Connecting adjacent active layers with structural pillars for high-performance Li-organic batteries
Kun Zhang, You Pan, Xingyu Guo, Jifeng Wang, Chuanfa Li, Jiaxin Li, Meng Liao, Yi Jiang, Wenjun Li, Kailin Zhang, Qian Ye, Longmei Ma, Xiaocheng Gong, Kai Li, Ying Wang, Yue Gao, Xin-Gao Gong, Huisheng Peng, Bingjie Wang
Abstract
Organic electrode materials with the versatility of molecular engineering emerge as promising alternatives to construct high-performance batteries. However, a weak binding force between active layers leads to poor structural stability accompanied by a multi-electron redox, thus hindering the construction of practical devices based on organic materials. Herein, we report a structural engineering approach to improve the structural stability of organic molecules by pre-intercalating potassium ions (K + ) as pillars into the adjacent rhodizonate (C 6 O 6 2− ) layers. This enhanced binding, with increased coordination sites of K-O, effectively prevents the exfoliation of C 6 O 6 2− layers and provides stable diffusion channels for lithium ions (Li + ). The resulting batteries exhibit accelerated reaction kinetics and enhanced Li + diffusion, leading to a high energy density of 722 Wh kg −1 (based on active materials) and reversible capacity of 315 mAh g −1 at 1.0 C, with a capacity retention of 225 mAh g −1 after 500 cycles. In addition, by virtue of the flexible nature, a Li-K 2 C 6 O 6 battery has been made into flexible fibers for next-generation wearable systems, offering a new avenue for realizing practical devices based on organic single molecules. This work presents a general and efficient strategy to unlock theoretically high-performance organic electrode materials for advanced Li-organic batteries. • Pre-intercalating K + as pillars into adjacent layers enables stable configuration. • Enhanced structural stability and facilitated ionic diffusion are achieved in organic single molecules. • Novel fiber-shaped Li-K 2 C 6 O 6 batteries with high flexibility are constructed.