As advancements in the Internet of Things(IoT)and unmanned technologies continues to progress,the development of unmanned system of systems(USS)has reached unprecedented levels.While prior research has predominantly e...As advancements in the Internet of Things(IoT)and unmanned technologies continues to progress,the development of unmanned system of systems(USS)has reached unprecedented levels.While prior research has predominantly examined temporal variations in USS resilience,spatial changes remain underexplored.However,USS may involve kinetic engagements and frequent spatial changes during mission execution,affecting signal interference in data layer communications.Although time-dependent factors primarily govern mission effectiveness of the USS,spatial factors influence the transmission stability of the data layer.Consequently,assessing spatiotemporal variations in USS performance is critical.To address these challenges,this study introduces a spatiotemporal resilience assessment framework,which evaluates USS resilience across both temporal and spatial dimensions.Furthermore,we propose a spatiotemporal resilience optimization scheme that enhances system adaptability throughout the mission lifecycle,with a particular emphasis on prevention and recovery strategies.Finally,we validate the validity of the proposed concepts and methods with a case study featuring a regular hexagonal deployment of USS.The results show that the spatiotemporal resilience can better reflect the spatial change characteristics of USS,and the proposed optimization strategy improves the prevention spatiotemporal resilience,recovery spatiotemporal resilience,and entire-process spatiotemporal resilience of USS by 0.22%,8.39%,and 11.29%,respectively.展开更多
Sodium-ion batteries have been deemed as a sustainable alternative to lithium-ion systems due to the abundance and affordability of sodium sources.Nevertheless,developing high-energy-density P2-type layered oxide cath...Sodium-ion batteries have been deemed as a sustainable alternative to lithium-ion systems due to the abundance and affordability of sodium sources.Nevertheless,developing high-energy-density P2-type layered oxide cathodes with long-term cycling stability poses challenges,stemming from irreversible phase transitions,structural degradation,and lattice oxygen instability during electrochemical cycling.Here,we propose a one-step NbB_(2)modification strategy that enhances both bulk and surface properties of Na_(0.8)Li_(0.12)Ni_(0.22)Mn_(0.66)O_(2)cathodes.By exploiting different techniques,we disclose that bulk Nb and B doping combined with a Nb-Transition Metal-BO_(3)surface layer reconstruction enable a reversible P2-OP4 phase transition and,meanwhile,improve anionic redox reversibility.In addition,Li^(+)migrates into alkali-metal layers and underpins the layered structure through the“pillar effect”,thereby facilitating the Na^(+)diffusion in Na_(0.8)Li_(0.12)Ni_(0.22)Mn_(0.66)O_(2)cathodes and retaining their structural integrity at high voltage.As a result,the modified cathodes achieve 93.6%capacity retention after 500 cycles at 1C and deliver specific capacities above 114 m A h g^(-1)at 10C within 2.0-4.3 V.Contrary to the previous studies reporting that OP4 phase are detrimental to the structural stability of layered cathodes,we experimentally validate that a well-regulated P2-OP4 phase transition is beneficial for structural and electrochemical stabilities.展开更多
Solid oxide fuel cells(SOFCs)are widely presented as a sustainable solution to future energy challenges.Nevertheless,solid oxide fuel cells presently rely on significant use of several critical raw materials to enable...Solid oxide fuel cells(SOFCs)are widely presented as a sustainable solution to future energy challenges.Nevertheless,solid oxide fuel cells presently rely on significant use of several critical raw materials to enable optimized electrode reaction kinetics.This challenge can be addressed by using thinfilm electrode materials;however,this is typically accompanied by complex device fabrication procedures as well as poor mechanical/chemical stability.In this work,we conduct a systematic study of a range of promising thin-film electrode materials based on vertically aligned nanocomposite(VAN)thin films.We demonstrate low area specific resistance(ASR)values of 0.44 cm^(2) at 650℃ can be achieved using(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80)(LSCF-SDC)thin films,which are also characterized by a low degradation rate,approximately half that of planar LSCF thin films.We then integrate these(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80) vertically aligned nanocomposite films directly with commercial anode supported half cells through a single-step deposition process.The resulting cells exhibit peak power density of 0.47W cm^(-2) at 750℃,competitive with 0.64W cm^(-2) achieved for the same cells operating with a bulk(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3) cathode,despite 99.5% reduction in cathode critical raw material use.By demonstrating such competitive performance using thin-film cathode functional layers,this work also paves the way for further cost reductions in solid oxide fuel cells,which could be achieved by likewise applying thin-film architectures to the anode functional layer and/or current collecting layers,which typically account for the greatest materials cost in solid oxide fuel cell stacks.Therefore,the present work marks a valuable step towards the sustainable proliferation of solid oxide fuel cells.展开更多
基金support for this research from the Natural Science Foundation of Henan Province(252300421005).
