Alkynyl‐Bipyridine–Based Conjugated Microporous Polymer Anode for Lithium Storage

ABSTRACT Conjugated microporous polymer (CMP) anode materials composed of sp‐ and sp ² ‐hybridized carbons are promising for lithium storage, owing to their π ‐electron‐delocalization framework and abundant active sites. Unfortunately, such CMP‐based materials have rarely been reported, largely stemming from the synthetic challenge of achieving the predesigned structural characteristics (e.g., uniform pores). Herein, we synthesize an alkynyl‐bipyridine‐CMP (Alk‐Bpy‐CMP) which features a well‐defined six‐membered ring structure. The smallest structural unit consisting of alkynyl linkages, bipyridine, and aromatic rings processes high‐density distributed active sites and an extended π ‐conjugated system. At a current density of 0.1 A g ⁻¹ , the Alk‐Bpy‐CMP shows a specific capacity of 674 mAh g ⁻¹ after 100 cycles. This phenomenon can be ascribed to the preferential lithium storage behavior of bipyridine and alkynyl linkages, which possess a high proportion of storage sites. By boosting conductive property via reduced graphene oxide (rGO) encapsulation, the specific capacity was further enhanced to 1020 mAh g ⁻¹ after 200 cycles at 0.1 A g ⁻¹ , approaching the theoretical specific capacity (1145.4 mAh g ⁻¹ ) and exceeding the majority of reported CMP. A stable 1000‐cycle discharge and charge test indicates the robust cycling performance of the resultant Alk‐Bpy‐CMP@rGO.