Li Ying,Gong Yufei,Che Yongjie,Xu Xiaopeng,Yu Liyang,Peng Qiang
Perylene diimide (PDI) is a widely explored chromophore for constructing non-fullerene acceptors (NFAs) for polymer solar cells (PSCs). The advantage of using PDI derivatives lies in the readily availability of PDI unit which largely reduces the synthesis cost and improves material stability. Indeed, the recent development of high performance NFAs shed light on the feasibility of the commercialization, but the complex synthesis and poor stability of the top performing NFAs cast a shadow on this bright future. Our previous work has demonstrated a propeller-like structure with three PDIs lined to a benzene center core with a C-C bond which prevented the PDIs to aggregate into undesired large crystals. In this work, we designed and synthesized three new propeller-like PDI derivatives with extra chalcogen linkages between the PDIs and the center core to form all-fused rigid structures. These molecules showed more suitable absorption range than that of their unfused counterparts when blend with donor polymer PTB7-Th. Comparing between the molecules with extra oxygen, sulfur or selenium linkages, the sulfur-based BTT-PDI outperformed the others due to its higher photon absorption and charge transport abilities. This work demonstrated the great potential of PDI derivatives for PSC applications and explored the influences of linkage type on the fused PDI derivatives, which provided a useful tuning knob for molecular design of PDI-based NFAs in the future.
The development of organic lithium batteries (OLBs) offers a promising opportunity for the advancement of green and sustainable energy storage systems. However, organic cathode materials face challenges in terms of conductivity, electrochemical activity, and dissolution. Here, we address these limitations by introducing a sulfur-linked carbonyl compound called poly(dichlorobenzoquinone sulfide) (PDBS), which is polymerized in situ on reduced graphene oxide by a mixed solvent thermal method. The resulting carbonyl compound electrode materials exhibit favorable properties as organic cathode materials for OLBs. After 4000 cycles at a current density of 1000 mA g −1 , the carbonyl compound electrodes exhibit a discharge capacity of 102 mAh g −1 . This remarkable performance indicates excellent stability and long cycle life, which are crucial for practical applications. These results suggest that PDBS, a designable sulfur-linked carbonyl compound, holds great promise as an effective organic cathode material for OLBs. In addition, this work provides valuable insights into improving the electrochemical performance of organic cathode materials.