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High-voltage LiCoO_(2) cathodes for high-energy-density lithiumion battery

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Rare Metals 2022年第12期41卷 3946-3956页

作者： Jing-Chao Zhang Zhe-Dong Liu Cui-Hua Zeng Jia-Wei Luo Yi-Da Deng Xiao-ya Cui ya-nan chen School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Beijing Frontier Research Center for Biological Structures Tsinghua UniversityBeijing 100084China Ministry of Education Key Laboratory of Protein Sciences Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijing 100084China

As the earliest commercial cathode material for lithium-ion batteries,lithium cobalt oxide(LiCoO_(2)) shows various advantages,including high theoretical capacity,excellent rate capability,compressed electrode density,*** now,it still plays an important role in the lithium-ion battery *** to these advantages,further increasing the charging cutoff voltage of LiCoO_(2)to guarantee higher energy density is an irresistible development trend of LiCoO_(2)cathode materials in the ***,using high charging cutoff voltage may induce a lot of negative effects,especially the rapid decay of cycle *** are mainly caused by rapid destruction of crystal structure and aggravation of interface side reaction at high voltage during the ***,how to maintain a stable crystal structure of LiCoO_(2)to ensure the excellent long cycle performance at high voltage is a hot research issue in the further application of LiCoO_(2).In this review,we summarized the failure causes and extensive solutions of LiCoO_(2)at high voltage and promoted some new modification ***,the development trend of solving the failure problem of high-voltage LiCoO_(2)in the future such as defect engineering and high-temperature shock technique is also discussed.

关键词： Lithium-ion battery Lithium cobalt oxide(LiCoO_(2))cathode High voltage Cycle performance Crystal structure

Effects of calculation approaches for thermal conductivity on the simulation accuracy of billet continuous casting

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 18-25页

作者： Zun Peng yan-ping Bao ya-nan chen Li-kang yang Cao Xie Feng Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Hangzhou Iron and Steel Group Co.

An unsteady, two-dimensional, explicitly solved fmite difference heat transfer model of a billet caster was presented to clarify the influence of the thermal conductivity of steel on model accuracy. Different approaches were utilized for calculating the thermal conductivity of solid, mushy and liquid steels. Model results predicted by these approaches were compared, and the advantages of advocated approaches were discussed. It is found that the approach for calculating the thermal conductivity of solid steel notably influences model predictions. Convection effects of liquid steel should be considered properly while calculating the thermal conductivity of mushy steel. Different values of the effective thermal conductivity of liquid steel adopted could partly be explained by the fact that different models adopted dissimilar ap- proaches for calculating the thermal conductivity of solid and mushy steels.

关键词： continuous casting solidification heat transfer thermal conductivity mathematical models

Superior machinability of steel enhanced with BN and MnS particles

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 276-282页

作者： ya-nan chen yan-ping Bao Min Wang Xiao-feng Cai Lin-jing Wang Li-hua Zhao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083China National Engineering Research Center of Flat Rolling Equipment University of Science and Technology BeijingBeijing 100083China

The strategy that replacing part of MnS with BN was proposed in order to decrease the sulfur content in sulfur based free-cutting steel. The effects of BN and MnS inclusions on the microstructure and machinability of the steel were systematically investigated. The results show that most of the BN and MnS inclusions exist individually in the steel and only a small amount of them are in a composite state form- ing either isolated particles or clusters of particles. In the case of multi-phased steel, the theoretical calculation predicts that the volume of large BN particles should be 0.7 times of the volume of large MnS particles. The machinability of this type of BN and MnS alloy steel over a wide range of cutting speeds ranging from a low speed appropriate for drilling to a high speed appropriate for turning is confirmed as being equal to or superior to that of an MnS reference steel, even though the sulfur content in the composite steel is only half that of the MnS steel. The aptitude for cutting effect of 240 ppm nitrogen and 115 ppm boron in the composite steel is demonstrated to be equivalent or even better than 1000 ppm sulfur in MnS free-cutting steel.

关键词： boron nitride manganese sulfide inclusions machinability free cutting steel

Effect of Polymer Chain Regularity on the Photovoltaic Performance of Organic Solar Cells

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Chinese Journal of Polymer Science 2022年第8期40卷 996-1002,I0012页

作者： Hang Wang Hao Lu ya-nan chen Andong Zhang Yuqiang Liu Cai’e Zhang yahui Liu Xinjun Xu Zhishan Bo College of Textiles&Clothing State Key Laboratory of Bio-fibers and Eco-textilesQingdao UniversityQingdao266071China Beijing Key Laboratory of Energy Conversion and Storage Materials College of ChemistryBeijing Normal UniversityBeijing100875China College of Materials Science and Engineering Shenzhen UniversityShenzhen518060China

