Lithium-ion battery is facing the capacity fade in cold area. It reports in this paper to improve the temperature-tolerance using the novel materials in the battery design. Mesophase carbon microspheres (MG11) compose...Lithium-ion battery is facing the capacity fade in cold area. It reports in this paper to improve the temperature-tolerance using the novel materials in the battery design. Mesophase carbon microspheres (MG11) composed of 2H + 3R graphite phase with more uniform size were used as anode material and a new binder (WRA268) was used. The tests results show that at 0°C, MG11 using conventional binder (styrene butadiene rubber, SBR) attains 66% of reversible capacity retention rate, and synthetic graphite (FSN-1) using WRA268 as binder attains 76.9% of reversible capacity retention rate, but it attains 34% for the FSN-1 using SBR as the binder. These results show that MG11-WRA268 is promising materials using for battery in cold areas such as Tibet.展开更多
Disinfection by-products (DBPs) are regulated in drinking water in a number of countries. This critical review focuses on the issues associated with DBP regulatory compliance, including methods for DBP analysis, occ...Disinfection by-products (DBPs) are regulated in drinking water in a number of countries. This critical review focuses on the issues associated with DBP regulatory compliance, including methods for DBP analysis, occurrence levels, the regulation comparison among various countries, DBP compliance strategies, and emerging DBPs. The regulation comparison between China and the United States (US) indicated that the DBP regulations in China are more stringent based on the number of regulated compounds and maximum levels. The comparison assessment using the Information Collection Rule (ICR) database indicated that the compliance rate of 500 large US water plants under the China regulations is much lower than that under the US regulations (e.g. 62.2% versus 89.6% for total trihalomethanes). Precursor removal and alternative disinfectants are common practices for DBP regulatory compliance. DBP removal after formation, including air stripping for trihalomethane removal and biodegradation for haloacetic acid removal, have gained more acceptance in DBP control. Formation of emerging DBPs, including iodinated DBPs and nitrogenous DBPs, is one of unintended consequences of precursor removal and alternative disinfection. At much lower levels than carbonaceous DBPs, however, emerging DBPs have posed higher health risks.展开更多
In this work, nitrogen doped clews-like carbon materials were successfully fabricated through hydrothermal polymerization method, followed by post treatment that integrated the carbonization,activation and post-nitrog...In this work, nitrogen doped clews-like carbon materials were successfully fabricated through hydrothermal polymerization method, followed by post treatment that integrated the carbonization,activation and post-nitrogen doping into one process. This preparation method can form particular hierarchical porous structure without using any sacrificial templates. The experimental results show that the nitrogen doped clews-like hierarchical porous carbon materials possess a relatively high specific surface area of 815 m^2/g with the nitrogen content of 10.58 at%. The electrochemical properties show that the resulting sample delivers 258 F/g at a 0.5 A/g and excellent capacity retention of 79% at 20 A/g. After conducting 10,000 charge-discharge cycles at 10 A/g, the capacitance retention of 98.3% is achieved.These intriguing results demonstrate that the obtained nitrogen doped clews-like carbon materials will be promising electrode materials for supercapacitor and other energy storage devices.展开更多
Polymers have been widely used in energy storage,construction,medicine,aerospace,and so on.However,the complexity of chemical composition and morphology of polymers has brought challenges to their development.Thanks t...Polymers have been widely used in energy storage,construction,medicine,aerospace,and so on.However,the complexity of chemical composition and morphology of polymers has brought challenges to their development.Thanks to the integration of machine leaming algorithms and large data resources,the data-driven methods have opened up a new road for the development of poly-mer science and engineering.The emerging polymer informatics attempts to accelerate the performance prediction and process optimization of new poly-mers by using machine learning models based on reliable data.With the grad-ual supplement of currently available databases,the emergence of new databases and the continuous improvement of machine learning algorithms,the research paradigm of polymer informatics will be more efficient and widely used.Based on these points,this paper reviews the development trends of machine learning assisted polymer informatics and provides a simple introduc-tion for researchers in materials,artificial intelligence,and other fields.展开更多
LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)has become one of the most popular cathode materials for current lithium-ion batteries due to its high-energy density and cost performance.However,the rapid capacity fading of NC...LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)has become one of the most popular cathode materials for current lithium-ion batteries due to its high-energy density and cost performance.However,the rapid capacity fading of NCM severely hinders its development and applications.Here,the single crystal NCM523 materials under different degradation states are characterized using scanning transmission electron microscopy(STEM).Then we developed a neural network model with a two-sequential attention block to recognize the crystal structure and locate defects in STEM images.The number of point defects in NCM523 is observed to experience a trend of increasing first and then decreasing in the degradation process.The space between the transition metal columns shrinks obviously,inducing dramatic capacity decay.This analysis sheds light on the defect evolution and chemical transformation correlated with layered material degradation.It also provides interesting hints for researchers to regenerate the electrochemical capacity and design better battery materials with longer life.展开更多
文摘Lithium-ion battery is facing the capacity fade in cold area. It reports in this paper to improve the temperature-tolerance using the novel materials in the battery design. Mesophase carbon microspheres (MG11) composed of 2H + 3R graphite phase with more uniform size were used as anode material and a new binder (WRA268) was used. The tests results show that at 0°C, MG11 using conventional binder (styrene butadiene rubber, SBR) attains 66% of reversible capacity retention rate, and synthetic graphite (FSN-1) using WRA268 as binder attains 76.9% of reversible capacity retention rate, but it attains 34% for the FSN-1 using SBR as the binder. These results show that MG11-WRA268 is promising materials using for battery in cold areas such as Tibet.
