Electrochemical Performance and Phase Transitions between 1.5 and 4.9 V of Highly-Ordered LiNi0.5Mn1.5O4 with Tailored Morphology: Influence of the Lithiation Method. Issue 1 (13th December 2016)

• Record Type: Journal Article
• Authors: Mancini, M.; Gabrielli, G.; Axmann, P.; Wohlfahrt-Mehrens, M.
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 1(2017)
• Page Start: A6229
• Page End: A6235
• Publication Date: 2016-12-13
• Subjects: Cathode -- High-Energy -- Li-ion Batteries -- Lithium-Nickel-Manganese Oxide; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0291701jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : We report about the electrochemical performance in the potential range 1.5 to 4.9 V of highly ordered, stoichiometric LiNi0.5 Mn1.5 O4 with spinel structure and tailored morphology. Structural and morphological parameters are optimized for obtaining maximum energy density in Li-ion cell applications. The effect of the discharge cutoff on the cathode capacity, cycling stability and coulombic efficiency is discussed. Li-rich structures with composition Li1+x Ni0.5 Mn1.5 O4 (0 < × < 1) obtained via electrochemical lithiation are investigated via ex-situ XRD and SEM analysis. The results are compared with those obtained via a chemical lithiation method, showing that the phase transition from cubic LiNi0.5 Mn1.5 O4 to tetragonal Li2 Ni0.5 Mn1.5 O4 occurs via a two-phase mechanism with no evidence of intermediate phases. The superior electrochemical performance of the synthesized cathode material is ascribed to its specific morphology that provides suitable properties for reduced side-reactions with the electrolyte and low impact of the volumetric changes during cycling.