Work

p / n ‐Type Polyimide Covalent Organic Frameworks for High‐Performance Cathodes in Sodium‐Ion Batteries

Year: 2024

Type: article

Abstract: Covalent organic frameworks (COFs) are viewed as promising organic electrode materials for metal‐ion batteries due to their structural diversity and tailoring capabilities. In this work, firstly using the monomers N,N,N′,N′‐tetrakis(4‐aminophenyl)‐1,4‐phenylenediamine ( TPDA ) and terephthaldehyde ( TA ), p‐type phenylenediamine‐based imine‐linked TPDA‐TA‐COF is synthesized. To construct a bipolar redox‐active, porous and highly crystalline polyimide‐linked COF , i.e., TPDA‐NDI‐COF , n‐type 1,4,5,8‐naphthalene tetracarboxylic dianhydride ( NDA ) molecules are incorporated into p‐type TPDA‐TA‐COF structure via postsynthetic linker exchange method. This tailored COF demonstrated a wide potential window (1.03.6 V vs Na + /Na) with dual redox‐active centers, positioning it as a favorable cathode material for sodium‐ion batteries (SIBs). Owing to the inheritance of multiple redox functionalities, TPDA‐NDI‐COF can deliver a specific capacity of 67 mAh g −1 at 0.05 A g −1 , which is double the capacity of TPDA‐TA‐COF (28 mAh g −1 ). The incorporation of carbon nanotube (CNT) into the TPDA‐NDI‐COF matrix resulted in an enhancement of specific capacity to 120 mAh g −1 at 0.02 A g −1 . TPDA‐NDI‐50%CNT demonstrated robust cyclic stability and retained a capacity of 92 mAh g −1 even after 10 000 cycles at 1.0 A g −1 . Furthermore, the COF cathode exhibited an average discharge voltage of 2.1 V, surpassing the performance of most reported COF as a host material.

Source: Small

DOI: 10.1002/smll.202407525