The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes ...The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes regarded as the main cause of battery fire.Herein,a series of solid-state polyphosphate oligomers(SPPO)as a three-in-one electrolyte that integrated the roles of lithium salt,dissociation matrix,and flame retardant were synthesized.The well-designed SPPO electrolytes showed an optimal ionic conductivity of 5.5×10^(-4)S cm-1at 30℃,an acceptable electrochemical window up to 4.0 V vs.Li/Li+,and lithium ion transference number of 0.547.Stable Li-ion stripping/plating behavior for 500 h of charge-discharge cycles without internal short-circuit in a Li|SPPO|Li cell was confirmed,together with outstanding interface compatibility between the SPPO electrolyte and lithium foil.The optimal Li|SPPO|LiFePO4cell presented good reversible discharge capacity of 149.4 mA h g-1at 0.1 C and Coulombic efficiency of 96.4%after 120 cycles.More importantly,the prepared SPPO cannot be ignited by the lighter fire and show a limited-oxygen-index value as high as 35.5%,indicating splendid nonflammable nature.The SPPO could be a promising candidate as a three-in-one solid-state electrolyte for the improved safety of rechargeable lithium batteries.展开更多
Black phosphorus(BP)nano-materials,especially BP quantum dots(BPQDs),performs outstanding photothermal antitumor effects,excellent biocompatibility and biodegradability.However,there are several challenges to overcome...Black phosphorus(BP)nano-materials,especially BP quantum dots(BPQDs),performs outstanding photothermal antitumor effects,excellent biocompatibility and biodegradability.However,there are several challenges to overcome before offering real benefits,such as poor stability,poor dispersibility as well as difficulty in tailoring other functions.Here,a“three-in-one”mitochondria-targeted BP nano-platform,called as BPQD-PEG-TPP,was designed.In this nano-platform,BPQDs were covalently grafted with a heterobifunctional PEG,in which one end was an aryl diazo group capable of reacting with BPQDs to form a covalent bond and the other end was a mitochondria-targeted triphenylphosphine(TPP)group.In addition to its excellent near-infrared photothermal properties,BPQD-PEG-TPP had much enhanced stability and dispersibility under physiological conditions,efficient mitochondria targeting and promoted ROS production through a photothermal effect.Both in vitro and in vivo experiments demonstrated that BPQD-PEG-TPP performed much superior photothermal cytotoxicity than BPQDs and BPQD-PEG as the mitochondria targeted PTT.Thus this“three-in-one”nanoplatform fabricated through polymer grafting,with excellent stability,dispersibility and negligible side effects,might be a promising strategy for mitochondria-targeted photothermal cancer therapy.展开更多
Using porous carbon hosts in cathodes of Li-S cells can disperse S actives and offset their poor electrical conductivity.However,such reservoirs would in turn absorb excess electrolyte solvents to S-unfilled regions,c...Using porous carbon hosts in cathodes of Li-S cells can disperse S actives and offset their poor electrical conductivity.However,such reservoirs would in turn absorb excess electrolyte solvents to S-unfilled regions,causing the electrolyte overconsumption,specific energy decline,and even safety hazards for battery devices.To build better cathodes,we propose to substitute carbons by In-doped SnO_(2)(ITO)nano ceramics that own three-in-one functionalities:1)using conductive ITO enables minimizing the total carbon content to an extremely low mass ratio(~3%)in cathodes,elevating the electrode tap density and averting the electrolyte overuse;2)polar ITO nanoclusters can serve as robust anchors toward Li polysulfide(LiPS)by electrostatic adsorption or chemical bond interactions;3)they offer catalysis centers for liquid–solid phase conversions of S-based actives.Also,such ceramics are intrinsically nonflammable,preventing S cathodes away from thermal runaway or explosion.These merits entail our configured cathodes with high tap density(1.54 g cm^(−3)),less electrolyte usage,good security for flame retardance,and decent Li-storage behaviors.With lean and LiNO_(3)-free electrolyte,packed full cells exhibit excellent redox kinetics,suppressed LiPS shuttling,and excellent cyclability.This may trigger great research enthusiasm in rational design of low-carbon and safer S cathodes.展开更多
LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) is extensively researched as one of the most widely used commercially materials for Li-ion batteries at present.However,the poor high-voltage performance(≥4.3 V)with low reversible cap...LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) is extensively researched as one of the most widely used commercially materials for Li-ion batteries at present.However,the poor high-voltage performance(≥4.3 V)with low reversible capacity limits its replacement for LiCoO_(2) in high-end digital field.Herein,three-in-one modification,Na-doping and Al_(2)O_(3)@Li_(3)BO_(3) dual-coating simultaneously,is explored for single-crystalline LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(N-NCM@AB),which exhibits excellent high-voltage performance.N-NCM@AB displays a discharge-specific capacity of 201.8 mAh g^(−1) at 0.2 C with a high upper voltage of 4.6 V and maintains 158.9 mAh g^(−1) discharge capacity at 1 C over 200 cycles with the corresponding capacity retention of 87.8%.Remarkably,the N-NCM@AB||graphite pouch-type full cell retains 81.2% of its initial capacity with high working voltage of 4.4 V over 1600 cycles.More importantly,the fundamental understandings of three-in-one modification on surface morphology,crystal structure,and phase transformation of N-NCM@AB are clearly revealed.The Na+doped into the Li–O slab can enhance the bond energy,stabilize the crystal structure,and facilitate Li+transport.Additionally,the interior surface layer of Li^(+)-ions conductor Li_(3)BO_(3) relieves the charge transfer resistance with surface coating,whereas the outer surface Al_(2)O_(3) coating layer is beneficial for reducing the active materials loss and alleviating the electrode/electrolyte parasite reaction.This three-in-one strategy provides a reference for the further research on the performance attenuation mechanism of NCM,paving a new avenue to boost the high-voltage performance of NCM cathode in Li-ion batteries.展开更多
As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The ...As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.展开更多
基金the financial support of the National Natural Science Foundation of China(21961044,22169024)the Yunnan Fundamental Research Projects(202105AC160072,202101BC070001-019,202101AT070280,202102AB080017)the Yunnan University’s Research Innovation Fund for graduate students(2021Y394)。
文摘The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes regarded as the main cause of battery fire.Herein,a series of solid-state polyphosphate oligomers(SPPO)as a three-in-one electrolyte that integrated the roles of lithium salt,dissociation matrix,and flame retardant were synthesized.The well-designed SPPO electrolytes showed an optimal ionic conductivity of 5.5×10^(-4)S cm-1at 30℃,an acceptable electrochemical window up to 4.0 V vs.Li/Li+,and lithium ion transference number of 0.547.Stable Li-ion stripping/plating behavior for 500 h of charge-discharge cycles without internal short-circuit in a Li|SPPO|Li cell was confirmed,together with outstanding interface compatibility between the SPPO electrolyte and lithium foil.The optimal Li|SPPO|LiFePO4cell presented good reversible discharge capacity of 149.4 mA h g-1at 0.1 C and Coulombic efficiency of 96.4%after 120 cycles.More importantly,the prepared SPPO cannot be ignited by the lighter fire and show a limited-oxygen-index value as high as 35.5%,indicating splendid nonflammable nature.The SPPO could be a promising candidate as a three-in-one solid-state electrolyte for the improved safety of rechargeable lithium batteries.
基金We are grateful for the financial support from National Natural Science Foundation of China(51703258,81772449 and 81971081)Guangzhou science technology and innovation commission(201804010309 and 201803010090)Science,Technology&Innovation Commission of Shenzhen Municipality(JCYJ20180307154606793 and JCYJ20180507181654186).
文摘Black phosphorus(BP)nano-materials,especially BP quantum dots(BPQDs),performs outstanding photothermal antitumor effects,excellent biocompatibility and biodegradability.However,there are several challenges to overcome before offering real benefits,such as poor stability,poor dispersibility as well as difficulty in tailoring other functions.Here,a“three-in-one”mitochondria-targeted BP nano-platform,called as BPQD-PEG-TPP,was designed.In this nano-platform,BPQDs were covalently grafted with a heterobifunctional PEG,in which one end was an aryl diazo group capable of reacting with BPQDs to form a covalent bond and the other end was a mitochondria-targeted triphenylphosphine(TPP)group.In addition to its excellent near-infrared photothermal properties,BPQD-PEG-TPP had much enhanced stability and dispersibility under physiological conditions,efficient mitochondria targeting and promoted ROS production through a photothermal effect.Both in vitro and in vivo experiments demonstrated that BPQD-PEG-TPP performed much superior photothermal cytotoxicity than BPQDs and BPQD-PEG as the mitochondria targeted PTT.Thus this“three-in-one”nanoplatform fabricated through polymer grafting,with excellent stability,dispersibility and negligible side effects,might be a promising strategy for mitochondria-targeted photothermal cancer therapy.
