Ultralong-Lifespan Magnesium Batteries Enabled by the Synergetic Manipulation of Oxygen Vacancies and Electronic Conduction

• Published in: ACS applied materials & interfaces 2021-03, Vol.13 (10), p.12049-12058
• Main Authors: Wu, Dongzheng, Wen, Zhipeng, Jiang, Hongbei, Li, Hang, Zhuang, Yichao, Li, Jiyang, Yang, Yang, Zeng, Jing, Cheng, Jun, Zhao, Jinbao
• Format: Article
• Language: English
• Subjects: Energy, Environmental, and Catalysis Applications
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c00170

As a potential next-generation energy storage system, rechargeable magnesium batteries (RMBs) have been receiving increasing attention due to their excellent safety performance and high energy density. However, the sluggish kinetics of Mg2+ in the cathode has become one of the main bottlenecks restricting the development of RMBs. Here, we introduce oxygen vacancies to spherical NaV6O15 cross-linked with carbon nanotubes (CNTs) (denoted as SNVO X -CNT) as a cathode material to achieve an impressive long-term cycle life of RMBs. The introduction of oxygen vacancies can improve the electrochemical performance of the NaV6O15–X cathode material. Besides, owing to the introduction of CNTs, excellent internal/external electronic conduction paths can be built inside the whole electrode, which further achieves excellent electrochemical performance. Moreover, such a unique structure can efficiently improve the diffusion kinetics of Mg2+ (ranging from 1.28 × 10–12 to 7.21 × 10–12 cm2·s–1). Simulation calculations further prove that oxygen vacancies can cause Mg2+ to be inserted in NaV6O15–X . Our work proposes a strategy for the synergistic effect of oxygen vacancies and CNTs to improve the diffusion coefficient of Mg2+ in NaV6O15 and enhance the electrochemical performance of RMBs.