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

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. The market boom of Li‐ion batteries has exacerbated the resource shortage and environmentally unfriendly technologies in traditional cathodes. The in situ growth of graphdiyne fills the blank in coating technologies for organic cathodes to solve their issues of low conductivity and molecular dissolution. High‐energy‐density organic batteries can become compelling alternatives for Li‐ion batteries.