In this work,regio-regular and random polymers(reg-PTF and ran-PTF)comprising benzodithiophene and 3-fluorothiophene units are developed to investigate the influence of polymer chain regularity on the photovoltaic ***,reg-PTF exhibits higher HOMO energy level(∼0.2 eV)than that of ran-PTF due to the more ordered molecular structure and higher *** the result,the HOMO energy level offset between donor and acceptor can be well controlled by selecting different *** BTP-ec9-4F with a much deep HOMO energy level as acceptor,reg-PTF-based devices display an inferior PCE of 7.66%compared with ran-PTF based ones(11.78%)due to the too large HOMO energy levels *** blending with Y18-1F,the PCE of reg-PTF-based devices is increased to 13.23%due to the appropriate energy *** comparison,the ran-PTF-based devices nearly do not work because of the negative HOMO energy levels *** work indicates that both the polymer chain regularity and the energy level offset between the donor and acceptor material are important to the performance of organic solar cells.

关键词： Organic solar cells Polymer donor Regio-regular polymer Random polymer Energy level offset

High-performance nonfused ring electron acceptor with a steric hindrance induced planar molecular backbone

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Science China Chemistry 2022年第3期65卷 594-601页

作者： Hao Lu Xiaodong Wang Hang Wang Andong Zhang Xinming Zheng Na Yu Zheng Tang Xinjun Xu yahui Liu ya-nan chen Zhishan Bo College of Textiles&Clothing State Key Laboratory of Bio-fibers and Eco-textilesQingdao UniversityQingdao 266071China Beijing Key Laboratory of Energy Conversion and Storage Materials College of ChemistryBeijing Normal UniversityBeijing 100875China Center for Advanced Low-Dimension Materials State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620China

Three nonfused ring electron acceptors (NFREAs) TTC6,TT-C8T and TT-TC8 were purposefully designed and *** molecular geometry can be adjusted by the steric hindrance of lateral *** to the DFT calculations,from TTC6 to TT-C8T and TT-TC8,planarity of the molecular backbone is gradually improved,accompanying with the enhancing of intramolecular charge transfer *** for TT-TC8,the two phenyl substituents are almost perpendicular to the molecular backbone,which endues the acceptor with good solubility and suppresses it to form *** regular molecular orientation and closer molecular stacking are formed in TT-TC8 *** a result,TT-TC8 based devices afford the highest PCE of 13.13%,which is much higher than that of TTC6 (4.41%) and TT-C8T (10.42%) and among the highest PCE values based on NFREAs.

关键词： organic solar cells nonfused ring electron acceptors nonfullerene acceptors steric hindrance

Effect of titanium dioxide nanoparticles on zebrafish embryos and developing retina

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International Journal of Ophthalmology(English edition) 2014年第6期7卷 917-923页

作者： ya-Jie Wang Zi-Zi He yang-Wu Fang yang Xu ya-nan chen Guan-Qun Wang Yong-Qiang yang Zhuo yang Yu-Hao Li Key Laboratory of Tumor Microenviroment and Neurovascular Regulation Nankai University School of Medicine State Key Laboratory of Medicinal Chemical Biology College of ChemistryNankai University

AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal ***: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions were observed,and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to Ti O2 NPs until 72 h postfertilization(hpf). The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ ***: The 1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to Ti O2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms m RNA and the 4C4 antibody, which were specific to microglia in the central nervous system(CNS), closely resembled their endogenous ***: These data demonstrate that short-term exposure to Ti O2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.

关键词： titanium dioxide nanoparticles retina microglia zebrafish

Co-free/Co-poor high-Ni cathode for high energy,stable and low-cost lithium-ion batteries

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Rare Metals 2023年第7期42卷 2214-2225页

作者： Zhe-Dong Liu Chun-Ying Wang Jing-Chao Zhang Jia-Wei Luo Cui-Hua Zeng Wei-Di Liu Rui Liu ya-nan chen School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao266590China School of Materials Science and Engineering Tianjin UniversityTianjin300072China Australian Institute for Bioengineering and nanotechnology The University of QueenslandBrisbaneQLD4072Australia

Advanced cathode materials have been considered as the key to significantly improve the energy density of lithium-ion batteries(LIBs).High-Ni layer-structured cathodes,especially with Ni atomic content above 0.9(LiN1_(x)M_(1-x)O_(2),x≥0.9),exhibit high capacity to be commercially available in electric vehicles(EVs).However,the intrinsic structure instability of high-Ni materials and the negative impacts severely restrict their further applic *** addition,Co has various effective efforts to stabilize the layered ***,due to the high cost of Co,it is required to be ***,modification methods on increasing the stability of high-Ni cathode with the reduction of Co content have been widely *** this review,we summarized various effective research progresses and several potential modification strategies of Cofree/Co-poor layered c athodes with Ni content over *** challenges and development opportunities of high-Ni,Cofree/Co-poor cathodes are further overviewed to meet the future commercial energy demands.

