Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-i...Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-ion batteries.However,their practical deployment has long been plagued by the infamous“shuttle effect”of soluble Li polysulfides(LiPSs)and the rampant growth of Li dendrites.Therefore,it is important to specifically elucidate the solvation structure in the Li-S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications.This review attempts to achieve this goal.In this review,we first introduce the importance of developing Li-S batteries and highlight the key challenges.Then,we revisit the working principles of Li-S batteries and underscore the fundamental understanding of LiPSs.Next,we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs.Afterward,we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites.Finally,we conclude and propose personal insights and perspectives on the future development of Li-S batteries.We envisage that this timely review can provide some inspiration to build better Li-S batteries for promoting practical applications.展开更多
This article studies the effects of limestone powder on rheological properties of cement - fly ash mortar with RHEOLAB QC type rotation viscometer. The Bingham fluid model is introduced to fit the yielding stress and ...This article studies the effects of limestone powder on rheological properties of cement - fly ash mortar with RHEOLAB QC type rotation viscometer. The Bingham fluid model is introduced to fit the yielding stress and plastic viscosity of the mortar. The POWER LAW fluid model is introduced to fit the rheological index of the mortar. The results show that, adding limestone powder and fly ash to the cement mortar significantly decreases the yield stress of the mortar, changes the plastic viscosity of the mortar, increases the rheological index, decreases the degree of shear thinning of the mortar, and thereby improves the mortar＇ s workability. In the case of cement - fly ash mortar, with the increase of limestone powder content, both the yield stress and plastic viscosity of the mortar increase. When the limestone powder content is not higher than 14%, the increase of yield stress is not significant. When the limestone powder content is lower than 8%, the increase of plastic viscosity is not significant. When the content of limestone powder is higher than 22%, the rheological index of the mortar decreases and the degree of shear thinning increases. The effects of limestone powder＇ s packing density, shape and size, specific surface area, and fluid volume, are found to be the four major factors responsible for the changes ofrheological properties of the mortar.展开更多
基金financially supported by the National Natural Science Foundation of China(51972064 and 52222315)
文摘Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-ion batteries.However,their practical deployment has long been plagued by the infamous“shuttle effect”of soluble Li polysulfides(LiPSs)and the rampant growth of Li dendrites.Therefore,it is important to specifically elucidate the solvation structure in the Li-S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications.This review attempts to achieve this goal.In this review,we first introduce the importance of developing Li-S batteries and highlight the key challenges.Then,we revisit the working principles of Li-S batteries and underscore the fundamental understanding of LiPSs.Next,we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs.Afterward,we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites.Finally,we conclude and propose personal insights and perspectives on the future development of Li-S batteries.We envisage that this timely review can provide some inspiration to build better Li-S batteries for promoting practical applications.
文摘This article studies the effects of limestone powder on rheological properties of cement - fly ash mortar with RHEOLAB QC type rotation viscometer. The Bingham fluid model is introduced to fit the yielding stress and plastic viscosity of the mortar. The POWER LAW fluid model is introduced to fit the rheological index of the mortar. The results show that, adding limestone powder and fly ash to the cement mortar significantly decreases the yield stress of the mortar, changes the plastic viscosity of the mortar, increases the rheological index, decreases the degree of shear thinning of the mortar, and thereby improves the mortar＇ s workability. In the case of cement - fly ash mortar, with the increase of limestone powder content, both the yield stress and plastic viscosity of the mortar increase. When the limestone powder content is not higher than 14%, the increase of yield stress is not significant. When the limestone powder content is lower than 8%, the increase of plastic viscosity is not significant. When the content of limestone powder is higher than 22%, the rheological index of the mortar decreases and the degree of shear thinning increases. The effects of limestone powder＇ s packing density, shape and size, specific surface area, and fluid volume, are found to be the four major factors responsible for the changes ofrheological properties of the mortar.
