Luo Yiyuan, Cui Zhou, Wu Changxu, Sa Baisheng, Wen Cuilian, Li Hengyi, Huang Jianping, Xu Chao, Xu Zhengbing
State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Guangxi University, Nanning 530004, P. R. China.
Centre of Ecological Collaborative Innovation for Aluminum Industry in Guangxi, Guangxi University, Nanning 530004, P. R. China.
ACS Omega. 2023 Jun 14;8(25):22721-22731. doi: 10.1021/acsomega.3c01524. eCollection 2023 Jun 27.
Ti, Cr dual-element-doped LiMnNiO (LNMO) cathode materials (LTNMCO) were synthesized by a simple high-temperature solid-phase method. The obtained LTNMCO shows the standard structure of the 3 space group, and the Ti and Cr doped ions may replace the Ni and Mn sites in LNMO, respectively. The effect of Ti-Cr doping and single-element doping on the structure of LNMO was studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) characteristics. The LTNMCO exhibited excellent electrochemical properties with a specific capacity of 135.1 mAh·g for the first discharge cycle and a capacity retention rate of 88.47% at 1C after 300 cycles. The LTNMCO also has high rate performance with a discharge capacity of 125.4 mAh·g at a 10C rate, 93.55% of that at 0.1C. In addition, the CIV and EIS results show that the LTNMCO showed the lowest charge transfer resistance and the highest diffusion coefficient of lithium ions. The enhanced electrochemical properties may be due to a more stable structure and an optimized Mn content in LTNMCO through TiCr doping.
通过简单的高温固相法合成了Ti、Cr双元素掺杂的LiMnNiO（LNMO）正极材料（LTNMCO）。所获得的LTNMCO呈现出3种空间群的标准结构，且Ti和Cr掺杂离子可能分别取代了LNMO中的Ni和Mn位点。通过X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、X射线光电子能谱（XPS）以及扫描电子显微镜（SEM）表征研究了Ti-Cr掺杂和单元素掺杂对LNMO结构的影响。LTNMCO表现出优异的电化学性能，首次放电比容量为135.1 mAh·g，在1C倍率下300次循环后容量保持率为88.47%。LTNMCO还具有高倍率性能，在10C倍率下放电容量为125.4 mAh·g，是0.1C倍率下的93.55%。此外，循环伏安（CIV）和电化学阻抗谱（EIS）结果表明，LTNMCO的电荷转移电阻最低，锂离子扩散系数最高。电化学性能的增强可能归因于LTNMCO通过Ti-Cr掺杂具有更稳定的结构和优化的Mn含量。
