Well-ordered high crystalline LiNi 0 . 5 Mn 1 . 5 O 4 spinel has been readily synthesized by a molten salt method using a mixture of LiCl and LiOH salts. Synthetic variables on the synthesis of LiNi 0 . 5 Mn 1 . 5 O 4 , such as synthetic atmosphere, LiCl salt amount, synthetic temperature, and synthetic time, were intensively investigated. X-ray diffraction (XRD) patterns and scanning electron microscopic (SEM) images showed that LiNi 0 . 5 Mn 1 . 5 O 4 synthesized at 900 and 950 o C have cubic spinel structure (Fd3m) with clear octahedral dimension. LiNi 0 . 5 Mn 1 . 5 O 4 spinel phase began to decompose at around 1000 o C accompanied with structural and morphological degradation. LiNi 0 . 5 Mn 1 . 5 O 4 powders synthesized at 900 o C for 3h delivered an initial discharge capacity of 139mAh/g with excellent capacity retention rate more than 99% after 50 cycles.