In Situ Coating Graphdiyne for High‐Energy‐Density and Stable Organic Cathodes

Abstract

The preparation of organic small‐molecule cathodes is simple and low‐cost; however, their low conductivity and molecular dissolution are two key issues that mean their energy density and power performance are far lower than those of inorganic batteries, thus hindering their practical application. To develop an effective coating technology is the key to obtain high‐performance organic batteries. A general method of in situ weaving all‐carbon graphdiyne nanocoatings is demonstrated. The graphdiyne can be conformally weaved on organic particles under mild conditions so that the conductivity is increased and the dissolution is suppressed. After weaving graphdiyne nanocoat, the active mass of the small‐molecule organic cathodes rise to 93%, thus delivering a higher energy density of 310 W h kg−1 than previously reported, and the power performance and long‐term stability are greatly improved. Additionally, this method shows great potential to become the crucial technology for fabricating organic batteries with energy density close to prevailing lithium‐ion batteries.

A Biologically Muscle‐Inspired Polyurethane with Super‐Tough, Thermal Reparable and Self‐Healing Capabilities for Stretchable Electronics

“…On the other hand, DA‐PU showed us amazing mechanical performances with the elongation at break of 1900% and toughness of 175.9 MJ m −3 , which exceeded most polyurethane elastomers. [ 8d,10a,16a,17 ] And its tear resistance ability reached elongation at break of 1120% and toughness of 51.7 MJ m −3 , which were even higher than those of many polyurethane elastomers without notch. DA‐PU was used as a representative to demonstrate the attractive tear resistance performance during stretching (Figure 1c, above).…”

High Capacity and Energy Density Organic Lithium‐Ion Battery Based on Buckypaper with Stable π‐Radical

“…Despite these chemical and technical efforts, the active mass ratio of the most organic cathodes has been still much lower than those of inorganic oxides (>90 wt % of active material). A coating of organic active material was recently demonstrated as a new tool for realizing the cathodes with quite high active material contents (Table S3) [38–43] . As a distinguishable example, Li and co‐workers recently reported a cathode with active mass ratio of 93 wt % in which a 2D graphdiyne sheet was used as both conductive additive and coating agent, and achieved a high charge–discharge efficiency and rate characteristics (Table S3) [42] .…”

“…A coating of organic active material was recently demonstrated as a new tool for realizing the cathodes with quite high active material contents (Table S3). [38][39][40][41][42][43] As a distinguishable example, Li and co-workers recently reported a cathode with active mass ratio of 93 wt % in which a 2D graphdiyne sheet was used as both conductive additive and coating agent, and achieved a high charge-discharge efficiency and rate characteristics (Table S3). [42] Microcrystals of the cathode active molecule (3,4,9,10-perylenetetracarboxylic dianhydride) deposited on a copper foil was coated with the graphdiyne sheet by the polymerization of hexaethynylbenzene in a solution.…”

Nanostructured strategies towards boosting organic lithium-ion batteries

“…Herein, Li et al fabricated small organic molecular materials, 3, 4, 9, 10-perylenetetracarboxylic dianhydride (PTCDA) nanoparticles with seamlessly weaving an all-carbon GDY nanoshell outside (Fig. 4a, b) [76]. On account of the coreshell structure based on GDY nanocoating, the organic cathode delivers a higher capacity and superior cycle stability than the pristine PTCDA cathode ( Fig.…”