Phase image in tapping-mode atomic force microscope(TM-AFM)results from various dissipations in a microcantilever system.The phases mainly reflect the tip-sample contact dissipations which allow the nanoscale characte...Phase image in tapping-mode atomic force microscope(TM-AFM)results from various dissipations in a microcantilever system.The phases mainly reflect the tip-sample contact dissipations which allow the nanoscale characteristics to be distinguished from each other.In this work,two factors affecting the phase and phase contrast are analyzed.It is concluded from the theoretical and experimental results that the phases and phase contrasts in the TM-AFM are related to the excitation frequency and energy dissipation of the system.For a two-component blend,it is theoretically and experimentally proven that there exists an optimal excitation frequency for maximizing the phase contrast.Therefore,selecting the optimal excitation frequency can potentially improve the phase contrast results.In addition,only the key dissipation between the tip and sample is found to accurately reflect the sample properties.Meanwhile,the background dissipation can potentially reduce the contrasts of the phase images and even mask or distort the effective information in the phase images.In order to address the aforementioned issues,a self-excited method is adopted in this study in order to eliminate the effects of the background dissipation on the phases.Subsequently,the real phase information of the samples is successfully obtained.It is shown in this study that the eliminating of the background dissipation can effectively improve the phase contrast results and the real phase information of the samples is accurately reflected.These results are of great significance in optimizing the phases of two-component samples and multi-component samples in atomic force microscope.展开更多
Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of potass...Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of potassium.As electrode materials are the key factors to determine the electrochemical performance of devices,relevant research is being carried out to build high-performance PIBs.In recent years,significant progress has been made in the study of the design of inorganic electrode materials.Herein,we review the cathode materials(Prussian blue and its analogues,layered oxides and poly anionic compounds)and the anode materials(antimony-based,selenium-based and bismuth-based compounds).On the basis of previous work,the structural design principles for improving the performance of electrode materials are reasonably summarized.At the same time,the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.展开更多
Lithium-ion capacitors(LICs),consisting of a capacitor-type material and a battery-type material together with organic electrolytes,are the state-of-the-art electrochemical energy storage devices compared with superca...Lithium-ion capacitors(LICs),consisting of a capacitor-type material and a battery-type material together with organic electrolytes,are the state-of-the-art electrochemical energy storage devices compared with supercapacitors and batteries.Owing to their unique characteristics,LICs received a lot of attentions,and great progresses have been achieved,especially in the exploration of cathode and anode materials.Prelithiation techniques are regarded as indispensable procedures for LICs systems,which can compensate for the initial irreversible capacity loss,increase the Li^(+)concentration in the electrolyte,raise the working voltage and resolve the safety and cycle stability issues;however,its research progress is slow,and there is not enough attention until now.In this overview,we look into the ongoing processes on the recent development of prelithiation technologies,especially in organic electrolyte consumption-type LICs.In particular,some prelithiation strategies for LICs are summarized and discussed in detail,including the ex situ electrochemical method,in situ electrochemical method,and cathode prelithiation additives method.Moreover,we propose some unresolved challenges and prospects for prelithiation technologies from the basic research ideas and future key research directions.This work aims to bring up new insights to reassess the significance of premetallation strategies for advanced hybrid-ion capacitors based on the currently proposed prelithiation strategies.展开更多
基金the National Natural Science Foundation of China(Grant No.11572031)。
文摘Phase image in tapping-mode atomic force microscope(TM-AFM)results from various dissipations in a microcantilever system.The phases mainly reflect the tip-sample contact dissipations which allow the nanoscale characteristics to be distinguished from each other.In this work,two factors affecting the phase and phase contrast are analyzed.It is concluded from the theoretical and experimental results that the phases and phase contrasts in the TM-AFM are related to the excitation frequency and energy dissipation of the system.For a two-component blend,it is theoretically and experimentally proven that there exists an optimal excitation frequency for maximizing the phase contrast.Therefore,selecting the optimal excitation frequency can potentially improve the phase contrast results.In addition,only the key dissipation between the tip and sample is found to accurately reflect the sample properties.Meanwhile,the background dissipation can potentially reduce the contrasts of the phase images and even mask or distort the effective information in the phase images.In order to address the aforementioned issues,a self-excited method is adopted in this study in order to eliminate the effects of the background dissipation on the phases.Subsequently,the real phase information of the samples is successfully obtained.It is shown in this study that the eliminating of the background dissipation can effectively improve the phase contrast results and the real phase information of the samples is accurately reflected.These results are of great significance in optimizing the phases of two-component samples and multi-component samples in atomic force microscope.
基金supported by the National Natural Science Foundation of China (21975283)the Natural Science Foundation of Jiangsu Province (Youth Fund,Nos.BK20220601)+1 种基金State Key Laboratory of Chemistry and Utilization of Carbon-based Energy Resource (KFKT2021007)CAS Key Laboratory of Carbon Materials (KLCMKFJJ2010)。
文摘Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of potassium.As electrode materials are the key factors to determine the electrochemical performance of devices,relevant research is being carried out to build high-performance PIBs.In recent years,significant progress has been made in the study of the design of inorganic electrode materials.Herein,we review the cathode materials(Prussian blue and its analogues,layered oxides and poly anionic compounds)and the anode materials(antimony-based,selenium-based and bismuth-based compounds).On the basis of previous work,the structural design principles for improving the performance of electrode materials are reasonably summarized.At the same time,the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.
基金financially supported by the National Natural Science Foundation of China(Nos.U1802256,21975283,21773118 and 21875107)the Key Research and Development Program in Jiangsu Province(No.BE2018122)+1 种基金the general research Project of Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization(No.2022KF03)the Fundamental Research Funds for the Central Universities(No.2022QN1088)。
文摘Lithium-ion capacitors(LICs),consisting of a capacitor-type material and a battery-type material together with organic electrolytes,are the state-of-the-art electrochemical energy storage devices compared with supercapacitors and batteries.Owing to their unique characteristics,LICs received a lot of attentions,and great progresses have been achieved,especially in the exploration of cathode and anode materials.Prelithiation techniques are regarded as indispensable procedures for LICs systems,which can compensate for the initial irreversible capacity loss,increase the Li^(+)concentration in the electrolyte,raise the working voltage and resolve the safety and cycle stability issues;however,its research progress is slow,and there is not enough attention until now.In this overview,we look into the ongoing processes on the recent development of prelithiation technologies,especially in organic electrolyte consumption-type LICs.In particular,some prelithiation strategies for LICs are summarized and discussed in detail,including the ex situ electrochemical method,in situ electrochemical method,and cathode prelithiation additives method.Moreover,we propose some unresolved challenges and prospects for prelithiation technologies from the basic research ideas and future key research directions.This work aims to bring up new insights to reassess the significance of premetallation strategies for advanced hybrid-ion capacitors based on the currently proposed prelithiation strategies.
