Hydrophilic and Conductive Carbon Nanotube Fibers for High-Performance Lithium-Ion Batteries.

Carbon nanotube fiber (CNTF) is a highly conductive and porous platform to grow active materials of lithium-ion batteries (LIB). Here, we prepared SnO2@CNTF based on sulfonic acid-functionalized CNTF to be used in LIB anodes without binder, conductive agent, and current collector. The SnO2 nanoparticles were grown on the CNTF in an aqueous system without a hydrothermal method. The functionalized CNTF exhibited higher conductivity and effective water infiltration compared to the raw CNTF. Due to the enhanced water infiltration, the functionalized CNTF became SnO2@CNTF with an ideal core-shell structure coated with a thin SnO2 layer. The specific capacity and rate capability of SnO2@-functionalized CNTF were superior to those of SnO2@raw CNTF. Since the SnO2@CNTF-based anode was free of a binder, conductive agent, and current collector, the specific capacity of the anode studied in this work was higher than that of conventional anodes.