V6O13 nanosheets were successfully synthesized via a facile hydrothermal synthesis combined with an appropriate heat treatment. The evolutions in crystallization, chemical composition, structure, and consequent electrochemical performances upon different hydrothermal routes were briefly discussed. The lithium battery using VO2(B), V6O13 or V6O12.3 compound as the positive electrode exhibited a high discharge capacity. It enabled us to further demonstrate the differences and resemblance between V6O13 and V6O12.3 cells.