Thermal-electric bilayer invisibility cloak can prevent the heat flux and electric current from touching the object without distorting the external temperature and electric potential fields simultaneously.In this pape...Thermal-electric bilayer invisibility cloak can prevent the heat flux and electric current from touching the object without distorting the external temperature and electric potential fields simultaneously.In this paper,we design an omnidirectional thermal-electric invisibility cloak with anisotropic geometry.Based on the theory of neutral inclusion,the anisotropic effective thermal and electric conductivities of confocal elliptical bilayer core-shell structure are derived,thus obtaining the anisotropic matrix material to eliminate the external disturbances omnidirectionally.The inner shell of the cloak is selected as an insulating material to shield the heat flux and electric current.Then,the omnidirectional thermal-electric cloaking effect is verified numerically and experimentally based on the theoretical anisotropic matrix and manufactured composite structure,respectively.Furthermore,we achieve the thermal-electric cloaking effect under a specific direction of heat flux and electric current using the isotropic natural materials to broaden the selection range of materials.The method proposed to eliminate anisotropy and achieve the omnidirectional effect could also be expanded to other different physical fields for the metadevices with different functions.展开更多
Silicon monoxide(SiO)(silicon[Si]mixed with silicon dioxide[SiO_(2)])/graphite(Gr)composite material is one of the most commercially promising anode materials for the next generation of high-energy-density lithium-ion...Silicon monoxide(SiO)(silicon[Si]mixed with silicon dioxide[SiO_(2)])/graphite(Gr)composite material is one of the most commercially promising anode materials for the next generation of high-energy-density lithium-ion batteries.The major bottleneck for SiO/Gr composite anode is the poor cyclability arising from the stress/strain behaviors due to the mismatch between two heterogenous materials during the lithiation/delithiation process.To date,a meticulous and quantitative understanding of the highly nonlinear coupling behaviors of such materials is still lacking.Herein,an electro–chemo–mechanics-coupled detailed model containing particle geometries is established.The underlying mechanism of the regulation between SiO and Gr components during electrochemical cycling is quantitatively revealed.We discover that increasing the SiO weight percentage(wt%)reduces the utilization efficiency of the active materials at the same 1C rate charging and enhances the hindering effects of stress-driven flux on diffusion.In addition,the mechanical constraint demonstrates a balanced effect on the overall performance of cells and the local behaviors of particles.This study provides new insights into the fundamental interactions between SiO and Gr materials and advances the investigation methodology for the design and evaluation of next-generation high-energydensity batteries.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.11572090)the Fundamental Research Funds for the Central Universities(Grant No.3072022GIP0202).
文摘Thermal-electric bilayer invisibility cloak can prevent the heat flux and electric current from touching the object without distorting the external temperature and electric potential fields simultaneously.In this paper,we design an omnidirectional thermal-electric invisibility cloak with anisotropic geometry.Based on the theory of neutral inclusion,the anisotropic effective thermal and electric conductivities of confocal elliptical bilayer core-shell structure are derived,thus obtaining the anisotropic matrix material to eliminate the external disturbances omnidirectionally.The inner shell of the cloak is selected as an insulating material to shield the heat flux and electric current.Then,the omnidirectional thermal-electric cloaking effect is verified numerically and experimentally based on the theoretical anisotropic matrix and manufactured composite structure,respectively.Furthermore,we achieve the thermal-electric cloaking effect under a specific direction of heat flux and electric current using the isotropic natural materials to broaden the selection range of materials.The method proposed to eliminate anisotropy and achieve the omnidirectional effect could also be expanded to other different physical fields for the metadevices with different functions.
文摘Silicon monoxide(SiO)(silicon[Si]mixed with silicon dioxide[SiO_(2)])/graphite(Gr)composite material is one of the most commercially promising anode materials for the next generation of high-energy-density lithium-ion batteries.The major bottleneck for SiO/Gr composite anode is the poor cyclability arising from the stress/strain behaviors due to the mismatch between two heterogenous materials during the lithiation/delithiation process.To date,a meticulous and quantitative understanding of the highly nonlinear coupling behaviors of such materials is still lacking.Herein,an electro–chemo–mechanics-coupled detailed model containing particle geometries is established.The underlying mechanism of the regulation between SiO and Gr components during electrochemical cycling is quantitatively revealed.We discover that increasing the SiO weight percentage(wt%)reduces the utilization efficiency of the active materials at the same 1C rate charging and enhances the hindering effects of stress-driven flux on diffusion.In addition,the mechanical constraint demonstrates a balanced effect on the overall performance of cells and the local behaviors of particles.This study provides new insights into the fundamental interactions between SiO and Gr materials and advances the investigation methodology for the design and evaluation of next-generation high-energydensity batteries.
