Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics;however,conventional thermoelectric materials face significant drawbacks,including high ionic concentrati...Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics;however,conventional thermoelectric materials face significant drawbacks,including high ionic concentrations,toxicity,and limited thermoelectric efficiency.Here,we report an ionic thermoelectric hydrogel designed through precise supramolecular chemistry,utilizing dual molecular interactions,host-vip complexation ofα-cyclodextrin(α-CD)with I_(3)^(-)ions and hydrogen bonding between polyvinyl alcohol(PVA)polymer chains and I_(3)^(-).This molecularly tailored approach markedly amplifies thermoelectric performance,achieving a high thermopower of 2.21 mV/K and a tenfold enhancement in peak power output at an exceptionally low iodine concentration(10 mmol/L I^(-)+2.5 mmol/L I_(3)^(-)).The hydrogel maintains excellent biocompatibility and mechanical robustness,suitable for direct skin contact.Demonstrated applications include flexible thermoelectric devices generating nearly 100 mV from body heat and sensor arrays capable of motion and spatial temperature sensing.These results underscore the substantial potential of supramolecularly designed ionic thermoelectric hydrogels for wearable energy harvesting,personalized healthcare monitoring,and advanced human-computer interfaces.展开更多
Ionic thermoelectrics(i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin. However,as ions cannot enter external circuit, the uti...Ionic thermoelectrics(i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin. However,as ions cannot enter external circuit, the utilization of i-TE is currently based on capacitive charge/discharge, which results in discontinuous working mode and low energy density. Here,we introduce an ion–electron thermoelectric synergistic(IETS)effect by utilizing an ion–electron conductor. Electrons/holes can drift under the electric field generated by thermodiffusion of ions, thus converting the ionic current into electrical current that can pass through the external circuit. Due to the IETS effect, i-TE is able to operate continuously for over 3000 min.Moreover, our i-TE exhibits a thermopower of 32.7 mV K^(-1) and an energy density of 553.9 J m^(-2), which is more than 6.9 times of the highest reported value. Consequently, direct powering of electronics is achieved with i-TE. This work provides a novel strategy for the design of high-performance i-TE materials.展开更多
Converting low-grade waste heat into usable electricity and storing it simultaneously requires a new technology that realize the directional migration of electrons or ions under temperature difference and enrichment o...Converting low-grade waste heat into usable electricity and storing it simultaneously requires a new technology that realize the directional migration of electrons or ions under temperature difference and enrichment on the electrodes.Although the urgent demand of energy conversion-storage(ECS)has emerged in the field of wearable electronic,achieving the integrated bi-functional device remains challenge due to the different mechanisms of electrical transportation and storage.Here,we report an ionic thermoelectric supercapacitor that relies on the synergistic functions of thermoelectricity and supercapacitor in the thermoelectric ionogel electrolyte and high-performance hydrogel electrodes to enhance the ECS performance under a thermal gradient.The thermoelectric electrolyte is composed of polyacrylamide hydrogel and sodium carboxymethyl cellulose(PMSC),possessing cross-linked network with excellent cation selectivity,while the ionic thermoelectric properties are further improved in the presence of NaCl.The corresponding Seebeck coefficient and ionic conductivity of the NaCl–PMSC electrolyte reach 17.1 mV K^(-1)and 26.8 mS cm^(-1),respectively.Owing to good stretchability of both gel-based electrolyte and electrode,the fullstretchable integrated ECS device,termed ionic thermoelectric supercapacitor,presents promising thermal-charge storage capability(~1.3 mC,ΔT≈10 K),thus holds promise for wearable energy harvesting.展开更多
Compared with those traditional initiating devices of anti-scalding systems,ionic thermoelectric sensors with energyautonomous performance show higher reliability.However,the current ionic thermoelectric materials(i-T...Compared with those traditional initiating devices of anti-scalding systems,ionic thermoelectric sensors with energyautonomous performance show higher reliability.However,the current ionic thermoelectric materials(i-TEs)suffer from complex nano-/micro-channel design,high production costs,environmentally unfriendly,weak mechanical properties,as well as the low moving speed of ions.Herein,the functional leather collagen fibers-bearing natural channels are employed as the polymer matrixes,while the trisodium citrate(SC)organic acid salt exhibits the function of cationic moving selfenhancement as the primary mobile ions