1 Results The discovery of thefamily of mercury cupratesinthe eighties ,which present the highest Curie Temper-ature (Tc) among all known High Temperature Super-Conductors (HTSC) 。
Rechargeable aqueous Zn-ion batteries(AZIBs)are one of the most promising energy storage devices for large-scale energy storage owing to their high specific capacity,eco-friendliness,low cost and high safety.Neverthel...Rechargeable aqueous Zn-ion batteries(AZIBs)are one of the most promising energy storage devices for large-scale energy storage owing to their high specific capacity,eco-friendliness,low cost and high safety.Nevertheless,zinc metal anodes suffer from severe dendrite growth and side reactions,resulting in the inferior electrochemical performance of AZIBs.To address these problems,surface modification of zinc metal anodes is a facile and effective method to regulate the interaction between the zinc anode and an electrolyte.In this review,the current challenges and strategies for zinc metal anodes are presented.Furthermore,recent advances in surface modification strategies to improve their electrochemical performance are concluded and discussed.Finally,challenges and prospects for future development of zinc metal anodes are proposed.We hope this review will be useful for designing and fabricating highperformance AZIBs and boosting their practical applications.展开更多
Spinel LiMn2O4 and F, Al-doped spinel LiAl0.05Mn1.95O3.58F0.02 have been synthesized by a soft chemistry method using adipic acid as the chelating agent. The synthesized spine/materials were characterized by different...Spinel LiMn2O4 and F, Al-doped spinel LiAl0.05Mn1.95O3.58F0.02 have been synthesized by a soft chemistry method using adipic acid as the chelating agent. The synthesized spine/materials were characterized by differential thermal analysis （DTA） and thermogravimetery （TG）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, and chargedischarge testing. The results indicate that all the samples have high phase purity, and fluorine is important in controlling the morphology; the doped aluminum enhances the stability of spinel LiMn2O4. The charge-discharge tests indicate that LiAl0.05Mn1.95O4 has high capacity retention, which is 92.60% of the initial after 50 cycles. It is found that the novel compound LiAl0.05Mn1.95O3.98F0.02 with smaller particles can offer much higher capacity, whose initial discharge capacity is 126.5 mAh·g^-1. The cyclic voltammetric experiments disclose the enhanced reversibility of the F, Al^3＋-modified spinel as compared with the undoped spinel.展开更多
N-polar GaN film was obtained by using a high-temperature AlN buffer layer.It was found that the polarity could be inverted by a thin low-temperature AlN interlayer with the same V/III ratio as that of the high-temper...N-polar GaN film was obtained by using a high-temperature AlN buffer layer.It was found that the polarity could be inverted by a thin low-temperature AlN interlayer with the same V/III ratio as that of the high-temperature AlN layer.Continuing to increase the V/III ratio of the low-temperature AlN interlayer,the Ga-polarity of GaN film was inverted to N-polarity again but the crystal quality and surface roughness of GaN film greatly deteriorated.Finally,we analyzed the chemical environment of the AlN layer by x-ray photoelectron spectroscopy(XPS),which provides a new direction for the control of GaN polarity.展开更多
The bimolecular single collision reaction potential energy surface of an isocyanate NCO radical with a ketene CH2CO molecule was investigated by means of B3LYP and QCISD（T） methods. The computed results indicate tha...The bimolecular single collision reaction potential energy surface of an isocyanate NCO radical with a ketene CH2CO molecule was investigated by means of B3LYP and QCISD（T） methods. The computed results indicate that two possible reaction channels exist on the surface. One is an addition-elimination reaction process, in which the CH2CO molecule is attacked by the nitrogen atom at its methylene carbon atom to lead to the formation of the intermediate OCNCH2CO followed by a C-C rupture channel to the products CH2NCO＋CO. The other is a direct hydrogen abstraction channel from CHzCO by the NCO radical to afford the products HCCO＋HNCO. Because of a higher barrier in the hydrogen abstraction reaction than in the addition-elimination reaction, the direct hydrogen abstraction pathway can only be considered as a secondary reaction channel in the reaction kinetics of NCO＋ CH2CO. The predicted results are in good agreement with previous experimental and theoretical investigations.展开更多
