Effects of the triangular hollow tubes structure and carbon coating on the lithium storage performances of Co3O4/NiO microspheres

Co3O4/NiO@C (CNOT@C) microspheres were synthesized via a facile solvothermal method and annealing treatment under an argon atmosphere. A high initial reversible specific capacity of 1469.7 mA h g−1 of CNOT@C was attained due to its high specific surface area from its unique triangular hollow tube morphology. These triangular hollow tubes relieved volume expansion from repeated cycling processes, with CNOT@C attaining a high reversible specific capacity of 694.9 mA h g−1 after 1000 cycles at 6000 mA g−1. Furthermore, excellent rate performance of CNOT@C was achieved due to its carbon layer coating, exhibiting a reversible specific capacity of 429.8 mA h g−1 at 10 000 mA g−1.