Two‐Dimensional Crystalline Alkyne‐Rich Conjugated Carbonaceous Framework for Extremely Fast‐Charging Lithium‐Ion Batteries

ABSTRACT The development of high‐quality conjugated carbonaceous materials with fast mass transport kinetics is important for fast‐charging lithium (Li)‐ion batteries (LIBs). Here, we report a “molecular locking‐weaving” strategy to synthesize 2D alkyne‐rich Li carboxylate (LC) conjugated carbonaceous framework (LC‐ACF). Large‐area ultrathin LC‐ACF possesses high crystallinity, ordered stacking, and intrinsic mesoporous structure, creating well‐aligned and LC‐bridged fast Li‐ion diffusion channels. The incorporation of LC groups significantly changes the electronic structure of the conjugated framework to improve surface charge and electronic conductivity, endowing LC‐ACF with promoted electrokinetic effects to boost Li‐ion transport kinetics. Consequently, LC‐ACF shows exceptional fast‐charging capability, achieving high capacity (360.2 mA h g −1 , corresponding to 89.6% of the capacity at 0.2 A g −1 delivered in 1 min) and negligible capacity decay (30 000 cycles) at a high current density of 20 A g −1 . LC‐ACF||LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) full cells deliver an attractive capacity of 118.4 mA h g −1 (achieving 62.3% state‐of‐charge within 1.5 min) and a capacity retention of 90.3% after 3000 cycles at an extremely high rate of 20 C (1 C = 210 mA g −1 ). LC‐ACF||NCM811 pouch cells with outstanding fast‐charging performance were also achieved.