Facile synthesis of SnSe2 nanoparticles supported on graphite nanosheets for improved sodium storage and hydrogen evolution
Liu, YH (Liu, Yuhan)[ 1 ] ; Xu, YF (Xu, Yifan)[ 1 ] ; Han, Y (Han, Yu)[ 1 ] ; Zhang, ZZ (Zhang, Zhuangzhuang)[ 1 ] ; Xu, JY (Xu, Jingyi)[ 1 ] ; Du, YC (Du, Yichen)[ 1 ] ; Bao, JC (Bao, Jianchun)[ 1 ] ; Zhou, XS (Zhou, Xiaosi)[ 1 ]*（周小四）
[ 1 ] Nanjing Normal Univ, Jiangsu Key Lab New Power Batteries, Jiangsu Collaborat Innovat Ctr Biomed Funct Mat, Sch Chem & Mat Sci, Nanjing 210023, Jiangsu, Peoples R China
JOURNAL OF POWER SOURCES，201910,436
SnSe2 attract enormous attention in sodium-ion batteries since it has a high theoretical specific capacity of 756 mAh g(-1). However, the large volume expansion of SnSe2 during Na+ insertion/extraction processes seriously affects the cyclic stability of SnSe2-based electrodes. Herein, 5 nm SnSe2 nanoparticles supported on the graphite nanosheets are synthesized by two-step high-energy ball milling to obtain SnSe2/graphite nanosheet nano composite. By virtue of the ultrafine SnSe2 nanoparticles and the porous carbon skeleton constructed by highly conductive graphite nanosheets, the as-obtained SnSe2/graphite nanosheet nanocomposite presents a high specific capacity of 638.6 mAh g(-1) at 200 mA g(-1), excellent rate capacity of 517.8 mAh g(-1) at 5 A g(-1), and ultralong cyclic life (252.9 mAh g(-1) after 4000 cycles at 2 A g(-1)), which are superior to the previously reported SnSe2-based composites. Ex-situ X-ray diffraction, Raman mapping, high-resolution transmission electron microscope, and X-ray photoelectron spectroscopy characterizations show that the crystal structure of SnSe2 is reversible during sodium ions insertion/extraction processes and the distribution of SnSe2 nanoparticles on graphite nanosheets remains uniform. Moreover, this nanocomposite can not only be used as a high-performance anode for sodium-ion full cells, but also as an improved electrocatalyst for hydrogen evolution reaction.