A Monocrystalline Coordination Polymer with Multiple Redox Centers as a High-Performance Cathode for Lithium-Ion Batteries.

Abstract

Coordination polymers can take advantage of both transition metal redox and organic ligand redox, thus serving as promising cathodes with multiple redox centers toward higher-performance lithium-ion batteries (LIBs). Here, we selected the high-capacity carbonyl compound of chloranilic acid (CA) as organic ligand to coordinate with the high-voltage Cu2+ as transition metal node and successfully synthesized copper(II) chloranilate (CuCA) with π-d conjugation, layered structure and monocrystalline nature. The resulting CuCA presents inorganic and organic redox centers, high electronic conductivity and fast Li+ diffusion kinetics, leading to high discharge capacity (297.0 mAh g-1 at 50 mA g-1 ), excellent rate capability (160.6 mAh g-1 at 1000 mA g-1 ) and good cycling stability (165.5 mAh g-1 at 500 mA g-1 after 50 cycles) with quasi-solid-state electrolyte. This work will provide insightful understanding of the materials design strategies to develop more efficient coordination polymer cathodes for LIBs.