for signaling.Including numerous and suitable nano-/micro-channels together with fast-moving cations,the leather-based i-TEs(LITE),LITE-SC0.75 M,possess excellent thermoelectric properties,achieving a Seebeck coefficient of 6.23 mV/K,a figure of merit of 0.084,and an energy conversion efficiency of 2.12%.Combined with its excellent thermal stability,mechanical performance,flexibility,durability,low cost,and outstanding capabilities for low-grade heat harvesting and thermal sensing,the LITE-SC0.75 M detector bearing long service life would show great promise in automatic anti-scalding alarm suitable for multiple scenarios and extreme environments.Therefore,the present work aims to design an efficient,robust,and energy-autonomous leather collagen fibers-based thermoelectric detector to address the limitation of current anti-scalding alarm technology as well as drive advancements in the nano-energy and its effective conversion field.展开更多
Thermoelectric technology that utilizes thermodynamic effects to convert thermal energy into electrical energy has greatly expanded wearable health monitoring,personalized detecting,and communicating applications.Enco...Thermoelectric technology that utilizes thermodynamic effects to convert thermal energy into electrical energy has greatly expanded wearable health monitoring,personalized detecting,and communicating applications.Encouragingly,thermoelectric technology assisted by artificial intelligence exerts great development potential in wearable electronic devices that rely on the self-sustainable operation of human body heat.Ionic thermoelectric(i-TE)devices that possess high Seebeck coefficients and a constant and stable electrical output are expected to achieve an effective conversation of thermal energy harvesting.Herein,we developed an i-TE paster for thermal chargeable energy storage,temperature-triggered material recognition,contact/non-contact temperature detection,and photo thermoelectric conversion applications.An all-solid-state organic ionic gel electrolyte(PVDF-HFP-PEO gel)with onion epidermal cells-like structure was sandwiched between two electrodes,which take full advantage of a synergy between the Soret effect and the polymer thermal expansion effect,thus achieving the enhanced ZT value up to 900%compared with the PEO-free electrolyte.The i-TE device delivers a Seebeck coefficient of 28 mV K^(−1),a maximum energy conversion efficiency of 1.3%in performance,and ultra-thin and skin-attachable properties in wearability,which demonstrate the great potential and application prospect of the i-TE paster in self-sustainable wearable electronics.展开更多
Lithium-ion thermoelectrochemical cell(LTEC), featuring simultaneous energy conversion and storage, has emerged as promising candidate for low-grade heat harvesting. However, relatively poor thermosensitivity and heat...Lithium-ion thermoelectrochemical cell(LTEC), featuring simultaneous energy conversion and storage, has emerged as promising candidate for low-grade heat harvesting. However, relatively poor thermosensitivity and heat-to-current behavior limit the application of LTECs using LiPF_6 electrolyte. Introducing additives into bulk electrolyte is a reasonable strategy to solve such problem by modifying the solvation structure of electrolyte ions. In this work, we develop a dual-salt electrolyte with fluorosurfactant(FS) additive to achieve high thermopower and durability of LTECs during the conversion of low-grade heat into electricity. The addition of FS induces a unique Li~+ solvation with the aggregated double anions through a crowded electrolyte environment,resulting in an enhanced mobility kinetics of Li~+ as well as boosted thermoelectrochemical performances. By coupling optimized electrolyte with graphite electrode, a high thermopower of 13.8 mV K^(-1) and a normalized output power density of 3.99 mW m^(–2) K^(–2) as well as an outstanding output energy density of 607.96 J m^(-2) can be obtained.These results demonstrate that the optimization of electrolyte by regulating solvation structure will inject new vitality into the construction of thermoelectrochemical devices with attractive properties.展开更多
Thermally chargeable supercapacitors(TCSCs)have offered exceptional energy-converting efficiency for absorbing human epidermal heat and generating and storing electrical energy,which then realize continuous power supp...Thermally chargeable supercapacitors(TCSCs)have offered exceptional energy-converting efficiency for absorbing human epidermal heat and generating and storing electrical energy,which then realize continuous power supply to electronic devices,such as sensors and wearable electronic products,in a wide range of practical significance.Here,we proposed a flexible TCSC by attaching binder-free Ti_(3)C_(2)T_(x) MXene@PPy electrodes on both ends of the H_(3)PO_(4)@P(AM-co-AA-co-AYP K^(+))hydrogel electrolyte,which exhibits a large thermal power of 35.2 mV K^(−1) at 50%relative humidity and maximum figure of merit of 2.1.The high performances of the fabricated devices can be attributed to the tunable electrical,thermodynamic,thermoelectric,and mechanical properties of the hydrogel electrolyte by adjusting the acid content and the proportion of zwitterionic compound AYP K^(+)in the hydrogel,and the high photothermal conversion efficiency and electrochemical performance of the electrodes.Moreover,the stable and outstanding thermofvoltage output(∼200 mV)under different time scenarios of the TCSC makes it possible to drive a strain sensor,accomplishing the objectives of a human activity monitor.展开更多
