Electrospun Cu/Sn/C Nanocomposite Fiber Anodes with Superior Usable Lifetime for Lithium‐ and Sodium‐Ion Batteries

Abstract

Cu/Sn/C composite nanofibers were synthesized by using dual-nozzle electrospinning and subsequent carbonization. The composite nanofibers are a homogeneous amorphous matrix comprised of Cu, Sn, and C with a trace of crystalline Sn. The Li- and Na-ion storage performance of the Cu/Sn/C fiber electrodes were investigated by using cyclic voltammetry, galvanostatic cycling, and electrochemical impedance spectroscopy. Excellent, stable cycling performance indicates capacities of 490 and 220 mA h g(-1) for Li-ion (600 cycles) and Na-ion (200 cycles) batteries, respectively. This is a significant improvement over other reported Sn/C nanocomposite devices. These superior electrochemical properties could be attributed to the advantages of incorporating one-dimensional nanostructures into the electrodes, such as short electron diffusion lengths, large specific surface areas, ideal homogeneous structures for buffering volume changes, and better electronic conductivity that results from the amorphous copper and carbon matrix.

A review of nanofibrous structures in lithium ion batteries

“…The highest cycling stability of 490 mA h g À1 after 600 cycles, at a current density of 156 mA g À1 was achieved by incorporating amorphous Cu into Sn/CNF (Fig. 7), in which the Sn occurred both amorphously and as crystalline nanoparticles [194].…”

“…Dual-nozzle electrospinning process and formation mechanism of Cu/Sn/C nanofibers (adopted from Ref. [194]). at 100 mA g À1 current density [195].…”

Na‐Ion Batteries for Large Scale Applications: A Review on Anode Materials and Solid Electrolyte Interphase Formation

“…[201] However, the amorphous alloy exhibi ted a specific charge of around 100 mA h g −1 . Electrospun Cu/Sn/C amorphous fibers prepared by Kim et al [206] showed good cycle life, giving 220 mA h g −1 after 200 cycles. [203] Higher specific charge of 300 mA h g −1 for 30 cycles was obtained with a Sn 0.9 Co 0.1 alloy, which is composed by micrometer-sized porous cubes of small amounts of CoSn, Co 3 Sn 2 , and mainly unreacted Sn.…”

“…Several inactive elements toward Na, such as Co, [201][202][203] Fe, [203] Cu, [204][205][206][207] or Ni [208,209] have been recently proposed for MSn-based negative electrodes. The intermetallics can convert to M/Sn composites with M providing electrical conductivity and acting as a matrix to alleviate the strain produced by volume changes.…”

Carbon‐Based Alloy‐Type Composite Anode Materials toward Sodium‐Ion Batteries

“…As an anode, Fe 0.74 Sn 5 @RGO nanocomposite can achieve capacity retention three times that of the pristine, after 100 charge/discharge cycles . Similarly, other elements such as TiO 2 , SnO 2 , Cu, MoS 2 , and Sb accompanied with Sn encapsulated by carbonaceous matrix acting as a very good stress reliever during alloying mechanism resulted in outstanding anode composites for SIBs . During the last few years, several types of other carbonaceous materials have been explored like mesoporous carbon matrix (CMK‐3), natural wood fibers, N‐doped carbon fibers, carbon nanotubes (CNTs), carbon nanosphere, and graphite; thereby obtaining attractive coulombic efficiencies at different currents in SIBs.…”