Synthesis of a microporous poly-benzimidazole as high performance anode materials for lithium-ion batteries

A novel 2D microporous poly-benzimidazole is designed and synthesized. Using pyromellitic acid as a replacement reactant allows it to fill the vacancy in the poly-bezimidazole family because of the instability of tetraformylbenzene. Heated sample is used as anode for lithium-ion batteries and exhibits a remarkable long cycling life, high reversible capacity and good rate performance. [Display omitted] •A strategy for design of novel microporous poly-bezimidazole (MPBI) is proposed.•The residual edge groups of MPBI were selectively removed by heat-treatment.•The heat-treatment MPBI (MPBI-550) based LIB anode delivered high capacity.•MPBI-550 afforded an excellent cycle durability and rate performance. Heteroatom-rich two-dimensional graphene-like structure polymers are highly demanded as high-performance anode materials for lithium ion batteries. Here, a new microporous poly-benzimidazole (MPBI) is accomplished by a condensation reaction between pyromellitic acid and 1,2,4,5-tetraaminobenzene in polyphosphoric acid medium. After heat-treatment at 550 °C, the integrated frame structure of the obtained MPBI-550 remains unchanged without the residual edge groups. Due to the holey pore framework, nitrogen-rich aromatic rings and two-dimensional graphene-like structure, MPBI-550 is suitable for lithium-ion battery anode. It exhibits a remarkable long cycling life, high reversible capacity of 700 mAh g−1 (at 1 A g−1) after 500 cycles and a good rate performance. Such a low-cost and high-performance material constitutes a step towards the design and manufacture of functional anode materials for next generation lithium-ion batteries.