Flake (NH4)6Mo7O24/ Polydopamine as a High Performance Anode for Lithium Ion Batteries.

Ammonium molybdate tetrahydrate ((NH4)6Mo7O24) (AMT) is commonly used as the precursor to synthesize Mo‑based oxides or sulfides for lithium ion batteries (LIBs). However, the electrochemical lithium storage ability of AMT itself is unclear so far. In the present work, AMT is directly examined as a promising anode material for Li‑ion batteries with good capacity and cycling stability. To further improve the electrochemical performance of AMT, AMT/polydopamine (PDA) composite was simply synthesized via recrystallization and freeze drying methods. Unlike with block shape for AMT, the as‑prepared AMT/PDA composite shows flake morphology. The initial discharge capacity of AMT/PDA is reached up to 1471 mAh g-1. It delivers a reversible discharge capacity of 702 mAh g-1 at a current density of 300 mA g-1, and a stable reversible capacity of 383.6 mA h g-1 is retained at a current density of 0.5 A g-1 after 400 cycles. Moreover, the lithium storage mechanism is fully investigated. The results of this work could potentially expand the application of AMT and Mo‑based anode for LIBs.