To meet the requirements of strict fuel consumption and emission limits,continuously increasing the thermal efficiency of an internal combustion engine and decreasing its exhaust emissions are the main challenges to i...To meet the requirements of strict fuel consumption and emission limits,continuously increasing the thermal efficiency of an internal combustion engine and decreasing its exhaust emissions are the main challenges to its sustainable development within the automotive industry.Considering the competition with other zero-emission powertrain systems,such as vehicle batteries and fuel cells,the development of the internal combustion engine needs to focus on producing higher efficiency and zero emissions to meet the request of CO_(2) reduction.This paper introduces two novel concepts for an internal combustion engine featuring high efficiency and zero emissions.Referred to as the argon power cycle engine fueled with either hydrogen or natural gas within an oxygen–argon mixture,its fundamentals and characteristics are expounded.This includes a method necessary to absorb carbon dioxide when natural gas is used as fuel instead of hydrogen.展开更多
Lithium metal has gained extensive attention as the most ideal candidate for next-generation battery anode owing to the ultrahigh specific capacity and the lowest electrochemical potential.However,uncontrollable dendr...Lithium metal has gained extensive attention as the most ideal candidate for next-generation battery anode owing to the ultrahigh specific capacity and the lowest electrochemical potential.However,uncontrollable dendrite growth and huge volume variation extremely restrict the future deployment of lithium metal batteries.Herein,we report metal chalcogenide SnSSe with unique nanoplate stacking structure as a robust substrate for stable Li metal anode.During the initial Li plating process,lithiophilic Li_(22)Sn_(5) alloy and Li_(2)S/Li_(2)Se sites are obtained via in-situ electrochemical reaction of Li metal and SnSSe.Density functional theory(DFT)calculation demonstrates that the formed Li_(2)S/Li_(2)Se achieves low Li diffusion energy barrier,ensuring rapid Li~+migration.Li_(22)Sn_(5) alloy provides strong nucleation sites,promoting uniform Li nucleation.Furthermore,in-situ optical microscopy analysis suggests that the synthesized effect fundamentally inhibits lithium dendrite growth.Consequently,SnSSe modified Cu foil delivered an ultralow nucleation overpotential,superior cycling stability with 450 cycles(Coulombic efficiency,>98%),and excellent plating/stripping behavior over 2200 h at 0.5 mA cm^(-2).Moreover,the brilliant reversible cycles and rate capability were also realized in Li@SnSSe//LiFePO_(4)(LFP)full cell,shedding light on the feasibility of SnSSe for stable and dendrite-free lithium metal anode.展开更多
The suppression of nitrogen oxides(NO_x) is the key to reducing pollutant emission of a domestic coal-fired stove due to the limitation of technology condition and economic cost. The decoupling combustion(DC) technolo...The suppression of nitrogen oxides(NO_x) is the key to reducing pollutant emission of a domestic coal-fired stove due to the limitation of technology condition and economic cost. The decoupling combustion(DC) technology invented by Institute of Process Engineering(IPE), Chinese Academy of Sciences(CAS) is characterized by that a traditional stove is separated into a pyrolysis and a combustion chamber as well as a bottom passage between them. In this study, the combustion of briquette from bituminous coal in different operation modes in a typical decoupling stove is tested and simulated to validate the advantage of DC technology over so-called reverse combustion. The smokeless and high-efficiency combustion of bituminous briquette with low emissions of NO_x and CO can be implemented by utilizing low NO_x combustion under low temperature and reduction atmosphere in the pyrolysis chamber as well as after-combustion of char and pyrolysis gas under high temperature and oxidation atmosphere in the combustion chamber. The effects of the main reducing components in pyrolysis gas as well as char on NO_x reduction were numerically investigated in this study, which shows that the reducing ability increases gradually from CH_4, CO to char, but the combined reducing ability of them cannot be determined by a simple addition.展开更多
基金The authors thank the National Natural Science Foundation of China(51576164)R&D Center of FAW and CDHK KSPG Professorship Chair Funds on Argon Power Cycle Engine Stud-ies.
