Advanced photovoltaics,such as ultra-flexible perovskite solar cells(UF-PSCs),which are known for their lightweight design and high power-to-mass ratio,have been a long-standing goal that we,as humans,have continuousl...Advanced photovoltaics,such as ultra-flexible perovskite solar cells(UF-PSCs),which are known for their lightweight design and high power-to-mass ratio,have been a long-standing goal that we,as humans,have continuously pursued.Unlike normal PSCs fabricated on rigid substrates,producing high-efficiency UF-PSCs remains a challenge due to the difficulty in achieving full coverage and minimizing defects of metal halide perovskite(MHP)films.In this study,we utilized Al_(2)O_(3) nanoparticles(NPs)as an inorganic surface modifier to enhance the wettability and reduce the roughness of poly-bis(4-phenyl)(2,4,6-trimethylphenyl)amine simultaneously.This approach proves essentials in fabricating UF-PSCs,enabling the deposition of uniform and dense MHP films with full coverage and fewer defects.We systematically investigated the effect of Al_(2)O_(3) NPs on film formation,combining simulation with experiments.Our strategy not only significantly increases the power conversion efficiency(PCE)from 11.96%to 16.33%,but also promotes reproducibility by effectively addressing the short circuit issue commonly encountered in UF-PSCs.Additionally,our UF-PSCs demonstrates good mechanical stability,maintaining 98.6%and 79.0%of their initial PCEs after 10,000 bending cycles with radii of 1.0 and 0.5 mm,respectively.展开更多
High-performance thermally insulating ceramic materials with excellent mechanical and thermal insulation properties are essential for thermal management in extreme environments.In this work,SiO_(2) was introduced into...High-performance thermally insulating ceramic materials with excellent mechanical and thermal insulation properties are essential for thermal management in extreme environments.In this work,SiO_(2) was introduced into the crystalline lattice and grain boundary of TiO_(2) to inhibit its phase transition and grain growth.Meanwhile,layered TiO_(2)/SiO_(2) nanofiber membranes(TS NFMs)were designed and prepared.The TS NFMs had lightweight(44 mg/cm^(3)),high tensile strength(4.55 MPa),ultra-flexibility,and low thermal conductivity(31.5 mW·m^(-1)·K^(-1)).The prepared TS-1100 NFMs had excellent buckling fatigue resistance,which could undergo 100 buckling-recovery cycles at up to 80%strain.Low density and high diffuse reflectance endow the TS NFMs with excellent thermal insulation effects.A single-layer nanofiber membrane was composed of multiple layers of nanofibers.According to the principle of multi-level reflection,the multilayer structure had a better near-infrared reflection effect.Through the stacking effect of layers,a 10 mm thick sample composed of about 300 layers of nanofiber membranes could reduce the hot surface temperature from 1,200℃to about 220℃,demonstrating an excellent comprehensive thermal insulation effect.The layered TS NFMs with ultra-flexibility,high tensile strength and high-temperature resistance(1,100℃)provide a dominant pathway in producing materials in extremely high-temperature environments.展开更多
Thermal superinsulation,arising from nanoporous aerogels with pore sizes<70 nm,involves ultralow heat conduction with a thermal conductivity lower than that of stationary air(24 mW m^(−1)K^(−1)).However,the inheren...Thermal superinsulation,arising from nanoporous aerogels with pore sizes<70 nm,involves ultralow heat conduction with a thermal conductivity lower than that of stationary air(24 mW m^(−1)K^(−1)).However,the inherently weak necklace connection mechanism between building units and the confined deformation space within nanopores result in the intrinsic brittleness of these materials.Additionally,improvements in their mechanical flexibility typically result in compromised thermal insulation performance.To address this limitation,we herein report a core–sheath structure design of La_(2)Y_(0.4)TiZr_(2)O_(9.6)ceramic aerogel(CSCA)featuring a nanofibrous core framework for flexible deformation and a nanoporous aerogel sheath for thermal superinsulation.The resulting aerogel demonstrates remarkable mechanical flexibility with a compressive strain of up to 80%,a fracture strain of up to 21.9%and a bending strain of up to 100%,as well as thermal superinsulation with a conductivity of 21.96 mW m^(−1)K^(−1)at 26℃and remains stable at working temperatures exceeding 1300℃.Ultimately,proposed CSCA constitutes a fundamentally new approach in structure design to resolving the formidable mechanical–thermal tradeoff of aerogels,and it offers promising material configuration for further advancements in thermal superinsulation.展开更多
