NaTi2(PO4)3 modified O3-type NaNi1/3Fe1/3Mn1/3O2 as high rate and air stable cathode for sodium-ion batteries. (10th February 2023)

• Record Type: Journal Article
• Authors: Zhao, Shengyu; Shi, Qinhao; Qi, Ruijuan; Zou, Xingli; Wang, Jing; Feng, Wuliang; Liu, Yang; Lu, Xionggang; Zhang, Jiujun; Yang, Xinxin; Zhao, Yufeng
• Is Part Of: Electrochimica acta. Volume 441(2023)
• Publication Date: 2023-02-10
• Subjects: Sodium ion batteries -- Surface modification -- Air stability -- Rate capability; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2023.141859
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Layered transition metal oxides O3-NaNi1/3 Fe1/3 Mn1/3 O2 (NFM) have been extensively studied due to their low cost and high reversible specific capacity. However, the inferior rate and cycle performance, as well as the poor air stability severely limit its practical applications. In this work, O3-NaNi1/3 Fe1/3 Mn1/3 O2 is successfully modified with an unintermittent and thin NaTi2 (PO4 )3 (NTP) coating layer, which plays a critical role in preventing the highly corrosive hydrofluoric acid (HF) attacks from decomposition of electrolyte and subsequent dissolution of the redox-active metal from the cathode particles. Meanwhile, partial Ti 4+ ions were doped in the bulk NaNi1/3 Fe1/3 Mn1/3 O2, which can enlarge the interslab spacing. DFT calculations confirm the reduced Na + migration energy barrier for the as produced sample. As a consequence, the NTP coated NFM sample presents a superior rate capacity (103.1 mAh g −1 at 5 C), significantly enhanced capacity retention (77.5% at 1 C after 100 cycles), outperforming the state of the art literatures. Besides, the air stability of the sample is well improved and the full cells deliver good cyclic performance when coupled with hard carbon, which will promote the large-scale application of O3-tpye cathode material.