Solid solution phosphide (Mn1−xFexP) as a tunable conversion/alloying hybrid anode for lithium-ion batteries

Abstract

The substitutional solid solution Mn_1−xFe_xP compounds between alloying reaction-type MnP and conversion reaction-type FeP are successfully synthesized via facile high energy mechanical milling and their electrochemical properties as an anode for lithium ion batteries (LIBs) are investigated. A complete solid solution is formed between two end members and the Mn_1−xFe_xP solid solution phosphide electrodes show an enhanced electrochemical performance, delivering a capacity of 360 mA h g⁻¹ after 100 cycles at a high current density of 2 A g⁻¹ when the advantages of the two reaction mechanisms are beneficially combined. These synergistic effects resulted from the in situ generated nanocomposite of the Li–Mn–P alloying element and the Fe nano-network in combination with the surrounding amorphous lithium phosphide, which effectively buffers the accompanying volume variation, hinders the aggregation of the alloying element, and ensures the electron and ion transport.