Abstract
The polymer-assisted oxalate co-precipitation method has been developed to synthesize nanostructured LiNi 0.5 Mn 1.5 O 4 . In this method, polyacrylic acid (PAA) as a dispersant agent was applied in the co-precipitation process to achieve the well-dispersed and homogenous precursor route. The obtained powder possesses small particle around 50-100 nm as compared to the one synthesized by traditional co-precipitation method. Besides, the porous texture was also found in as-fabricated LiNi 0.5 Mn 1.5 O 4 . The X-ray diffraction reveals the well-crystallized cubic spinel structure without the presence of undesired impurities, such as NiO or Li x Ni 1-x O, commonly found in other fabrication method. An excellent cycling stability is obtained with the capacity retention over 90% after 100 cycles in 1 C at room temperature. Moreover, the superior rate capability was also derived by nanostructured LiNi 0.5 Mn 1.5 O 4 , in which the discharge capacity in 5 and 7 C is around 110 and 100 mAhg -1 , respectively. The greatly enhanced rate capability is attributed to the significantly shortened Li-ion diffusion pathway, associating with the nano-textured particle morphology. © 2012 Elsevier B.V.