Srout Mohammed, Kwon Nam Hee, Ben Youcef Hicham, Semlal Nawal, Fromm Katharina M, Saadoune Ismael
IMED-Lab., Cadi Ayyad University (UCA), Av. A. El Khattabi, P.B. 549, 40000 Marrakesh, Morocco.
Department of Chemistry, University of Fribourg, Chemin du Musée 9, 1700 Fribourg, Switzerland.
ACS Appl Mater Interfaces. 2020 Apr 22;12(16):18496-18503. doi: 10.1021/acsami.0c00712. Epub 2020 Apr 13.
Natrium super ionic conductor (NASICON) materials providing attractive properties such as high ionic conductivity and good structural stability are considered as very promising materials for use as electrodes for lithium- and sodium-ion batteries. Herein, a new high-performance electrode material, LiNiTiFe(PO)/C, was synthesized via the sol-gel method and was electrochemically tested as an anode for lithium ion batteries, providing enhanced electrochemical performance as a result of nickel substitution into the lithium site in the LiTi(PO) family of materials. The synthesized material showed good ionic conductivity, excellent structural stability, stable long-term cycling performance, and improved high rate cycling performance compared to LiTi(PO). The LiNiTiFe(PO)/C electrode delivered reversible capacities of about 93 and 68% of its theoretical one at current rates of 0.1 C (6.42 mA·g) after 100 cycles and 5 C (320.93 mA·g) after 1000 cycles, respectively. Theoretically, three Li ions can be inserted into the vacancies of the LiNiTiFe(PO)/C structure. However, when the electrode is discharged to 0.5 V, more than three Li ions are inserted into the NASICON structure, leading to its structural transformation, and thus to an irreversible electrochemical behavior after the first discharge process.
钠超离子导体（NASICON）材料具有诸如高离子电导率和良好结构稳定性等吸引人的特性，被认为是用作锂离子和钠离子电池电极的非常有前景的材料。在此，通过溶胶 - 凝胶法合成了一种新型高性能电极材料LiNiTiFe(PO)/C，并将其作为锂离子电池的阳极进行了电化学测试，由于在LiTi(PO)族材料中镍取代了锂位点，该材料具有增强的电化学性能。与LiTi(PO)相比，合成材料表现出良好的离子电导率、优异的结构稳定性、稳定的长期循环性能和改善的高倍率循环性能。LiNiTiFe(PO)/C电极在100次循环后，在0.1 C（6.42 mA·g）的电流倍率下，以及在1000次循环后，在5 C（320.93 mA·g）的电流倍率下，分别提供了约为其理论容量93%和68%的可逆容量。理论上，三个锂离子可以插入LiNiTiFe(PO)/C结构的空位中。然而，当电极放电至0.5 V时，超过三个锂离子插入NASICON结构中，导致其结构转变，从而在第一次放电过程后产生不可逆的电化学行为。
