Electrochimica Acta, Vol.312, 224-233, 2019
Robust spindle-structured FeP@C for high-performance alkali-ion batteries anode
To solve the agglomeration of Fe and low electronic conductivity of FeP anode, a simple route through metal organic framework (MOF)-derived phosphorization has been successfully explored for in situ encapsulation of FeP nanoparticles in porous carbon framework (FeP@C). The MOF-derived FeP@C anode can substantially inhibit the coarsening of small Fe, improve the electroconductivity and moderate the volume expansion of electrode, leading to superior rate capability and excellent cycling performance for Li-, Na- and K-ions storage. For example, the FeP@C anode delivers a high reversible capacity of 700 mAh g(-1) at 0.1 A g(-1) over 180 cycles for Li-ion batteries, displays a high reversible capacity of 387 mAh g(-1) at 0.1 A g(-1) over 100 cycles for Na-ion batteries and achieve a high reversible capacity of 163 mAh g(-1) at 0.2 A g(-1) over 100 cycles for K-ion batteries. The kinetic analysis, calculated diffusion coefficient and partial density of states (PDOS) results also confirmed this in-situ carbon encapsulated strategy improves the conductivity of FeP particles facilitating the alkali-ion/electron's transportation. (C) 2019 Elsevier Ltd. All rights reserved.
Keywords:Metal organic frameworks;Iron phosphide;Superior rate capability;Alkali-ion batteries;Carbon-encapsulation