Abstract
Carbonaceous materials represent the dominant choice of materials for anodic lithium storage in many energy storage devices. Nevertheless, the nonpolar carbonaceous materials offer weak adsorption toward Li+ that largely denies the high-rate Li+ storage. Herein, the atomic Fe sites decorated carbon nanofibers (AICNFs) facilely produced by electrospinning are reported for kinetically accelerated Li* storage. Theoretical calculation reveals that the atomic Fe sites possess coordination unsaturated electronic configuration, enabling suitable bonding energy and facilitated diffusion path of Li+. As a result, the optimal structure displays a high capacitive contribution up to 95.9% at a scan rate of 2.0 mV.s(-1). In addition, ultrahigh capacity retention of 97% is afforded after 5,000 cycles at a current density of 3 A.g(-1). Moreover, the interlaced fiber structure enabled by electrospinning benefits structural stability and improved conductivity even at thick electrodes, thus allowing a high areal capacity of 1.76 mAh.cm(-2) at a loading of 8 mg.cm(-2). Because of these structure and performance merits, the lithium-ion capacitor containing the AICNF-based anode delivers a high energy density and large power density.