The development of flexible and wearable devices is mainly required for tactile sensing;as such devices can adapt to complicated nonuniform surfaces,they can be applied to the human body.Nevertheless,it remains necess...The development of flexible and wearable devices is mainly required for tactile sensing;as such devices can adapt to complicated nonuniform surfaces,they can be applied to the human body.Nevertheless,it remains necessary to simultaneously achieve small-scale,portable,and stable developments in such devices.Thus,this work aims at fabricating a novel,lightweight,ultra-flexible,and fiber-shaped coaxial structure with a diameter of 0.51 mm using polydimethylsiloxane/graphene/nylon material,based on piezoresistive and triboelectric principles.The piezoresistive-based robotic-hand-controlled sensor thus realized exhibits a response time of 120 ms and a fast recovery time of 55 ms.Further,the piezoresistive-based sensors effectively feature whisker/joystick-guided behaviors and also sense the human finger contact.Owing to the triboelectric-based selfpowered nanogenerator behavior,the resulting sensor can convert mechanical motion into electrical energy,without adversely affecting human organs.Moreover,this triboelectric-based human finger sensor can be operated under different bending modes at specific angles.Notably,this multifunctional sensor is cost-effective and suitable for various applications,including robotichand-controlled operations in medical surgery,whisker/joystick motions in lightweight drone technology,and navigation with highsensitivity components.展开更多
Herein,a flexible ZIF-67/PAN hybrid membrane was successfully prepared by the incorporation of ZIF-67 nanoparticles and PAN nanofibers through electrospinning method.The hybrid membrane presented tomatoes on sticks st...Herein,a flexible ZIF-67/PAN hybrid membrane was successfully prepared by the incorporation of ZIF-67 nanoparticles and PAN nanofibers through electrospinning method.The hybrid membrane presented tomatoes on sticks structures with one single PAN fiber stringing series of ZIF-67 nanoparticles.The morphology,electrolyte wettability,heat resistance,flexibility,and electrochemical properties of the electrospun ZIF-67/PAN membranes were discussed.Among the membranes prepared with different percentage of ZIF-67,the 30% ZIF-67/PAN membrane exhibited outstanding heat shrinkage resistance(remained intact at 200℃ for 1 h),excellent electrolyte uptake(556.39%),wide electrochemical window(~5.25 V)and high ionic conductivity(2.98 mS cm^(−1)).When used as lithium-ion batteries(LIBs)separators,the cells assembled by 30% ZIF-67/PAN membrane presented excellent rate capacity and high capacity retention of 86.9% after 300 cycles at 1C.More importantly,the cells assembled with ZIF-67/PAN membranes repeated bent for 1000 times also exhibited high rate performance and maintained capacity retention of 92% after 100 cycles at 1 C.The characterization and the electrochemical testing suggest the electrospinning prepared ZIF-67/PAN flexible membranes can be expected to be used as potential separator for advanced batteries with high safety and high performance.展开更多
基金supported by the National Natural Science Foundation of China(22005043,52272193)the National Key Research and Development Program of China(2019YFA0709102 and 2020YFA0714502)+1 种基金the Liaoning Revitalization Talents Program(XLYC2007038,XLYC2008032)the Fundamental Research Funds for the Central Universities(DUT22LAB602,DUT22GJ201).
