Modification of the electrochemical activity of LiMn1.95Si0.05O4 spinel via addition of phases with different physico-chemical properties

Abstract

We report the synthesis of composites based on freeze–dried LiMn_1.95Si_0.05O₄ spinel. In order to improve the active material–electrolyte interface for better cyclability, three different additive materials were chosen: LiMn_1.9Ga_0.1O₄, Al₂O₃ and Li₃PO₄. A morphologic examination of the composites demonstrated a good connection of the homogeneous primary particles about 50 nm in diameter and the different additive materials, especially when adding LiMn_1.9Ga_0.1O₄ and Al₂O₃. The nature of the additives was confirmed by XPS and magnetic measurements. The electrochemical study revealed that LiMn_1.9Ga_0.1O₄ is a suitable complement to LiMn_1.95Si_0.05O₄. Due to the similar transport properties, the concurrence of both differently substituted spinels in the electrode material has a synergistic effect favoring the electrochemical response of the cathode composite.