Physical mixtures of Si nanoparticles and carbon nanofibers as anode materials for lithium-ion batteries

Abstract

Silicon nanoparticles (Si NPs) were simply mixed with carbon nanofibers (CNFs) without any chemical process at various weight ratios, and the electrochemical properties of these nanoparticles as anode materials were investigated in lithium-ion batteries (LIBs). To study the effects of the physical incorporation of CNFs on the volumetric variations in Si NPs, the dilations of full cells were measured. The measured volumetric change of the anode using a mixture of Si NPs and CNFs was smaller than that calculated from the theoretical volumetric changes of Si and graphite. Although the reversible capacity of Si NPs faded sharply, the fading was mitigated by increasing the mixing ratio of CNFs. In particular, the Si NP/CNF mixture prepared at weight ratio retained a reversible capacity of >800 mAh/g with a capacity retention of 53.2% even after 100 cycles. CNFs alleviated stress and strain during the charge–discharge process even though there was no tight chemical bonding with Si NPs.

Composite Nanofibers as Advanced Materials for Li-ion, Li-O2 and Li-S Batteries

“…Li-ion, Li-sulfur, and Li-air batteries), sodium (Na) , magnesium (Mg), aluminum (Al) and zinc (Zn) batteries and supercapacitors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The popularity of these nanofibers stem from the many attributes such as; controllable fiber diameter, high surface areato-volume ratio, low density, and high pore volume [6,[19][20][21]. These properties make the nanofiber structure more advantageous when used in LIBs as they deliver a superior electrochemical properties; stable cycle performance, enhanced capacity, superior low temperature performance [21][22][23][24], compared to their powder, crystal, nanowire, thin film, etc.…”