Electrospinning-assisted construction of 3D LiFePO4@rGO/carbon nanofibers as flexible cathode to boost the rate capabilities of lithium-ion batteries

Rational design and construction of cathode materials with high ion transport coefficient and high electrical conductivity is of great importance for improving the reaction kinetics of Li-ion batteries (LIBs). Herein, we develop the three-dimensional (3D) LiFePO 4 @reduced graphene oxide/carbon nanofibers (LiFePO 4 @rGO/CNFs) to serve as flexible cathodes for LIBs. Through the electrospinning technique combined with the subsequent pyrolysis , the composite nanofiber precursors have been successfully converted into flexible electrodes . As demonstrated, the as-prepared electrodes present uniform nanofibers, in which the rGO sheets are evenly attached to CNFs , and LiFePO 4 nanoparticles are homogeneously distributed in CNFs. Benefited by the structural advantages and the improving conductivity, the optimum LiFePO 4 @rGO/CNFs cathode exhibits a high initial capacity of 167 mAh g −1 at 0.5 C, and maintains a reversible capacity of 150 mAh g −1 after 200 cycles at 1 C. Galvanostatic intermittent titration technique (GITT) shows that LiFePO 4 @rGO/CNFs has a high ion diffusion rate (8.82 × 10 −12  cm 2  s −1 ), further suggesting that such 3D structures are appropriate as cathode materials for LIBs. These findings demonstrate that the 3D continuously conductive network of LiFePO 4 composites is a promising cathode material for LIBs.