H$_{\bm 2}$O $_{\bm 2}$-Aided One-Pot Hydrothermal Synthesis of Nanocrystalline LiMn$_{\bm 2}$O$_{\bm 4}$ Cathode for Lithium Batteries

A simple and H
₂
O
₂
-aided hydrothermal (HDT) method has been deployed to synthesize nanocrystalline LiMn
₂
O
₄
at 140°C using an in-house-made hydrothermal reaction vessel. Phase pure, highly crystalline, and uniformly distributed nanorods of 100 nm length are obtained from the H
₂
O
₂
aided exothermic oxidation of precursor mix, especially when an excess amount of lithium (Li: Mn as 2:1) is used. The crystalline nature of LiMn
₂
O
₄
and the growth of nanorods along (111) crystallographic direction are understood from powder x-ray diffraction (PXRD) and selective area electron diffraction (SAED) analysis, respectively. The synthesized cathode exhibited an initial capacity of 118 mAh g
^-1
with a slightly higher initial capacity fade (9%) and a progressively stabilized (<; 3% capacity fade) specific capacity behavior upon cycling. An equivalent circuit model is proposed to fit with the observed impedance behavior of LiMn
₂
O
₄
cathode. The exploitation of low temperature assisted one-pot hydrothermal synthesis to prepare nanocrystalline LiMn
₂
O
₄
compound and the suitability of the same to exhibit better lithium intercalation behavior are demonstrated in this communication.