实验以废弃小麦秸秆为原料,基于KOH活化-高温烧结法制备了多孔碳材料,采用扫描电子显微镜(SEM)、N_(2)吸附/脱附测试和拉曼光谱(Raman)等测试方法,表征了材料的结构及形貌,并结合恒流充放电(GCD)和循环伏安(CV)测试技术,探究了其在锂离...实验以废弃小麦秸秆为原料,基于KOH活化-高温烧结法制备了多孔碳材料,采用扫描电子显微镜(SEM)、N_(2)吸附/脱附测试和拉曼光谱(Raman)等测试方法,表征了材料的结构及形貌,并结合恒流充放电(GCD)和循环伏安(CV)测试技术,探究了其在锂离子电池中的应用。实验结果表明,采用10 mol·L^(-1)KOH活化的碳材料所制备的电极在循环100次后,依然能具有348.4 m Ah·g^(-1)的比容量,且当电流密度增加到3.5 A·g^(-1)时,其比容量高达431.2 m Ah·g^(-1),表现出较高的倍率性能,这主要是由于材料较多的微孔空隙和较高的无序度,提供了更多的电化学活性点。展开更多
A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and...A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.展开更多
The practical application of lithium metal batteries(LMBs)requires electrolytes that simultaneously ensure high safety and interfacial stability.Although locally concentrated ionic liquid electrolytes(LCILEs)exhibit e...The practical application of lithium metal batteries(LMBs)requires electrolytes that simultaneously ensure high safety and interfacial stability.Although locally concentrated ionic liquid electrolytes(LCILEs)exhibit exceptional electrochemical stability and compatibility with electrode electrolyte interfaces(EEIs),two major challenges persist:(i)safety risks caused by excessive low-flash-point diluents,and(ii)insufficient understanding of how diluents modulate solvation structures.Herein,we introduce a low-diluent-content LCILE system composed of lithium bis(fluorosulfonyl)imide(LiFSI)salt,N-methyl-N-propyl-pyrrolidinium bis(fluorosulfonyl)imide(Pyr_(13)FSI)ionic liquid,and trifluoromethanesulfonate(TFS)diluent.The TFS diluent strengthens ion-ion interactions by lowering the dielectric constant of the electrolyte,resulting in the formation of a unique nanometric anion aggregates(N-AGGs)reinforced solvation structure.These large anionic clusters exhibit accelerated redox decomposition kinetics,facilitating the rapid formation of a thin,dense,and low-impedance EEI.Consequently,the Li/LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)coin cell achieves 87.8%capacity retention over 300 cycles at 4.3 V,while a practical 1.4 Ah Li/NCM622 pouch cell retains 84.5%capacity after 80 cycles at 4.5 V.Furthermore,the electrolyte demonstrates exceptional safety,and 2 Ah Li metal pouch cells successfully pass rigorous nail penetration tests without any ignition or explosion.This work not only provides a design strategy for intrinsically safe and high-performance electrolytes but also highlights the critical role of anion cluster decomposition kinetics in shaping EEI formation.展开更多
Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_...Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.展开更多
文摘实验以废弃小麦秸秆为原料,基于KOH活化-高温烧结法制备了多孔碳材料,采用扫描电子显微镜(SEM)、N_(2)吸附/脱附测试和拉曼光谱(Raman)等测试方法,表征了材料的结构及形貌,并结合恒流充放电(GCD)和循环伏安(CV)测试技术,探究了其在锂离子电池中的应用。实验结果表明,采用10 mol·L^(-1)KOH活化的碳材料所制备的电极在循环100次后,依然能具有348.4 m Ah·g^(-1)的比容量,且当电流密度增加到3.5 A·g^(-1)时,其比容量高达431.2 m Ah·g^(-1),表现出较高的倍率性能,这主要是由于材料较多的微孔空隙和较高的无序度,提供了更多的电化学活性点。
文摘A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.
基金supported by the National Key R&D Program of China(Grant No.2022YFE0207300)the National Natural Science Foundation of China(Grant Nos.22179142 and 22075314)+1 种基金Jiangsu Provincial Science and Technology Program(Grant No.BG 2024020).XPSWAXS and TOF-SIMS characterizations were supported by Nano-X(Vacuum Interconnected Nanotech Workstation,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(SINANO),Suzhou 215123,China)。
文摘The practical application of lithium metal batteries(LMBs)requires electrolytes that simultaneously ensure high safety and interfacial stability.Although locally concentrated ionic liquid electrolytes(LCILEs)exhibit exceptional electrochemical stability and compatibility with electrode electrolyte interfaces(EEIs),two major challenges persist:(i)safety risks caused by excessive low-flash-point diluents,and(ii)insufficient understanding of how diluents modulate solvation structures.Herein,we introduce a low-diluent-content LCILE system composed of lithium bis(fluorosulfonyl)imide(LiFSI)salt,N-methyl-N-propyl-pyrrolidinium bis(fluorosulfonyl)imide(Pyr_(13)FSI)ionic liquid,and trifluoromethanesulfonate(TFS)diluent.The TFS diluent strengthens ion-ion interactions by lowering the dielectric constant of the electrolyte,resulting in the formation of a unique nanometric anion aggregates(N-AGGs)reinforced solvation structure.These large anionic clusters exhibit accelerated redox decomposition kinetics,facilitating the rapid formation of a thin,dense,and low-impedance EEI.Consequently,the Li/LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)coin cell achieves 87.8%capacity retention over 300 cycles at 4.3 V,while a practical 1.4 Ah Li/NCM622 pouch cell retains 84.5%capacity after 80 cycles at 4.5 V.Furthermore,the electrolyte demonstrates exceptional safety,and 2 Ah Li metal pouch cells successfully pass rigorous nail penetration tests without any ignition or explosion.This work not only provides a design strategy for intrinsically safe and high-performance electrolytes but also highlights the critical role of anion cluster decomposition kinetics in shaping EEI formation.
基金funding from the National Natural Science Foundation of China (Award 91745203) supplemented by Central Universities’ Basic Research Funds.
文摘Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.
