Comparison of Metal Ion Dissolutions from Lithium Ion Battery Cathodes

Abstract

With an aim to develop a better understanding of the capacity fade mechanisms of manganese spinel oxide cathodes, the amount of metal ion dissolution from various lithium ion battery cathodes (layered, orthorhombic , spinel, spinel, and olivine) is compared. Orthorhombic , layered , and spinel containing exhibit much higher amounts of manganese dissolution irrespective of the structure compared to the total transition metal ion dissolution found from cathodes containing , such as layered and spinel or from layered and olivine . However, the manganese dissolution from the -containing spinel oxides could be lowered significantly to the levels found from , , and by appropriate cationic and anionic (fluorine) substitutions, which leads to excellent capacity retention at elevated temperatures. For example, and exhibit manganese dissolutions of 1.5 and 1.1%, respectively, compared to 3.2% for . Furthermore, manganese dissolution is found to bear a clear relationship to the lattice parameter difference between the two cubic phases formed during the charge–discharge process; Mn dissolution decreases with decreasing .