TY  - JOUR
AU  - Wei, Wei
AU  - Wang, Huaying
AU  - Xiang, Kejia
AU  - Ye, Tao
AU  - Mo, Shaoyu
AU  - Yao, Weihua
AU  - Zhang, Zhangtai
AU  - Xiao, Zunqiu
AU  - Wang, Shitong
AU  - Tang, Zilong
PY  - 2025
TI  - A novel dual carbon source improvement strategy for optimizing the ultra-high rate performance of Na4Fe3(PO4)2P2O7 cathode for sodium-ion batteries
JO  - Nano Research
SN  - 1998-0124
SP  - 94907517
VL  - 18
IS  - 6
AB  - Iron-based mixed polyanion-type sodium-ion cathode materials like Na4Fe3(PO4)2P2O7 (NFPP) typically suffer from poor electronic conductivity, resulting in capacity retention under high-rate cycling and rapid capacity degradation. In this study, we introduce an innovative dual-carbon enhancement strategy that integrates carbon nanotubes (CNTs) into the precursor mixing stage, combined with citric acid as both an organic carbon source and a dispersant. Unlike conventional methods where CNTs are added post-synthesis or during slurry preparation—often leading to uneven dispersion—we incorporate CNTs during the initial mixing process. Citric acid not only provides carbon for pyrolysis but also forms a gel-like precursor that ensures homogeneous dispersion of CNTs and raw materials. This one-step sintering approach produces NFPP particles uniformly coated with carbon layers intimately connected to well-dispersed CNTs, potentially forming chemical bonds between them. The resulting pyrolytic carbon and CNT-coated NFPP (NFPP-CNT) exhibits a dense and interconnected electron-conductive network, significantly enhancing its electronic conductivity and electrochemical performance. The precisely designed NFPP-CNT delivers a reversible capacity of 111 mAh/g at 0.1 C and maintains a reversible capacity of 78.8 mAh/g even at an ultra-high rate of 100 C. NFPP-CNT also demonstrates outstanding high-rate capacity retention, with 85.7% capacity remaining after 27,000 cycles at 100 C. This novel synthesis method and the multifaceted role of citric acid endow NFPP with superior high-rate, long-cycle, and low-temperature performance, making it a highly competitive material for large-scale electric energy storage systems (EESs).
UR  - https://doi.org/10.26599/NR.2025.94907517
DO  - 10.26599/NR.2025.94907517