基金support by the National Natural Science Foundation of China(51802269,21773138)Fundamental Research Funds for the Central Universities(XDJK2019AA002)+1 种基金the Venture&Innovation Support Program for Chongqing Overseas Returnees(cx2018027)the innovation platform for academicians of Hainan province.
文摘Using porous carbon hosts in cathodes of Li-S cells can disperse S actives and offset their poor electrical conductivity.However,such reservoirs would in turn absorb excess electrolyte solvents to S-unfilled regions,causing the electrolyte overconsumption,specific energy decline,and even safety hazards for battery devices.To build better cathodes,we propose to substitute carbons by In-doped SnO_(2)(ITO)nano ceramics that own three-in-one functionalities:1)using conductive ITO enables minimizing the total carbon content to an extremely low mass ratio(~3%)in cathodes,elevating the electrode tap density and averting the electrolyte overuse;2)polar ITO nanoclusters can serve as robust anchors toward Li polysulfide(LiPS)by electrostatic adsorption or chemical bond interactions;3)they offer catalysis centers for liquid–solid phase conversions of S-based actives.Also,such ceramics are intrinsically nonflammable,preventing S cathodes away from thermal runaway or explosion.These merits entail our configured cathodes with high tap density(1.54 g cm^(−3)),less electrolyte usage,good security for flame retardance,and decent Li-storage behaviors.With lean and LiNO_(3)-free electrolyte,packed full cells exhibit excellent redox kinetics,suppressed LiPS shuttling,and excellent cyclability.This may trigger great research enthusiasm in rational design of low-carbon and safer S cathodes.
基金We gratefully acknowledge the financial support from the National Natural Science Foundation of China(52070194,51902347,51908555,and 51822812)Natural Science Foundation of Hunan Province(2020JJ5741)the Graduate Innovation Project of Central South University(2020zzts093).
文摘LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) is extensively researched as one of the most widely used commercially materials for Li-ion batteries at present.However,the poor high-voltage performance(≥4.3 V)with low reversible capacity limits its replacement for LiCoO_(2) in high-end digital field.Herein,three-in-one modification,Na-doping and Al_(2)O_(3)@Li_(3)BO_(3) dual-coating simultaneously,is explored for single-crystalline LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(N-NCM@AB),which exhibits excellent high-voltage performance.N-NCM@AB displays a discharge-specific capacity of 201.8 mAh g^(−1) at 0.2 C with a high upper voltage of 4.6 V and maintains 158.9 mAh g^(−1) discharge capacity at 1 C over 200 cycles with the corresponding capacity retention of 87.8%.Remarkably,the N-NCM@AB||graphite pouch-type full cell retains 81.2% of its initial capacity with high working voltage of 4.4 V over 1600 cycles.More importantly,the fundamental understandings of three-in-one modification on surface morphology,crystal structure,and phase transformation of N-NCM@AB are clearly revealed.The Na+doped into the Li–O slab can enhance the bond energy,stabilize the crystal structure,and facilitate Li+transport.Additionally,the interior surface layer of Li^(+)-ions conductor Li_(3)BO_(3) relieves the charge transfer resistance with surface coating,whereas the outer surface Al_(2)O_(3) coating layer is beneficial for reducing the active materials loss and alleviating the electrode/electrolyte parasite reaction.This three-in-one strategy provides a reference for the further research on the performance attenuation mechanism of NCM,paving a new avenue to boost the high-voltage performance of NCM cathode in Li-ion batteries.
基金supported by the Meteorological Soft Science Project(Grant No.2023ZZXM29)the Natural Science Fund Project of Tianjin,China(Grant No.21JCYBJC00740)the Key Research and Development-Social Development Program of Jiangsu Province,China(Grant No.BE2021685).
文摘As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.