文摘Advanced photovoltaics,such as ultra-flexible perovskite solar cells(UF-PSCs),which are known for their lightweight design and high power-to-mass ratio,have been a long-standing goal that we,as humans,have continuously pursued.Unlike normal PSCs fabricated on rigid substrates,producing high-efficiency UF-PSCs remains a challenge due to the difficulty in achieving full coverage and minimizing defects of metal halide perovskite(MHP)films.In this study,we utilized Al_(2)O_(3) nanoparticles(NPs)as an inorganic surface modifier to enhance the wettability and reduce the roughness of poly-bis(4-phenyl)(2,4,6-trimethylphenyl)amine simultaneously.This approach proves essentials in fabricating UF-PSCs,enabling the deposition of uniform and dense MHP films with full coverage and fewer defects.We systematically investigated the effect of Al_(2)O_(3) NPs on film formation,combining simulation with experiments.Our strategy not only significantly increases the power conversion efficiency(PCE)from 11.96%to 16.33%,but also promotes reproducibility by effectively addressing the short circuit issue commonly encountered in UF-PSCs.Additionally,our UF-PSCs demonstrates good mechanical stability,maintaining 98.6%and 79.0%of their initial PCEs after 10,000 bending cycles with radii of 1.0 and 0.5 mm,respectively.
基金support from the National Natural Science Foundation of China(Grant No.52202090)Shandong Provincial Natural Science Foundation(Grant Nos.ZR2020ME023 and ZR2020QE037)+2 种基金the Shandong University Young Scholars Program(Grant No.2016WLJH27)the Fundamental Research Funds for the Central Universities(Grant No.2082019014)State Key Laboratory of Intelligent Manufacturing Equipment and Technology(IMETKF2023004).
文摘High-performance thermally insulating ceramic materials with excellent mechanical and thermal insulation properties are essential for thermal management in extreme environments.In this work,SiO_(2) was introduced into the crystalline lattice and grain boundary of TiO_(2) to inhibit its phase transition and grain growth.Meanwhile,layered TiO_(2)/SiO_(2) nanofiber membranes(TS NFMs)were designed and prepared.The TS NFMs had lightweight(44 mg/cm^(3)),high tensile strength(4.55 MPa),ultra-flexibility,and low thermal conductivity(31.5 mW·m^(-1)·K^(-1)).The prepared TS-1100 NFMs had excellent buckling fatigue resistance,which could undergo 100 buckling-recovery cycles at up to 80%strain.Low density and high diffuse reflectance endow the TS NFMs with excellent thermal insulation effects.A single-layer nanofiber membrane was composed of multiple layers of nanofibers.According to the principle of multi-level reflection,the multilayer structure had a better near-infrared reflection effect.Through the stacking effect of layers,a 10 mm thick sample composed of about 300 layers of nanofiber membranes could reduce the hot surface temperature from 1,200℃to about 220℃,demonstrating an excellent comprehensive thermal insulation effect.The layered TS NFMs with ultra-flexibility,high tensile strength and high-temperature resistance(1,100℃)provide a dominant pathway in producing materials in extremely high-temperature environments.
基金supported by the National Natural Science Foundation of China(52322803)the Key Program of National Natural Science Foundation of China(52192661)the National Key Research and Development Program of China(2022YFC3005800).
