Oxygen redox chemistry in P2-Na0.6Li0.11Fe0.27Mn0.62O2 cathode for high-energy Na-ion batteries

Autor: Renyan Li, Sha Tan, Zheng-Wen Fu, Xiao-Qing Yang, Shaodi Zheng, Enyuan Hu, Shiya Lin, Lu Ma, Ming-Hui Cao, Zulipiya Shadike
Rok vydání: 2021
Předmět:
Zdroj: Journal of Materials Chemistry A. 9:27651-27659
ISSN: 2050-7496
2050-7488
DOI: 10.1039/d1ta08471b
Popis: Owing to the abundance of raw material reserves and low cost, Na-ion batteries (NIBs) have successfully gained widespread attention from academic and industrial communities in the past few decades. However, the insufficient cathode energy density is still one of the critical bottlenecks restricting the development of NIBs. Following a strategy of inducing Li+ into the transition-metal (TM) layer to enhance the oxygen redox reaction, a novel layered cathode material P2-Na0.6Li0.11Fe0.27Mn0.62O2 (NLFMO) was designed and successfully synthesized. This NLFMO cathode not only delivers a large initial reversible capacity of 207.3 mAh g-1, but also showing a good cyclic performance (104.2 mAh g−1 after 80 cycles) and rate capability (126.2 mAh g−1 at 1C). The ultrahigh capacity is contributed by both cationic (Fe3+/Fe4+, Mn3+/Mn4+) and partially reversible anionic redox (O2-/On-) reactions, revealed by in situ X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) techniques. Moreover, no detrimental P2-O2 phase transition was observed through ex situ X-ray diffraction (XRD) patterns, confirming the high structural stability during Na+ deintercalation/intercalation processes. These results provide valuable information about the high-energy density layered cathode materials based on anionic redox reaction for NIBs.
Databáze: OpenAIRE