Zero-Strain Na3 V2 (PO4 )2 F3 @Rgo/CNT Composite as a Wide-Temperature-Tolerance Cathode for Na-Ion Batteries with Ultrahigh-Rate Performance

Chenglong Shi; Junling Xu; Tao Tao; Xiaoyi Lu; Guoping Liu; Fuqiang Xie; Sheng Wu; Yanxue Wu; Zhipeng Sun

doi:10.1002/smtd.202301277

Zero-Strain Na₃ V₂ (PO₄ )₂ F₃ @Rgo/CNT Composite as a Wide-Temperature-Tolerance Cathode for Na-Ion Batteries with Ultrahigh-Rate Performance

Small Methods. 2024 Mar;8(3):e2301277. doi: 10.1002/smtd.202301277. Epub 2023 Nov 27.

Authors

Chenglong Shi¹, Junling Xu¹, Tao Tao¹, Xiaoyi Lu¹, Guoping Liu¹, Fuqiang Xie¹, Sheng Wu¹, Yanxue Wu², Zhipeng Sun^{1

3}

Affiliations

¹ School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, China.
² Analysis and Test Center, Guangdong University of Technology, Guangzhou, Guangdong, 510006, China.
³ Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin, 300071, China.

PMID: 38009495
DOI: 10.1002/smtd.202301277

Abstract

Sodium-ion batteries (SIBs) are widely considered a hopeful alternative to lithium-ion battery technology. However, they still face challenges, such as low rate capability, unsatisfactory cycling stability, and inferior variable-temperature performance. In this study, a hierarchical Na₃ V₂ (PO₄ )₂ F₃ (NVPF) @reduced graphene oxide (rGO)/carbon nanotube (CNT) composite (NVPF@rGO/CNT) is successfully constructed. This composite features 0D Na₃ V₂ (PO₄ )₂ F₃ nanoparticles are coated by a cross-linked 3D conductive network composed of 2D rGO and 1D CNT. Furthermore, the intrinsic Na⁺ storage mechanism of NVPF@rGO/CNT through comprehensive characterizations is unveiled. The synthesized NVPF@rGO/CNT exhibits fast ionic/electronic transport and excellent structural stability within wide working temperatures (-40-50 °C), owing to the zero-strain NVPF and the coated rGO/CNT conductive network that reduces diffusion distance for ions and electrons. Moreover, the stable integration between NVPF and rGO/CNT enables outstanding structural stability to alleviate strain and stress induced during the cycle. Additionally, a practice full cell is assembled employing a hard carbon anode paired with an NVPF@rGO/CNT cathode, which provides a decent capacity of 105.2 mAh g^-1 at 0.2 C, thereby attaining an ideal energy density of 242.7 Wh kg^-1 . This work provides valuable insights into developing high-energy and power-density cathode materials for SIBs.

Keywords: Na-ion batteries; cathodes; ultrahigh-rate; wide-temperature-tolerance; zero-strain Na3V2(PO4)2F3.