Boosting the Lithium-Ion Storage Performance of Perovskite SrxVO3-δ Via Sr Cation and O Anion Deficient Engineering.

Perovskite SrVO3 has been investigated as a promising lithium storage anode where the V cation plays the role of the redox center,combining excellent cycle stability and safe operating potential versus Li metal plating,with limited capacity.Here,we demonstrate the possibility to boost the lithium storage proper-ties,by reducing the non-redox active Sr cation content and fine-tuning the O anion vacancies while maintaining a non-stoichiometric SrxVO3-δ perovskite structure.Theoretical investigations suggest that Sr vacancy can work as favorable Li+storage sites and preferential transport channels for guest Li+ions,contributing to the increased specific capacity and rate performance.In contrast,inducing O anion vacancy in SrxVO3-δcan improve rate performance while compromising the specific capacity.Our exper-imental results confirm the enhancement of specific capacities by fine adjusting the Sr and O vacancies,with a maximum capacity of 444 mAh g-1 achieved with Sr0.63VO3-δ,which is a 37％increase versus sto-ichiometric SrVO3.Although rich defects have been induced,SrxVO3-δ electrodes maintain a stable per-ovskite structure during cycling versus a LiFePO4 cathode,and the full-cell could achieve more than 6000 discharge/charge cycles with 80％capacity retention.This result highlights the possibility to use the cation defective-based engineering approach to design high-capacity perovskite oxide anode materials.