文摘To meet the requirements of strict fuel consumption and emission limits,continuously increasing the thermal efficiency of an internal combustion engine and decreasing its exhaust emissions are the main challenges to its sustainable development within the automotive industry.Considering the competition with other zero-emission powertrain systems,such as vehicle batteries and fuel cells,the development of the internal combustion engine needs to focus on producing higher efficiency and zero emissions to meet the request of CO_(2) reduction.This paper introduces two novel concepts for an internal combustion engine featuring high efficiency and zero emissions.Referred to as the argon power cycle engine fueled with either hydrogen or natural gas within an oxygen–argon mixture,its fundamentals and characteristics are expounded.This includes a method necessary to absorb carbon dioxide when natural gas is used as fuel instead of hydrogen.
基金financially supported by the National Natural Science Foundation of China(52074113,22005091,and 22005092)the Hunan University Outstanding Youth Science Foundation(531118040319)+5 种基金the Science and Technology Innovation Program of Hunan Province(2021RC3055)the Changsha Municipal Natural Science Foundation(kq2014037)the CITIC Metals Ningbo Energy Co.Ltd.(H202191380246)the Chongqing Talents:Exceptional Young Talents Project(CQYC202105015)the Shenzhen Virtual University Park Basic Research Project of Free exploration(2021Szvup036)financially supported by the Graduate Research and Innovation Projects of Hunan Province(QL20210088)。
文摘Lithium metal has gained extensive attention as the most ideal candidate for next-generation battery anode owing to the ultrahigh specific capacity and the lowest electrochemical potential.However,uncontrollable dendrite growth and huge volume variation extremely restrict the future deployment of lithium metal batteries.Herein,we report metal chalcogenide SnSSe with unique nanoplate stacking structure as a robust substrate for stable Li metal anode.During the initial Li plating process,lithiophilic Li_(22)Sn_(5) alloy and Li_(2)S/Li_(2)Se sites are obtained via in-situ electrochemical reaction of Li metal and SnSSe.Density functional theory(DFT)calculation demonstrates that the formed Li_(2)S/Li_(2)Se achieves low Li diffusion energy barrier,ensuring rapid Li~+migration.Li_(22)Sn_(5) alloy provides strong nucleation sites,promoting uniform Li nucleation.Furthermore,in-situ optical microscopy analysis suggests that the synthesized effect fundamentally inhibits lithium dendrite growth.Consequently,SnSSe modified Cu foil delivered an ultralow nucleation overpotential,superior cycling stability with 450 cycles(Coulombic efficiency,>98%),and excellent plating/stripping behavior over 2200 h at 0.5 mA cm^(-2).Moreover,the brilliant reversible cycles and rate capability were also realized in Li@SnSSe//LiFePO_(4)(LFP)full cell,shedding light on the feasibility of SnSSe for stable and dendrite-free lithium metal anode.
基金financial supports from the "Transformational Technologies for Clean Energy and Demonstration",Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA21040400)the National Natural Science Foundation of China(Nos21376244 and 91334107)
文摘The suppression of nitrogen oxides(NO_x) is the key to reducing pollutant emission of a domestic coal-fired stove due to the limitation of technology condition and economic cost. The decoupling combustion(DC) technology invented by Institute of Process Engineering(IPE), Chinese Academy of Sciences(CAS) is characterized by that a traditional stove is separated into a pyrolysis and a combustion chamber as well as a bottom passage between them. In this study, the combustion of briquette from bituminous coal in different operation modes in a typical decoupling stove is tested and simulated to validate the advantage of DC technology over so-called reverse combustion. The smokeless and high-efficiency combustion of bituminous briquette with low emissions of NO_x and CO can be implemented by utilizing low NO_x combustion under low temperature and reduction atmosphere in the pyrolysis chamber as well as after-combustion of char and pyrolysis gas under high temperature and oxidation atmosphere in the combustion chamber. The effects of the main reducing components in pyrolysis gas as well as char on NO_x reduction were numerically investigated in this study, which shows that the reducing ability increases gradually from CH_4, CO to char, but the combined reducing ability of them cannot be determined by a simple addition.
