Improved Electrochemical Properties of LiMn2O4-Based Cathode Material Co-Modified by Mg-Doping and Octahedral Morphology.

Hongyuan Zhao,Dongyang Que,Yongfeng Li,Youzuo Hu,Yongfang Nie

doi:10.3390/ma12172807

Hongyuan Zhao, Dongyang Que + Show 3 more

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https://doi.org/10.3390/ma12172807

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Abstract

In this work, the spinel LiMn2O4 cathode material was prepared by high-temperature solid-phase method and further optimized by co-modification strategy based on the Mg-doping and octahedral morphology. The octahedral LiMn1.95Mg0.05O4 sample belongs to the spinel cubic structure with the space group of Fd3m, and no other impurities are presented in the XRD patterns. The octahedral LiMn1.95Mg0.05O4 particles show narrow size distribution with regular morphology. When used as cathode material, the obtained LiMn1.95Mg0.05O4 octahedra shows excellent electrochemical properties. This material can exhibit high capacity retention of 96.8% with 100th discharge capacity of 111.6 mAh g−1 at 1.0 C. Moreover, the rate performance and high-temperature cycling stability of LiMn2O4 are effectively improved by the co-modification strategy based on Mg-doping and octahedral morphology. These results are mostly given to the fact that the addition of magnesium ions can suppress the Jahn–Teller effect and the octahedral morphology contributes to the Mn dissolution, which can improve the structural stability of LiMn2O4.

Highlights

With the increasingly serious environmental pollution, new energy and environmental technology have caught more and more extensive attention
After introducing a small amount of magnesium ions, the obtained LiMn1.95Mg0.05O4 sample was still present in the spinel cubic structure of LiMn2 O4, which indicates that the addition sample was still present in the spinel cubic structure of LiMn2O4, which indicates that the addition of of magnesium ions did not change the crystal structure [32,33]
For the LiMn1.95Mg0.05O4 sample obtained obtained from Mn3 O4 octahedra, the characteristic diffraction peaks were indexed to the spinel from Mn3O4 octahedra, the characteristic diffraction peaks were indexed to the spinel LiMn2O4

Summary

Introduction

With the increasingly serious environmental pollution, new energy and environmental technology have caught more and more extensive attention. As an important cathode material, LiMn2 O4 possesses a rather high cost advantage because of the abundant manganese resource and this material can be obtained by many preparation technologies [4,5,6,7,8]. This material does not involve the use of toxic metal elements. All these advantages can promote large-scale applications of LiMn2 O4. That the cycling stability and high temperature performance cannot meet the requirement of long endurance mileage [9,10,11,12]

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Conclusion