MXene,a transition metal carbide/nitride,has been prominent as an ideal electrochemical active material for supercapacitors.However,the low MXene load limits its practical applications.As environmental concerns and su...MXene,a transition metal carbide/nitride,has been prominent as an ideal electrochemical active material for supercapacitors.However,the low MXene load limits its practical applications.As environmental concerns and sustainable development become more widely recognized,it is necessary to explore a greener and cleaner technology to recycle textile by-products such as cotton.The present study proposes an effective 3D fabrication method that uses MXene to fabricate waste denim felt into ultralight and flexible supercapacitors through needling and carbonization.The 3D structure provided more sites for loading MXene onto Z-directional fiber bundles,resulting in more efficient ion exchange between the electrolyte and electrodes.Furthermore,the carbonization process removed the specific adverse groups in MXenes,further improving the specific capacitance,energy density,power density and electrical conductivity of supercapacitors.The electrodes achieve a maximum specific capacitance of 1748.5 mF cm-2 and demonstrate remarkable cycling stability maintaining more than 94%after 15,000 galvanostatic charge/discharge cycles.Besides,the obtained supercapacitors present a maximum specific capacitance of 577.5 mF cm^(-2),energy density of 80.2μWh cm^(-2)and power density of 3 mW cm^(-2),respectively.The resulting supercapacitors can be used to develop smart wearable power devices such as smartwatches,laying the foundation for a novel strategy of utilizing waste cotton in a high-quality manner.展开更多
The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage devices.However,it is a challenge to obtain both positive and negative e...The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage devices.However,it is a challenge to obtain both positive and negative electrodes with excellent mechanical strength and match positive and negative charges to achieve high energy densities and operate voltages to satisfy practical application requirements.Here,flexible MXene(Ti_(3)C_(2)Tx)/cellulose nanofiber(CNF)composite film negative electrodes(MCNF)were fabricated with a vacuum filtration method,as well as positive electrodes(CP)by combining polyaniline(PANI)with carbon cloth(CC)using an in-situ polymerization method.Both positive and negative free-standing electrodes exhibited excellent electrochemical behavior and bendable/foldable flexibility.As a result,the all-pseudocapacitance asymmetric device of MCNF//CP assembled with charge-matched between anode and cathode achieves an extended voltage window of 1.5 V,high energy density of 30.6 Wh·kg^(−1)(1211 W·kg^(−1)),86%capacitance retention after 5000 cycles,the device maintains excellent bendability,simultaneously.This work will pave the way for the development of all-pseudocapacitive asymmetric supercapacitors(ASC)with simultaneously preeminent mechanical properties,high energy density,wide operating voltage window.展开更多
Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are wi...Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are widely used in highly developed industries. Unfortunately, environmental contamination and the loss of natural resources have led to the reemergence of biomass resources as efficient and sustainable energy sources. Notably, simple and direct applications can no longer meet the demand for functionalization, high performance of materials and construction materials. Therefore, it is imperative to modify biomass and combine its utilisation to produce functionalization and high performance materials. For example, construction materials with superior mechanical properties and water resistance can be produced by reinforcing fibres to facilitate crosslinking. Water-oil separation or adsorption effects of hydrogels and aerogels are determined by the porosity and lightness of biomass, biocomposite conductor is prepared by chimaeric conductive material. Here, we review the approaches that have been taken to devise an environmentally friendly yet fully recyclable and sustainable functionalised biocomposites from biomass and its potential directions for future research.展开更多
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(Nos.52073224,32201491)the Textile Vision Basic Research Program of China(No.J202110)+3 种基金the Scientific Research Project of Shaanxi Provincial Education Department,China(No.22JC035)the Advanced Manufacturing Technology Program of Xi’an Science and Technology Bureau,China(No.21XJZZ0019)the Research Fund for the Doctoral Program of Xi’an Polytechnic University(No.BS202053)the Youth Innovation Team of Shaanxi Universities and Institute of Flexible electronics and Intelligent Textile.