Buildings and infrastructure significantly contribute to global energy consumption and CO_(2) emissions.Transforming cement,the most widely used construction material,into a functional medium for heat harvesting prese...Buildings and infrastructure significantly contribute to global energy consumption and CO_(2) emissions.Transforming cement,the most widely used construction material,into a functional medium for heat harvesting presents a promising avenue to offset the energy demands of buildings.The disparity in diffusion rate between cations and anions within cement pore solution due to variations in interactions with pore walls,endows cement with inherent ionic thermoelectric properties.However,the isolation of pores by the dense cement matrix hinders the rapid transportation of ions with superior diffusion rates,impeding the enhancement of mobility difference between ions and limiting the enhancement of Seebeck coefficient.Inspired by the stem structure of plants,we present a cement-polyvinyl alcohol(PVA)composite(CPC)featuring aligned cement and PVA hydrogel layers.While PVA hydrogel layers provide ion diffusion highways for OH-ions,cement-PVA interfaces establish strong coordination bonds with Ca^(2+)ions and weaker interactions with OH-ions,enabling selective immobilization,which amplifies the diffusion rate disparity between Ca^(2+)and OH^(-).The CPC's multilayer structure yields abundant interfaces,providing ample interaction sites that maximize the contribution of cement ions to thermoelectric performance.The as-prepared composite achieves an impressive Seebeck coefficient of-40.5 mV/K and a figure of merit(ZT)of 6.6×10^(-2).Due to the engineered multilayer structure,the CPC also demonstrates superior mechanical strength and intrinsic energy storage potential,which has been assembled into a selfpowered architecture.The biomimetic structure and interfacial selective immobilization mechanism may pave the way for the design and fabrication of high-performance ionic thermoelectric materials.展开更多
Ionic thermoelectric conversion based on Soret effect,a phenomenon of converting heat into electricity,has been popularized in establishing self-powering systems where thermal exchange is associated.It works in the pr...Ionic thermoelectric conversion based on Soret effect,a phenomenon of converting heat into electricity,has been popularized in establishing self-powering systems where thermal exchange is associated.It works in the presence of a temperature gradient,but becomes invalid if there is no significant temperature difference between two electrodes,especially in miniaturized devices and large thermal field.Herein,we break this cognition by discovering thermoelectric conversion in isothermal environments resulting from a heterogeneous system consisting of Metal A/Ionic liquid/Metal B.Asymmetric ion rearrangement is proposed on two ionic liquid/electrode interfaces when temperature varies,accounting for the generation of thermoelectric voltage.This principle can be applied to many electrodes/ionic liquids groups.The advantages of temperature gradient independence lay the ground for the creation of powerless thermometers to alarm large area of fire.展开更多
Stretchable ionic thermoelectric(i-TE) materials have attracted growing interest in converting low-grade thermal energy into electricity. However, substantial improvement on i-TE performance of quasi-solid ionogels re...Stretchable ionic thermoelectric(i-TE) materials have attracted growing interest in converting low-grade thermal energy into electricity. However, substantial improvement on i-TE performance of quasi-solid ionogels remains a significant challenge.Here, a nanocomposite ionogel with skin-like stretchability, high i-TE performance, thermostability and durability is prepared by hybridizing ionic liquid(IL) and Laponite nanosheets into waterborne polyurethane(WPU). With multiple H-bond, WPU can accommodate a higher content of IL, thereby improving its ionic conductivity. After cation exchange between IL and Laponite,the negatively charged Laponite sheets and released Na+can enhance the ionic Seebeck coefficient by enlarging thermophoretic mobility difference between the cations and anions in ionogel. Besides, incorporation of Laponite causes the decrease of thermal conductivity. Thus, the WPU-IL-Laponite ionogel exhibits a high ionic thermopower of 44.1 m V K-1, high ionic conductivity of 14.1 m S cm-1and low thermal conductivity of 0.43 W m-1K-1at a relative humidity of 90%. The corresponding ionic figure of merit of the ionogel is 1.90±0.27. Moreover, the ionogel demonstrates excellent durability during repeated stretching process.The stretchable ionogel can be fabricated into ionic thermoelectric capacitor to convert thermal energy from solar radiation into electricity.展开更多
