A Cobalt-Free Li(Li0.16 Ni0.19 Fe0.18 Mn0.46 )O2 Cathode for Lithium-Ion Batteries with Anionic Redox Reactions

Xiaolu Cheng; Hezhuan Wei; Weijian Hao; Huiyu Li; Huinan Si; Shengli An; Wentao Zhu; Guixiao Jia; Xinping Qiu

doi:10.1002/cssc.201802436

A Cobalt-Free Li(Li_0.16 Ni_0.19 Fe_0.18 Mn_0.46 )O₂ Cathode for Lithium-Ion Batteries with Anionic Redox Reactions

ChemSusChem. 2019 Mar 21;12(6):1162-1168. doi: 10.1002/cssc.201802436. Epub 2019 Feb 25.

Authors

Xiaolu Cheng¹, Hezhuan Wei², Weijian Hao¹, Huiyu Li¹, Huinan Si¹, Shengli An², Wentao Zhu¹, Guixiao Jia², Xinping Qiu¹

Affiliations

¹ Key Laboratory of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, P.R. China.
² School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou, Inner Mongolia, 014010, P.R. China.

PMID: 30600937
DOI: 10.1002/cssc.201802436

Abstract

Lithium-rich, Mn-based layered oxides Li₂ MnO₃ -LiMO₂ (M=Ni, Co) have been considered as promising cathode candidates owing to their high capacity. However, the resources shortage and high price of cobalt make it imperious to substitute cobalt with other high-abundance elements. Here, we synthesized a low-cost, cobalt-free, Fe-substituted oxide material, Li(Li_0.16 Ni_0.19 Fe_0.18 Mn_0.46 )O₂ . It exhibited a high reversible capacity of 169.2 mAh g^-1 after 100 cycles and maintained an extraordinarily high discharge potential during cycling. X-ray photoelectron spectroscopy and DFT calculations revealed that super iron Fe^IV exists in the delithiated state, and oxygen participates in the redox reaction in addition to the Ni²⁺ /Ni⁴⁺ and Fe³⁺ /Fe⁴⁺ redox couples. The anionic oxidation preferentially occurred on oxygen with a Li-O-Li configuration and with oxidized Fe and Ni coordination.

Keywords: Fe substitution; anionic redox reactions; batteries; cathode; lithium.

Abstract

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