Well-ordered high crystalline LiNi0.5Mn1.5O4 spinel has been readily synthesized by a molten salt method using a mixture of LiCl and LiOH salts. Synthetic variables on the synthesis of LiNi0.5Mn1.5O4, 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 LiNi0.5Mn1.5O4 synthesized at 900 and 950degreesC have cubic spinel structure (Fd (3) over barm) with clear octahedral dimension. LiNi0.5Mn1.5O4 spinel phase began to decompose at around 1000degreesC accompanied with structural and morphological degradation. LiNi0.5Mn1.5O4 powders synthesized at 900degreesC for 3 It delivered an initial discharge capacity of 139 mAh/g with excellent capacity retention rate more than 99% after 50 cycles. (C) 2003 Elsevier Ltd. All rights reserved.