Ultra-Fast-Charging, Long-Duration, and Wide-Temperature-Range Sodium Storage Enabled by Multiwalled Carbon Nanotube-Hybridized Biphasic Polyanion-Type Phosphate Cathode Materials

作者：Wen-Long Ma, Yue Zhou, Xiaowen Zhao, Xin Cao, Ping Wu, Xiaoshu Zhu, Shaohua Wei, Kang Sun, Haoshen Zhou, Yiming Zhou · 发表于：ACS Applied Materials & Interfaces · 年份：2024 · DOI：10.1021/acsami.4c02565 · 被引用次数：10 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced Battery Technologies Research

Sodium-ion batteries (SIBs) represent a promising energy storage technology with great safety. Because of their high operating potential, superior structural stability, and prominent thermal stability, polyanion-type phosphates have garnered significant interest in superior prospective cathode materials for SIBs. Nevertheless, the disadvantages of poor intrinsic electronic conductivity, sluggish kinetics, and volume variation during sodiation/desodiation remain great challenges for satisfactory rate performance and cycle stability, which severely hinder their further practical applications. In this work, by adjusting the amounts of pretreated multiwalled carbon nanotubes (CNT) added intentionally at the beginning of the preparation, biphasic polyanion-type phosphate materials (marked as NFC) are synthesized through a one-pot solid state reaction methodology, which are composed of CNT-interwoven Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) and a small amount of Na 3 V 2 (PO 4 ) 3 (NVP). Benefiting from the improved electronic conductivity and unique composition and structure, the optimized sample (labeled as NFC-2) illustrates exceptional cycle stability and remarkable rate performance. The discharge capacities of the NFC-2 electrode are 114.8 and 78.6 mAh g –1 tested at 20 and 5000 mA g –1, respectively. Notably, such an electrode still gives out 75.7% capacity retention upon 10 000 cycles at 5000 mA g –1 . In situ X-ray diffraction analysis demonstrates that the NFC-2 cathode has outstandi...