An Azamacrocyclic Ligand-Functionalized Transition-Metal Scavenging Polymer for 5.0 V Class High-Energy Lithium-Ion Batteries

The electrochemical performance of 5.0 V class full cells comprising LiNi0.5Mn1.5O4-graphite is improved by applying metal scavenging coats on the negative electrode surface. To achieve this transition-metal scavenging ability, a tetradentate azamacrocyclic ligand is introduced into a poly(vinyl alcohol) (PVA) backbone through a one-step esterification reaction. The azamacrocyclic ligand-functionalized PVA scavenged five times as many metal ions as that of the pristine polymer counterpart. Due to this scavenging ability, the Coulombic efficiency and cyclability are greatly enhanced in a LiNi0.5Mn1.5O4/functionalized graphite cell composition. Consequently, the increase in discharge resistance during cycles was well retained due to the introduction of this functional polymer on the negative electrode surface.