Synthesis and Study of Cathode Materials Based on Carbon Nanotubes for Lithium-Ion Batteries
А. V. Shchegolkov, Ф. Ф. Комаров, М. С. Липкин, O. V. Milchanin, И. Д. Парфимович, А. V. Shchegolkov, A. V. Semenkova, A. V. Velichko, K. D. Chebotov, V. A. Nokhaeva
Abstract
Abstract This work presents a study of the conditions and possibilities for the intercalation of hexafluorophosphate anions into CNT-based electrodes. For this, cathodes based on CNTs synthesized on different catalysts (Co–Mo)/(Al2O3–MgO) and (Fe–Co)/2.1Al2O3 were produced. As a result, electrode materials were obtained at various concentrations of CNT/graphite: CNT-4F, CNT-6, and CNT-6F. The resulting electrodes were studied by cyclic voltammetry (CVA) in an electrolyte of a dissolved LiPF 6 salt based on EC : DEC (ethylene carbonate : diethylene carbonate) solvents (in the ratio 1 : 1 : 1) with an admixture of 3% VC at a sweep speed of 4 mV/s. On the basis of the obtained CVA dependences, the specific charge/discharge capacity of the electrodes CNT-4F, CNT-6, and CNT-6F was determined. The largest specific charge/discharge capacity calculated per mass of CNTs was 292 and 164.22 (mA h)/g for CNT-4/graphite electrodes, and the minimum specific charge/discharge capacity was 41.67 and 1.5 (mA h)/g for CNT-4 electrodes without graphite, respectively. Also, the dependences of the average electrode utilization coefficient on the charge time at constant current on the cycle number at a charge of 300 s were obtained. For chronoamperograms of individual steps of the СNT-6F electrode, the values of lithium diffusion coefficients were calculated.