Study of LiNi0.5Mn1.5O4 Morphological Features for Reduced Electrolyte Decomposition at High Potential

A stoichiometric, high density LiMn1.5Ni0.5O4.0 (HD-LMNO) with tailored morphology and particle architecture is electrochemically evaluated as high-voltage cathode material in standard organic electrolyte. The aim of the study is to demonstrate significant influence of the active material morphology on the electrolyte decomposition at high voltage. HD-LMNO electrodes tested according specific electrochemical protocols show reduced electrolyte decomposition at high potential in comparison with a standard LMNO. The reduced decomposition is ascribed to the optimized particle architecture, which guarantees elevated electrochemical performances and limited surface area directly in contact with the electrolyte. The electrolyte decomposition can be further reduced by determining the optimal working conditions for HD-LMNO electrodes. The optimal working conditions are determined by adopting different charge/discharge protocols, which include potentiostatic steps in case of fast-charging rates. Using the appropriate charging protocol leads to higher reversible capacities and coulombic efficiencies for both fast and low cycling rates. (C) 2015 The Electrochemical Society. All rights reserved.