Ionic thermoelectricity(i-TE),as a new energy conversion and storage technology,has been widely discussed by the academic community.As one of the representatives of low-grade thermal energy recovery,i-TE has made rema...Ionic thermoelectricity(i-TE),as a new energy conversion and storage technology,has been widely discussed by the academic community.As one of the representatives of low-grade thermal energy recovery,i-TE has made remarkable progress and become an influential research direction in the energy field.Among them,thermoelectric ionogels have a wide range of applications in the field of energy recovery and utilization due to their excellent flexibility,stability,and thermoelectric conversion ability,providing many application possibilities for such materials.The development of highly efficient and stable ionic thermoelectric devices is largely dependent on the development of new materials and structural designs.This paper focuses on the recent strategies for improving the efficiency of thermoelectric conversion in the field of ionic thermoelectric gels,including new methods for material design,structural optimization,and innovative developments in the application of thermoelectric materials.The evaluation indicators of thermoelectric conversion efficiency are discussed,including ionic thermal voltage,ionic conductivity and power output,ductility,and self-healing properties.Additionally,various application devices based on thermoelectric materials with excellent thermoelectric conversion properties are highlighted.Further,different challenges and strategies that need to be addressed are presented in the hope of providing inspiration and guidance for the commercialization of i-TE.展开更多
基金supported by the National Natural Science Foundation of China(22271110)the Natural Science Founda-tion of Hubei Province(2022CFA031)。
文摘Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics;however,conventional thermoelectric materials face significant drawbacks,including high ionic concentrations,toxicity,and limited thermoelectric efficiency.Here,we report an ionic thermoelectric hydrogel designed through precise supramolecular chemistry,utilizing dual molecular interactions,host-vip complexation ofα-cyclodextrin(α-CD)with I_(3)^(-)ions and hydrogen bonding between polyvinyl alcohol(PVA)polymer chains and I_(3)^(-).This molecularly tailored approach markedly amplifies thermoelectric performance,achieving a high thermopower of 2.21 mV/K and a tenfold enhancement in peak power output at an exceptionally low iodine concentration(10 mmol/L I^(-)+2.5 mmol/L I_(3)^(-)).The hydrogel maintains excellent biocompatibility and mechanical robustness,suitable for direct skin contact.Demonstrated applications include flexible thermoelectric devices generating nearly 100 mV from body heat and sensor arrays capable of motion and spatial temperature sensing.These results underscore the substantial potential of supramolecularly designed ionic thermoelectric hydrogels for wearable energy harvesting,personalized healthcare monitoring,and advanced human-computer interfaces.
基金financially supported by research grants from the Natural Science Foundation of China [Grant No. 62074022 (K.S.), 12004057 (Y.J.Z.), 52173235 (M.L.)]the Natural Science Foundation of Chongqing [cstc2021jcyj-jqX0015 (K.S.)]+3 种基金Chongqing Talent Plan [cstc2021ycjh-bgzxm0334 (S.S.C.), CQYC2021059206 (K.S.)]Fundamental Research Funds for the Central Universities [No. 2020CDJQY-A055 (K.S.)]the Key Laboratory of Low-grade Energy Utilization Technologies and Systems [Grant No. LLEUTS-201901 (K.S.)]support from Chongqing Postgraduate Research and Innovation Project (CYS22032)。
文摘Ionic thermoelectrics(i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin. However,as ions cannot enter external circuit, the utilization of i-TE is currently based on capacitive charge/discharge, which results in discontinuous working mode and low energy density. Here,we introduce an ion–electron thermoelectric synergistic(IETS)effect by utilizing an ion–electron conductor. Electrons/holes can drift under the electric field generated by thermodiffusion of ions, thus converting the ionic current into electrical current that can pass through the external circuit. Due to the IETS effect, i-TE is able to operate continuously for over 3000 min.Moreover, our i-TE exhibits a thermopower of 32.7 mV K^(-1) and an energy density of 553.9 J m^(-2), which is more than 6.9 times of the highest reported value. Consequently, direct powering of electronics is achieved with i-TE. This work provides a novel strategy for the design of high-performance i-TE materials.
