Low electrolyte/sulfur ratio(E/S)is an important factor in increasing the energy density of lithium-sulfur batteries(LSBs).Recently,the E/S has been widely lowered using catalytic hosts that can suppress“shuttle eff...Low electrolyte/sulfur ratio(E/S)is an important factor in increasing the energy density of lithium-sulfur batteries(LSBs).Recently,the E/S has been widely lowered using catalytic hosts that can suppress“shuttle effect”during cycling by relying on a limited adsorption area.However,the shelf-lives of these cathodes have not yet received attention.Herein,we show that the selfdischarge of sulfur cathodes based on frequently-used catalytic hosts is serious under low E/S because the“shuttle effect”during storage process caused by polysulfides(PSs)disproportionation cannot be suppressed using a limited adsorption area.We further prove that the adsorption strength toward PSs,which is unfortunately weak in commonly-used catalytic hosts,is critical for effectively hindering the disproportionation of the PSs.Subsequently,to verify this conclusion,we prepare a sulfur-doped titanium nitride(S-TiN)catalytic array host.As the adsorption strength and catalytic activity of TiN can be improved by S doping simultaneously,the constructed S/S-TiN cathodes under a low E/S(6.5μL·mg−1)exhibit better shelf-life and cycle-stability than those of S/TiN cathodes.Our work suggests that enhancing the adsorption strength of catalytic hosts,while maintaining their function to reduce E/S,is crucial for practical LSBs.展开更多
The exploration of new catalytic hosts is highly important to tackle the sluggish electrochemical kinetics of sulfur redox for achieving high energy density of lithium–sulfur batteries.Herein,for the first time,we pr...The exploration of new catalytic hosts is highly important to tackle the sluggish electrochemical kinetics of sulfur redox for achieving high energy density of lithium–sulfur batteries.Herein,for the first time,we present high-entropy oxide(HEO,(Mg_(0.2)Mn_(0.2)Ni_(0.2)Co_(0.2)Zn_(0.2))Fe_(2)O_(4))nanofibers as catalytic host of sulfur.The HEO nanofibers show a synergistic effect among multiple metal cations in spinel structure that enables strong chemical confinement of soluble polysulfides and fast kinetics for polysulfide conversion.Consequently,the S/HEO composite displays the high gravimetric capacity of 1368.7 mAh g^(−1) at 0.1 C rate,excellent rate capability with the discharge capacity of 632.1 mAh g^(−1) at 5 C rate,and desirable cycle stability.Furthermore,the S/HEO composite shows desirable sulfur utilization and good cycle stability under a harsh operating condition of high sulfur loading(4.6 mg cm^(−2))or low electrolyte/sulfur ratio(5μL mg^(−1)).More impressively,the high volumetric capacity of 2627.9 mAh cm^(−3) is achieved simultaneously for the S/HEO composite due to the high tap density of 1.92 g cm^(−3),nearly 2.5 times of the conventional sulfur/carbon composite.Therefore,based on high-entropy oxide materials,this work affords a fresh concept of elevating the gravimetric/volumetric capacities of sulfur cathodes for lithium–sulfur batteries.展开更多
Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle sta...Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle stability mainly due to the low intrinsic electrical conductivity of sulfur and its discharged products(Li_(2)S_(2)/Li_(2)S),the sluggish reaction kinetics of sulfur cathode,and the“shuttle effect”of soluble intermediate lithi-um polysulfides in ether-based electrolyte.To address these challenges,catalytic hosts have recently been introduced in sulfur cathodes to en-hance the conversion of soluble polysulfides to the final solid products and thus prevent the dissolution and loss of active-sulfur material.In this review,we summarize the recent progress on the use of metal phosphides and borides of different dimensions as the catalytic host of sulfur cathodes and demonstrate the catalytic conversion mechanism of sulfur cathodes with the help of metal phosphides and borides for high-en-ergy and long-life lithium-sulfur batteries.Finally,future outlooks are proposed on developing advanced catalytic host materials to improve battery performance.展开更多
