Construction of π–d metal–organic frameworks featuring butterfly-inspired building blocks as efficient anodes for high-performance lithium-ion batteries

Abstract

By leveraging the intrinsic advantages of electrical conductivity, enhanced π-electron transfer, synergistic active sites, tunable electronic structures, and improved stability, a butterfly-shaped conjugated π–d copper-catecholate-based metal–organic framework (Cu-DBC MOF), is constructed and delivered as a novel anodic electrode for lithium-ion batteries. The unique π–d conjugation between copper ions and catecholate ligands in Cu-DBC significantly enhances its electrical conductivity and facilitates lithium-ion transport, addressing key limitations of conventional MOF-based anodes. As a result, Cu-DBC demonstrates exceptional electrochemical behavior, achieving a reversible capacity of 550 mAh g⁻¹ within 100 mA g⁻¹, showcasing excellent rate-capability properties with 192 mAh g⁻¹ under 1000 mA g⁻¹, and maintaining prolonged cycling stability, delivering 410 ± 10 mAh g⁻¹ after 100 cycles within 100 mA g⁻¹ and 170 ± 10 mAh g⁻¹ after 2500 cycles even under 1000 mA g⁻¹, respectively, based on the lithiation–delithiation reactions involving both redox reactions of Cu²⁺/Cu⁺ and [Cu(OR)₄]³⁻/[Cu(OR)₄]²⁻ couples.