Effects of Ti 4+ Doping on the Structural Stability and Electrochemical Performance of Layered P2-Na 0.7 MnO 2.05 Cathodes for Sodium-Ion Batteries

• Published in: Nanomaterials (Basel, Switzerland) Switzerland), 2024-12, Vol.14 (24)
• Main Authors: Zheng, Kexin, Wang, Jiawei, Wang, Haifeng, Pei, Zhengqing, Wang, Qian, Zhou, Xinjie, Ma, Dehua, Lu, Ju
• Format: Article
• Language: English
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano14241989

The P2-Na MnO cathode material has long been constrained by phase transitions induced by the Jahn-Teller (J-T) effect during charge-discharge cycles, leading to suboptimal electrochemical performance. In this study, we employed a liquid phase co-precipitation method to incorporate Ti during the precursor Mn O synthesis, followed by calcination to obtain Na Ti Mn O materials. We investigated the effects of Ti doping on the structure, morphology, Mn concentration, and Na diffusion coefficients of Na Ti Mn O . Our findings revealed that the 7% Ti-doped NTMO-007 sample exhibited reduced grain agglomeration and smaller particle sizes compared to the undoped sample, thereby enhancing the electrode-electrolyte contact area and electrochemical activity. Additionally, Ti doping increased the crystal cell volume of Na MnO and broadened the Na transport channels, significantly enhancing the Na diffusion coefficient. At a 0.5 C rate, the NTMO-007 sample demonstrated a specific capacity of 143.3 mAh g with an 81.8% capacity retention after 100 cycles, markedly outperforming the undoped NMO sample, which had a capacity retention of only 61.5%.