Crepe Cake Structured Ca-Organic-CNT Frameworks to Boost Zn2+ Intercalation in Aqueous Zn/Organic Battery

Organic-based frameworks are increasingly recognized as promising cathode materials for aqueous zinc–ion batteries (AZIBs), owing to their structural specificity and renewable/safety nature. The electrochemical performance, however, is less than optimal due to the inadequate structural stability and poor electronic/ionic conductivity of the organic-based frameworks, resulting in rapid capacity decay and poor rate capability. Herein, a crepe cake structured Ca-Organic-CNT framework is designed to address these two problems. In this material architecture, the porous carbon nanotube (CNT) network facilitates efficient electron transfer and enhances structural stability, while Ca-Organic frameworks with crystal enlargement boost Zn 2+ intercalation and release. The hybrid material exhibits balanced high performance with respect to specific capacity and cycling stability. A reversible specific capacity of 475 mAh g −1 is achieved at 50 mA g −1 with a high capacity retention rate of 91% even after 400 cycles. This work provides a strategy for the rational design of organic electrode materials for high performance AZIBs.