Binder-free C@NiCo2O4 on Ni foam with ultra-stable pseudocapacitive lithium ion storage

• Published in: Nanotechnology Vol. 30; no. 12; p. 125402
• Main Authors: Zhang, Jie, Chu, Ruixia, Chen, Yanli, Jiang, Heng, Zeng, Yibo, Zhang, Ying, Huang, Nay Ming, Guo, Hang
• Format: Journal Article
• Language: English
• Published: IOP Publishing 22.03.2019
• Subjects: carbon coating; electrodeposition; pseudocapacitance
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/aafa25

Carbon-coated nickel cobaltate on nickel foam (C@NCO@NF) with stable pseudocapacitive lithium storage capacity was prepared via a two-step strategy. NiCo hydroxide was initially grown on Ni foam via electrodeposition. Subsequent glucose soaking and annealing converted the intermediate into C@NCO@NF. Carbon coating could significantly improve the cycling stability and rate performance of the binder-free anode. The C@NCO@NF electrode could stably deliver a reversible capacity of 513 mAh g−1 after 500 cycles at a current density of 500 mA g−1. It could even stably cycle at a high current density of 5000 mA g−1 for 3000 cycles, with a reversible capacity of 115 mAh g−1. Kinetic analysis revealed that surface-controlled pseudocapacitance plays a dominant role in the lithium ion storage. Improved electrochemical performance is attributed to the synergetic effect of pseudocapacitance and carbon coating.