Designing 3D Porous Organic Polymers for High-Performance Organic Battery Cathodes
Bei-Chun Liao, Bo-Han Jian, Ming‐Jung Wu, Jyh‐Tsung Lee
Abstract
Organic batteries offer several advantages, including high energy density, tunable voltage, environmental friendliness, and low cost. To enhance cell performance, porous organic polymers (POPs) with high surface areas and cross-linked structures are used. In this study, we designed three-dimensional (3D) and two-dimensional (2D) POPs as organic cathodes using tetrahedral and planar building blocks, respectively, and studied their electrochemical performance. Tetrakis(4-ethynylphenyl)methane or 1,3,5-triethynylbenzene as a tetrahedral or planar core and 9,10-anthraquinone (AQ) azide as a linker were used to synthesize 3D or 2D POPs through click polymerization. The chemical structures of the POPs were characterized by nuclear magnetic resonance and infrared spectroscopy. The results confirm that the POPs are cross-linked by forming 1,2,3-triazolyl rings. Brunauer–Emmett–Teller surface area analysis revealed that the 3D AQ-POP had a high surface area of 456 m 2 g –1, compared to 0.3 m 2 g –1 for the 2D AQ-POP. Additionally, the cell with the 3D AQ-POP cathode exhibited high energy capacity (115 mAh g –1 at 1C), improved C-rate, and enhanced cycle life performance (85% retention after 300 cycles). Compared to 2D POP cathodes, 3D POP cathodes offer excellent cell performance.