Theoretical research into low-voltage Na2TiSiO5 anode for lithium-ion battery

• Published in: Rare metals Vol. 41; no. 10; pp. 3412 - 3420
• Main Authors: Zhao, Shu, Wu, Tian-Hao, He, Di, Zhang, Zi-He, Wang, Bo-Ya, Wang, Li-Hang, Yu, Hai-Jun
• Format: Journal Article
• Language: English
• Published: Beijing Nonferrous Metals Society of China 2022; Springer Nature B.V
• Subjects: Biomaterials; Chemistry and Materials Science; Electrochemical analysis; Energy; Insertion; Ion currents; Lithium-ion batteries; Low voltage; Materials Engineering; Materials Science; Metallic Materials; Nanoscale Science and Technology; Original Article; Physical Chemistry; Rechargeable batteries; Lithium-ion batteries; First-principles calculations; Titanosilicates; Anode materials; Flexible redox pair
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-022-02051-9

Na 2 TiSiO 5 (NTSO) is a low-cost Li-ion battery anode with great application potential, such as the tetragonal NTSO (T-NTSO) with a high capacity and a low voltage. In addition to the tetragonal structure, NTSO has two other polymorphs. However, the basic understanding of the structure, ion insertion and transport mechanisms of these new materials is still lacking. Herein, we present a combined experimental and computational investigation of the tetragonal and orthorhombic NTSO to reveal the intrinsic mechanism leading to the superior electrochemical performance of T-NTSO. We determined that the insertion site with a flexible Ti 4+ /Ti 3+ redox pair is critical for Li + insertion stability. The large number of such flexible sites in the T-NTSO results in a higher capacity and higher ionic conductivity than those of orthorhombic polymorph. The understanding of intrinsic properties will accelerate the development and utilization of titanosilicates as the next generation low-voltage anode of Li-ion battery. Graphical abstract