Oxygen vacancies induced by vanadium doping regulate electronic structure of molybdenum dioxide for efficient lithium storage

As an efficient lithium-ion-storage material, molybdenum dioxide (MoO2) 2 ) is still troubled by poor intrinsic electron conductivity and large volume expansion, leading to suboptimal cycle life and rate performance. Heteroatoms doping strategy becomes a prevalent method to address the above problems. In this work, hierarchical porous vanadium-doped MoO2@polyvinyl 2 @polyvinyl pyrrolidone-derived carbon (V-PCM) composite was prepared through a metal oxyacid salts-confined pyrolysis strategy, in which V-doped MoO2 2 nanoparticles are successfully encapsulated inside the PVP-derived carbon structure. The doping of V atoms into MoO2 2 can regulate its electronic structure and induce the formation of oxygen vacancy, resulting in enhanced conductivity and improved reaction kinetics. In addition, the hierarchical porous carbon framework with sufficient spaces can not only inhibit the aggregation of V-MoO2 2 nanoparticles, but also alleviate the mechanical stress caused by the lithium insertion process. Accordingly, an optimized V-PCM electrode manifests superior lithium storage properties including a high initial specific capacity (1761.0 mAh g- 1 at 0.1 A g-- 1 ), a remarkable rate capability (516.7 mAh g- 1 at 2.0 A g-- 1 ), and excellent long-term cycle stability (530.0 mAh g- 1 at 1.0 A g- 1 after 1000 cycles). This work demonstrates a feasible metal atom doping method that enables the preparation of high-performance anode materials for lithium-ion batteries.