Iron Phosphide Confined in Carbon Nanofibers as a Free-Standing Flexible Anode for High-Performance Lithium-Ion Batteries

Abstract

Iron phosphide with high specific capacity has emerged as an appealing candidate for next-generation lithium-ion battery anodes. However, iron phosphide could undergo conversion reactions and generally suffer from a rapid capacity degradation upon cycling due to its structure pulverization. Chemomechanical breakdown of iron phosphide due to its rigidity has been a challenge to fully realizing its electrochemical performance. To address this challenge, we report here on an enticing opportunity: a flexible, free-standing iron phosphide anode with Fe2P nanoparticles confined in carbon nanofibers may overcome existing challenges. For the synthesis, we introduce a facile electrospinning strategy that enables in situ formation of Fe2P within a carbon matrix. Such a carbon matrix can effectively minimize the structure change of Fe2P particles and protect them from pulverization, allowing the electrodes to retain a free-standing structure after long-term cycling. The produced electrodes showed excellent electrochemical performance in lithium-ion half and full cells, as well as in flexible pouch cells. These results demonstrate the successful development of iron phosphide materials toward high capacity, light weight, and flexible energy storage.

Honeycomb-like 3D carbon skeletons with embedded phosphorus-rich phosphide nanoparticles as advanced anodes for lithium-ion batteries

“…The characteristic peaks of FeP 2 gradually disappear in the first lithiation process, but don't gradually increase and return to the initial state of FeP 2 in the following delithiation processes, suggesting that the electrochemically formed FeP 2 is amorphous. 30 After the activation of the first cycle, the reduction peak moves to about 0.59 V, and the oxidation peak moves to about 1.29 V. Such a voltage shift can be ascribed to the strain and structure changes of the FeP 2 crystal in the initial lithiation process. A similar phenomenon was also observed for FeP 2 NAs@C, FeP 2 NAs, and other conversion-based anode materials (Fig.…”

“…Such good rate performance of FeP 2 NPs@CK is better than that of carbon-coated phosphorus-rich iron phosphides in previously reported studies. 17,20,22,23,30,[33][34][35][36] To further demonstrate the stable cycle performance of FeP 2 NPs@CK, the cell was repeatedly cycled for 500 cycles at the high current density of 1 A g −1 , as depicted in Fig. 4f.…”

“…Such good rate performance of FeP 2 NPs@CK is better than that of carbon-coated phosphorus-rich iron phosphides in previously reported studies. 17,20,22,23,30,33–36…”

Phosphorus/Phosphide‐Based Materials for Alkali Metal‐Ion Batteries

“…Fe forms diverse metal phosphides, including FeP 2 , [113] Fe 2 P, [114,115] and FeP. [116] Particularly, amorphous Fe-based phosphides buffered the volume changes, preventing performance degradation during cycles.…”

Engineering a ternary one-dimensional Fe2P@SnP0.94@MoS2 mesostructure through magnetic-field-induced self-assembly as a high-performance lithium-ion battery anode

“…3,4 Yang et al developed a Fe 2 P@carbon matrix using an electrospinning technique that showed a capacity of 573 mA h g À1 at the 300th cycle under 0.2 A g À1 . 5 Tang and co-workers synthesized a FeS 2 /Fe 7 S 8 -rGO composite through a solvothermal method that displayed 514 mA h g À1 after long-term cycling and good rate performance. 6 Liu et al prepared a graphene-supported MoS 2 nanosheet.…”