Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the r...Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the rational design of well-matched donor and acceptor materials is extremely essential.In this work,two new small molecular donor materials with subtle change in the conjugated side thiophene rings are synthesized.The subtle change significantly affects the photovoltaic performance of molecular donors.Compared with chlorinated molecule MDJ-Cl,the non-chlorinated analogue MDJ exhibits decreased miscibility with the non-fullerene acceptor Y6,can more efficiently quench the excitons of Y6.As a result,a improved PCE of 11.16% is obtained for MDJ:Y6 based SMOSCs.The results highlight the importance of fine-tuning the molecular structure to achieve high-performance SMOSCs.展开更多
Epoxy resins(EPs)are widely used in structural and functional applications due to their excellent mechanical properties,chemical resistance,and dimensional stability.However,their inherent flammability and non-recycla...Epoxy resins(EPs)are widely used in structural and functional applications due to their excellent mechanical properties,chemical resistance,and dimensional stability.However,their inherent flammability and non-recyclability pose significant fire safety and environmental challenges.The emergence of dynamic covalent chemistry and advanced flame-retardant strategies has enabled the design of EP systems with both recyclability and intrinsic flame retardancy.Nevertheless,the introduction of reversible dynamic covalent bonds to facilitate network adaptability often compromises structural integrity,resulting in increased susceptibility to creep and deteriorated in-service performance(e.g.,mechanical properties,thermal stability,and durability).This review outlines the state-of-the-art research on flame-retardant,recyclable EPs in recent years and highlights feasible and potential strategies to improve the creep resistance and in-service performance of flame-retardant,recyclable EPs.Finally,potential future development directions for the development of flame-retardant,recyclable and high-stability EPs are proposed.展开更多
Lithium-sulfur(Li-S) batteries have shown promises for the next-generation, high-energy electrochemical storage, yet are hindered by rapid performance decay due to the polysulfide shuttle in the cathode and safety con...Lithium-sulfur(Li-S) batteries have shown promises for the next-generation, high-energy electrochemical storage, yet are hindered by rapid performance decay due to the polysulfide shuttle in the cathode and safety concerns about potential thermal runaway. To address the above challenges, herein, we show a flame-retardant cathode binder that simultaneously improves the electrochemical stability and safety of batteries. The combination of soft and hard segments in the polymer framework of binders allows high flexibility and mechanical strength for adapting to the drastic volume change during the Li(de)intercalation of the S cathode. The binder contains a large number of polar groups, which show the high affinity to polysulfides so that they help to anchor active S species at the cathode. These polar groups also help to regulate and facilitate the Li-ion transport, promoting the kinetics of polysulfide conversion reaction. The binder contains abundant phosphine oxide groups, which, in the case of battery's thermal runaway, decompose and release PO· radicals to quench the combustion reactions and stop the fire. Consequently, Li-S batteries using the new cathode binder show the improved electrochemical performance, including a low-capacity decay of 0.046% per cycle for 800 cycles at 1 C and favorable rate capabilities of up to 3 C. This work offers new insights on the practical realization of high-energy rechargeable batteries with stable storage electrochemistry and high safety.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Nos.51973169,51703172)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015)the Science Foundation of Wuhan Institute of Technology(No.K202025).
文摘Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the rational design of well-matched donor and acceptor materials is extremely essential.In this work,two new small molecular donor materials with subtle change in the conjugated side thiophene rings are synthesized.The subtle change significantly affects the photovoltaic performance of molecular donors.Compared with chlorinated molecule MDJ-Cl,the non-chlorinated analogue MDJ exhibits decreased miscibility with the non-fullerene acceptor Y6,can more efficiently quench the excitons of Y6.As a result,a improved PCE of 11.16% is obtained for MDJ:Y6 based SMOSCs.The results highlight the importance of fine-tuning the molecular structure to achieve high-performance SMOSCs.
基金support received from the Australian Research Council(Nos.DE230100616,DP230103008,LP230100278,DP240102628,and DP240102728).
文摘Epoxy resins(EPs)are widely used in structural and functional applications due to their excellent mechanical properties,chemical resistance,and dimensional stability.However,their inherent flammability and non-recyclability pose significant fire safety and environmental challenges.The emergence of dynamic covalent chemistry and advanced flame-retardant strategies has enabled the design of EP systems with both recyclability and intrinsic flame retardancy.Nevertheless,the introduction of reversible dynamic covalent bonds to facilitate network adaptability often compromises structural integrity,resulting in increased susceptibility to creep and deteriorated in-service performance(e.g.,mechanical properties,thermal stability,and durability).This review outlines the state-of-the-art research on flame-retardant,recyclable EPs in recent years and highlights feasible and potential strategies to improve the creep resistance and in-service performance of flame-retardant,recyclable EPs.Finally,potential future development directions for the development of flame-retardant,recyclable and high-stability EPs are proposed.
基金financially supported by the National Key R&D Program of China(2019YFA0705703)Natural Science Foundation of Hubei Province(2021CFB082)+4 种基金Scientific Research Foundation of Wuhan Institute of Technology(K2021042)the Open Key Fund Project of State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology,2022-KF-10)National Natural Science Foundation of China(22275142,U22B6011)China Postdoctoral Science Foundation(2021M703268)the Junior Fellow Program of Beijing National Laboratory for Molecular Sciences(2021BMS20062)。
文摘Lithium-sulfur(Li-S) batteries have shown promises for the next-generation, high-energy electrochemical storage, yet are hindered by rapid performance decay due to the polysulfide shuttle in the cathode and safety concerns about potential thermal runaway. To address the above challenges, herein, we show a flame-retardant cathode binder that simultaneously improves the electrochemical stability and safety of batteries. The combination of soft and hard segments in the polymer framework of binders allows high flexibility and mechanical strength for adapting to the drastic volume change during the Li(de)intercalation of the S cathode. The binder contains a large number of polar groups, which show the high affinity to polysulfides so that they help to anchor active S species at the cathode. These polar groups also help to regulate and facilitate the Li-ion transport, promoting the kinetics of polysulfide conversion reaction. The binder contains abundant phosphine oxide groups, which, in the case of battery's thermal runaway, decompose and release PO· radicals to quench the combustion reactions and stop the fire. Consequently, Li-S batteries using the new cathode binder show the improved electrochemical performance, including a low-capacity decay of 0.046% per cycle for 800 cycles at 1 C and favorable rate capabilities of up to 3 C. This work offers new insights on the practical realization of high-energy rechargeable batteries with stable storage electrochemistry and high safety.
