Fueled by the increasing imperative for sustainable energy solutions and the burgeoning emphasis on health awareness,self-powered techniques have undergone notable strides in advancement.Triboelectric nanogenerators(T...Fueled by the increasing imperative for sustainable energy solutions and the burgeoning emphasis on health awareness,self-powered techniques have undergone notable strides in advancement.Triboelectric nanogenerators(TENGs)stand out as a prominent device capitalizing on the principles of triboelectrification and electrostatic induction to generate electricity or electrical signals.In efforts to augment the electrical output performance of TENGs and broaden their range of applications,researchers have endeavored to refine materials,surface morphology,and structural design.Among them,physical morphological modifications play a pivotal role in enhancing the electrical properties of TENGs by increasing the contact surface area,which can be achieved by building micro-/nano-structures on the surface or inside the friction material.In this review,we summarize the common morphologies of TENGs,categorize the morphologies into surface and internal structures,and elucidate their roles in enhancing the electric output performance of devices.Moreover,we systematically classify the methodologies employed for morphological preparation into physical and chemical approaches,thereby furnishing a comprehensive survey of the diverse techniques.Subsequently,typical applications of TENGs with special morphology divided by energy harvesting and self-powered sensors are presented.Finally,an overview of the challenges and future trajectories pertinent to TENGs is conducted.Through this endeavor,the aim of this article is to catalyze the evolution of further strategies for enhancing performance of TENGs.展开更多
Bifacial photovoltaic (PV) modules offer potentially enhanced power output over conventional modules due to their reported ability to harvest reflected radiation, increasing output up to an additional 30%. However, th...Bifacial photovoltaic (PV) modules offer potentially enhanced power output over conventional modules due to their reported ability to harvest reflected radiation, increasing output up to an additional 30%. However, this enhancement has yet to be confirmed in the literature. This paper reports on a study comparing the power output of two nominally identical 700 W photovoltaic arrays utilizing equivalent system components and data logging equipment with varying configurations of reflecting geometries and materials. This study was undertaken at the Appalachian State University Solar Research Laboratory in Boone, NC, which houses two Class 1 pyranometers and pyrheliometer. PV power was reported under well-quantified irradiance conditions, including direct beam fraction. Six trials over six months (November-April) with varying reflective materials and geometries revealed that different reflecting materials did not significantly change power output. Mounting an array at 0° did adversely affect power output compared to the array at a 36° angle relative to horizontal using the same reflective material. Additional studies with varied materials, panel locations and geometries different from those tested may improve the power output.展开更多
The hybrid photovoltaic solar-assisted heat pump are primarily used to generate electricity and provide thermal energy for heating applications.This study investigates the performance enhancement of a hybrid Photovolt...The hybrid photovoltaic solar-assisted heat pump are primarily used to generate electricity and provide thermal energy for heating applications.This study investigates the performance enhancement of a hybrid Photovoltaic Thermal Solar-Assisted Heat Pump(PV/T-SAHP)system integrated with a solar tracking mechanism.The system was simulated using TRNSYS to evaluate its monthly electrical output and coefficient of performance(COP)of the heat pump system over a year.The results showed a significant improvement in energy generation and efficiency compared to a conventional PV/T system without SAHP system.Overall,the solar tracking configuration of the PV/T-SAHP generated 10%–40%more electricity than the fixed system.The system for the tracking mode achieved a maximum monthly average electrical energy output of 634.349 kWh in June.Throughout the year,the tracking mode consistently outperformed the fixed mode.During the winter months of January and December,the tracking system produced 328.7 and 323.6 kWh,respectively,compared to 297.8 and 299.7 kWh for the fixed mode.The highest COP of 5.65 occurred in July,indicating a strong seasonal correlation with solar irradiance.In contrast,the minimum COP of 4.55 was observed in the months,February and March,reflecting reduced solar availability.The solar tracking feature consistently maintained an optimal panel angle,increasing energy gains and improving system efficiency.Overall,the integration of a heat pump and tracking control significantly improved system performance,making the hybrid PV/T-SAHP configuration a promising solution for year-round renewable energy generation.展开更多
Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can b...Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.展开更多
The enhancement of photoelectric-thermal conversion efficiency of solar energy holds considerable promise for achieving substantial energy savings and emission reductions in the domain of residential heating and elect...The enhancement of photoelectric-thermal conversion efficiency of solar energy holds considerable promise for achieving substantial energy savings and emission reductions in the domain of residential heating and electricity supply.This paper proposed a novel approach for converting a photovoltaic system into a roll-bond panel-based photovoltaic thermal(PVT)heat pump system capable of concurrently generating electricity and domestic hot water.A test rig was constructed to assess its comprehensive cogeneration performance.The results demonstrated significant cogeneration capabilities,with an average electrical efficiency of 19.66%,an average heat gain factor of 0.89,and an average heating performance coefficient of 5.15 