Sulfur element possesses an ultrahigh theoretical specific capacity,while the utilization of sulfur in the whole cathode is lower obviously owing to the sluggish kinetics of sulfur and discharged products,limiting the...Sulfur element possesses an ultrahigh theoretical specific capacity,while the utilization of sulfur in the whole cathode is lower obviously owing to the sluggish kinetics of sulfur and discharged products,limiting the enhancement on energy density of lithium-sulfur batteries.Herein,for the first time,Fe_(0.24)Co_(0.26)Ni_(0.10)Cu_(0.15)Mn_(0.25)high-entropy alloy is introduced as the core catalytic host to activate the electrochemical performance of the sulfur cathode for lithium-sulfur batteries.It is manifested that Fe_(0.24)Co_(0.26)Ni_(0.10)Cu_(0.15)Mn_(0.25)high-entropy alloy nanocrystallites distributed on nitrogen-doped carbon exhibit high electrocatalytic activity toward the conversion of solid sulfur to solid discharged products across soluble intermediate lithium polysulfides.In particular,benefiting from the accelerated kinetics by high-entropy alloy nanocrystallites and synergistic adsorption by nitrogen-doped carbon,the cathode exhibits high reversible capacity of 1079.5 mAh g_(-cathode)^(-1)(high utilization of 89.4%)with the whole cathode as active material,instead of sulfur element.Moreover,under both lean electrolyte(3μmg^(-1))and ultrahigh sulfur loading(27.0 mg cm^(-2))condition,the high discharge capacity of 868.2 mAh g_(-cathode)^(-1)can be still achieved for the sulfur cathode.This strategy opens up a new path to explore catalytic host materials for enhancing the utilization of sulfur in the whole cathode for lithium-sulfur batteries.展开更多
With the high theoretical specific capacity and energy density,lithium-sulfur batteries(LSBs)have been intensively studied as promising candidates for energy storage devices.However,LSBs are largely hindered by inferi...With the high theoretical specific capacity and energy density,lithium-sulfur batteries(LSBs)have been intensively studied as promising candidates for energy storage devices.However,LSBs are largely hindered by inferior sulfur utilization and uncontrollable dendritic growth.Herein,a hierarchical functionalization strategy of stepwise catalytic-adsorption-conversion for sulfur species via the synergetic of the efficiently catalytic host cathode and light multifunctional interlayer has been proposed to concurrently address the issues arising on the dual sides of the LSBs.The multi-layer SnS_(2) micro-flowers embedded into the natural three-dimensional(3D)interconnected carbonized bacterial cellulose(CBC)nanofibers are fabricated as the sulfur host that provides numerous catalytic sites for the rapid catalytic conversion of sulfur species.Moreover,the distinctive CBC-based SnO_(2)-SnS_(2) heterostructure network accompanied high conductive carbon nanofibers as the multifunctional interlayer promotes the rapid anchoringdiffusion-conversion of lithium polysulfides,Li^(+)flux redistribution,and uniform Li deposition.LSBs equipped with our strategy exhibit a high reversible capacity of 1361.5 m A h g^(-1)at 0.2 C and superior cycling stability with an ultra-low capacity fading of 0.031%per cycle in 1000 cycles at 1.5 C and 0.046%at 3 C.A favorable specific capacity of 859.5 m A h g^(-1)at 0.3 C is achieved with a high sulfur mass loading of 5.2 mg cm^(-2),highlighting the potential of practical application.The rational design in this work can provide a feasible solution for high-performance LSBs and promote the development of advanced energy storage devices.展开更多
A dual-regulation strategy of adopting B/N codoped carbon nanotube-encapsulated nickel nanoparticles(Ni@BNCNT) as a sulfur host and separator coating is proposed for high-performance Li-S batteries. On the cathode sid...A dual-regulation strategy of adopting B/N codoped carbon nanotube-encapsulated nickel nanoparticles(Ni@BNCNT) as a sulfur host and separator coating is proposed for high-performance Li-S batteries. On the cathode side, the 3D conductive network structure of Ni@BNCNT is favorable for high sulfur utilization, and the collaboration between polar metal Ni nanoparticles(NPs) and doped B/N elements facilitates the chemical adsorption of Li polysulfides(Li PSs). In addition, these metal Ni NPs exhibit a satisfactory catalytic effect on the polysulfide conversion. Moreover, using the Ni@BNCNT interlayer can further capture the soluble Li PSs, make them convert quickly, and prevent them from diffusing toward the anode side. The Li-S batteries simultaneously equipped with a S/Ni@BNCNT cathode and Ni@BNCNT interlayer show high reversible capacity and good cycle stability. Additionally, even at a sulfur loading of 3.5 mg cm;and an electrolyte/sulfur ratio of 3 μL mg;, excellent battery performance can be achieved. We believe that this work offers a new strategy based on combining a catalytic host and separator coating to construct high-efficiency Li-S batteries.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.52102318 and 52172229)the Natural Science Foundation of Henan(No.202300410427)+1 种基金fellowship of China Postdoctoral Science Foundation(No.2021TQ0287)the Zhengzhou Materials Genome Institute.The author would like to thank Shiyanjia Lab(www.shiyanjia.com)for the DFT calculation.
