The Zn₃V₃O8 was synthesized by solvothermal method combined with heat treatment using Zn(NO₃)₃ · 6H₂O and NH₄VO₃ as raw materials. The Zn₃V₃O8 was doped by Co2+ to form Zn2.88Co0.12V₃O8. The samples were characterized by X-ray diffraction and scanning electron microscopy techniques. Electrochemical tests showed that the initial discharge specific capacity for Zn2.88Co0.12V₃O8 was 640.4 mAh·g-1 when the current density was 100 mA·g-1, which was higher than that of pure Zn₃V₃O8 (563.5 mAh · g-1). After 80 cycles, the discharge specific capacity of Zn2.88Co0.12V₃O8 could maintain at 652.2 mAh · g-1, which was higher than that of pure Zn₃V₃O8 (566.8 mAh·g-1) under same condition. The Zn2.88Co0.12V₃O8 owned better rate performances than those of pure Zn₃V₃O8 also. The related modification mechanisms were discussed in this paper.