Abstract: The control of the morphology and structure has an important influence on the electrochemical properties of materials. In this work, NiCo₂O₄ samples with different morphologies and structures were synthesized by solvothermal method combined with calcination at different solvent ratios and temperatures. The phase composition and morphology of the samples were characterized by XRD, SEM and TEM et al, and the electrochemical performance was further studied. The results show that the sample is hollow sea urchin-like NiCo₂O₄, when the volume ratio of water to ethanol is 1∶1. With the increase of the content of water, the morphology gradually changes to regular central radial needle-like morphology, and there is a second phase substance. Under the condition of the volume ratio of water to ethanol is 1∶1, with the increase of temperature, the morphology mainly changes from fluffy ball to a flower-like, sea urchin-like, and center-radiating needle, while the phases of samples are pure NiCo₂O₄. The sample synthesized at 90℃ exhibits better electrochemical performance. The specific capacitance is up to 1287.5 F·g⁻¹ at a current density of 1 A·g⁻¹. The specific capacitance retention rate reaches 59.4% with the scan rate changes from 20-100 mV·s⁻¹, and the specific capacitance retention rate is up to 80.1% after 1500 cycles. In addition, the whole electrochemical reaction is dominated by the diffusion-controlled process.