基金financial support by the National Natural Science Foundation of China(No.51873033 and No.52073057)the Fundamental Research Funds for the Central Universities(2232020A-01 and 2232019A3-02)+3 种基金DHU Distinguished Young Professor Program(LZB2019002)Shanghai Rising-Star Program(20QA1400300)the Fundamental Research Funds for the Central University and Graduate Student Innovation Fund of Donghua University(CUSFDH-D-2020033)State Key Laboratory for Space Power Sources Technology(No.YF07050117F0768)。
文摘Converting low-grade waste heat into usable electricity and storing it simultaneously requires a new technology that realize the directional migration of electrons or ions under temperature difference and enrichment on the electrodes.Although the urgent demand of energy conversion-storage(ECS)has emerged in the field of wearable electronic,achieving the integrated bi-functional device remains challenge due to the different mechanisms of electrical transportation and storage.Here,we report an ionic thermoelectric supercapacitor that relies on the synergistic functions of thermoelectricity and supercapacitor in the thermoelectric ionogel electrolyte and high-performance hydrogel electrodes to enhance the ECS performance under a thermal gradient.The thermoelectric electrolyte is composed of polyacrylamide hydrogel and sodium carboxymethyl cellulose(PMSC),possessing cross-linked network with excellent cation selectivity,while the ionic thermoelectric properties are further improved in the presence of NaCl.The corresponding Seebeck coefficient and ionic conductivity of the NaCl–PMSC electrolyte reach 17.1 mV K^(-1)and 26.8 mS cm^(-1),respectively.Owing to good stretchability of both gel-based electrolyte and electrode,the fullstretchable integrated ECS device,termed ionic thermoelectric supercapacitor,presents promising thermal-charge storage capability(~1.3 mC,ΔT≈10 K),thus holds promise for wearable energy harvesting.
基金supported by the National Natural Science Foundation of China(22308210)the Young Talent Fund of the Association for Science and Technology in Shaanxi of China(20240412)the Natural Science Foundation of Shaanxi University of Science&Technology(2019BT-44).
文摘Compared with those traditional initiating devices of anti-scalding systems,ionic thermoelectric sensors with energyautonomous performance show higher reliability.However,the current ionic thermoelectric materials(i-TEs)suffer from complex nano-/micro-channel design,high production costs,environmentally unfriendly,weak mechanical properties,as well as the low moving speed of ions.Herein,the functional leather collagen fibers-bearing natural channels are employed as the polymer matrixes,while the trisodium citrate(SC)organic acid salt exhibits the function of cationic moving selfenhancement as the primary mobile ions for signaling.Including numerous and suitable nano-/micro-channels together with fast-moving cations,the leather-based i-TEs(LITE),LITE-SC0.75 M,possess excellent thermoelectric properties,achieving a Seebeck coefficient of 6.23 mV/K,a figure of merit of 0.084,and an energy conversion efficiency of 2.12%.Combined with its excellent thermal stability,mechanical performance,flexibility,durability,low cost,and outstanding capabilities for low-grade heat harvesting and thermal sensing,the LITE-SC0.75 M detector bearing long service life would show great promise in automatic anti-scalding alarm suitable for multiple scenarios and extreme environments.Therefore,the present work aims to design an efficient,robust,and energy-autonomous leather collagen fibers-based thermoelectric detector to address the limitation of current anti-scalding alarm technology as well as drive advancements in the nano-energy and its effective conversion field.
基金supported by National Natural Science Foundation of China(62474019)Beijing Natural Science Foundation(L223006)BIT Research and Innovation Promoting Project(2024YCXY001).