文摘1 Results The discovery of thefamily of mercury cupratesinthe eighties ,which present the highest Curie Temper-ature (Tc) among all known High Temperature Super-Conductors (HTSC) 。
基金supported by the National Key Research and Development Program of China(2020YFB1713500)the Chinese 02 Special Fund(2017ZX02408003)+2 种基金the Open Fund of National Joint Engineering Research Center for abrasion control and molding of metal materials(HKDNM201807)the Student Research Training Plan of Henan University of Science and Technology(2020026)the National Undergraduate Innovation and Entrepreneurship Training Program(202010464031,202110464005)。
文摘Rechargeable aqueous Zn-ion batteries(AZIBs)are one of the most promising energy storage devices for large-scale energy storage owing to their high specific capacity,eco-friendliness,low cost and high safety.Nevertheless,zinc metal anodes suffer from severe dendrite growth and side reactions,resulting in the inferior electrochemical performance of AZIBs.To address these problems,surface modification of zinc metal anodes is a facile and effective method to regulate the interaction between the zinc anode and an electrolyte.In this review,the current challenges and strategies for zinc metal anodes are presented.Furthermore,recent advances in surface modification strategies to improve their electrochemical performance are concluded and discussed.Finally,challenges and prospects for future development of zinc metal anodes are proposed.We hope this review will be useful for designing and fabricating highperformance AZIBs and boosting their practical applications.
文摘Spinel LiMn2O4 and F, Al-doped spinel LiAl0.05Mn1.95O3.58F0.02 have been synthesized by a soft chemistry method using adipic acid as the chelating agent. The synthesized spine/materials were characterized by differential thermal analysis （DTA） and thermogravimetery （TG）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, and chargedischarge testing. The results indicate that all the samples have high phase purity, and fluorine is important in controlling the morphology; the doped aluminum enhances the stability of spinel LiMn2O4. The charge-discharge tests indicate that LiAl0.05Mn1.95O4 has high capacity retention, which is 92.60% of the initial after 50 cycles. It is found that the novel compound LiAl0.05Mn1.95O3.98F0.02 with smaller particles can offer much higher capacity, whose initial discharge capacity is 126.5 mAh·g^-1. The cyclic voltammetric experiments disclose the enhanced reversibility of the F, Al^3＋-modified spinel as compared with the undoped spinel.
基金Project supported by the National Natural Science Foundation of China(Grant No.62004218)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘N-polar GaN film was obtained by using a high-temperature AlN buffer layer.It was found that the polarity could be inverted by a thin low-temperature AlN interlayer with the same V/III ratio as that of the high-temperature AlN layer.Continuing to increase the V/III ratio of the low-temperature AlN interlayer,the Ga-polarity of GaN film was inverted to N-polarity again but the crystal quality and surface roughness of GaN film greatly deteriorated.Finally,we analyzed the chemical environment of the AlN layer by x-ray photoelectron spectroscopy(XPS),which provides a new direction for the control of GaN polarity.
文摘The bimolecular single collision reaction potential energy surface of an isocyanate NCO radical with a ketene CH2CO molecule was investigated by means of B3LYP and QCISD（T） methods. The computed results indicate that two possible reaction channels exist on the surface. One is an addition-elimination reaction process, in which the CH2CO molecule is attacked by the nitrogen atom at its methylene carbon atom to lead to the formation of the intermediate OCNCH2CO followed by a C-C rupture channel to the products CH2NCO＋CO. The other is a direct hydrogen abstraction channel from CHzCO by the NCO radical to afford the products HCCO＋HNCO. Because of a higher barrier in the hydrogen abstraction reaction than in the addition-elimination reaction, the direct hydrogen abstraction pathway can only be considered as a secondary reaction channel in the reaction kinetics of NCO＋ CH2CO. The predicted results are in good agreement with previous experimental and theoretical investigations.
