Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiv...Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.展开更多
Biomass-derived self-supporting carbon materials are considered promising cathodes for zinc-ion capacitors owing to their structural tunability and cost-effectiveness.Natural ramie fibers form a 3D interpenetrating ne...Biomass-derived self-supporting carbon materials are considered promising cathodes for zinc-ion capacitors owing to their structural tunability and cost-effectiveness.Natural ramie fibers form a 3D interpenetrating network,which provides excellent mechanical support for flexible electrodes.However,conventional high-temperature activation often induces structural collapse.Although surface etching preserves flexible frameworks,it limits pore development,resulting in underutilized surface area and poor pore-carrier compatibility.These limitations create a trade-off between electrochemical performance and structural flexibility.This study presents a top-down intercalation activation strategy for precise pore regulation in natural plant fiber-derived carbon.To completely preserve the flexible fiber skeleton,this approach successfully constructs an interconnected hierarchical channel system,which effectively reduces the ion diffusion barrier.Consequently,the flexible electrode exhibits abundant defect structures and a high specific surface area of 2477 m2 g^(-1),which is 50 times that of directly carbonized ramie fibers.These features significantly increase the number of active sites available for charge storage.The assembled zinc-ion hybrid capacitor exhibits an excellent specific capacity of 212 mAh g^(-1) at 0.2 A g^(-1) and an energy density of 168 Wh kg^(-1),and retains 91% of its capacity after 50,000 cycles.Notably,the assembled flexible device maintains normal operations under multi-angle bending conditions,indicating excellent stability.The proposed strategy provides an innovative approach for the precise regulation of pore size in biomass-derived carbon fibers and enables the efficient preparation of other cellulose-based self-supporting carbon materials.展开更多
Recent research efforts in the field of electromagnetic interference shielding(EMI)materials have focused on biomass as a green and sustainable resource.More specifically,wood and cellulose nano fiber(CNF)have many ad...Recent research efforts in the field of electromagnetic interference shielding(EMI)materials have focused on biomass as a green and sustainable resource.More specifically,wood and cellulose nano fiber(CNF)have many advantages,some of which include lightweight,porosity,widespread availability,low cost,and easy processing.These favorable properties have led researchers to consider these types of biomass as an EMI shielding material with great potential.At present,while many excellent published works in EMI shielding materials have investigated wood and CNF,this research area is still new,compared with non-biomass EMI shielding materials.More specifically,there is still a lack of in-depth research and summary on the preparation process,pore structure regulation,component optimization,and other factors affecting the EMI shielding of wood and CNF based EMI shielding materials.Thus,this review paper presents a comprehensive summary of recent research on wood and CNF based EMI shielding materials in recent three years in terms of the preparation methods,material structure design,component synergy,and EMI mechanism,and a forward future perspective for existing problems,challenges,and development trend.The ultimate goal is to provide a comprehensive and informative reference for the further development and exploration of biomass EMI shielding materials.展开更多
文摘Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.
基金financially supported by the Natural Science Foundation of Jiangsu Province(No.BK20241898).
文摘Biomass-derived self-supporting carbon materials are considered promising cathodes for zinc-ion capacitors owing to their structural tunability and cost-effectiveness.Natural ramie fibers form a 3D interpenetrating network,which provides excellent mechanical support for flexible electrodes.However,conventional high-temperature activation often induces structural collapse.Although surface etching preserves flexible frameworks,it limits pore development,resulting in underutilized surface area and poor pore-carrier compatibility.These limitations create a trade-off between electrochemical performance and structural flexibility.This study presents a top-down intercalation activation strategy for precise pore regulation in natural plant fiber-derived carbon.To completely preserve the flexible fiber skeleton,this approach successfully constructs an interconnected hierarchical channel system,which effectively reduces the ion diffusion barrier.Consequently,the flexible electrode exhibits abundant defect structures and a high specific surface area of 2477 m2 g^(-1),which is 50 times that of directly carbonized ramie fibers.These features significantly increase the number of active sites available for charge storage.The assembled zinc-ion hybrid capacitor exhibits an excellent specific capacity of 212 mAh g^(-1) at 0.2 A g^(-1) and an energy density of 168 Wh kg^(-1),and retains 91% of its capacity after 50,000 cycles.Notably,the assembled flexible device maintains normal operations under multi-angle bending conditions,indicating excellent stability.The proposed strategy provides an innovative approach for the precise regulation of pore size in biomass-derived carbon fibers and enables the efficient preparation of other cellulose-based self-supporting carbon materials.
基金the National Natural Science Foundation of China(No.22078184)China Postdoctoral Science Foundation(No.2019M653853XB)Natural science advance research foundation of Shaanxi University of Science and Technology(No.2018QNBJ-03).
文摘Recent research efforts in the field of electromagnetic interference shielding(EMI)materials have focused on biomass as a green and sustainable resource.More specifically,wood and cellulose nano fiber(CNF)have many advantages,some of which include lightweight,porosity,widespread availability,low cost,and easy processing.These favorable properties have led researchers to consider these types of biomass as an EMI shielding material with great potential.At present,while many excellent published works in EMI shielding materials have investigated wood and CNF,this research area is still new,compared with non-biomass EMI shielding materials.More specifically,there is still a lack of in-depth research and summary on the preparation process,pore structure regulation,component optimization,and other factors affecting the EMI shielding of wood and CNF based EMI shielding materials.Thus,this review paper presents a comprehensive summary of recent research on wood and CNF based EMI shielding materials in recent three years in terms of the preparation methods,material structure design,component synergy,and EMI mechanism,and a forward future perspective for existing problems,challenges,and development trend.The ultimate goal is to provide a comprehensive and informative reference for the further development and exploration of biomass EMI shielding materials.
