Single-crystalline LiMn_2O_4 nanorods as cathode material with enhanced performance for Li-ion battery synthesized via template-engaged reaction

摘要

Single-crystalline LiMn_2O_4 nanorods with a diameter of ~ 100 nm were synthesized via a template-engaged reaction by using tetragonal β-MnO_2 nanorods as starting material. The investigations on the structures and morphologies of both the precursor and the final product reveal that a minimal structure reconstruction can be responsible for the chemical transformation from tetragonal β-MnO_2 nanorods to cubic LiMn_2O_4 nanorods. The obtained LiMn_2O _4 nanorods as cathode material for Li-ion battery exhibit superior high-rate capability and good cycling stability in a potential range of 3.5-4.3 V vs. Li~+/Li, which can deliver an initial discharge capacity of 125 mAh g~(- 1) (> 84% of the theoretical capacity of LiMn _2O_4) at a current rate of 0.5 C, and about 75% of its initial capacity can be remained after 500 charge-discharge cycles at a current rate of 3 C. Importantly, the rod-like nanostructure and single-crystalline nature are also well preserved after prolonging the charge/discharge cycling time at a relatively high current rate, indicating good structural stability of the single-crystalline nanorods during the lithium intercalation/deintercalation processes, and such high-rate capacity and cycling performance can be ascribed to the favorable morphology and the high crystallinity of the obtained LiMn _2O_4 nanorods.