Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries.

Pan Han,Long Yao,Tao Yuan,Shiyou Zheng,Zhuo Han,Junhe Yang

doi:10.1186/s11671-016-1389-6

Abstract

Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g−1 at a current density of 100 mA g−1 with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g−1, the Cu/CF-800 anode can still deliver a capacity of 300 mAh g−1. This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li+ active positions by Cu nanoinclusion.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1389-6) contains supplementary material, which is available to authorized users.

Highlights

Rechargeable lithium-ion batteries are used extensively due to their high energy and power densities [1,2,3]
The elemental mapping images of Cu and C show that the Cu maps cover the C maps. This clearly indicates that the Cu is well dispersed in the Cu/CF-800 composites fabricated by in situ electrospun technique
HR-transmission electron microscope (TEM) image of Cu/CF-800 composite (Fig. 2d) shows that Cu nanoparticles with a size of ~10 nm are distributed in the carbon matrix

Summary

Introduction

Rechargeable lithium-ion batteries are used extensively due to their high energy and power densities [1,2,3]. New carbon-based anode materials such as carbon nanotube [5], nanofiber [6], nanobead [7], hollow nanosphere [8], graphene [9], and their hybrids [10] with enhanced Li+ storage capacities and high rate performance have been explored as alternative candidates for anode of Li-ion batteries. Many advanced techniques have been developed to fabricate flexible free-standing carbonous electrodes, for instance, vacuum filtration [11, 12], aerosol pyrolysis [13, 14], anodic oxidation [15], chemical vapor deposition [16], solgel deposition [17,18,19], sputtering [20], and spreading [21]. Several researchers have successfully applied the electrospinning technique for the fabrication of non-woven film electrodes in lithium-ion batteries [26,27,28,29]

Methods

Results

Conclusion