Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels...Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels and planar conjugated backbones.Herein,three CPs have been synthesized by copolymerizing an indandione-terminated quinoidal unit with bithiophene derivatives.Owning to the high electron affinity of the indandione-terminated quinoidal unit,all polymers showed deep LUMO energy levels below-4.10 eV.Incorporating electron-withdrawing substituents(F or CN)on the bithiophene comonomer can further downshift the LUMO energy levels.As a result,a more efficient n-doping process can be realized when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine(N-DMBI)as the dopant.Ultimately,the polymer with CN substituents delivered the best thermoelectric performance with a power factor of up to 2.14μW·m^(−1)·K^(−2),because it possessed the lowest LUMO energy level among the three CPs.This work highlights that the modulation of LUMO energy level is an effective strategy to optimize the thermoelectric performance of CPs.展开更多
Fullerene derivatives are classic electron acceptor materials for organic solar cells (Oscs) but possess some intrinsic drawbacks such as weak visiblelightabsorption,limitedoptoelectronic property tunability,dificult ...Fullerene derivatives are classic electron acceptor materials for organic solar cells (Oscs) but possess some intrinsic drawbacks such as weak visiblelightabsorption,limitedoptoelectronic property tunability,dificult purification and photochemical/morphological instability.Fullereneacceptors area bottleneck restricting further development of this field. Ourgroup pioneered the exploration of novel nonfulerene acceptors in China in 2006,andinitiated the research of two representative acceptor systems, rylene dimide polymer and fused-ring electron acceptor (FREA).FREA breaks the theoreticalefficiencylimit of fullerene-based OsCs (-13%) and promotes the whole field to an unprecedented prosperity with efficiency of 20%, heraldinga nonfullerene era for OsCs.In this review, we revisit 15-year nonfullerene exploration journey,summarize the design principles,molecular engineeringstrategies, physical mechanisms and device applications of these two nonfullerene acceptor systems, and propose some possible researchtopics in the nearfuture.展开更多
Recently, graphene foam (GF) with a three-dimensional (3D) interconnected network produced by template-directed chemical vapor deposition (CVD) has been used to prepare composite phase-change materials (PCMs) ...Recently, graphene foam (GF) with a three-dimensional (3D) interconnected network produced by template-directed chemical vapor deposition (CVD) has been used to prepare composite phase-change materials (PCMs) with enhanced thermal conductivity. However, the pore size of GF is as large as hundreds of micrometers, resulting in a remarkable thermal resistance for heat transfer from the PCM inside the large pores to the GF strut walls. In this study, a novel 3D hierarchical GF (HGF) is obtained by filling the pores of GF with hollow graphene networks. The HGF is then used to prepare a paraffin wax (PW)-based composite PCM. The thermal conductivity of the PW/HGF composite PCM is 87% and 744% higher than that of the PW/GF composite PCM and pure PW, respectively. The PW/HGF composite PCM also exhibits better shape stability than the PW/GF composite PCM, negligible change in the phase-change temperature, a high thermal energy storage density that is 95% of pure PW, good thermal reliability, and chemical stability with cycling for 100 times. More importantly, PW/HGF composite PCM allows light-driven thermal energy storage with a high light-to- thermal energy conversion and storage efficiency, indicating its great potential for applications in solar-energy utilization and storage.展开更多
The ever-growing demand for wearable electronics drives the development of stretchable lithium-ion batteries(LIBs)with fast charging capability,in which stretchable polymer electrolytes(PEs)with high ionic conductivit...The ever-growing demand for wearable electronics drives the development of stretchable lithium-ion batteries(LIBs)with fast charging capability,in which stretchable polymer electrolytes(PEs)with high ionic conductivity and lithium-ion transference numbers(urn:x-wiley:1001604X:media:cjoc202200287:cjoc202200287-math-0001)are highly desirable.Herein,we report a highly stretchable and elastic PE with high ionic conductivity and urn:x-wiley:1001604X:media:cjoc202200287:cjoc202200287-math-0001,which is applicable in high-rate and stretchable LIBs.The PE was fabricated by incorporating polyethylene glycol(PEG)and lithium salts into polyurethane networks,whereinα-cyclodextrin(α-CD)acts as the cross-linker.The PEG chains are cross-linked by covalent and noncovalent bonds,and some PEG chains enter into the cavity ofα-CD to form PEG/α-CD inclusions.These structural features effectively suppress crystallization of the PEG chains,hinder movement of the counterions of Li+,and endow PE with satisfactory mechanical robustness.展开更多
基金supported by National Key R&D Program of China(2021YFA0717900)National Natural Science Foundation of China(52073209,52121002 and 22222506)the Fundamental Research Funds forthe Central Universities.
