The development of flexible supercapacitors(FSCs) capable of operating at high temperatures is crucial for expanding the application areas and operating conditions of supercapacitors. Gel polymer electrolytes and elec...The development of flexible supercapacitors(FSCs) capable of operating at high temperatures is crucial for expanding the application areas and operating conditions of supercapacitors. Gel polymer electrolytes and electrode materials stand as two key components that significantly impact the efficacy of hightemperature-tolerant FSCs(HT-FSCs). They should not only exhibit high electrochemical performance and excellent flexibility, but also withstand intense thermal stress. Considerable efforts have been devoted to enhancing their thermal stability while maintaining high electrochemical and mechanical performance. In this review, the fundamentals of HT-FSCs are outlined. A comprehensive overview of state-of-the-art progress and achievements in HT-FSCs, with a focus on thermally stable gel polymer electrolytes and electrode materials is provided. Finally, challenges and future perspectives regarding HT-FSCs are discussed, alongside strategies for elevating operational temperatures and performance.This review offers both theoretical foundations and practical guidelines for designing and manufacturing HT-FSCs, further promoting their widespread adoption across diverse fields.展开更多
Lithium?ion batteries(LIBs), which are high?energy?density and low?safety?risk secondary batteries, are underpinned to the rise in electrochemical energy storage devices that satisfy the urgent demands of the global e...Lithium?ion batteries(LIBs), which are high?energy?density and low?safety?risk secondary batteries, are underpinned to the rise in electrochemical energy storage devices that satisfy the urgent demands of the global energy storage market. With the aim of achiev?ing high energy density and fast?charging performance, the exploitation of simple and low?cost approaches for the production of high capacity, high density, high mass loading, and kinetically ion?accessible electrodes that maximize charge storage and transport in LIBs, is a critical need. Toward the construction of high?performance electrodes, carbons are promisingly used in the enhanced roles of active materials, electrochemi?cal reaction frameworks for high?capacity noncarbons, and lightweight current collectors. Here, we review recent advances in the carbon engi?neering of electrodes for excellent electrochemical performance and structural stability, which is enabled by assembled carbon architectures that guarantee su cient charge delivery and volume fluctuation bu ering inside the electrode during cycling. Some specific feasible assem?bly methods, synergism between structural design components of carbon assemblies, and electrochemical performance enhancement are highlighted. The precise design of carbon cages by the assembly of graphene units is potentially useful for the controlled preparation of high?capacity carbon?caged noncarbon anodes with volumetric capacities over 2100 mAh cm^(-3). Finally, insights are given on the prospects and challenges for designing carbon architectures for practical LIBs that simultaneously provide high energy densities(both gravimetric and volumetric) and high rate performance.展开更多
The low spatial charge-storage density of porous carbons greatly limits volumetric performance in electrochemical capacitors.An increase of charge-storage density requires structural refinements to balance the trade-o...The low spatial charge-storage density of porous carbons greatly limits volumetric performance in electrochemical capacitors.An increase of charge-storage density requires structural refinements to balance the trade-offs between the porosity and density of materials,but the limited mechanical properties of carbons usually fail to withstand effective densifying processes and obtain an ideal pore structure.Herein,we design the stiffened graphene of superior bending rigidity,enabling the fine adjustments of pore structure to maximize the volumetric capacitance for the graphene-based electrodes.The inplane crumples on graphene sheets are found to contribute largely to the bending rigidity,which is useful to control the structural evolution and maintain sufficient ion-accessible surface area during the assembling process.This makes the capacitance of stiffening activated graphene keep 98%when the electrode density increases by 769%to reach 1.13 g cm^(-3) after mechanical pressure,an excellent volumetric energy density of 98.7 Wh L^(-1) in an ionic-liquid electrolyte is achieved.Our results demonstrate the role of intrinsic material properties on the performance of carbon-based electrodes for capacitive energy storage.展开更多
基金Fundamental Research Funds for the Central Universities of China(Grant No. SWU-KT22030)Scientific and Technological Research Program of Chongqing Municipal Education Commission of China (No.KJQN202300205)financial support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under the project of 457444676。
文摘The development of flexible supercapacitors(FSCs) capable of operating at high temperatures is crucial for expanding the application areas and operating conditions of supercapacitors. Gel polymer electrolytes and electrode materials stand as two key components that significantly impact the efficacy of hightemperature-tolerant FSCs(HT-FSCs). They should not only exhibit high electrochemical performance and excellent flexibility, but also withstand intense thermal stress. Considerable efforts have been devoted to enhancing their thermal stability while maintaining high electrochemical and mechanical performance. In this review, the fundamentals of HT-FSCs are outlined. A comprehensive overview of state-of-the-art progress and achievements in HT-FSCs, with a focus on thermally stable gel polymer electrolytes and electrode materials is provided. Finally, challenges and future perspectives regarding HT-FSCs are discussed, alongside strategies for elevating operational temperatures and performance.This review offers both theoretical foundations and practical guidelines for designing and manufacturing HT-FSCs, further promoting their widespread adoption across diverse fields.
