The ever-increasing need for sustainable development requires advanced battery techniques beyond the current generation of lithium ion batteries.Among all candidates being explored,lithium-sulfur batteries are a very ...The ever-increasing need for sustainable development requires advanced battery techniques beyond the current generation of lithium ion batteries.Among all candidates being explored,lithium-sulfur batteries are a very promising system to be commercialized in the near future.Towards this end,the development of lithium sulfide(Li_(2)S)nanocrystal-based cathodes has received tremendous effort and witnessed multiple reviews.Differentiated from the focus on performance improvement in previous reviews,this review summarizes the research progress in line with the approaches of materials synthesis and electrode fabrication.The key chemistry,operation procedure,materials characterizations and performance assessments are all given a balanced description.Moreover,all approaches are collectively analyzed along the lines of six criteria towards practical applications,i.e.,electrode performance,materials quality,resources sustainability,production cost,operation procedure,and consumed energy.Finally,some perspective viewpoints on the future research directions are offered.展开更多
Alkali metal chalcogenides have emerged as a new class of inorganic materials with diverse applications in energy conversion and storage owing to their structural versatility and wide range of properties.Strategies ar...Alkali metal chalcogenides have emerged as a new class of inorganic materials with diverse applications in energy conversion and storage owing to their structural versatility and wide range of properties.Strategies are needed for simple and cost-efficient synthetic approaches that enable the composition and functional properties of these materials to be systematically tuned.Herein,we present a novel wet-chemistry approach to produce ternary Na-based metal chalcogenides with varying compositions.Phase-pure Na3SbCh4(Ch=S,Se)solid-state electrolytes are synthesized in a single-step fashion by reacting an ethanolic solution of Na chalcogenides with appropriately selected metal halides at room temperature.This process simplifies the reaction protocols,improves yield,and decreases the raw material loss incurred in multistep systems by eliminating the need for phase-pure binary metal chalcogenides.The reaction mechanisms and impurity profile of various sodium metal chalcogenides introduced in this work were methodically investigated through characterization techniques such as X-ray diffraction(XRD)and Raman spectroscopy.Among the chalcogenides,synthesis of the sulfide compounds(∼99 wt%purity)was straightforward,achieving a yield of 92-95%whereas the selenides required more control to generate the appropriate mix of precursors,which resulted in a lower yield of 74-79%but with a high purity of 97.5-99.6 wt%.Electrochemical impedance spectroscopy of as-synthesized Na3SbCh4(Ch=S,Se)showed a high ionic conductivity of 0.17-0.38 mS cm^(-1 )and low activation energy of 0.19-0.21 eV comparable with other reports of solution-based synthesis.The one-pot scheme was successfully extended to the NaSbCh2(Ch=S,Se)system,producing phase pure ternary sodium metal chalcogenides with tunable band gaps(1.6-1.8 eV)appropriate for solar energy conversion applications.The“one-pot”approach offers a simple yet economical route for scalable production of bulk sodium ternary chalcogenides at ambient conditions.展开更多
基金supported by the National Key Research and Development Program of China(2018YFE0111600)financial support from China Postdoctoral Science Foundation(BX20190231 and 2019M661009)。
文摘The ever-increasing need for sustainable development requires advanced battery techniques beyond the current generation of lithium ion batteries.Among all candidates being explored,lithium-sulfur batteries are a very promising system to be commercialized in the near future.Towards this end,the development of lithium sulfide(Li_(2)S)nanocrystal-based cathodes has received tremendous effort and witnessed multiple reviews.Differentiated from the focus on performance improvement in previous reviews,this review summarizes the research progress in line with the approaches of materials synthesis and electrode fabrication.The key chemistry,operation procedure,materials characterizations and performance assessments are all given a balanced description.Moreover,all approaches are collectively analyzed along the lines of six criteria towards practical applications,i.e.,electrode performance,materials quality,resources sustainability,production cost,operation procedure,and consumed energy.Finally,some perspective viewpoints on the future research directions are offered.
基金supported by the National Science Foundation through award 2219184Some of the work was performed in the following core facility,which is a part of Colorado School of Mines’Shared Instrumentation Facility(X-ray Diffraction&Computed Tomography:RRID:SCR_022053Scanning Probe and Optical Microscopy:RRID:SCR_022048).
文摘Alkali metal chalcogenides have emerged as a new class of inorganic materials with diverse applications in energy conversion and storage owing to their structural versatility and wide range of properties.Strategies are needed for simple and cost-efficient synthetic approaches that enable the composition and functional properties of these materials to be systematically tuned.Herein,we present a novel wet-chemistry approach to produce ternary Na-based metal chalcogenides with varying compositions.Phase-pure Na3SbCh4(Ch=S,Se)solid-state electrolytes are synthesized in a single-step fashion by reacting an ethanolic solution of Na chalcogenides with appropriately selected metal halides at room temperature.This process simplifies the reaction protocols,improves yield,and decreases the raw material loss incurred in multistep systems by eliminating the need for phase-pure binary metal chalcogenides.The reaction mechanisms and impurity profile of various sodium metal chalcogenides introduced in this work were methodically investigated through characterization techniques such as X-ray diffraction(XRD)and Raman spectroscopy.Among the chalcogenides,synthesis of the sulfide compounds(∼99 wt%purity)was straightforward,achieving a yield of 92-95%whereas the selenides required more control to generate the appropriate mix of precursors,which resulted in a lower yield of 74-79%but with a high purity of 97.5-99.6 wt%.Electrochemical impedance spectroscopy of as-synthesized Na3SbCh4(Ch=S,Se)showed a high ionic conductivity of 0.17-0.38 mS cm^(-1 )and low activation energy of 0.19-0.21 eV comparable with other reports of solution-based synthesis.The one-pot scheme was successfully extended to the NaSbCh2(Ch=S,Se)system,producing phase pure ternary sodium metal chalcogenides with tunable band gaps(1.6-1.8 eV)appropriate for solar energy conversion applications.The“one-pot”approach offers a simple yet economical route for scalable production of bulk sodium ternary chalcogenides at ambient conditions.