under specified weather conditions.The heating performance coefficient of this system was 12%higher than the designated first-class energy efficiency rating(4.60)for air-source heat pump water heaters.Controlled experiments were also conducted to evaluate the systematic electrical output compared to the photovoltaic system with an identical electrical subsystem configuration.A considerable decrease in PVT module temperature was witnessed,resulting in an enhancement of electrical production by 4.4%during the test period.Furthermore,a mathematical model was developed and validated by the experimental outcomes.The systematic annual cogeneration performance and the potential for CO_(2)emissions reduction were also assessed.The simulated annual average heating performance coefficient and the electrical output improvement were 4.90 and 3.67%,respectively.In light of this,annual CO_(2)emissions of the proposed system were calculated to be 192.3 kg CO_(2),representing a reduction of 91.1%compared to the emissions from the pathways of natural gas-fired power and gas water heater heating.展开更多
The triboelectric nanogenerator(TENG)offers a novel approach to harness mechanical energy continuously and sustainably.It has emerged as a leading technology for converting mechanical energy into electricity.The deman...The triboelectric nanogenerator(TENG)offers a novel approach to harness mechanical energy continuously and sustainably.It has emerged as a leading technology for converting mechanical energy into electricity.The demand for self-powered wearable microelectronics and energy generation in extreme conditions underscores the need for efficient high-temperature operatable TENGs(HTO-TENGs).However,the operating environment temperature not only affects the storage and dissipation of electrons during triboelectrification,leading to decreased output performance of TENG and instability at high temperatures,but also damage to the mechanical stability and effective defects in most tribomaterials,resulting in a further reduction in TENG’s effective output power.Moreover,the unstable material properties of the triboelectric layer at high temperatures also restrict the use of the TENG in harsh environments.Therefore,it is imperative to consider the structural durability and electrical output stability of TENG when applying it in challenging working environments.This review aims to bridge this gap by providing a comprehensive overview of the current state and research advancements in HTO-TENG for the first time.Finally,this review presents insights into future research prospects and proposes design strategies to facilitate the rapid development of the field.展开更多
Composite-type piezoelectric nanogenerator(PENG)can potentially provide power to the flexible electronics devices by harvesting the mechanical energy.The electricity output of the PENG is not entirely excavated until ...Composite-type piezoelectric nanogenerator(PENG)can potentially provide power to the flexible electronics devices by harvesting the mechanical energy.The electricity output of the PENG is not entirely excavated until now because the polarization dipoles are not sufficiently aligned during the high-voltage poling process.In this study,some Ag particles are attached on the(K_(0.4425)Na_(0.52)Li_(0.0375))(Nb_(0.86)Ta_(0.06)Sb_(0.08))O_(3)(KNN)piezoelectric particles and then they are mixed with multi-walled carbon nanotubes and polydimethylsiloxane to fabricate the PENG device.The Ag particles can reduce the optimal poling electric field from 10 kV/mm down to 5 kV/mm.The PENG device with Ag particles poled at 5 kV/mm can generate the highest open-circuit voltage of 282 V,short-circuit voltage of 32.2 mA,and maximum instantaneous power of 3.5mW under the external mechanical stress of 10 kPa without timedependent degradation(only 27.9 V and 2.6 mA for the pure KNN-based PENG poled at 10 kV/mm).These are much better than previously reported composite-type PENG.The electrical energy generated from the PENG(20mm×40 mm)can light up 40 white light emitting diodes instantaneously without any storage unit during the stomping stage.展开更多
基金financially supported by the Natural Science Foundation of Guangdong Province(No.2024A1515010639)PolyU Postdoc Matching Fund Scheme(No.1-W327),PolyU Grant(No.1-CE0H)+3 种基金Shenzhen Science and Technology Program(No.ZDSYS20220606100406016)Shenzhen Key Laboratory of Photonics and Biophotonics(No.ZDSYS20210623092006020)National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment(Shenzhen)(No.868-000003010103)National Natural Science Foundation of China(No.52208272)。
文摘Fueled by the increasing imperative for sustainable energy solutions and the burgeoning emphasis on health awareness,self-powered techniques have undergone notable strides in advancement.Triboelectric nanogenerators(TENGs)stand out as a prominent device capitalizing on the principles of triboelectrification and electrostatic induction to generate electricity or electrical signals.In efforts to augment the electrical output performance of TENGs and broaden their range of applications,researchers have endeavored to refine materials,surface morphology,and structural design.Among them,physical morphological modifications play a pivotal role in enhancing the electrical properties of TENGs by increasing the contact surface area,which can be achieved by building micro-/nano-structures on the surface or inside the friction material.In this review,we summarize the common morphologies of TENGs,categorize the morphologies into surface and internal structures,and elucidate their roles in enhancing the electric output performance of devices.Moreover,we systematically classify the methodologies employed for morphological preparation into physical and chemical approaches,thereby furnishing a comprehensive survey of the diverse techniques.Subsequently,typical applications of TENGs with special morphology divided by energy harvesting and self-powered sensors are presented.Finally,an overview of the challenges and future trajectories pertinent to TENGs is conducted.Through this endeavor,the aim of this article is to catalyze the evolution of further strategies for enhancing performance of TENGs.