文摘Disinfection by-products (DBPs) are regulated in drinking water in a number of countries. This critical review focuses on the issues associated with DBP regulatory compliance, including methods for DBP analysis, occurrence levels, the regulation comparison among various countries, DBP compliance strategies, and emerging DBPs. The regulation comparison between China and the United States (US) indicated that the DBP regulations in China are more stringent based on the number of regulated compounds and maximum levels. The comparison assessment using the Information Collection Rule (ICR) database indicated that the compliance rate of 500 large US water plants under the China regulations is much lower than that under the US regulations (e.g. 62.2% versus 89.6% for total trihalomethanes). Precursor removal and alternative disinfectants are common practices for DBP regulatory compliance. DBP removal after formation, including air stripping for trihalomethane removal and biodegradation for haloacetic acid removal, have gained more acceptance in DBP control. Formation of emerging DBPs, including iodinated DBPs and nitrogenous DBPs, is one of unintended consequences of precursor removal and alternative disinfection. At much lower levels than carbonaceous DBPs, however, emerging DBPs have posed higher health risks.
基金supported by the National Natural Science Foundation of China(No. 51802122)the Natural Science Fund of Hubei Province(No.2017CFB155)+4 种基金China Scholarship Council (No. 201808420401)Scientific Research Plan Project of Hubei Education Department(No. B2017269)Scientific Research Initial funding for the Advanced Talent of Jianghan University (No. 1009-06810001)Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices, Ministry of Education, Jianghan University(Nos. JDGD-201702,JDGD-201811)Hubei Provincial Department of Education for the "Chutian Scholar" program
文摘In this work, nitrogen doped clews-like carbon materials were successfully fabricated through hydrothermal polymerization method, followed by post treatment that integrated the carbonization,activation and post-nitrogen doping into one process. This preparation method can form particular hierarchical porous structure without using any sacrificial templates. The experimental results show that the nitrogen doped clews-like hierarchical porous carbon materials possess a relatively high specific surface area of 815 m^2/g with the nitrogen content of 10.58 at%. The electrochemical properties show that the resulting sample delivers 258 F/g at a 0.5 A/g and excellent capacity retention of 79% at 20 A/g. After conducting 10,000 charge-discharge cycles at 10 A/g, the capacitance retention of 98.3% is achieved.These intriguing results demonstrate that the obtained nitrogen doped clews-like carbon materials will be promising electrode materials for supercapacitor and other energy storage devices.
基金National Natural Science Foundation of China(52077096)China Southern Power research fund for fire safety for large scale grid energy storage system(090000KK52190179).
文摘Polymers have been widely used in energy storage,construction,medicine,aerospace,and so on.However,the complexity of chemical composition and morphology of polymers has brought challenges to their development.Thanks to the integration of machine leaming algorithms and large data resources,the data-driven methods have opened up a new road for the development of poly-mer science and engineering.The emerging polymer informatics attempts to accelerate the performance prediction and process optimization of new poly-mers by using machine learning models based on reliable data.With the grad-ual supplement of currently available databases,the emergence of new databases and the continuous improvement of machine learning algorithms,the research paradigm of polymer informatics will be more efficient and widely used.Based on these points,this paper reviews the development trends of machine learning assisted polymer informatics and provides a simple introduc-tion for researchers in materials,artificial intelligence,and other fields.
基金This project was supported by the fund from National Natural Science Foundation of China(NSFC No.52077096 and 52107224)China Postdoctoral Science Foundation under Grant No.2019M662612+1 种基金the Interdisciplinary Program of Wuhan National High Magnetic Field Center from Huazhong University of Science and Technology(Grant No.WHMFC202138)State Grid Zhejiang Electric Power Co.,Ltd.technology project 5211UZ2000K1.
文摘LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)has become one of the most popular cathode materials for current lithium-ion batteries due to its high-energy density and cost performance.However,the rapid capacity fading of NCM severely hinders its development and applications.Here,the single crystal NCM523 materials under different degradation states are characterized using scanning transmission electron microscopy(STEM).Then we developed a neural network model with a two-sequential attention block to recognize the crystal structure and locate defects in STEM images.The number of point defects in NCM523 is observed to experience a trend of increasing first and then decreasing in the degradation process.The space between the transition metal columns shrinks obviously,inducing dramatic capacity decay.This analysis sheds light on the defect evolution and chemical transformation correlated with layered material degradation.It also provides interesting hints for researchers to regenerate the electrochemical capacity and design better battery materials with longer life.