检索结果-南通市图书馆

High temperature X-ray diffraction study of the formation of Na_(2)Ti_(3)O_(7) from a mixture of sodium carbonate and titanium oxide

引用

Journal of Energy Chemistry 2022年第2期31卷 210-218页

作者： Caroline Piffet Bénédicte Vertruyen Frédéric Hatert Rudi Cloots Frédéric Boschini Abdelfattah Mahmoud GREENMAT CESAM Research UnitChemistry DepartmentUniversity of Liège4000 LiègeBelgium Laboratory of Mineralogy Geology Research UnitUniversity of Liège4000 LiègeBelgium

Na2Ti3O7 has attracted much attention in the field of anode materials for Na-ion batteries thanks to its non-toxicity and very low working potential of 0.3 V vs Na0/Na+.Building a clearer picture of its formation from cheap Na_(2)CO_(3) and TiO_(2) starting materials is therefore of obvious interest.Here,we report new insights from an in-situ high temperature X-ray diffraction study conducted from room temperature to 800°C,complemented by ex-situ characterizations.We were thereby able to position the previously reported Na_(4)Ti_(5)O_(12) and Na_(2)Ti_(6)O_(13) intermediate phases in a reaction scheme involving three successive steps and temperature ranges.Shifts and/or broadening of a subset of the Na_(2)Ti_(6)O_(13) reflections suggested a combination of intra-layer disorder with the well-established ordering of successive layers.This in-situ study was carried out on reproducible mixtures of Na_(2)CO_(3) and TiO_(2) in 1:3 molar ratio prepared by spraydrying of mixed aqueous suspensions.Single-phase Na_(2)Ti_(3)O_(7) was obtained after only 8 h at 800°C in air,instead of a minimum of 20 h for a conventional solid-state route using the same precursors.Microstructure analysis revealed~15 mm diameter granules made up from rectangular rods of a fewmm length presenting electrochemical properties in line with expectations.In the absence of grinding or formation of intimate composites with conductive carbon,the specific capacity of 137 m Ah/g at C/5 decreased at higher rates.

关键词： Formation mechanism High temperature XRD Na_(2)Ti_(3)O_(7) Spray-drying synthesis Na-ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Elaboration of a Road Material Based on Clayey Soil and Crushed Sand

引用

Fluid Dynamics & Materials Processing 2022年第6期18卷 1595-1605页

作者： H.G.R.Sekloka C.P.Yabi R.Cloots M.Gibigaye Group of Research in Energy and Environment from Materials(GREENMAT) LiègeBelgium Laboratory of Energetics and Applied Mechanics(LEMA) CotonouBenin Laboratory of Tests and Studies in Civil Engineering(L2EGC) AbomeyBenin

To contribute to the enhancement of unconventional local materials used for road construction,this study characterizes a crushed sand 0/5,a clayey soil and the litho-stabilized material without and with hydraulic binder and determines their use in accordance with some reference specifications(CEBTP 1984).It is shown that the different components are not usable alone in pavement base.Indeed,the plasticity index obtained for the clayey soil is 21%,a value higher than the imposed standards.In addition,the grading of the 0/5 crushed sand does not fit into the range proposed by CEBTP.A combination of these two(02)components is therefore considered to obtain a suitable material usable for the sub-base.This new material does not enter any class of the CEBTP lateritic soils.In order to be used in base layer,a treatment with hydraulic binder is carried out with the intention to improve its mechanical performances.The optimal dosage of hydraulic binder to achieve the desired mechanical performance is obtained by studying the evolution of the mechanical characteristics of the mixture.After this treatment,the Bearing Ratio index of the mix increases from 37 to 223 for the optimal dosage and the dry compaction density decreases from 2.11 to 2.06 g/cm3 while the optimal water content increases from 9%to 10.1%.

关键词： Clayey sand crushed sand hydraulic binder road base

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：