Rational design of nanocubic Fe3O4/FeP@C with heterostructure as advanced anode material towards enhanced lithium storage

Lithium-ion batteries have attracted considerable attention due to their potential in energy storage applications. However, a primary challenge lies in identifying suitable host materials that can effectively manage the kinetic properties and substantial volumetric variations associated with lithium-ion storage. In this study, we present a unique nanocube composed of numerous heterostructured Fe3O4/FeP nanoparticles, encapsulated within a nitrogen-doped thin carbon layer (Fe3O4/FeP@C). This structure is achieved through a straightforward hydrothermal and partial phosphating technique. Impressively, a reversible capacity of the Fe3O4/FeP@C anode maintains at 379.4 mAh g−1 at 2 A g−1 even after 800 cycles. When paired with a commercial LiFePO4 cathode, the full cells display a high reversible capacity. Additionally, the adsorption energies barrier of Li+ on Fe3O4/FeP, calculated using density functional theory, is lower than those of the control samples. Additionally, the Fermi energy of the Fe3O4/FeP surface is lower, and the peak of the density of states of Fe3O4/FeP is slightly higher than its counterparts. These findings suggest that the construction of the nanocubic Fe3O4/FeP@C with heterostructure significantly enhances electronic and ionic migration. These discoveries create opportunities for additional research into high-performance anode materials for lithium-ion storage.