One-Pot Aqueous Spray Drying of Hierarchical Na3V2(PO4)3 (NVP) Particles for High-Performance Sodium-Ion Batteries
Authors: Boutelle Ethan , Chen Arden , Gopal Rajeev , Bai Peng 
Published: August 2024

Sodium-ion batteries (NIBs) have been recognized as a promising alternative to lithium-ion batteries (LIBs), especially for stationary large-scale applications that favor inexpensive storage over high energy density, as their cathode materials don’t require scarce and expensive elements such as Li, Co, and Ni.1,2 Na3V2(PO4)3 (NVP) offers high ionic conductivity and long term stability due to its sodium super ionic conductor (NASICON) structure3. However, it suffers from poor electronic conductivity and requires energy-intensive synthesis routes4. Spray drying has recently become a common energy-effective route but requires organic solvents5 or complex carbon additives6. In this study, a more efficient and sustainable aqueous spray-drying method is presented to synthesize carbon-coated NVP by using L-ascorbic acid as a carbon source. Additionally, the role of conductive additives is explored in low-carbon samples. NVP sodium-ion half cells showed very high reversible capacity (114.7 mAh g-1 at 0.2C), high rate capability (80.8% capacity retention at 30C), and long cycling performance (93.8% capacity retention after 5000 cycles at 10C). The exceptional cycle life makes it a promising candidate for grid level energy storage. Furthermore, if configured without an intercalation anode material, the "host-free" NVP cells hold the promise to substitute the widely used LiFePO4 batteries for EV applications7.

References

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(6) Zhang, J.; Fang, Y.; Xiao, L.; Qian, J.; Cao, Y.; Ai, X.; Yang, H. Graphene-Scaffolded Na3V2(PO4)3 Microsphere Cathode with High Rate Capability and Cycling Stability for Sodium Ion Batteries. ACS Appl Mater Interfaces 2017, 9 (8), 7177–7184. https://doi.org/10.1021/acsami.6b16000.

(7) Ma, B.; Lee, Y.; Bai, P. Dynamic Interfacial Stability Confirmed by Microscopic Optical Operando Experiments Enables High-Retention-Rate Anode-Free Na Metal Full Cells. Advanced Science 2021, 8 (12). https://doi.org/10.1002/advs.202005006.

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