The practical application of lithium-sulfur(Li-S)batteries is still impeded by the severe shuttle effect of lithium polysulfides(LiPSs)and sluggish reaction kinetics of active sulfur.Designing catalytic carriers with ...The practical application of lithium-sulfur(Li-S)batteries is still impeded by the severe shuttle effect of lithium polysulfides(LiPSs)and sluggish reaction kinetics of active sulfur.Designing catalytic carriers with abundant active sites and strong chemisorption capability for LiPSs,is regarded as effective strategy to address these issues.Herein,Se-doping is introduced into the nitrogen-doped carbon coated CoP composite(Se-CoP@NC)to generate structural defects,which effectively enlarges the lattice spacing of CoP and reduces the conversion reaction energy barriers of LiPSs.Meanwhile,Se-doping sites bridges the interface of CoP and nitrogen-doped carbon,accelerating the charge transfer behavior and conversion reaction kinetics of LiPSs.Benefiting from the structural advantages,the assembled Li-S batteries with S/Se-CoP@NC as cathode exhibit high reversible capacity of 779.6 mAh/g at 0.5 C after 500 cycles,and high specific capacity of 805.9 mAh/g at 2 C.Even under extreme conditions(high sulfur-loading content of 6.9 mg/cm^(2);lean electrolyte dosage of 7μL/mg),the corresponding Li-S batteries also keep high reversible areal capacity of 4.5 mAh/cm^(2) after 100 cycles at 0.1 C.This work will inspire the design of metal compounds-based catalysts from atomic level to facilitate the practicability of Li-S batteries.展开更多
Sulfur-containing polymer(SCP)is considered as an outstanding cathode material for lithium-sulfur batteries.However,undesirable soluble polysulfides may shuttle in electrolyte,concluding long-chain Li_(2)S_(n)(n>4)...Sulfur-containing polymer(SCP)is considered as an outstanding cathode material for lithium-sulfur batteries.However,undesirable soluble polysulfides may shuttle in electrolyte,concluding long-chain Li_(2)S_(n)(n>4)and short-chain Li2Sn(n≤4),as well as the sluggish conversion kinetics are yet to be solved to enhance the performance of lithium-sulfur batteries.Here Se-doped sulfurized polyaniline with adjusted sulfur-chain-S_(x)-(x≤6)contribute to ensure the absence of long-chain polysulfides,and the skeleton with quinoid imine can endow strongly adsorption towards short-chain polysulfides by the reversible transition between deprotonated/protonated imine(-NH^(+)=and-N=),which offer double insurance against suppressing“shuttle effect”.Furthermore,Se atoms are doped into sulfurized polysulfides to accelerate the redox conversion and take a frontier orbital theory-oriented view into catalytic mechanism.Se-doped sulfurized polyaniline as active materials for lithium-organosulfur batteries delivers good electrochemical performance,including high rate,reversible specific capacity(680 mA h g^(-1)at 0.1 A g^(-1)),and lower capacity decay rate only of 0.15%with near 100%coulomb efficiency during long-term cycle.This work provides a valuable guiding ideology and promising solution for the chemistry-oriented structure design and practical application for lithium-organosulfur batteries.展开更多
基金the financial support from the National Natural Science Foundation of China(No.52101250)the S&T program of Hebei(Nos.215A4401D and 225A4404D)+5 种基金the Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC14)the Fundamental Research Funds for the Hebei University(No.2021YWF11)the Science Research Project of Hebei Education Department(No.QN2024087)the Xingtai City Natural Science Foundation(No.2023ZZ027)the Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),College of Chemistry,Nankai Universitypartially supported by the Pico Election Microscopy Center of Hainan University。
文摘The practical application of lithium-sulfur(Li-S)batteries is still impeded by the severe shuttle effect of lithium polysulfides(LiPSs)and sluggish reaction kinetics of active sulfur.Designing catalytic carriers with abundant active sites and strong chemisorption capability for LiPSs,is regarded as effective strategy to address these issues.Herein,Se-doping is introduced into the nitrogen-doped carbon coated CoP composite(Se-CoP@NC)to generate structural defects,which effectively enlarges the lattice spacing of CoP and reduces the conversion reaction energy barriers of LiPSs.Meanwhile,Se-doping sites bridges the interface of CoP and nitrogen-doped carbon,accelerating the charge transfer behavior and conversion reaction kinetics of LiPSs.Benefiting from the structural advantages,the assembled Li-S batteries with S/Se-CoP@NC as cathode exhibit high reversible capacity of 779.6 mAh/g at 0.5 C after 500 cycles,and high specific capacity of 805.9 mAh/g at 2 C.Even under extreme conditions(high sulfur-loading content of 6.9 mg/cm^(2);lean electrolyte dosage of 7μL/mg),the corresponding Li-S batteries also keep high reversible areal capacity of 4.5 mAh/cm^(2) after 100 cycles at 0.1 C.This work will inspire the design of metal compounds-based catalysts from atomic level to facilitate the practicability of Li-S batteries.
基金partly supported by the National Natural Science Foundation of China(51763014 and 52073133)the Key Talent Project Foundation of Gansu Province+3 种基金Joint fund between Shenyang National Laboratory for Materials Science and State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals(18LHPY002)the Incubation Program of Excellent Doctoral Dissertation-Lanzhou University of Technologyexcellent doctoral Program of Gansu Province(22JR5RA240)the Program for Hongliu Distinguished Young Scholars in Lanzhou University of Technology。
文摘Sulfur-containing polymer(SCP)is considered as an outstanding cathode material for lithium-sulfur batteries.However,undesirable soluble polysulfides may shuttle in electrolyte,concluding long-chain Li_(2)S_(n)(n>4)and short-chain Li2Sn(n≤4),as well as the sluggish conversion kinetics are yet to be solved to enhance the performance of lithium-sulfur batteries.Here Se-doped sulfurized polyaniline with adjusted sulfur-chain-S_(x)-(x≤6)contribute to ensure the absence of long-chain polysulfides,and the skeleton with quinoid imine can endow strongly adsorption towards short-chain polysulfides by the reversible transition between deprotonated/protonated imine(-NH^(+)=and-N=),which offer double insurance against suppressing“shuttle effect”.Furthermore,Se atoms are doped into sulfurized polysulfides to accelerate the redox conversion and take a frontier orbital theory-oriented view into catalytic mechanism.Se-doped sulfurized polyaniline as active materials for lithium-organosulfur batteries delivers good electrochemical performance,including high rate,reversible specific capacity(680 mA h g^(-1)at 0.1 A g^(-1)),and lower capacity decay rate only of 0.15%with near 100%coulomb efficiency during long-term cycle.This work provides a valuable guiding ideology and promising solution for the chemistry-oriented structure design and practical application for lithium-organosulfur batteries.