文摘Bifacial photovoltaic (PV) modules offer potentially enhanced power output over conventional modules due to their reported ability to harvest reflected radiation, increasing output up to an additional 30%. However, this enhancement has yet to be confirmed in the literature. This paper reports on a study comparing the power output of two nominally identical 700 W photovoltaic arrays utilizing equivalent system components and data logging equipment with varying configurations of reflecting geometries and materials. This study was undertaken at the Appalachian State University Solar Research Laboratory in Boone, NC, which houses two Class 1 pyranometers and pyrheliometer. PV power was reported under well-quantified irradiance conditions, including direct beam fraction. Six trials over six months (November-April) with varying reflective materials and geometries revealed that different reflecting materials did not significantly change power output. Mounting an array at 0° did adversely affect power output compared to the array at a 36° angle relative to horizontal using the same reflective material. Additional studies with varied materials, panel locations and geometries different from those tested may improve the power output.
文摘The hybrid photovoltaic solar-assisted heat pump are primarily used to generate electricity and provide thermal energy for heating applications.This study investigates the performance enhancement of a hybrid Photovoltaic Thermal Solar-Assisted Heat Pump(PV/T-SAHP)system integrated with a solar tracking mechanism.The system was simulated using TRNSYS to evaluate its monthly electrical output and coefficient of performance(COP)of the heat pump system over a year.The results showed a significant improvement in energy generation and efficiency compared to a conventional PV/T system without SAHP system.Overall,the solar tracking configuration of the PV/T-SAHP generated 10%–40%more electricity than the fixed system.The system for the tracking mode achieved a maximum monthly average electrical energy output of 634.349 kWh in June.Throughout the year,the tracking mode consistently outperformed the fixed mode.During the winter months of January and December,the tracking system produced 328.7 and 323.6 kWh,respectively,compared to 297.8 and 299.7 kWh for the fixed mode.The highest COP of 5.65 occurred in July,indicating a strong seasonal correlation with solar irradiance.In contrast,the minimum COP of 4.55 was observed in the months,February and March,reflecting reduced solar availability.The solar tracking feature consistently maintained an optimal panel angle,increasing energy gains and improving system efficiency.Overall,the integration of a heat pump and tracking control significantly improved system performance,making the hybrid PV/T-SAHP configuration a promising solution for year-round renewable energy generation.
基金the Natural Science Foundation of Beijing Municipality(2222075)National Natural Science Foundation of China(22279010,21671020,51673026)Analysis&Testing Center,Beijing Institute of Technology.
文摘Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.
基金supported by the project“Key Technologies and Pilot Applications of High-efficiency and Low-cost Hybrid Solar Photovoltaic-thermal System”from the Science and Technology Commission of Shanghai Municipality(Grant No.22dz1206200)the Key Research and Development Program of Shandong(Grant No.2024CXGC010705)The authors also gratefully acknowledge the support from the Fundamental Research Funds for the Central Universities(Grant No.AF0200316).
