Design of two-dimensional coordination polymer with multiple redox-active sites for high-performance lithium-ion batteries anode material

Coordination polymers (CPs) have received a lot of attention as lithium-ion battery (LIB) anode electrode materials because of their varied chemical structure. In this paper, a novel two-dimensional (2D) [Co(BDC)_1/2(PZA)(H₂O)₂]_n (Co-CP) as anode material for rechargeable LIBs is introduced to meet the challenges of poor cycling performance and low specific capacity of organic electrode materials by a simple hydrothermal reaction. The Co-CP delivered high electrolyte stability due to the combination of the metal center and the organic ligand, and it has a significant reversible capacity of 843 mAh g⁻¹ at 200 mA g⁻¹ after 200 cycles when tested as LIB anode materials. The electrode was able to regain its initial capabilities when the current rate was reduced to 100 mA g⁻¹ after elevating at the high current density test of 2000 mA g⁻¹, suggesting the good rate performance of Co-CP. The experimental results show that the synergistic redox reaction of the metal center and the organic ligand contributes to the high lithium storage performance.