Conductive single-walled carbon nanotubes synthesized using a Fe–Mo/MgO catalyst for LiNi0.5Co0.2Mn0.3O2 lithium-ion batteries

Abstract

Herein, single-walled carbon nanotubes (SWNTs) with few defects and high aspect ratios were fabricated using a MgO-loaded Fe–Mo alloy as a catalyst for catalytic cracking of methane at 1000 °C. The metal impurities in SWNTs were removed via acid washing, and a SWNT (slurry) conductive agent was prepared by adding a dispersant (polyvinylpyrrolidone) to SWNTs and subjected to ultrasonic dispersion. Additionally, the addition of 2 wt% SWNTs (slurry) to the LiNi_0.5Co_0.2Mn_0.3O₂ cathode was sufficient to form an electronically conductive network, which improved the electronic conductivity of the cathode and optimized the battery performance at high rate currents. The results show that batteries fabricated using SWNTs (slurry) as a conductive additive in the LiNi_0.5Co_0.2Mn_0.3O₂ cathode exhibit excellent conductivity, with a specific capacity of 174.05 mA h g⁻¹ at a first discharge at 0.1 C and a high specific discharge capacity of 112.5 mA h g⁻¹ at 5 C. Additionally, the capacity retention of 100 cycles at 0.5 C was 98.75%, and their charge transfer impedance was minimized.