Preparation of lithium‑doped NaV<sub>6</sub>O<sub>15</sub> thin film cathodes with high cycling performance in SIBs

Xu, Hai Yan; Ruan, Jun Hai; Liu, Fang Lin; Li, Dong Cai; Zhang, Feng Jun; Wang, Ai Guo; Sun, Dao Sheng; Oh, Won‑Chun; Xu, Hai Yan; Ruan, Jun Hai; Liu, Fang Lin; Li, Dong Cai; Zhang, Feng Jun; Wang, Ai Guo; Sun, Dao Sheng; Oh, Won‑Chun

doi:2022.59.3.289

J. Korean Ceram. Soc. > Volume 59(3); 2022 > Article

Original Article

Journal of the Korean Ceramic Society 2022;59(3): 289-301.
doi: https://doi.org/10.1007/s43207-021-00127-3

Preparation of lithium‑doped NaV₆O₁₅ thin film cathodes with high cycling performance in SIBs

Hai Yan Xu^1,2, Jun Hai Ruan¹, Fang Lin Liu¹, Dong Cai Li¹, Feng Jun Zhang¹, Ai Guo Wang¹, Dao Sheng Sun¹, Won‑Chun Oh³

¹Anhui Key Laboratory of Advanced Building Materials, Anhui Jianzhu University, Hefei 230022, People’s Republic of China
²Key Laboratory of Functional Molecule Design and Interface Process, Anhui Jianzhu University, Hefei 230601, People’s Republic of China
³Department of Advanced Materials Science and Engineering, Hanseo University, Seosan 31962, South Korea

Correspondence

Hai Yan Xu ,Email: xuhaiyan@ahjzu.edu.cn
Jun Hai Ruan ,Email: xuhaiyan@ahjzu.edu.cn
Won‑Chun Oh ,Email: wc_oh@hanseo.ac.kr

Received: April 2, 2021; Revised: May 20, 2021 Accepted: May 27, 2021. Published online: May 31, 2022.

ABSTRACT

Lithium ions-doped NaV₆O₁₅ thin films have been prepared using a simple low temperature liquid phase deposition method and subsequent annealing process. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), and photoelectron spectroscopy (XPS) have been used to study the structural and physicochemical characteristics of the NaV₆O₁₅film. The films were grown on the FTO conductive glass and used directly as an electrode of sodium ion batteries. The prepared lithium ions-doped NaV₆O₁₅ thin film electrodes showed an excellent cycling stability and discharge capacity, which may be attributed to the stability of the Li+ embedded into the gap between the V–O layers to maintain the structure and its stable β-phase structure transformed after the first cycle. The cycling stability greatly improved with increasing annealing temperature, while the discharge capacity decreased. The capacities of the film electrodes annealed at 400 °C and 450 °C maintained above 97% after 100 cycles. The lithium-doped NaV₆O₁₅ underwent a phase transition during the first charge/discharge cycle. The new transformed phase has perfect crystal structure stability undergoing insertion and deinsertion of Na⁺. Therefore, the lithium-doped NaV₆O₁₅ thin film possesses good cycling stability and is expected to be a promising thin film cathode for sodium-ion batteries.

Key words: Lithium-doped NaV₆O₁₅ · Liquid phase deposition · Film electrodes · Cycling stability · Phase transition