文摘Thermoelectric technology that utilizes thermodynamic effects to convert thermal energy into electrical energy has greatly expanded wearable health monitoring,personalized detecting,and communicating applications.Encouragingly,thermoelectric technology assisted by artificial intelligence exerts great development potential in wearable electronic devices that rely on the self-sustainable operation of human body heat.Ionic thermoelectric(i-TE)devices that possess high Seebeck coefficients and a constant and stable electrical output are expected to achieve an effective conversation of thermal energy harvesting.Herein,we developed an i-TE paster for thermal chargeable energy storage,temperature-triggered material recognition,contact/non-contact temperature detection,and photo thermoelectric conversion applications.An all-solid-state organic ionic gel electrolyte(PVDF-HFP-PEO gel)with onion epidermal cells-like structure was sandwiched between two electrodes,which take full advantage of a synergy between the Soret effect and the polymer thermal expansion effect,thus achieving the enhanced ZT value up to 900%compared with the PEO-free electrolyte.The i-TE device delivers a Seebeck coefficient of 28 mV K^(−1),a maximum energy conversion efficiency of 1.3%in performance,and ultra-thin and skin-attachable properties in wearability,which demonstrate the great potential and application prospect of the i-TE paster in self-sustainable wearable electronics.
基金supported by the Leading Edge Technology of Jiangsu Province (BK20220009, BK20202008)Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘Lithium-ion thermoelectrochemical cell(LTEC), featuring simultaneous energy conversion and storage, has emerged as promising candidate for low-grade heat harvesting. However, relatively poor thermosensitivity and heat-to-current behavior limit the application of LTECs using LiPF_6 electrolyte. Introducing additives into bulk electrolyte is a reasonable strategy to solve such problem by modifying the solvation structure of electrolyte ions. In this work, we develop a dual-salt electrolyte with fluorosurfactant(FS) additive to achieve high thermopower and durability of LTECs during the conversion of low-grade heat into electricity. The addition of FS induces a unique Li~+ solvation with the aggregated double anions through a crowded electrolyte environment,resulting in an enhanced mobility kinetics of Li~+ as well as boosted thermoelectrochemical performances. By coupling optimized electrolyte with graphite electrode, a high thermopower of 13.8 mV K^(-1) and a normalized output power density of 3.99 mW m^(–2) K^(–2) as well as an outstanding output energy density of 607.96 J m^(-2) can be obtained.These results demonstrate that the optimization of electrolyte by regulating solvation structure will inject new vitality into the construction of thermoelectrochemical devices with attractive properties.
基金This work was supported by the Beijing Natural ScienceFoundation(L.223006)Beijing Institute of Technol-ogy Research Found Program for Young Scholars.
文摘Thermally chargeable supercapacitors(TCSCs)have offered exceptional energy-converting efficiency for absorbing human epidermal heat and generating and storing electrical energy,which then realize continuous power supply to electronic devices,such as sensors and wearable electronic products,in a wide range of practical significance.Here,we proposed a flexible TCSC by attaching binder-free Ti_(3)C_(2)T_(x) MXene@PPy electrodes on both ends of the H_(3)PO_(4)@P(AM-co-AA-co-AYP K^(+))hydrogel electrolyte,which exhibits a large thermal power of 35.2 mV K^(−1) at 50%relative humidity and maximum figure of merit of 2.1.The high performances of the fabricated devices can be attributed to the tunable electrical,thermodynamic,thermoelectric,and mechanical properties of the hydrogel electrolyte by adjusting the acid content and the proportion of zwitterionic compound AYP K^(+)in the hydrogel,and the high photothermal conversion efficiency and electrochemical performance of the electrodes.Moreover,the stable and outstanding thermofvoltage output(∼200 mV)under different time scenarios of the TCSC makes it possible to drive a strain sensor,accomplishing the objectives of a human activity monitor.
基金supported by the National Natural Science Foundation of China(52250010 and 52379120)the Natural Science Foundation of Jiangsu Province(BK20230086)。
文摘Buildings and infrastructure significantly contribute to global energy consumption and CO_(2) emissions.Transforming cement,the most widely used construction material,into a functional medium for heat harvesting presents a promising avenue to offset the energy demands of buildings.The disparity in diffusion rate between cations and anions within cement pore solution due to variations in interactions with pore walls,endows cement with inherent ionic thermoelectric properties.However,the isolation of pores by the dense cement matrix hinders the rapid transportation of ions with superior diffusion rates,impeding the enhancement of mobility difference between ions and limiting the enhancement of Seebeck coefficient.Inspired by the stem structure of plants,we present a cement-polyvinyl alcohol(PVA)composite(CPC)featuring aligned cement and PVA hydrogel layers.While PVA hydrogel layers provide ion diffusion highways for OH-ions,cement-PVA interfaces establish strong coordination bonds with Ca^(2+)ions and weaker interactions with OH-ions,enabling selective immobilization,which amplifies the diffusion rate disparity between Ca^(2+)and OH^(-).The CPC's multilayer structure yields abundant interfaces,providing ample interaction sites that maximize the contribution of cement ions to thermoelectric performance.The as-prepared composite achieves an impressive Seebeck coefficient of-40.5 mV/K and a figure of merit(ZT)of 6.6×10^(-2).Due to the engineered multilayer structure,the CPC also demonstrates superior mechanical strength and intrinsic energy storage potential,which has been assembled into a selfpowered architecture.The biomimetic structure and interfacial selective immobilization mechanism may pave the way for the design and fabrication of high-performance ionic thermoelectric materials.