关键词： Lithium-ion batteries(LIBs) Co-free/poor High-Ni Cathode materials

A Simple Nonfused Ring Electron Acceptor with a Power Conversion Efficiency over 16%

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Chinese Journal of Chemistry 2023年第6期41卷 665-671页

作者： Xiaodong Wang Rui Zeng Hao Lu Guangliu Ran Andong Zhang ya-nan chen yahui Liu Feng Liu Wenkai Zhang Zheng Tang Zhishan Bo College of Textiles&Clothing State Key Laboratory of Bio-fibers and Eco-textilesQingdao UniversityQingdaoShandong 266071China Frontiers Science CenterforTransformative Molecules In-situ Centerfor Physical Scienceand Center of Hydrogen Science Schoolof Chemistryand Chemical EngineeringShanghai JiaoTong UniversityShanghai 200240China Departmentof Physics and Applied Optics Beijing Area Major Laboratory Bejing Normal UniversityBeijing 100875China Center for Advanced Low-dimension Materials State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620China

By simplifying the r-bridge unit,a nonfused ring electron acceptor(NFREA)BM-2F was designed and synthesized with several high-yield *** specific molecular structure features of BM-2F are planar molecular backbone and out-of-plane side chain,which is favorable for charge transport and can suppress the ***-2F based neat and blend films display obvious face-on molecular ***,D18:BM-2F based blend film can form good bicontinuous interpenetrating *** excitingly,a power conversion efficiency of 16.15%was achieved with D18:BM-2F based photovoltaic devices,which is the highest one based on *** researches manifest that NFREA is a promising direction for low-cost and high-performance organic solar cells.

关键词： Organic solar cells Nonfused ring electron acceptors Nonfullerene acceptors Low-cost acceptors High-performance acceptors

Expression of pituitary homeobox 1 gene in human gastric carcinogenesis and its clinicopathological significance

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World Journal of Gastroenterology 2008年第2期14卷 292-297页

作者： ya-nan chen Hong chen yan Xu Xue Zhang yang Luo Research Center for Medical Genomics and MOH Key Laboratory of Cell Biology China Medical University Shenyang 110001Liaoning Province China Department of Surgical Oncology the First Hospital of China Medical University Shenyang 110001 Liaoning ProvinceChina

AIM： To investigate the effect of pituitary homeobox 1 （PITX1） expression in cases of human gastric cancer on cancer differentiation and progression, and carcinogenesis. METHODS： Using polyclonal PITX1 antibodies, we studied the expression of PITX1 in normal gastric mucosa, atypical hyperplasia, intestinal metaplasia, and cancer tissue samples from 83 gastric cancer patients by immunohistochemistry. Moreover, semi-reverse transcription polymerase chain reaction （semi-RT-PCR） was performed to detect the mRNA level of PITX1 in three gastric cancer cell lines and a normal gastric epithelial cell line. Subsequently, somatic mutations of the PITX1 gene in 71 gastric cancer patients were analyzed by a combination of denaturing high performance liquid chromatography （DHPLC） and DNA sequencing. RESULTS： Immunohistochemistry showed that PITXl was strongly or moderately expressed in the parietal cells of normal gastric mucosa （100%）, while 55 （66.3%） out of 83 samples of gastric cancers showed decreased PITXl expression. Moreover, PITXl expression was reduced in 20 out of 28 cases （71.5%） of intestinal metaplasia, but in only 1 out of 9 cases （11%） of atypical hyperplasia. More importantly, PITXl expression was significantly associated with the differentiation, position and invasion depth of gastric cancers （r = -0.316, P 〈 0.01; r = 0.213, P 〈 0.05; r = -0.259, P 〈 0.05, respectively）. Similarly, levels of PITXl mRNA were significantly decreased in 2 gastric cancer cell lines, BGC-823 and SGC-7901, compared with the normal gastric epithelial cell line GES-1 （0.306 ± 0.060 vs 0.722 ± 0.102, P 〈 0.05; 0.356 ± 0.081 vs 0.722 ± 0.102, P 〈 0.05, respectively）. Nevertheless, no somatic mutation of PITX1 gene was found in 71 samples of gastric cancer by DHPLC analysis followed by sequencing. CONCLUSION： Down-regulation of PITX1 may be a frequent molecular event in gastric carcinogenesis. Aberrant levels of PITXl expression may be closely correlated with the progression and diff

关键词： Pituitary homeobox 1 Gastric cancer Immunohistochemistry Reverse transcription polymerase chain reaction Denaturing high performance liquid chromatography