Monodisperse V2O5 microspheres with a porous structure were synthesized by a very simple hydrolysis method and subsequent reduction/oxidation treatment at high temperatures. The porous V2O5 used as a cathode material for lithium-ion batteries (LIBs) shows a stable and highly reversible capacity. It also shows excellent low-temperature behavior with a reversible capacity of 102 mA h g−1 at −20 °C. The excellent performance can be attributed to the porous structure of the V2O5 spheres, which are more electrochemically active due to a large interfacial contact area with the electrolyte. We believe the strategy of creating porosity may be extended to other electrode materials to improve the performance of lithium ion batteries.