Single-crystalline LiMn2O4 nanorods as cathode material with enhanced performance for Li-ion battery synthesized via template-engaged reaction

• Single-crystalline LiMn2O4 nanorods were synthesized via template-engaged reaction.
• Phase transformation from tetragonal β-MnO2 to cubic LiMn2O4 was explored.
• LiMn2O4 nanorods deliver 125 mAh g-1 at 1C and 75% capacity retention at 3C.
• Recycled LiMn2O4 nanorods still keep spinel structure and single-crystal nature.

Single-crystalline LiMn2O4 nanorods with a diameter of ~ 100 nm were synthesized via a template-engaged reaction by using tetragonal β-MnO2 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-MnO2 nanorods to cubic LiMn2O4 nanorods. The obtained LiMn2O4 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 LiMn2O4) 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 LiMn2O4 nanorods.