Lithium-oxygen(Li-O_(2)) batteries are considered as the next generation for energy storages systems due to the higher theoretical energy density than that of Li-ion batteries. However, the high charge overpotential c...Lithium-oxygen(Li-O_(2)) batteries are considered as the next generation for energy storages systems due to the higher theoretical energy density than that of Li-ion batteries. However, the high charge overpotential caused by the insulated Li_(2)O_(2)results in low energy efficiency, side reaction from electrolyte and cathode, and therefore poor battery performance. Designing noble metal-based catalysts can be an effective strategy to develop high-performance Li-O_(2)batteries with low charge overpotentials and outstanding cycle stability. However, the charge mechanism for noble metal-based catalysts is not clear and even contradictory. Herein, several charge mechanisms of Li_(2)O_(2)are first discussed. Subsequently, the possible charge processes of Li-O_(2)batteries with noble metal-based catalysts are illustrated. In addition, the future development for noble metal-based catalysts is outlined.展开更多
Numerous exotic properties have been discovered in Dirac Semimetals(DSMs) and Weyl Semimetals(WSMs). In a given DSM/WSM, the Dirac/Weyl nodes usually coexist with other bulk states, making their respective contributio...Numerous exotic properties have been discovered in Dirac Semimetals(DSMs) and Weyl Semimetals(WSMs). In a given DSM/WSM, the Dirac/Weyl nodes usually coexist with other bulk states, making their respective contribution elusive. In this work, we distinguish the role of bulk states from the tilted Dirac nodes on the transport properties in DSMs. Specifically, we applied pressure to a type-II DSM material, PtTe2, and studied its pressure modified electronic and lattice structure systematically by using in situ transport measurements and X-ray diffraction(XRD). A pressure-induced transition at about 20 GPa is revealed in the transport properties, while the layered lattice structure is robust against pressure as illustrated in XRD measurement results.Density functional theory(DFT) calculations suggest that this is originated from the Lifshitz transition in the bulk states. Our findings provide evidence to identify the bulk states' influence on transport from the topologically-protected DSM states in the DSM material.展开更多
基金the financial support from the National Natural Science Foundation of China (No. 12175098)Hundred Talents Sailing Project of Jiangxi Province, China。
文摘Lithium-oxygen(Li-O_(2)) batteries are considered as the next generation for energy storages systems due to the higher theoretical energy density than that of Li-ion batteries. However, the high charge overpotential caused by the insulated Li_(2)O_(2)results in low energy efficiency, side reaction from electrolyte and cathode, and therefore poor battery performance. Designing noble metal-based catalysts can be an effective strategy to develop high-performance Li-O_(2)batteries with low charge overpotentials and outstanding cycle stability. However, the charge mechanism for noble metal-based catalysts is not clear and even contradictory. Herein, several charge mechanisms of Li_(2)O_(2)are first discussed. Subsequently, the possible charge processes of Li-O_(2)batteries with noble metal-based catalysts are illustrated. In addition, the future development for noble metal-based catalysts is outlined.
基金supported by the National Key Research Program of China(Grant No.2016YFA0300702)the National Basic Research Program of China(Grant No.2014CB921104)+5 种基金the Shanghai Municipal Natural Science Foundation(Grant Nos.18JC1411400,18ZR1403200,and 17ZR1442400)the National Natural Science Foundation of China(Grant No.U1530402)the National Natural Science Foundation of China(Grant No.11674188)China Postdoctoral Science Foundation(Grant No.2017M610221)Shanghai Sailing Program(Grant No.17YF1429000)the National Postdoctoral Program for Innovative Talents(Grant No.BX201600036)
文摘Numerous exotic properties have been discovered in Dirac Semimetals(DSMs) and Weyl Semimetals(WSMs). In a given DSM/WSM, the Dirac/Weyl nodes usually coexist with other bulk states, making their respective contribution elusive. In this work, we distinguish the role of bulk states from the tilted Dirac nodes on the transport properties in DSMs. Specifically, we applied pressure to a type-II DSM material, PtTe2, and studied its pressure modified electronic and lattice structure systematically by using in situ transport measurements and X-ray diffraction(XRD). A pressure-induced transition at about 20 GPa is revealed in the transport properties, while the layered lattice structure is robust against pressure as illustrated in XRD measurement results.Density functional theory(DFT) calculations suggest that this is originated from the Lifshitz transition in the bulk states. Our findings provide evidence to identify the bulk states' influence on transport from the topologically-protected DSM states in the DSM material.