文摘The enhancement of photoelectric-thermal conversion efficiency of solar energy holds considerable promise for achieving substantial energy savings and emission reductions in the domain of residential heating and electricity supply.This paper proposed a novel approach for converting a photovoltaic system into a roll-bond panel-based photovoltaic thermal(PVT)heat pump system capable of concurrently generating electricity and domestic hot water.A test rig was constructed to assess its comprehensive cogeneration performance.The results demonstrated significant cogeneration capabilities,with an average electrical efficiency of 19.66%,an average heat gain factor of 0.89,and an average heating performance coefficient of 5.15 under specified weather conditions.The heating performance coefficient of this system was 12%higher than the designated first-class energy efficiency rating(4.60)for air-source heat pump water heaters.Controlled experiments were also conducted to evaluate the systematic electrical output compared to the photovoltaic system with an identical electrical subsystem configuration.A considerable decrease in PVT module temperature was witnessed,resulting in an enhancement of electrical production by 4.4%during the test period.Furthermore,a mathematical model was developed and validated by the experimental outcomes.The systematic annual cogeneration performance and the potential for CO_(2)emissions reduction were also assessed.The simulated annual average heating performance coefficient and the electrical output improvement were 4.90 and 3.67%,respectively.In light of this,annual CO_(2)emissions of the proposed system were calculated to be 192.3 kg CO_(2),representing a reduction of 91.1%compared to the emissions from the pathways of natural gas-fired power and gas water heater heating.
基金supported by the National Natural Sci-ence Foundation of China(No.52003074,52125205,U20A20166,52192614,52003073,and 62174049)the Project funded by China Postdoctoral Science Foundation(No.2020M680097)+5 种基金the Postdoctoral Fellowship Program of CPSF(No.GZC20230681)the Natural Science Foundation of Henan Province(No.202300410058)the National Sci-ence Fund for Excellent Young Scholars of Henan Province(No.222300420033)National key R&D program of China(2021YFB3200302 and 2021YFB3200304),Natural Science Foundation of BeijingMunicipality(Z180011 and 2222088)Shenzhen Science and Technology Program(grant number KQTD20170810105439418)the Fundamental Research Funds for the Central Universities.
文摘The triboelectric nanogenerator(TENG)offers a novel approach to harness mechanical energy continuously and sustainably.It has emerged as a leading technology for converting mechanical energy into electricity.The demand for self-powered wearable microelectronics and energy generation in extreme conditions underscores the need for efficient high-temperature operatable TENGs(HTO-TENGs).However,the operating environment temperature not only affects the storage and dissipation of electrons during triboelectrification,leading to decreased output performance of TENG and instability at high temperatures,but also damage to the mechanical stability and effective defects in most tribomaterials,resulting in a further reduction in TENG’s effective output power.Moreover,the unstable material properties of the triboelectric layer at high temperatures also restrict the use of the TENG in harsh environments.Therefore,it is imperative to consider the structural durability and electrical output stability of TENG when applying it in challenging working environments.This review aims to bridge this gap by providing a comprehensive overview of the current state and research advancements in HTO-TENG for the first time.Finally,this review presents insights into future research prospects and proposes design strategies to facilitate the rapid development of the field.
基金supported by the China Postdoctoral Science Foundation(Grant No.2017M612177)National Natural Science Foundation of China(Grant Nos.51702119,51702122)Postdoctoral Science Foundation from University of Jinan.
文摘Composite-type piezoelectric nanogenerator(PENG)can potentially provide power to the flexible electronics devices by harvesting the mechanical energy.The electricity output of the PENG is not entirely excavated until now because the polarization dipoles are not sufficiently aligned during the high-voltage poling process.In this study,some Ag particles are attached on the(K_(0.4425)Na_(0.52)Li_(0.0375))(Nb_(0.86)Ta_(0.06)Sb_(0.08))O_(3)(KNN)piezoelectric particles and then they are mixed with multi-walled carbon nanotubes and polydimethylsiloxane to fabricate the PENG device.The Ag particles can reduce the optimal poling electric field from 10 kV/mm down to 5 kV/mm.The PENG device with Ag particles poled at 5 kV/mm can generate the highest open-circuit voltage of 282 V,short-circuit voltage of 32.2 mA,and maximum instantaneous power of 3.5mW under the external mechanical stress of 10 kPa without timedependent degradation(only 27.9 V and 2.6 mA for the pure KNN-based PENG poled at 10 kV/mm).These are much better than previously reported composite-type PENG.The electrical energy generated from the PENG(20mm×40 mm)can light up 40 white light emitting diodes instantaneously without any storage unit during the stomping stage.
