Structural and Electrochemical Properties of Calendered Lithium Manganese Oxide Cathodes

Lithium manganese oxide in a spinel structure (LiMn2O4, LMO) is a cathode material of non-toxicity, low costs, and a high electrochemical potential. In contrast manganese dissolution, structural fatigue, and microcracks lead to poor cycling stability and capacity fading. Regarding a basic understanding of the influence of the calendering process and the consequent electrode structure on the life span of sensitive active materials, cathodes with various coating densities have been manufactured and analyzed in terms of structural and mechanical properties. Consequences of high mechanical stress applied by calendering in order to achieve the desired cathode densities are breakages of the active material particles, leading to a diminished life span during the electrochemical characterization. An optimal coating density of ca. 2 gcm(-3) for the investigated cathodes as a compromise of Crate performance, due to electrical conductivity, and long-term cycling has been found.