文摘Low electrolyte/sulfur ratio(E/S)is an important factor in increasing the energy density of lithium-sulfur batteries(LSBs).Recently,the E/S has been widely lowered using catalytic hosts that can suppress“shuttle effect”during cycling by relying on a limited adsorption area.However,the shelf-lives of these cathodes have not yet received attention.Herein,we show that the selfdischarge of sulfur cathodes based on frequently-used catalytic hosts is serious under low E/S because the“shuttle effect”during storage process caused by polysulfides(PSs)disproportionation cannot be suppressed using a limited adsorption area.We further prove that the adsorption strength toward PSs,which is unfortunately weak in commonly-used catalytic hosts,is critical for effectively hindering the disproportionation of the PSs.Subsequently,to verify this conclusion,we prepare a sulfur-doped titanium nitride(S-TiN)catalytic array host.As the adsorption strength and catalytic activity of TiN can be improved by S doping simultaneously,the constructed S/S-TiN cathodes under a low E/S(6.5μL·mg−1)exhibit better shelf-life and cycle-stability than those of S/TiN cathodes.Our work suggests that enhancing the adsorption strength of catalytic hosts,while maintaining their function to reduce E/S,is crucial for practical LSBs.
基金Financial supports from the National Natural Science Foundation of China(21935006 and 22008102)are gratefully acknowledged.
文摘The exploration of new catalytic hosts is highly important to tackle the sluggish electrochemical kinetics of sulfur redox for achieving high energy density of lithium–sulfur batteries.Herein,for the first time,we present high-entropy oxide(HEO,(Mg_(0.2)Mn_(0.2)Ni_(0.2)Co_(0.2)Zn_(0.2))Fe_(2)O_(4))nanofibers as catalytic host of sulfur.The HEO nanofibers show a synergistic effect among multiple metal cations in spinel structure that enables strong chemical confinement of soluble polysulfides and fast kinetics for polysulfide conversion.Consequently,the S/HEO composite displays the high gravimetric capacity of 1368.7 mAh g^(−1) at 0.1 C rate,excellent rate capability with the discharge capacity of 632.1 mAh g^(−1) at 5 C rate,and desirable cycle stability.Furthermore,the S/HEO composite shows desirable sulfur utilization and good cycle stability under a harsh operating condition of high sulfur loading(4.6 mg cm^(−2))or low electrolyte/sulfur ratio(5μL mg^(−1)).More impressively,the high volumetric capacity of 2627.9 mAh cm^(−3) is achieved simultaneously for the S/HEO composite due to the high tap density of 1.92 g cm^(−3),nearly 2.5 times of the conventional sulfur/carbon composite.Therefore,based on high-entropy oxide materials,this work affords a fresh concept of elevating the gravimetric/volumetric capacities of sulfur cathodes for lithium–sulfur batteries.
基金financially supported by the National Natural Science Foundation of China (Nos. 51725401, 51904030, and 21935006)
文摘Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle stability mainly due to the low intrinsic electrical conductivity of sulfur and its discharged products(Li_(2)S_(2)/Li_(2)S),the sluggish reaction kinetics of sulfur cathode,and the“shuttle effect”of soluble intermediate lithi-um polysulfides in ether-based electrolyte.To address these challenges,catalytic hosts have recently been introduced in sulfur cathodes to en-hance the conversion of soluble polysulfides to the final solid products and thus prevent the dissolution and loss of active-sulfur material.In this review,we summarize the recent progress on the use of metal phosphides and borides of different dimensions as the catalytic host of sulfur cathodes and demonstrate the catalytic conversion mechanism of sulfur cathodes with the help of metal phosphides and borides for high-en-ergy and long-life lithium-sulfur batteries.Finally,future outlooks are proposed on developing advanced catalytic host materials to improve battery performance.
