Investigation of the Reversible Intercalation/Deintercalation of Al into the Novel Li3VO4@C Microsphere Composite Cathode Material for Aluminum-Ion Batteries

• Published in: ACS applied materials & interfaces Vol. 9; no. 34; pp. 28486 - 28494
• Main Authors: Jiang, Jiali, Li, He, Huang, Jianxing, Li, Kun, Zeng, Jing, Yang, Yang, Li, Jiaqi, Wang, Yunhui, Wang, Jing, Zhao, Jinbao
• Format: Journal Article
• Language: English
• Published: American Chemical Society 30.08.2017
• Subjects: ionic liquid; aluminum-ion battery; cathode; mechanism; Li3VO4@C
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.7b07503

The Li3VO4@C microsphere composite was first reported as a novel cathode material for rechargeable aluminum-ion batteries (AIBs), which manifests the initial discharge capacity of 137 mAh g–1 and and remains at 48 mAh g–1 after 100 cycles with almost 100% Coulombic efficiency. The detailed intercalation mechanism of Al into the orthorhombic Li3VO4 is investigated by ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) of Li3VO4@C electrodes and the nuclear magnetic resonance aluminum spectroscopy (27Al NMR) of ionic liquid electrolytes in different discharge/charge states. First-principle calculations are also carried out to investigate the structural change as Al inserts into the framework of Li3VO4. It is revealed that the Al/Li3VO4@C battery goes through electrochemical dissolution and deposition of metallic aluminum in the anode, as well as the insertion and deinsertion of Al3+ cations in the cathode in the meantime. The rechargeable AIBs fabricated in this work are of low cost and high safety, which may make a step forward in the development of novel cathode materials based on the acidic ionic liquid electrolyte system.