Ordered LiMPO4 (M = Fe, Mn) nanorods synthesized from NH4MPO4·H2O microplates by stress involved ion exchange for Li-ion batteries

Abstract

Nanoengineering has proven to be an effective strategy to improve the electrochemical properties of LiMPO₄ (M = Fe, Mn). In this work, we report an ‘up-to-down’ way to synthesize LiMPO₄ nanorods through an ion-exchange route using pre-prepared NH₄MPO₄·H₂O microplates as the precursor and LiAc as the Li source. The similarity in crystal structure between NH₄MPO₄·H₂O and LiMPO₄ allows the occurrence of the ion-exchange reaction, while their structural difference induces lattice stress that breaks the NH₄MPO₄·H₂O microplates to form interconnected, orderly arranged LiMPO₄ nanorods. This work provides a general method to synthesize nanosized LiMPO₄ from microsized NH₄MPO₄·H₂O by taking advantage of their crystallization characteristics. The nanoscaled LiMPO₄/C composites exhibit promising electrochemical properties after carbon coating.