Dilithium pyridine-2, 5-dicarboxylate as potential anode material for Li-ion battery

Amongst various small molecules with different functional groups, conjugated carbonyls are the most promising materials for lithium storage at low potential. This work reports lithium storage in dilithium pyridine-2, 5-dicarboxylate small molecule. We show here that dilithium pyridine-2, 5-dicarboxylate reversibly stores 2 mol of Li-ion per molecule, giving a reversible capacity of 307 mAh/g at an average voltage of 1.0 V. The capacity retention after 500 cycles at 1C rate is 69 %. This material shows impressive rate performance with a capacity retention of 140 mAh/g at 5C rate. The inclusion of electronegative nitrogen in the benzene ring helps in improving the storage performance compared to lithium terephthalate. Further ex-situ studies demonstrate possible mechanism for reversible lithium storage. Our findings showcase that the deliberately engineered organic electrode material facilitates the development of high capacity lithium-ion battery.