Research Article Boosted electrochemical performance of Na3V2(PO4)3 at low temperature through synergistical F substitution and construction of interconnected nitrogen-doped carbonaceous network

作者：Li, Jiabao^*; Li, Ziqian; Tang, Shaocong; Wang, Tianyi; Pan, Likun^*; Wang, Chengyin^*

来源：JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 2023, 150: 159-167.

DOI：10.1016/j.jmst.2022.11.048

• Na 3 V 2 (PO 4 ) 3
• F substitution
• Interconnected carbonaceous frameworks
• Ionic
• electronic conductivity
• Performance at low temperature

Benefitting from its unique NASICON-type framework, the Na3V2(PO4)3 (NVP) cathodes have aroused extensive interest and have been deemed as the promising cathode candidate for sodium-ion batter-ies (SIBs). Unfortunately, the poor electronic conductivity, combined with the undesirable volume varia-tions, seriously hinders the practical application of NVP cathode, especially at low temperatures. Herein, a dual-strategy, F substitution accompanied by V vacancies and the construction of three-dimensional (3D) nitrogen-doped carbonaceous frameworks (NC), were employed for the NVP cathode (F-NVP/C@3DNC). The former can remarkably decrease the particle size and enhance Na + migration capability, increasing the ionic conductivity. Meanwhile, the electronic connection and effective buffering can be obtained from the latter, strengthening the electrode integrity. Consequently, up to 100 cycles at 0.1 A g-1, a reversible capacity of 113.8 mAh g-1, approaching the theoretical value (117 mAh g-1), is demonstrated, accompa-nied by impressive capacity retentions at 1.0 (93.75% after 4800 cycles) and 20.0 A g-1 (92.7% after 10 0 0 cycles). More importantly, even at -20 degrees C, a superior specific capacity (102.6 mAh g-1 after 100 cycles at 0.1 A g-1) and high capacity retention (86.6% at 20.0 A g-1 up to 10 0 0 cycles) can still be obtained simul-taneously. Significantly, the design of F-NVP/C@3DNC provides insights for the fabrication of polyanion cathodes for applications at low temperatures with modified structure stability and reaction kinetics.