Fig. 7.

Electrochemical properties of the CYS-NiO/C, CYS-Ni/NiO/C, and hollow NiO microspheres for lithium-ion storage: a CV curves of the CYS-NiO/C microspheres, b 1st charge/discharge curves at the current density of 1.0 A g⁻¹, c cycling performance at the current density of 1.0 A g⁻¹, d rate performance of the CYS-NiO/C microspheres, and e long-term cycling performance of the CYS-NiO/C microspheres at the current density of 2.0 A g⁻¹