Oxygen vacancy (V(o)) is important in the modification of electrode for rechargeable batteries.However,due to the scarcity of suitable preparation strategy with controllable V(o) incorporation,the impact of V(o) concentration on the electrochemical performances remains unclear.Thus,in this work,V(o)-V2O5-PEDOT (V(o)VP) with tunable V(o) concentration is achieved via a spontaneous polymerization strategy,with the capability of mass-production.The introduction of poly(2,3-dihydrothieno-1,4-dioxin) (PEDOT) not only leads to the formation of V(o) in V2O5,but it also results in a larger interlayer spacing.The as-prepared V(o)-V2O5-PEDOT-20.3％ with V(o) concentration of 20.3％ (denoted as V(o)VP-20) is able to exhibit high capacity of 449 mAh·g-1 at current density of 0.2 A·g-1,with excellent cyclic performance of 94.3％ after 6,000 cycles.It is shown in the theoretical calculations that excessive V(o) in V2O5 will lead to an increase in the band gap,which inhibits the electrochemical kinetics and charge conductivity.This is further demonstrated in the experimental results as the electrochemical performance starts to decline when V(o) concentration increases beyond 20.3％.Thus,based on this work,scalable fabrication of high-performance electrode with tunable V(o) concentration can be achieved with the proposed strategy.