Transition metal selenides nanoparticles/carbon composites have been one of the promising lithium/sodium ion battery anodes. In the present study, NiSe
x
nanoparticles encapsulated into microporous flowerlike carbon have been prepared by a hydrothermal route directed by the flowerlike Ni/C composite template. In a low hydrothermal temperature (i.e., 120 °C), the metallic Ni nanoparticles are transformed into Ni
0.85
Se, which has an average particle size of ~ 13.02 nm. The selenization degree and particle size can be obviously improved at a higher hydrothermal temperature (i.e., 160 or 180 °C), accompanying with the decrease in carbon content, and partial Ni
0.85
Se nanoparticles have been transformed into NiSe
2
. As anode of lithium ion batteries, the NiSe
x
obtained at 180 °C (i.e., 180 °C-NiSe) can deliver a higher discharge capacity (e.g., 851.0 mA h g
−1
after 100 cycles at 0.2 A g
−1
) and better cycling stability compared with the low temperature obtained sample. However, the rate capability and sodium ion storage performance of 120 °C-Ni
0.85
Se are better than the 180 °C-NiSe
x
, and a discharge capacity of 326.5 mA h g
−1
can be reached at a high rate of 5 A g
−1
for 120 °C-Ni
0.85
Se. Also, a high capacity retention ratio of 64.3% after 100 cycles can be reached for 120 °C-Ni
0.85
Se as sodium ion battery anode. The different electrochemical performance can be attributed to the decreased particle size.