文摘Thermal superinsulation,arising from nanoporous aerogels with pore sizes<70 nm,involves ultralow heat conduction with a thermal conductivity lower than that of stationary air(24 mW m^(−1)K^(−1)).However,the inherently weak necklace connection mechanism between building units and the confined deformation space within nanopores result in the intrinsic brittleness of these materials.Additionally,improvements in their mechanical flexibility typically result in compromised thermal insulation performance.To address this limitation,we herein report a core–sheath structure design of La_(2)Y_(0.4)TiZr_(2)O_(9.6)ceramic aerogel(CSCA)featuring a nanofibrous core framework for flexible deformation and a nanoporous aerogel sheath for thermal superinsulation.The resulting aerogel demonstrates remarkable mechanical flexibility with a compressive strain of up to 80%,a fracture strain of up to 21.9%and a bending strain of up to 100%,as well as thermal superinsulation with a conductivity of 21.96 mW m^(−1)K^(−1)at 26℃and remains stable at working temperatures exceeding 1300℃.Ultimately,proposed CSCA constitutes a fundamentally new approach in structure design to resolving the formidable mechanical–thermal tradeoff of aerogels,and it offers promising material configuration for further advancements in thermal superinsulation.
基金The study was supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science(Nos.2022R1I1A1A01064248,2021R1A4A2001658,and 2022R1A2C1003853)the Korea Innovation Foundation(INNOPOLIS)grant funded by the Korea government(MIST)(No.2020-DD-UP-0278)partially supported by the National Research Foundation of Korea grant funded by the Korea Government(MSIP)(No.NRF-2018R1A6A1A03025761).
文摘The development of flexible and wearable devices is mainly required for tactile sensing;as such devices can adapt to complicated nonuniform surfaces,they can be applied to the human body.Nevertheless,it remains necessary to simultaneously achieve small-scale,portable,and stable developments in such devices.Thus,this work aims at fabricating a novel,lightweight,ultra-flexible,and fiber-shaped coaxial structure with a diameter of 0.51 mm using polydimethylsiloxane/graphene/nylon material,based on piezoresistive and triboelectric principles.The piezoresistive-based robotic-hand-controlled sensor thus realized exhibits a response time of 120 ms and a fast recovery time of 55 ms.Further,the piezoresistive-based sensors effectively feature whisker/joystick-guided behaviors and also sense the human finger contact.Owing to the triboelectric-based selfpowered nanogenerator behavior,the resulting sensor can convert mechanical motion into electrical energy,without adversely affecting human organs.Moreover,this triboelectric-based human finger sensor can be operated under different bending modes at specific angles.Notably,this multifunctional sensor is cost-effective and suitable for various applications,including robotichand-controlled operations in medical surgery,whisker/joystick motions in lightweight drone technology,and navigation with highsensitivity components.
基金This work was supported by the National Natural Science Foundation of China(51563002,52101243)the“100-level”Innovative Talents Project of Guizhou Province China([2016]5653)+1 种基金Natural Science Foundation of Guangdong Province(2020A1515010886)the Science and Technology Planning Project of Guangzhou(202102010373).
文摘Herein,a flexible ZIF-67/PAN hybrid membrane was successfully prepared by the incorporation of ZIF-67 nanoparticles and PAN nanofibers through electrospinning method.The hybrid membrane presented tomatoes on sticks structures with one single PAN fiber stringing series of ZIF-67 nanoparticles.The morphology,electrolyte wettability,heat resistance,flexibility,and electrochemical properties of the electrospun ZIF-67/PAN membranes were discussed.Among the membranes prepared with different percentage of ZIF-67,the 30% ZIF-67/PAN membrane exhibited outstanding heat shrinkage resistance(remained intact at 200℃ for 1 h),excellent electrolyte uptake(556.39%),wide electrochemical window(~5.25 V)and high ionic conductivity(2.98 mS cm^(−1)).When used as lithium-ion batteries(LIBs)separators,the cells assembled by 30% ZIF-67/PAN membrane presented excellent rate capacity and high capacity retention of 86.9% after 300 cycles at 1C.More importantly,the cells assembled with ZIF-67/PAN membranes repeated bent for 1000 times also exhibited high rate performance and maintained capacity retention of 92% after 100 cycles at 1 C.The characterization and the electrochemical testing suggest the electrospinning prepared ZIF-67/PAN flexible membranes can be expected to be used as potential separator for advanced batteries with high safety and high performance.