文摘MXene,a transition metal carbide/nitride,has been prominent as an ideal electrochemical active material for supercapacitors.However,the low MXene load limits its practical applications.As environmental concerns and sustainable development become more widely recognized,it is necessary to explore a greener and cleaner technology to recycle textile by-products such as cotton.The present study proposes an effective 3D fabrication method that uses MXene to fabricate waste denim felt into ultralight and flexible supercapacitors through needling and carbonization.The 3D structure provided more sites for loading MXene onto Z-directional fiber bundles,resulting in more efficient ion exchange between the electrolyte and electrodes.Furthermore,the carbonization process removed the specific adverse groups in MXenes,further improving the specific capacitance,energy density,power density and electrical conductivity of supercapacitors.The electrodes achieve a maximum specific capacitance of 1748.5 mF cm-2 and demonstrate remarkable cycling stability maintaining more than 94%after 15,000 galvanostatic charge/discharge cycles.Besides,the obtained supercapacitors present a maximum specific capacitance of 577.5 mF cm^(-2),energy density of 80.2μWh cm^(-2)and power density of 3 mW cm^(-2),respectively.The resulting supercapacitors can be used to develop smart wearable power devices such as smartwatches,laying the foundation for a novel strategy of utilizing waste cotton in a high-quality manner.
基金the National Natural Science Foundation of China(No.32201491)Major projects of Natural Science Foundation of Jiangsu(No.18KJA220002)China Postdoctoral Science Foundation:Special Program(No.2017T100313).
文摘The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage devices.However,it is a challenge to obtain both positive and negative electrodes with excellent mechanical strength and match positive and negative charges to achieve high energy densities and operate voltages to satisfy practical application requirements.Here,flexible MXene(Ti_(3)C_(2)Tx)/cellulose nanofiber(CNF)composite film negative electrodes(MCNF)were fabricated with a vacuum filtration method,as well as positive electrodes(CP)by combining polyaniline(PANI)with carbon cloth(CC)using an in-situ polymerization method.Both positive and negative free-standing electrodes exhibited excellent electrochemical behavior and bendable/foldable flexibility.As a result,the all-pseudocapacitance asymmetric device of MCNF//CP assembled with charge-matched between anode and cathode achieves an extended voltage window of 1.5 V,high energy density of 30.6 Wh·kg^(−1)(1211 W·kg^(−1)),86%capacitance retention after 5000 cycles,the device maintains excellent bendability,simultaneously.This work will pave the way for the development of all-pseudocapacitive asymmetric supercapacitors(ASC)with simultaneously preeminent mechanical properties,high energy density,wide operating voltage window.
基金the National Natural Science Foundation of China (No.32201491)China Postdoctoral Science Foundation (No.2021M690847)+5 种基金Natural Science Foundation of Jiangsu Province (No.BK20200775)Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No.21KJB220011)Science and Technology Innovation Program of Hunan Province (No.2021RC2106)Deputy General Project of Science and Technology of Jiangsu Province (No.FZ20211507)Hunan Province Biomass-based Materials Green and Low-carbon Intelligent Manufacturing Engineering Technology Research centre (No.2022TP2033)Technology centre of Hunan Hongsen Novel Material Technology Co., Ltd. (No.HNJSZX2022290)。
文摘Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are widely used in highly developed industries. Unfortunately, environmental contamination and the loss of natural resources have led to the reemergence of biomass resources as efficient and sustainable energy sources. Notably, simple and direct applications can no longer meet the demand for functionalization, high performance of materials and construction materials. Therefore, it is imperative to modify biomass and combine its utilisation to produce functionalization and high performance materials. For example, construction materials with superior mechanical properties and water resistance can be produced by reinforcing fibres to facilitate crosslinking. Water-oil separation or adsorption effects of hydrogels and aerogels are determined by the porosity and lightness of biomass, biocomposite conductor is prepared by chimaeric conductive material. Here, we review the approaches that have been taken to devise an environmentally friendly yet fully recyclable and sustainable functionalised biocomposites from biomass and its potential directions for future research.