基金supported by the National Science Fund for Distinguished Young Scholars of China (No. 51525204)National Key Basic Research Program of China (2014CB932400)the National Natural Science Foundation of China (No. 51872195 and U1401243)
文摘Lithium?ion batteries(LIBs), which are high?energy?density and low?safety?risk secondary batteries, are underpinned to the rise in electrochemical energy storage devices that satisfy the urgent demands of the global energy storage market. With the aim of achiev?ing high energy density and fast?charging performance, the exploitation of simple and low?cost approaches for the production of high capacity, high density, high mass loading, and kinetically ion?accessible electrodes that maximize charge storage and transport in LIBs, is a critical need. Toward the construction of high?performance electrodes, carbons are promisingly used in the enhanced roles of active materials, electrochemi?cal reaction frameworks for high?capacity noncarbons, and lightweight current collectors. Here, we review recent advances in the carbon engi?neering of electrodes for excellent electrochemical performance and structural stability, which is enabled by assembled carbon architectures that guarantee su cient charge delivery and volume fluctuation bu ering inside the electrode during cycling. Some specific feasible assem?bly methods, synergism between structural design components of carbon assemblies, and electrochemical performance enhancement are highlighted. The precise design of carbon cages by the assembly of graphene units is potentially useful for the controlled preparation of high?capacity carbon?caged noncarbon anodes with volumetric capacities over 2100 mAh cm^(-3). Finally, insights are given on the prospects and challenges for designing carbon architectures for practical LIBs that simultaneously provide high energy densities(both gravimetric and volumetric) and high rate performance.
基金financial support from the National Natural Science Foundation of China(22078164,and 22079164)the Major Special Projects of the Plan“Science and Technology Innovation 2025”in Ningbo(2019B10045)。
文摘The low spatial charge-storage density of porous carbons greatly limits volumetric performance in electrochemical capacitors.An increase of charge-storage density requires structural refinements to balance the trade-offs between the porosity and density of materials,but the limited mechanical properties of carbons usually fail to withstand effective densifying processes and obtain an ideal pore structure.Herein,we design the stiffened graphene of superior bending rigidity,enabling the fine adjustments of pore structure to maximize the volumetric capacitance for the graphene-based electrodes.The inplane crumples on graphene sheets are found to contribute largely to the bending rigidity,which is useful to control the structural evolution and maintain sufficient ion-accessible surface area during the assembling process.This makes the capacitance of stiffening activated graphene keep 98%when the electrode density increases by 769%to reach 1.13 g cm^(-3) after mechanical pressure,an excellent volumetric energy density of 98.7 Wh L^(-1) in an ionic-liquid electrolyte is achieved.Our results demonstrate the role of intrinsic material properties on the performance of carbon-based electrodes for capacitive energy storage.
