Table 2 Comparative analysis of the results with literature data.

Co₃O₄/graphene hybrid anode in the form of nanoparticles whose average size did not exceed 5 nm.

Haegyeom Kim et al.⁵⁷

Tests for the study of the reversibility of the specific capacitance depending on the charge/discharge rate

It has been established that the Co₃O₄/graphene-based anode material provides a reversible capacity of more than 800 mAh*g⁻¹ at a speed of 200 mA*g⁻¹ in the voltage range from 3.0 to 0.001 V. It is also shown that the value of the reversible capacity remains at elevated densities current. At current speeds up to 1000 mA * g⁻¹, the anode material based on Co₃O₄/graphene has a reversible capacity of more than 550 mAh*g⁻¹, which is significantly higher than the capacity of modern graphite anodes.

Co₃O₄ nanostructures of nanoparticles, nanocubes, and hierarchical pompon-like microspheres

Guo B. et al.⁵⁸

Tests to determine the dependence of the change in specific discharge capacity on the number of cycles

During life tests, it was found that the pompon-like Co₃O₄ microspheres show the highest discharge capacity (980–1000 mAh*g⁻¹) and the longest life time as an anode material (more than 50 cycles).

Co₃O₄@graphene Composites

Baojun Li et al.⁵⁹

Tests to determine the dependence of the change in specific discharge capacity on the number of cycles.

As a result of tests, it was found that the performance of nanostructures during testing in the regime of 60 cycles showed good stability and charge/discharge rate. At the same time, CGC structures demonstrated improved intercalation properties of lithium ions, with a specific discharge capacity of 941 mAh*g⁻¹, in the first cycle and 740 мА mAh*g⁻¹, after 60 cycles (which corresponds to 88.3% of the initial value).

Arrays of Co₃O₄ Nanowires

Li Y. et al.⁶⁰

Tests for the study of the reversibility of the specific capacitance depending on the charge/discharge rate

During the life tests of arrays of oxide nanowires, it was found that at a current of 1 C, arrays of nanowires retain a capacitance of 700 mAh*g⁻¹ after 20 discharge/charge cycles. With an increase in the charge rate to 50 °C, the specific capacitance value remains within 50% of the initial value.

Co₃O₄ Hollow Microspheres

Wang, J. et al.⁶¹

Tests for the study of the reversibility of the specific capacitance depending on the charge/discharge rate

During life tests as anode materials, the hollow Co₃O₄ microspheres showed excellent throughput, good cycling performance and ultra-high specific capacity (1615.8 mAh*g⁻¹ at the 30th cycle). Superior performance in the casting process is ensured by a porous hollow multilayer microstructure.

The initial nanowires, as well as annealed at temperatures of 300 °C and 500 °C.

Our work

Tests for the study of the reversibility of the specific capacitance depending on the charge/discharge rate

It was established that the longest life time as a result of life tests was shown by oxide nanostructures for which the lifetime is more than 500 charge/discharge cycles, for the initial nanostructures and annealed at a temperature of 300 °C, the lifetimes are 297 and 411 cycles, respectively. The largest value of specific capacity at normal charge speed is observed for oxide nanostructures and is 235–240 mAh*g⁻¹, for initial and annealed at 300°С the value of specific capacity is 200–205 mAh*g⁻¹ and 220–225 mAh*g⁻¹, respectively.