Abstract:
Sodium-ion batteries (SIBs) have recently gained wildly interest due to the abundance of sodium, lower production costs, and better low-temperature performance compared to lithium-ion batteries (LIBs). Among various cathode materials of SIBs, O3-type NaNi
0.4Fe
0.2Mn
0.4O
2 (NFM424) demonstrates high capacity and ease of synthesis, yet suffers from structural degradation and sluggish Na
+ kinetics caused by large ionic radius and strong electrostatic interactions. To overcome these issues, a configuration strategy combined with TiO
2 and Co
3O
4 by a simple solid-state reaction method was introduced to improve structural and electrochemical stability. XRD, SEM, TEM, and various electrochemical characterizations as well as TGA/DSC tests were conducted. The resulting NaNi
0.4Fe
0.2Mn
0.3Co
0.05Ti
0.05O
2 (NFMCT) cathode mitigated Jahn-Teller distortions and Na
+/vacancy ordering while enhancing phase integrity and diffusion pathways. The obtained NFMCT maintained 93.7 mAh·g
−1 after 550 cycles at 1 C, with superior rate capabilities at 2 C and 5 C. These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.