Solvothermal synthesis of sea urchin-like NaxV2O5 structure for ultra-high stability aqueous zinc ion batteries

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2023-09, Vol.944, p.117665, Article 117665
• Main Authors: Xu, Yao, Bai, Meng-Xin, He, Zheng-Hua, Hou, Jing-Feng, Kong, Ling-Bin
• Format: Article
• Language: English
• Subjects: Aqueous zinc-ion batteries; Sea urchin-like; Sodium vanadate; Solvothermal method
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2023.117665

The solvothermal method successfully synthesized sea urchin-like vanadate cathode materials for aqueous zinc ion batteries, and the abundant nanowires on sea urchins not only increase the wetting area with the electrolyte, but also provide more ion propagation paths. In addition, sodium ions are embedded in vanadium pentoxide frame to play a structural supporting role, and the electrochemical cycle test shows that at the current density of 5 A/g, the capacity retention rate is still higher than 100% after 1000 cycles, showing excellent cycle stability. [Display omitted] •A sea urchin-like NaxV2O5 is used as a cathode material of aqueous zinc-ion batteries.•Sea urchin morphology can increase specific surface area and provide more sites for redox reactions.•The cathode material has high specific capacity and excellent cycle stability. Vanadium pentoxide, as a low-cost, safe and reliable cathode electrode material. Its structure is prone to collapse during the process of repeated Zn2+ intercalation and deintercalation of aqueous zinc-ion batteries (AZIBs), so enhancing the structural stability of vanadium pentoxide and improving the rate performance has always been a challenge. In this work, sea urchin-like NaxV2O5 vanadate materials are obtained by solvothermal reaction, and the prepared samples exhibit a fast ion transport path during the process of Na+ chemical embedding in V2O5 framework, which is due to the plentiful active sites that nanowires can provide. This paves the way for high magnification performance. In addition, the unique sea urchin-like morphology with a large specific surface can continuously adapt to strain during ion insertion to obtain excellent long cycle performance. The above merits endow NaVO with a highly stable discharge capacity of 250.5 mA g−1 at 0.5 A/g and a long cycle capacity of 100 mA h g−1 maintains for more than 11,000 cycles at 10 A/g. Remarkably, the capacity retention rate up to 85.7%.