A Novel Salen-based Porous Framework Polymer as Durable Anode for Lithium-Ion Storage

Organic electrode materials with abundant resources, environmental friendliness and recyclability play a crucial role in rechargeable lithium-ion batteries (LIBs). However, the inferior electrical conductivity and unsatisfactory long-term cycling performance seriously impede their large-scale application in LIBs. Herein, a novel salen-based porous framework polymer (SPP) with a large conjugated skeleton was constructed and utilized as anode for LIBs. Owing to its unique architecture with a large conjugated skeleton facilitating the electron transport, rich pores accelerating the organic electrolyte infiltration, and stable skeleton structure improving the long-term cycling performance, SPP delivered a high specific capacity of 337 mA h g⁻¹ at 0.1 C (1 C=250 mA g⁻¹) after 100 cycles, and robust rate capacity of 95.5 mA h g⁻¹ at 32 C. Importantly, an impressive long-term cycling performance with a storage capacity of 155.7 mA h g⁻¹ at 8 C after 4000 cycles was obtained, showing a durable cyclic stability of SPP. Furthermore, the lithium storage mechanism of SPP was evaluated by ex-situ X-ray photoelectron spectroscopy, manifesting that the multiple active sites of C=N, −OH, and benzene ring were responsible for the superior lithium storage performance. The novel SPP presented in this work should be a promising organic electrode for energy storage applications.