Effect of carbon and N-doped carbon nanomaterials on the electrochemical performance of lithium titanate-based composites

Electrochimica Acta. 2020. Vol. 364. Article 137330.

Stenina Irina A, Shaydullin R., Desyatov A., Kulova T., Yaroslavtsev Andrey B

The composite nanomaterials based on hydrothermally synthesized Li4Ti5O12 and carbon
nanotubes (CNTs) or carbon nanoflakes, including N-doped ones were prepared. The composites
were investigated by X-ray powder diffraction, TEM, SEM, Raman spectroscopy, BET, dcmeasurements,
galvanostatic charge-discharge tests, cyclic voltammetry and electrochemical
impedance spectroscopy. Carbon nanomaterial addition provides the formation of a highly
conductive 3D network leading to a significant increase in the electrical conductivity and
excellent electrochemical performance of the composites at high charge-discharge rates. At a
current density of 6400 mA/g (~37C), the reversible discharge capacities of Li4Ti5O12 and its
composites with CNTs and N-doped CNTs are 60, 92, and 96 mAh/g, respectively. They exhibit
a remarkable long-term cycling stability: less than 0.034%, 0.013% and 0.005% loss per cycle
over 500 cycles, respectively. The results obtained by Raman spectroscopy, BET, and
electrochemical measurements suggest the interaction between polar fragments of the N-doped
carbon nanomaterials and Li4Ti5O12 surface.

Keywords: углеродные нанотрубки, carbon nanotubes, Nanocomposites, нанокомпозиты, Lithium titanate, lithium-ion batteries, Nitrogen-doped carbon nanomaterials, литий-ионные аккумуляторы, титанат лития