FeP:  Another Attractive Anode for the Li-Ion Battery Enlisting a Reversible Two-Step Insertion/Conversion Process

Abstract

FeP y (y = 1, 2, 4) anodes all react with lithium through a conversion reaction FeP y + 3yLi → yLi3P + Fe0 in their first discharge, leading to nanocomposite discharged electrodes described by nanosized Fe0 particles embedded in yLi3P matrixes. From electrochemical and complementary in situ X-ray diffraction and high-resolution transmission electron microscopy studies, we deduce that the conversion reaction occurring during the first discharge is followed by two successive insertion and conversion processes in further cycles for the FeP electrode. The insertion process is highly reversible, leading to a capacity retention of 300 mA h g-1 and 1900 mA h cm-3 after 100 cycles, and corresponds to the formation of an intermediate tetragonal LiFeP phase as deduced from first-principles T = 0 K phase diagram calculations and preliminary Mössbauer analyses. We expect the kinetics of this reaction to be strongly limited by the increase in y, thus leading to an increasing capacity fading when increasing the y P/Fe ratio.

Beyond Intercalation‐Based Li‐Ion Batteries: The State of the Art and Challenges of Electrode Materials Reacting Through Conversion Reactions

“…In the case of the last two, competition between lithium insertion and partial conversion is reported. The intermediate processes can be kinetically (e.g., in Co 3 O 4 [ 89 ] or CuS, [ 190 ] NiP 3 [ 251 ] or FeP [ 242 ] ) or thermodynamically-controlled (e.g., in Fe 2 O 3 [ 305 ] ), with particle size either having an indirect effect on the current density for the former or a direct energetic effect for the latter.…”

Nanostructured transition metal phosphide as negative electrode for lithium-ion batteries

“…They display different redox reactions depending on the 3d transition metal. With middle and late transition metals (M=Mn, Fe, Co, Ni), it generally proceeds through the conversion of MP y into a composite electrode made of metallic nanosized particles embedded into a Li 3 P matrix (MP y + 3yLi→yLi 3 P + M°) [2,3]. These so-called conversion reactions [4] offer a new type of energy storage involving a larger exchange of Li.…”

Tunable and Specific Formation of C@NiCoP Peapods with Enhanced HER Activity and Lithium Storage Performance

“…[14][15][16][17] Above all, identifying and developing highlye fficient electrode materials for LIBs and highly active catalystsf or the HER, and Co-and Ni-based phosphide compounds holds significant promise.…”

“…[7,9,14] However,numerousefforts have been devoted to developingm ethods for the preparation of pure-phased Co-and Ni-based phosphide. Co-andN i-based phosphides have showns ome amazingp otential when applied in the fields of catalyst,e nergy storage, magnets, and so on.…”

“…Co-andN i-based phosphides have showns ome amazingp otential when applied in the fields of catalyst,e nergy storage, magnets, and so on. [6][7][8]14] Besides, the Ni-Co-based phases (NiÀCo, NiCoP,N iCoÀCH, etc.) have receivedcontinuous attention in recenty ears owing to their synergy efficiencya fforded by ternary phases.…”