Defect-rich hierarchical porous spinel MFe2O4 (M = Ni, Co, Fe, Mn) as high-performance anode for lithium ion batteries

Abstract

Exploring innovative anode materials with excellent lithium storage capability is an urgent and challenging task. Among various candidates, the spinel ferrites based anodes received huge attention owing to the high theoretical capacity. However, the rapid capacity decaying and sluggish reaction kinetics during cycling have severely hampered their commercialization process. Herein, the hierarchical porous spinel MFe₂O₄ (M = Ni, Co, Mn, Fe), comprised of Mn doped porous NiFe₂O₄/CoFe₂O₄ heterostructure ligament network and Ni/Co/Mn co-doped Fe₃O₄ nanosheets network, is synthesized through a facile chemical dealloying strategy. The as-prepared MFe₂O₄ anode shows impressive cycling stability, revealing a discharge capacity of 1161.6 mAh g⁻¹ after cycling for 1500 cycles at 500 mA g⁻¹. Furthermore, the assembled LiFePO₄//MFe₂O₄ full cell can display a reversible capacity of 111.2 mAh g⁻¹ at 0.5 C after 150 cycles, exhibiting the great potential of the practical application of the MFe₂O₄ in the next-generation LIBs. The remarkable Li storage properties can be attributed to the particular hierarchical porous structure, highly active NiFe₂O₄/CoFe₂O₄ heterointerface and abundant surficial oxygen defects, high stable spinel structure contributed from high conformational entropy of polymetallic ions, and a double role of Mn doping in the cycling process. The structure regulating strategy proposed here is greatly expected to boost the developing of high-performance spinel ferrites based anodes.