Understanding the construction of nano-structured LiMn0.6Fe0.4PO4 by a co-precipitation strategy and Mg2+ doping towards high-performance lithium-ion batteries

Jie Wu; Liuquan Hu; Zhuang Hu; Wentian Yi; Zhe Mu; Jinjin Zhang; Yuede He; Jilei Liu; Changling Fan

doi:10.1039/d5nr01304f

Understanding the construction of nano-structured LiMn_0.6Fe_0.4PO₄ by a co-precipitation strategy and Mg²⁺ doping towards high-performance lithium-ion batteries

Nanoscale. 2025 Jul 11. doi: 10.1039/d5nr01304f. Online ahead of print.

Authors

Jie Wu¹, Liuquan Hu², Zhuang Hu¹, Wentian Yi¹, Zhe Mu¹, Jinjin Zhang², Yuede He¹, Jilei Liu^{1

3

4}, Changling Fan^{1

3

4}

Affiliations

¹ College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, China. heyuede@163.com.
² Minmetals New Energy Materials (Hunan) Co., Ltd., Changsha, Hunan, 410205, China.
³ Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha, Hunan, 410082, China.
⁴ Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy, Hunan University, Changsha, Hunan, 410082, China.

PMID: 40642936
DOI: 10.1039/d5nr01304f

Abstract

LiMn_1-xFe_xPO₄ has attracted wide attention due to its higher voltage platform and energy density without sacrificing several excellent properties of pure LiFePO₄. However, the conventional co-precipitation route for preparing LiFePO₄ is not applicable to LiMn_1-xFe_xPO₄. In this paper, nano-structured LiMn_0.6Fe_0.4PO₄/C microspheres with high dispersibility and high compaction density are synthesized by using NH₄Mn_0.6Fe_0.4PO₄·H₂O obtained via a co-precipitation strategy as a precursor for the first time, which enables Mn, Fe and P to be uniformly deposited. Furthermore, the in situ Mg²⁺ doping strategy is also carried out to optimize the electrochemical performance. Our results show that the introduction of Mg²⁺ can alleviate the lattice expansion and deformation caused by the Jahn-Teller effect, improving the structural stability of LiMn_0.6Fe_0.4-xMg_xPO₄/C. Meanwhile, the diffusion kinetics are investigated by in situ electrochemical impedance spectroscopy and cyclic voltammetry, revealing that Mg²⁺ doping effectively reduces the interfacial resistance and increases the lithium-ion diffusion coefficient. As a result, the LiMn_0.5978Fe_0.3522Mg_0.0506PO₄/C cathode exhibits superior rate performance, delivering capacities of 150.1, 141.4 and 111.6 mAh g^-1 at 0.1, 1 and 5C, respectively. This work provides important guidance for the industrial-scale manufacturing and practical application of LiMn_1-xFe_xPO₄/C, which is conducive to its further development.