Low-Dimensional and High-Crystallinity Carbonyl Cathodes Prepared by Physical Vapor Deposition for Green Aluminum Organic Batteries

Abstract

We report a low-cost, high theoretical specific capacity π-conjugated organic compound (PTCDA) with CO active centers as the cathode material in aluminum organic batteries. In addition, in order to improve the electron transport rate of PTCDA, a new method is proposed in this paper, which uses physical vapor deposition (PVD) method to make PTCDA recrystallize and grow on stainless steel and quartz glass substrates to improve its crystallinity. The increase of crystallinity expands the PTCDA π–π-conjugated system, making electrons more delocalized, which is beneficial to the transmission rate of electrons and ions, thereby enhancing the conductivity of the material. The experimental results show that compared with pristine PTCDA, PTCDA(Ss) and PTCDA(G) with higher crystallinity have better cycling stability and rate capability. The DFT (density functional theory) results indicated that the electron-deficient carbonyl group in the PTCDA molecule could reversibly coordinate/dissociate with the positively charged Al complex ions (AlCl2 +). This research work provides insights into the rational design of low-dimensional, high-crystallinity, high-performance cathode materials for green aluminum organic batteries.

Organic cathode materials for aqueous zinc-organic batteries

“…In general, the electronic conductivity of most organic compounds is relatively poor, and their rate capability is often unsatisfactory. Expanding the π-conjugated structures in organics is an efficacious way to enhance its intrinsic conductivity, which can increase π-electron delocalization and thus improve electron migration and further the conductivity of organics [44,137] . For example, HATTA cathodes obtained by introducing electron-withdrawing conjugative groups (-COOH) into the HATN molecule delivered a capacity of 136.1 mAh•g -1 under 25 A•g -1 , higher than HATN cathodes (123 mAh•g -1 under 20 A•g -1 ) [79] .…”