Bimetallic CoNiSe2/C nanosphere anodes derived from Ni-Co-metal-organic framework precursor towards higher lithium storage capacity

Through uncomplicated carbonation process, a carbon-embedded CoNiSe 2 /C nanosphere was synthesized from Ni-Co-MOF (metal-organic framework) precursor whose controllable structure and synergistic effect of bimetallic Ni/Co brought CoNiSe 2 /C anodes with high specific surface area (172.79 m 2 /g) and outstanding electrochemical performance. CoNiSe 2 /C anodes obtained reversible discharge capacities of 850.9 mAh/g at 0.1 A/g after cycling for 100 cycles. In addition, CoNiSe 2 /C exhibits excellent cycle stability and reversibility in the rate test at a current density of 0.1-2.0 A/g. When the current density returns to 0.5 A/g for 150 cycles, its discharge ratio the capacity is 330.8 mAh/g. Electrochemical impedance spectroscopy (EIS) tests suggested that CoNiSe 2 /C anodes had a lower charge transfer impedance of 130.02 Q after 30 cycles. In-situ X-ray diffraction (XRD) tests confirmed the alloying mechanism of CoNiSe 2 /C which realized higher lithium storage capacity. This work affords substantial evidence for the extension of bimetallic selenides in secondary batteries, promoting the development of bimetallic selenides in anode materials for LIBs. (c) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

A carbon-embedded CoNiSe2/C nanosphere was synthesized through a simple carbonation process, resulting in high specific surface area (172.79 m2/g) and excellent electrochemical performance of the CoNiSe2/C anodes. After 100 cycles, the CoNiSe2/C anodes exhibited a reversible discharge capacity of 850.9 mAh/g at 0.1 A/g. The CoNiSe2/C also demonstrated remarkable cycle stability and reversibility in rate tests. In addition, in-situ X-ray diffraction tests confirmed the alloying mechanism of CoNiSe2/C, enabling higher lithium storage capacity.