High Conductive Two-Dimensional Covalent Organic Framework for Lithium Storage with Large Capacity

Abstract

A high conductive 2D COF polyporphyrin (TThPP) linked by 4-thiophenephenyl groups was synthesized through an in situ chemical oxidative polymerization on the surface of copper foil. The TThPP films were used as the anode of lithium-ion battery, which exhibited high specific capacities, excellent rate performances, and long cycle lives due to the alignment of 2D polyporphyrin nanosheets, and they (i) can highly efficiently adsorb Li atoms, (ii) have short-ended paths for the fast lithium ion diffusion, and (iii) open nanopores holding electrolyte. The reversible capacity is up to 666 mAh/g. This is the first example of an organic 2D COF for an anode of lithium-ion battery and represents an important step toward the use of COFs in the next-generation high-performance lithium-ion battery.

A Dual Threat: Redox‐Activity and Electronic Structures of Well‐Defined Donor–Acceptor Fulleretic Covalent‐Organic Materials

“…The detailed procedure of iodine doping can be found in the Supporting Information. The values obtained herein are among some of the highest values reported in COFs to date . In addition, these conductivity studies are the first reports for COFs with covalently bound TCNQ moieties.…”

“…Herein, we demonstrate that the donor–acceptor alignment in well‐defined frameworks could drastically affect the electronic properties of the materials, resulting in circa 100 000 000‐fold conductivity enhancement, one of the largest increases reported for COFs . We probed charge transfer rates within the Marcus theory as a function of acceptor stacking.…”

Conjugated Microporous Polytetra(2‐Thienyl)ethylene as High Performance Anode Material for Lithium‐ and Sodium‐Ion Batteries

“…The low initial Coulombic efficiency can be attributed to irreversible reaction, which is a common phenomenon of anode materials for LIBs and could be mitigated by some prelithiation processes . Figure c shows the rate performance of PTTE‐based LIBs, PTTE can deliver specific capacitance of 973 mA h g −1 at a current density of 100 mA g −1 , which is much higher than that of most reported organic anode materials, such as Li 4 C 8 H 4 O 4 nanosheets (232 mA h g −1 at 24.1 mA g −1 ), CMP from porphyrin with 4‐thiophenephenyl groups (TThPP) (666 mA h g −1 at 200 mA g −1 ), poly(bithiophene)/carbon (PBT/C) composite (650 mA h g −1 at 320 mA g −1 ), PDCzBT (404 mA h g −1 at 100 mA g −1 ) and the ordered polypyrrole film (285 mA h g −1 at 300 mA g −1 ) . The high specific capacity of PTTE might be attributed to its high surface area and inherent homogeneous microporous structure, endowing PTTE with abundant active sites for Li ion storage.…”

Directional Charge Transport in Layered Two‐Dimensional Triazine‐Based Graphitic Carbon Nitride

“…[13] In contrast, substantially higher currents in the mAr ange were recorded for out-of-plane measurements (60 mAa t1V, Figure 2b). This conductivity value is comparable to some conjugated covalent organic frameworks (COFs) [14] and two orders of magnitude lower than for MoS 2 ,a2D semiconducting material (Table S2). This conductivity value is comparable to some conjugated covalent organic frameworks (COFs) [14] and two orders of magnitude lower than for MoS 2 ,a2D semiconducting material (Table S2).…”