文摘Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels and planar conjugated backbones.Herein,three CPs have been synthesized by copolymerizing an indandione-terminated quinoidal unit with bithiophene derivatives.Owning to the high electron affinity of the indandione-terminated quinoidal unit,all polymers showed deep LUMO energy levels below-4.10 eV.Incorporating electron-withdrawing substituents(F or CN)on the bithiophene comonomer can further downshift the LUMO energy levels.As a result,a more efficient n-doping process can be realized when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine(N-DMBI)as the dopant.Ultimately,the polymer with CN substituents delivered the best thermoelectric performance with a power factor of up to 2.14μW·m^(−1)·K^(−2),because it possessed the lowest LUMO energy level among the three CPs.This work highlights that the modulation of LUMO energy level is an effective strategy to optimize the thermoelectric performance of CPs.
基金This work is supported by the National Natural Science Foundation of China(U21A20101).
文摘Fullerene derivatives are classic electron acceptor materials for organic solar cells (Oscs) but possess some intrinsic drawbacks such as weak visiblelightabsorption,limitedoptoelectronic property tunability,dificult purification and photochemical/morphological instability.Fullereneacceptors area bottleneck restricting further development of this field. Ourgroup pioneered the exploration of novel nonfulerene acceptors in China in 2006,andinitiated the research of two representative acceptor systems, rylene dimide polymer and fused-ring electron acceptor (FREA).FREA breaks the theoreticalefficiencylimit of fullerene-based OsCs (-13%) and promotes the whole field to an unprecedented prosperity with efficiency of 20%, heraldinga nonfullerene era for OsCs.In this review, we revisit 15-year nonfullerene exploration journey,summarize the design principles,molecular engineeringstrategies, physical mechanisms and device applications of these two nonfullerene acceptor systems, and propose some possible researchtopics in the nearfuture.
基金This work was funded by the National Thousand Young Talents of China, the National Natural Science Foundation of China (Nos. 21544001, 21603038, 51422305, and 51421061), the Innovation Team Program of Science & Technology Department of Sichuan Pro- vince (No. 2014TD0002) and State Key Laboratory of Polymer Materials Engineering (No. sklpme2014-2-02).
文摘Recently, graphene foam (GF) with a three-dimensional (3D) interconnected network produced by template-directed chemical vapor deposition (CVD) has been used to prepare composite phase-change materials (PCMs) with enhanced thermal conductivity. However, the pore size of GF is as large as hundreds of micrometers, resulting in a remarkable thermal resistance for heat transfer from the PCM inside the large pores to the GF strut walls. In this study, a novel 3D hierarchical GF (HGF) is obtained by filling the pores of GF with hollow graphene networks. The HGF is then used to prepare a paraffin wax (PW)-based composite PCM. The thermal conductivity of the PW/HGF composite PCM is 87% and 744% higher than that of the PW/GF composite PCM and pure PW, respectively. The PW/HGF composite PCM also exhibits better shape stability than the PW/GF composite PCM, negligible change in the phase-change temperature, a high thermal energy storage density that is 95% of pure PW, good thermal reliability, and chemical stability with cycling for 100 times. More importantly, PW/HGF composite PCM allows light-driven thermal energy storage with a high light-to- thermal energy conversion and storage efficiency, indicating its great potential for applications in solar-energy utilization and storage.
基金X.L.thanks the National Key R&D Program of China(2018YFC1105401)for the financial support.
文摘The ever-growing demand for wearable electronics drives the development of stretchable lithium-ion batteries(LIBs)with fast charging capability,in which stretchable polymer electrolytes(PEs)with high ionic conductivity and lithium-ion transference numbers(urn:x-wiley:1001604X:media:cjoc202200287:cjoc202200287-math-0001)are highly desirable.Herein,we report a highly stretchable and elastic PE with high ionic conductivity and urn:x-wiley:1001604X:media:cjoc202200287:cjoc202200287-math-0001,which is applicable in high-rate and stretchable LIBs.The PE was fabricated by incorporating polyethylene glycol(PEG)and lithium salts into polyurethane networks,whereinα-cyclodextrin(α-CD)acts as the cross-linker.The PEG chains are cross-linked by covalent and noncovalent bonds,and some PEG chains enter into the cavity ofα-CD to form PEG/α-CD inclusions.These structural features effectively suppress crystallization of the PEG chains,hinder movement of the counterions of Li+,and endow PE with satisfactory mechanical robustness.