文摘As advancements in the Internet of Things(IoT)and unmanned technologies continues to progress,the development of unmanned system of systems(USS)has reached unprecedented levels.While prior research has predominantly examined temporal variations in USS resilience,spatial changes remain underexplored.However,USS may involve kinetic engagements and frequent spatial changes during mission execution,affecting signal interference in data layer communications.Although time-dependent factors primarily govern mission effectiveness of the USS,spatial factors influence the transmission stability of the data layer.Consequently,assessing spatiotemporal variations in USS performance is critical.To address these challenges,this study introduces a spatiotemporal resilience assessment framework,which evaluates USS resilience across both temporal and spatial dimensions.Furthermore,we propose a spatiotemporal resilience optimization scheme that enhances system adaptability throughout the mission lifecycle,with a particular emphasis on prevention and recovery strategies.Finally,we validate the validity of the proposed concepts and methods with a case study featuring a regular hexagonal deployment of USS.The results show that the spatiotemporal resilience can better reflect the spatial change characteristics of USS,and the proposed optimization strategy improves the prevention spatiotemporal resilience,recovery spatiotemporal resilience,and entire-process spatiotemporal resilience of USS by 0.22%,8.39%,and 11.29%,respectively.
基金financially supported by the National Key R&D Program of China(2020YFA0406203)National Natural Science Foundation of China(92472115,52371225 and 52072008)+5 种基金Guangdong Basic and Applied Basic Research Foundation(2022B1515120070,2022A1515110816 and 2022A1515110596)the Large Scientific Facility Open Subject of Songshan Lake,Dongguan,Guangdong(KFKT2022A04)Jialin Xie Fund(E4546IU2)the open research fund of Songshan Lake Materials Laboratory(2023SLABFN02)The Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by the Municipal Development and Reform Commission of Shenzhen also contributed to this researchthe allocation of beamtime at BL15U and BL02B02 beamlines at SSRF。
文摘Sodium-ion batteries have been deemed as a sustainable alternative to lithium-ion systems due to the abundance and affordability of sodium sources.Nevertheless,developing high-energy-density P2-type layered oxide cathodes with long-term cycling stability poses challenges,stemming from irreversible phase transitions,structural degradation,and lattice oxygen instability during electrochemical cycling.Here,we propose a one-step NbB_(2)modification strategy that enhances both bulk and surface properties of Na_(0.8)Li_(0.12)Ni_(0.22)Mn_(0.66)O_(2)cathodes.By exploiting different techniques,we disclose that bulk Nb and B doping combined with a Nb-Transition Metal-BO_(3)surface layer reconstruction enable a reversible P2-OP4 phase transition and,meanwhile,improve anionic redox reversibility.In addition,Li^(+)migrates into alkali-metal layers and underpins the layered structure through the“pillar effect”,thereby facilitating the Na^(+)diffusion in Na_(0.8)Li_(0.12)Ni_(0.22)Mn_(0.66)O_(2)cathodes and retaining their structural integrity at high voltage.As a result,the modified cathodes achieve 93.6%capacity retention after 500 cycles at 1C and deliver specific capacities above 114 m A h g^(-1)at 10C within 2.0-4.3 V.Contrary to the previous studies reporting that OP4 phase are detrimental to the structural stability of layered cathodes,we experimentally validate that a well-regulated P2-OP4 phase transition is beneficial for structural and electrochemical stabilities.
基金support from the Royal Academy of Engineering Chair in Emerging technologies(grant number CIET1819_24)the EPSRC Centre of Advanced Materials for Integrated Energy Systems(CAM-IES)(grant number EP/P007767/1)+2 种基金the EU-H2020-ERC-ADG EROS(grant number 882929)support provided by Deutsche Forschungsgemeinschaft(Project no.424789449,grant no.HA1344-45-1)support from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement no.836503.We acknowledge use of the Thermo Fisher Spectra 300 TEM at the Wolfson Electron Microscopy Suite at the University of Cambridge funded by EPSRC under grant EP/R008779/1.
文摘Solid oxide fuel cells(SOFCs)are widely presented as a sustainable solution to future energy challenges.Nevertheless,solid oxide fuel cells presently rely on significant use of several critical raw materials to enable optimized electrode reaction kinetics.This challenge can be addressed by using thinfilm electrode materials;however,this is typically accompanied by complex device fabrication procedures as well as poor mechanical/chemical stability.In this work,we conduct a systematic study of a range of promising thin-film electrode materials based on vertically aligned nanocomposite(VAN)thin films.We demonstrate low area specific resistance(ASR)values of 0.44 cm^(2) at 650℃ can be achieved using(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80)(LSCF-SDC)thin films,which are also characterized by a low degradation rate,approximately half that of planar LSCF thin films.We then integrate these(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3)-(Sm_(2)O_(3))_(0.20)(CeO_(2))_(0.80) vertically aligned nanocomposite films directly with commercial anode supported half cells through a single-step deposition process.The resulting cells exhibit peak power density of 0.47W cm^(-2) at 750℃,competitive with 0.64W cm^(-2) achieved for the same cells operating with a bulk(La_(0.60)Sr_(0.40))_(0.95)Co_(0.20)Fe_(0.80)O_(3) cathode,despite 99.5% reduction in cathode critical raw material use.By demonstrating such competitive performance using thin-film cathode functional layers,this work also paves the way for further cost reductions in solid oxide fuel cells,which could be achieved by likewise applying thin-film architectures to the anode functional layer and/or current collecting layers,which typically account for the greatest materials cost in solid oxide fuel cell stacks.Therefore,the present work marks a valuable step towards the sustainable proliferation of solid oxide fuel cells.
基金北京林业大学研究生自选课题基金资助项目(06jj038)中美碳联盟USCCC国际合作资助项目美国宇航局项目“Effects of Land Use Change on The Energy and Water Balance of The Semi-Arid Region of Inner Mongolia”
