A LAYERED LI-MN-O BASED CATHODE MATERIAL FOR LITHIUM-ION BATTERIES WITH STABILIZED OXYGEN REDOX

Abstract

The primary cause of the recent, more severe improvement in the global energy problem is the sharp increase in energy consumption. The source of Li ions in the modern lithium-ion battery is the active material in the cathode, which also controls the battery's cost and energy density. Thus, the creation of cathode materials with improved electrochemical characteristics that can replace traditional cathode materials is essential to the evolution of lithium-ion batteries of the future. High-energy chemistry batteries are achieved via the grouping of cationic and anionic activities found in Li-rich materials, which overcomes the conventional capacity limit. Lately, the observed enhanced capacity in relevant systems has been attributed to the anionic electrochemical process associated with oxygen. Nevertheless, using anionic redox reactions unavoidably from the lattice hastens structural deformation and electrochemical performance degradation. Understanding their electrochemical properties becomes crucial to addressing these issues, and it is anticipated that this knowledge will provide helpful advice for the creation of both materials and cells. Due to Li-rich cathode materials’ ability to produce reversing capacities of 200 mAh/g, Li2Mn3O7 is a promising source of cathodes for Li-ion batteries. For this work, Li2Mn3O7 was synthesized using different precursors (Mn2+, Mn3+, and Mn4+ salts and oxides) and characterized by physicochemical and electrochemical methods. The electrodes used in tests were newly prepared and had undergone cycles between 4.8 and 2.0 V vs. Li+/Li to evaluate their electrochemical properties. Among the Li2Mn3O7-0 (LRM0), Li2Mn3O7-1 (LRM1), Li2Mn3O7-2 (LRM2), and Li2Mn3O7-3 (LRM3), the LRM0 showed higher specific capacity of 216 mAh/g with retained capacity of 74.8% after 50 cycles. Besides, LRM1 delivered the lowest capacity but highest capacity retention of 89% over 50 cycles. From electrochemical and characterization tests, the difference in performance of materials related to starting materials was identified, leading to the need for further studies. Considering the same synthesis condition and final chemical composition, the obtained results distinguished in cationic and anionic redox reactions.