基金financially supported by the National Natural Science Foundation of China(No.22335008).
文摘Ionic thermoelectric conversion based on Soret effect,a phenomenon of converting heat into electricity,has been popularized in establishing self-powering systems where thermal exchange is associated.It works in the presence of a temperature gradient,but becomes invalid if there is no significant temperature difference between two electrodes,especially in miniaturized devices and large thermal field.Herein,we break this cognition by discovering thermoelectric conversion in isothermal environments resulting from a heterogeneous system consisting of Metal A/Ionic liquid/Metal B.Asymmetric ion rearrangement is proposed on two ionic liquid/electrode interfaces when temperature varies,accounting for the generation of thermoelectric voltage.This principle can be applied to many electrodes/ionic liquids groups.The advantages of temperature gradient independence lay the ground for the creation of powerless thermometers to alarm large area of fire.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFA0703100)the National Natural Science Foundation of China (Grant No. 51733006)。
文摘Stretchable ionic thermoelectric(i-TE) materials have attracted growing interest in converting low-grade thermal energy into electricity. However, substantial improvement on i-TE performance of quasi-solid ionogels remains a significant challenge.Here, a nanocomposite ionogel with skin-like stretchability, high i-TE performance, thermostability and durability is prepared by hybridizing ionic liquid(IL) and Laponite nanosheets into waterborne polyurethane(WPU). With multiple H-bond, WPU can accommodate a higher content of IL, thereby improving its ionic conductivity. After cation exchange between IL and Laponite,the negatively charged Laponite sheets and released Na+can enhance the ionic Seebeck coefficient by enlarging thermophoretic mobility difference between the cations and anions in ionogel. Besides, incorporation of Laponite causes the decrease of thermal conductivity. Thus, the WPU-IL-Laponite ionogel exhibits a high ionic thermopower of 44.1 m V K-1, high ionic conductivity of 14.1 m S cm-1and low thermal conductivity of 0.43 W m-1K-1at a relative humidity of 90%. The corresponding ionic figure of merit of the ionogel is 1.90±0.27. Moreover, the ionogel demonstrates excellent durability during repeated stretching process.The stretchable ionogel can be fabricated into ionic thermoelectric capacitor to convert thermal energy from solar radiation into electricity.
基金supported by research grants from the National Key R&D Program of China(grant no.2023YFB4704000)National Natural Science Foundation of China(NSFC+3 种基金grant no.52203211)Fundamental Research Funds for the Central Universities,China(grant no.2024CDJZCQ-005)Exceptional Young Talents Project(grant no.cstc2021ycjh-bgzxm0334)Financial support(grant no.IDH2203003Y)from Fudan University。
文摘Ionic thermoelectricity(i-TE),as a new energy conversion and storage technology,has been widely discussed by the academic community.As one of the representatives of low-grade thermal energy recovery,i-TE has made remarkable progress and become an influential research direction in the energy field.Among them,thermoelectric ionogels have a wide range of applications in the field of energy recovery and utilization due to their excellent flexibility,stability,and thermoelectric conversion ability,providing many application possibilities for such materials.The development of highly efficient and stable ionic thermoelectric devices is largely dependent on the development of new materials and structural designs.This paper focuses on the recent strategies for improving the efficiency of thermoelectric conversion in the field of ionic thermoelectric gels,including new methods for material design,structural optimization,and innovative developments in the application of thermoelectric materials.The evaluation indicators of thermoelectric conversion efficiency are discussed,including ionic thermal voltage,ionic conductivity and power output,ductility,and self-healing properties.Additionally,various application devices based on thermoelectric materials with excellent thermoelectric conversion properties are highlighted.Further,different challenges and strategies that need to be addressed are presented in the hope of providing inspiration and guidance for the commercialization of i-TE.
