The anodic stability and reversibility of Ca metal electrodeposition/dissolution have always been hampered by surface passivation and anion corrosion,especially in F-based carbonate ester electrolytes at high device v...The anodic stability and reversibility of Ca metal electrodeposition/dissolution have always been hampered by surface passivation and anion corrosion,especially in F-based carbonate ester electrolytes at high device voltages.To avoid direct Ca metal/electrolyte reactions,an artificial hybrid solid electrolyte layer(AHSEL),which is characteristic of sodium/calcium carbonate and calcium hydride nitride nanocrystals of size<10 nm encapsulated by amorphous C,N species,is constructed on calcium with good ion conductivity(≈0.01 mS cm^(-1))and uniform coating of thickness≈20μm.After cycling in the KPF_(6) electrolyte,AHSEL is transformed into Na/K/Ca hybrid solid electrolyte interphases(SEIs),which is a compact layer composed of monodisperse nanocrystals(mostly Ca_(2)NH)and small amorphous zones,thus greatly suppressing the fluoridation of the Ca deposit.Consequently,the plating/stripping performance of AHSEL-modified Ca(AHSEL-Ca)is markedly improved compared with that of pristine Ca,lasting for>1400 h at a polarization shift of<0.4 mV/h.The AHSEL-Ca anode also endows Ca batteries with superior anodic stability with a ceiling voltage of up to 5.0 V,a high discharge voltage(>3.3 V),a large capacity of≈80 mAh g^(-1)at 200 mA g^(-1),and an ultralong lifespan≈5000 cycles.展开更多
Magnesium metal batteries are considered as viable alternatives of lithium-ion batteries for their low cost and high capacity of magnesium.Nevertheless,the practical application of magnesium metal batteries is extreme...Magnesium metal batteries are considered as viable alternatives of lithium-ion batteries for their low cost and high capacity of magnesium.Nevertheless,the practical application of magnesium metal batteries is extremely challenging due to a lack of suitable electrolyte that can stabilize magnesium metal anode and high-voltage cathode simultaneously.Herein,we found that in-situ formed lithium/magnesium hybrid electrolyte interphases in conventional LiPF6-containing carbonate-based electrolyte can not only prevent the production of passivation layer on the magnesium metal anode,but also inhibit the oxidation of the electrolyte under high voltage.The symmetric magnesium‖magnesium battery can achieve reversible stripping/plating for 1600 and 600 h at 0.02 and 0.1 mA cm^(-2),respectively.In addition,when coupled with a carbon fiber cathode,the magnesium metal battery exhibited a capacity retention rate of 96.3% for 1000 cycles at a current density of 500 mA g^(-1)and presented a working voltage of ~3.1 V.This research paves a new and promising path to the commercialization process of rechargeable magnesium metal batteries.展开更多
1 Introduction The lip reading involves converting the image sequence into the corresponding text sequence.Currently,lip reading has significant applications in many fields,such as assisted speech recognition,helping ...1 Introduction The lip reading involves converting the image sequence into the corresponding text sequence.Currently,lip reading has significant applications in many fields,such as assisted speech recognition,helping the speech impaired.Lip reading belongs to fine-grained video analysis and requires the local information and the overall spatial information of sequence.Most existing approaches capture local spatial information with CNN and temporal information with RNN generally.Considering these general methods,we propose a fine-grained method based on self-attention and self-distillation.The whole model mainly includes the CNN front-end,pixel-wise learning,temporal learning,and decoder.Specifically,we apply the CNN front-end to capture shallow spatial features inside the image sequence,and employ the Resformer module including self-attention to learn the global spatial correlation between pixels,namely,pixel-wise learning.展开更多
基金support from the National Natural Science Foundation of China(Nos.51872339,91963210,and U1801255)the Key Research and Development Program of Guangdong Province(No.2020B0101690001)。
文摘The anodic stability and reversibility of Ca metal electrodeposition/dissolution have always been hampered by surface passivation and anion corrosion,especially in F-based carbonate ester electrolytes at high device voltages.To avoid direct Ca metal/electrolyte reactions,an artificial hybrid solid electrolyte layer(AHSEL),which is characteristic of sodium/calcium carbonate and calcium hydride nitride nanocrystals of size<10 nm encapsulated by amorphous C,N species,is constructed on calcium with good ion conductivity(≈0.01 mS cm^(-1))and uniform coating of thickness≈20μm.After cycling in the KPF_(6) electrolyte,AHSEL is transformed into Na/K/Ca hybrid solid electrolyte interphases(SEIs),which is a compact layer composed of monodisperse nanocrystals(mostly Ca_(2)NH)and small amorphous zones,thus greatly suppressing the fluoridation of the Ca deposit.Consequently,the plating/stripping performance of AHSEL-modified Ca(AHSEL-Ca)is markedly improved compared with that of pristine Ca,lasting for>1400 h at a polarization shift of<0.4 mV/h.The AHSEL-Ca anode also endows Ca batteries with superior anodic stability with a ceiling voltage of up to 5.0 V,a high discharge voltage(>3.3 V),a large capacity of≈80 mAh g^(-1)at 200 mA g^(-1),and an ultralong lifespan≈5000 cycles.
基金supported by the National Natural Science Foundation of China,China(51972351,51802361)the Guangdong Basic and Applied Basic Research Foundation,China(2019B151502045)the Fundamental Research Funds for the Central Universities of China,China(22lgqb01)。
文摘Magnesium metal batteries are considered as viable alternatives of lithium-ion batteries for their low cost and high capacity of magnesium.Nevertheless,the practical application of magnesium metal batteries is extremely challenging due to a lack of suitable electrolyte that can stabilize magnesium metal anode and high-voltage cathode simultaneously.Herein,we found that in-situ formed lithium/magnesium hybrid electrolyte interphases in conventional LiPF6-containing carbonate-based electrolyte can not only prevent the production of passivation layer on the magnesium metal anode,but also inhibit the oxidation of the electrolyte under high voltage.The symmetric magnesium‖magnesium battery can achieve reversible stripping/plating for 1600 and 600 h at 0.02 and 0.1 mA cm^(-2),respectively.In addition,when coupled with a carbon fiber cathode,the magnesium metal battery exhibited a capacity retention rate of 96.3% for 1000 cycles at a current density of 500 mA g^(-1)and presented a working voltage of ~3.1 V.This research paves a new and promising path to the commercialization process of rechargeable magnesium metal batteries.
文摘1 Introduction The lip reading involves converting the image sequence into the corresponding text sequence.Currently,lip reading has significant applications in many fields,such as assisted speech recognition,helping the speech impaired.Lip reading belongs to fine-grained video analysis and requires the local information and the overall spatial information of sequence.Most existing approaches capture local spatial information with CNN and temporal information with RNN generally.Considering these general methods,we propose a fine-grained method based on self-attention and self-distillation.The whole model mainly includes the CNN front-end,pixel-wise learning,temporal learning,and decoder.Specifically,we apply the CNN front-end to capture shallow spatial features inside the image sequence,and employ the Resformer module including self-attention to learn the global spatial correlation between pixels,namely,pixel-wise learning.
