Abstract:

Nickel-cobalt oxide is considered as a promising anode for lithium-ion battery, owing to its high specific capacity, simple synthesis process and high safety. However, like most transition metal oxide anode materials, nickel-cobalt oxide suffers from poor conductivity, easy agglomeration and large volume expansion in the charging and discharging process, causing an inferior cycling lifespan. Here we report a structure design that CoNiO₂ particles are ingeniously interlaced on carbon nanotubes by a simple solvothermal method. These nanotubes are irregularly intertwined to obtain an independent electrode structure with high electronic conductivity, which can also alleviate the notorious volume expansion. Consequently, the corresponding lithium-ion battery shows superior electrochemical performance. It provides a discharge capacity of 1213.7 mAh g⁻¹ at 0.5 A g⁻¹, and can be stable over 100 cycles with a capacity retention of 96.45%. Furthermore, the battery can also deliver a reversible capacity of 544.8 mAh g⁻¹ at the high current density 3 A g⁻¹. This work provides a unique idea for the performance improvement of nickel-cobalt oxide anode for lithium-ion batteries.

Key words: CoNiO₂, Carbon nanotubes, Solvothermal method, Electrochemical performance, Lithium-ion battery