Manipulating amorphous and crystalline hybridization of Na3V2(PO4)3/C for enhancing sodium-ion diffusion kinetics

• Published in: Journal of colloid and interface science 2024-08, Vol.667, p.64-72
• Main Authors: Zhou, Yingjie, Yang, Xiecheng, Hou, Minjie, Zhao, Lanqing, Zhang, Xiyue, Liang, Feng
• Format: Article
• Language: English
• Subjects: Amorphous; Bi-phase coordination; Diffusion kinetics; Hybrid cathode; Na3V2(PO4)3/C; Sodium-ion battery
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2024.04.046

The synergistic effect of crystal and amorphous phases boosts the sodium ion transport kinetics in NVP, mitigates volume deformations during cycling, achieve a high capacity of 82 mAh/g at 10 C. [Display omitted] •A homogeneous hybridization of crystalline and amorphous phases in Na3V2(PO4)3/C was achieved through a straightforward design.•The inclusion of the amorphous phase indirectly enhances the proportion of active Na2 sites.•In-situ formation of high-speed sodium-ion diffusion channels in amorphous phases enhances diffusion kinetics, the biphasic synergy provided an impressive capacity of 114 mAh/g at 0.2 C and a rate performance 82 mAh/g at 10 C. Na3V2(PO4)3 (NVP) has attracted considerable attention as a promising cathode material for sodium-ion batteries (SIBs). But its insufficient electronic conductivity, limited capacities, and fragile structure hinder its extended application, particularly in scenarios involving rapid charging and prolonged cycling. A hybrid cathode material has been developed to integrate both amorphous and crystalline phases, with the objective of improving the rate performance and Na storage capacity by leveraging bi-phase coordination. Consequently, the combination of amorphous and crystalline phases enhanced the kinetics of Na-ion diffusion, resulting in a 1–2 orders of magnitude enhancement in diffusion dynamics. Furthermore, the existence of amorphous states has been demonstrated to elevate the active Na2 site content, resulting in an increased reversible capacity. This assertion is substantiated by evidence derived from solid-state nuclear magnetic resonance (ss-NMR) and electrochemical characteristics. The innovative bi-phase collaborative material provides a specific capacity of 114 mAh/g at 0.2 C, exceptional rate performance of 82 mAh/g at 10 C, and remarkable long-term cycle stability, retaining 95 mAh/g at 5 C even after 300 cycles. In conclusion, the homogeneous hybridization of amorphous and crystalline phases presents itself as a promising and effective strategy for improving Na-ion storage capacity of cathodes in SIBs.