Ascorbic Acid-Assisted Synthesis of Mesoporous Sodium Vanadium Phosphate Nanoparticles with Highly sp2-Coordinated Carbon Coatings as Efficient Cathode Materials for Rechargeable Sodium-Ion Batteries

• Published in: Chemistry : a European journal Vol. 22; no. 30; pp. 10620 - 10626
• Main Authors: Hung, Tai-Feng, Cheng, Wei-Jen, Chang, Wen-Sheng, Yang, Chang-Chung, Shen, Chin-Chang, Kuo, Yu-Lin
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 18.07.2016; Wiley Subscription Services, Inc
• Subjects: Argon; Ascorbic acid; Atmosphere; Batteries; Battery cycles; Carbon; Cathodes; Chemical composition; Chemical synthesis; Chemistry; Coating; Coatings; Conduction; Crystal structure; Efficiency; Electrochemistry; Electrode materials; Extraction; Insertion; mesoporous materials; Morphology; Nanoparticles; nanotechnology; Phosphate; Rechargeable batteries; Retention; Roasting; Sodium; Sodium-ion batteries; sp2 carbon coating; Stability; Surface area; Vanadium
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201602066

Herein, mesoporous sodium vanadium phosphate nanoparticles with highly sp2‐coordinated carbon coatings (meso‐Na3V2(PO4)3/C) were successfully synthesized as efficient cathode material for rechargeable sodium‐ion batteries by using ascorbic acid as both the reductant and carbon source, followed by calcination at 750 °C in an argon atmosphere. Their crystalline structure, morphology, surface area, chemical composition, carbon nature and amount were systematically explored. Following electrochemical measurements, the resultant meso‐Na3V2(PO4)3/C not only delivered good reversible capacity (98 mAh g−1 at 0.1 A g−1) and superior rate capability (63 mAh g−1 at 1 A g−1) but also exhibited comparable cycling performance (capacity retention: ≈74 % at 450 cycles at 0.4 A g−1). Moreover, the symmetrical sodium‐ion full cell with excellent reversibility and cycling stability was also achieved (capacity retention: 92.2 % at 0.1 A g−1 with 99.5 % coulombic efficiency after 100 cycles). These attributes are ascribed to the distinctive mesostructure for facile sodium‐ion insertion/extraction and their continuous sp2‐coordinated carbon coatings, which facilitate electronic conduction. Ever ready: Mesoporous sodium vanadium phosphate nanoparticles with highly sp2‐coordinated carbon coatings (meso‐Na3V2(PO4)3/C; see figure) were successfully synthesized using ascorbic acid as the reductant and carbon source, followed by calcination at 750 °C in an argon atmosphere. Given their distinctive mesostructure, high proportional and continuous sp2‐coordinated carbon coating, good reversible capacity, superior rate capability and comparable cycling performance was achieved.