A low-cost and one-step synthesis of a novel hierarchically porous Fe3O4/C composite with exceptional porosity and superior Li+ storage performance

Abstract

A hierarchical pore structure is believed to be an excellent architecture for metal oxide anode materials of lithium-ion batteries (LIBs). However, the difficulty and complication in synthesis limit their further application. In this work, a novel Fe₃O₄/C composite with a hierarchical pore carbon (HPC) network has been synthesized simply by one-step pyrolysis synthesis using ferrous gluconate as the precursor. This hierarchical porous framework derived from a loose assembly of the intersecting porous carbon rods presents a wide range of pore sizes and a rather large surface area (>226 cm² g⁻¹). Embedded with well-crystalline Fe₃O₄ particles, the resulting Fe₃O₄@HPC composite exhibits a high capacity of 1112 mA h g⁻¹ at the end of the 100th cycle and an enhanced rate performance of above 600 mA h g⁻¹ at a high current density of 2000 mA g⁻¹. This might derive from the unique hierarchical pore system with a high overall porosity, which can not only facilitate the electrolyte diffusion but also alleviate severe volume variation efficiently in lithium ion insertion/extraction. More importantly, this provides us with a successful example to fabricate advanced anode materials simply by one-step pyrolysis of cheap organic–inorganic hybrids at low-cost.