基金Financial support from National Natural Science Foundation of China(21935006)is gratefully acknowledged。
文摘Sulfur element possesses an ultrahigh theoretical specific capacity,while the utilization of sulfur in the whole cathode is lower obviously owing to the sluggish kinetics of sulfur and discharged products,limiting the enhancement on energy density of lithium-sulfur batteries.Herein,for the first time,Fe_(0.24)Co_(0.26)Ni_(0.10)Cu_(0.15)Mn_(0.25)high-entropy alloy is introduced as the core catalytic host to activate the electrochemical performance of the sulfur cathode for lithium-sulfur batteries.It is manifested that Fe_(0.24)Co_(0.26)Ni_(0.10)Cu_(0.15)Mn_(0.25)high-entropy alloy nanocrystallites distributed on nitrogen-doped carbon exhibit high electrocatalytic activity toward the conversion of solid sulfur to solid discharged products across soluble intermediate lithium polysulfides.In particular,benefiting from the accelerated kinetics by high-entropy alloy nanocrystallites and synergistic adsorption by nitrogen-doped carbon,the cathode exhibits high reversible capacity of 1079.5 mAh g_(-cathode)^(-1)(high utilization of 89.4%)with the whole cathode as active material,instead of sulfur element.Moreover,under both lean electrolyte(3μmg^(-1))and ultrahigh sulfur loading(27.0 mg cm^(-2))condition,the high discharge capacity of 868.2 mAh g_(-cathode)^(-1)can be still achieved for the sulfur cathode.This strategy opens up a new path to explore catalytic host materials for enhancing the utilization of sulfur in the whole cathode for lithium-sulfur batteries.
基金financially supported by the National Natural Science Foundation of China (52073212,52272303)。
文摘With the high theoretical specific capacity and energy density,lithium-sulfur batteries(LSBs)have been intensively studied as promising candidates for energy storage devices.However,LSBs are largely hindered by inferior sulfur utilization and uncontrollable dendritic growth.Herein,a hierarchical functionalization strategy of stepwise catalytic-adsorption-conversion for sulfur species via the synergetic of the efficiently catalytic host cathode and light multifunctional interlayer has been proposed to concurrently address the issues arising on the dual sides of the LSBs.The multi-layer SnS_(2) micro-flowers embedded into the natural three-dimensional(3D)interconnected carbonized bacterial cellulose(CBC)nanofibers are fabricated as the sulfur host that provides numerous catalytic sites for the rapid catalytic conversion of sulfur species.Moreover,the distinctive CBC-based SnO_(2)-SnS_(2) heterostructure network accompanied high conductive carbon nanofibers as the multifunctional interlayer promotes the rapid anchoringdiffusion-conversion of lithium polysulfides,Li^(+)flux redistribution,and uniform Li deposition.LSBs equipped with our strategy exhibit a high reversible capacity of 1361.5 m A h g^(-1)at 0.2 C and superior cycling stability with an ultra-low capacity fading of 0.031%per cycle in 1000 cycles at 1.5 C and 0.046%at 3 C.A favorable specific capacity of 859.5 m A h g^(-1)at 0.3 C is achieved with a high sulfur mass loading of 5.2 mg cm^(-2),highlighting the potential of practical application.The rational design in this work can provide a feasible solution for high-performance LSBs and promote the development of advanced energy storage devices.
基金supported by the National Natural Science Foundation of China (Grant No. 22008102)the Key Laboratory of Jiangxi Province for the Environment and Energy Catalysis (Grant No. 20181BCD40004)the Science Foundation of Jiangxi Province (Grant No. 20212BAB203031)。
文摘A dual-regulation strategy of adopting B/N codoped carbon nanotube-encapsulated nickel nanoparticles(Ni@BNCNT) as a sulfur host and separator coating is proposed for high-performance Li-S batteries. On the cathode side, the 3D conductive network structure of Ni@BNCNT is favorable for high sulfur utilization, and the collaboration between polar metal Ni nanoparticles(NPs) and doped B/N elements facilitates the chemical adsorption of Li polysulfides(Li PSs). In addition, these metal Ni NPs exhibit a satisfactory catalytic effect on the polysulfide conversion. Moreover, using the Ni@BNCNT interlayer can further capture the soluble Li PSs, make them convert quickly, and prevent them from diffusing toward the anode side. The Li-S batteries simultaneously equipped with a S/Ni@BNCNT cathode and Ni@BNCNT interlayer show high reversible capacity and good cycle stability. Additionally, even at a sulfur loading of 3.5 mg cm;and an electrolyte/sulfur ratio of 3 μL mg;, excellent battery performance can be achieved. We believe that this work offers a new strategy based on combining a catalytic host and separator coating to construct high-efficiency Li-S batteries.
