Zheng Kexin, Wang Jiawei, Wang Haifeng, Pei Zhengqing, Wang Qian, Zhou Xinjie, Ma Dehua, Lu Ju
School of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.
Guizhou Provincial Key Laboratory of Metallurgical Engineering and Energy Saving, Guiyang 550025, China.
Nanomaterials (Basel). 2024 Dec 12;14(24):1989. doi: 10.3390/nano14241989.
The P2-NaMnO 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 MnO synthesis, followed by calcination to obtain NaTiMnO materials. We investigated the effects of Ti doping on the structure, morphology, Mn concentration, and Na diffusion coefficients of NaTiMnO. 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 NaMnO 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%.
P2-NaMnO正极材料长期以来受到充放电循环过程中由 Jahn-Teller（J-T）效应引起的相变的限制，导致电化学性能欠佳。在本研究中，我们采用液相共沉淀法，在前体MnO合成过程中引入Ti，随后进行煅烧以获得NaTiMnO材料。我们研究了Ti掺杂对NaTiMnO的结构、形貌、Mn浓度和Na扩散系数的影响。我们的研究结果表明，与未掺杂的样品相比，7%Ti掺杂的NTMO-007样品表现出减少的晶粒团聚和更小的粒径，从而增加了电极-电解质的接触面积和电化学活性。此外，Ti掺杂增加了NaMnO的晶胞体积并拓宽了Na传输通道，显著提高了Na扩散系数。在0.5C倍率下，NTMO-007样品的比容量为143.3 mAh g，100次循环后容量保持率为81.8%，明显优于未掺杂的NMO样品，其容量保持率仅为61.5%。
