Cation-disordered rocksalt oxides(DRX)have been identified as promising cathode materials for high energy density applications owing to their variable elemental composition and cationic-anionic redox activity.However,...Cation-disordered rocksalt oxides(DRX)have been identified as promising cathode materials for high energy density applications owing to their variable elemental composition and cationic-anionic redox activity.However,their practical implementation has been impeded by unwanted phenomena such as irrepressible transition metal migration/dissolution and O_(2)/CO_(2)evolution,which arise due to parasitic reactions and densification-degradation mechanisms during extended cycling.To address these issues,a micron-sized DRX cathode Li_(1.2)Ni_(1/3)Ti_(1/3)W_(2/15)O_(1.85)F_(0.15)(SLNTWOF)with F substitution and ultrathin LiF coating layer is developed by alcohols assisted sol-gel method.Within this fluorination-induced integrated structure design(FISD)strategy,in-situ F substitution modifies the activity/reversibility of the cationic-anionic redox reaction,while the ultrathin LiF coating and single-crystal structure synergistically mitigate the cathode/electrolyte parasitic reaction and densification-degradation mechanism.Attributed to the multiple modifications and size effect in the FISD strategy,the SLNTWOF sample exhibits reversible cationic-anionic redox chemistry with a meliorated reversible capacity of 290.3 mA h g^(-1)at 0.05C(1C=200 mA g^(-1)),improved cycling stability of 78.5%capacity retention after 50 cycles at 0.5 C,and modified rate capability of 102.8 mA h g^(-1)at 2 C.This work reveals that the synergistic effects between bulk structure modification,surface regulation,and engineering particle size can effectively modulate the distribution and evolution of cationic-anionic redox activities in DRX cathodes.展开更多
Unilamellar vesicles from the mixtures of 1:1 sodium 10-undecenoate and trimethyl[2-(10-undecenoyloxy)ethyl]ammonium iodide in the mixed solvents of ethanol and heptane can be formed spontaneously or by sonication. Th...Unilamellar vesicles from the mixtures of 1:1 sodium 10-undecenoate and trimethyl[2-(10-undecenoyloxy)ethyl]ammonium iodide in the mixed solvents of ethanol and heptane can be formed spontaneously or by sonication. They can exist in the variation of concentrations and volume ratios of ethanol to heptane, which indicates to some extent the high capability of vesicle formation in such mixed systems.展开更多
In a previous paper, we have showed that, when aqueous solutions of cationicand anionic surfactants at certain concentrations were mixed, the solution separatedspontaneously into two immiscible phases (aqueous two-pha...In a previous paper, we have showed that, when aqueous solutions of cationicand anionic surfactants at certain concentrations were mixed, the solution separatedspontaneously into two immiscible phases (aqueous two-phases), one phase was rich,and the other was poor in the mixed surfactants. A clear interfacial boundary existsbetween two phases.展开更多
The prototype material,Li_(1.23)Ru_(0.41)Ni_(0.36)O_(2),is proposed to gain the deep and comprehensive understanding of chemical and structural changes of the novel layered/rocksalt intergrown cathodes.Synchrotronbase...The prototype material,Li_(1.23)Ru_(0.41)Ni_(0.36)O_(2),is proposed to gain the deep and comprehensive understanding of chemical and structural changes of the novel layered/rocksalt intergrown cathodes.Synchrotronbased X-ray absorption spectra and resonant inelastic X-ray scattering reveal that both cationic and anionic redox evolves in the charge compensation process of the intergrown material,while synchrotronbased extended X-ray fine structure spectra and in situ X-ray diffraction measurements demonstrates that the intergrown material undergoes minimal local-and long-range structural variations at deep de/lithiation.This work highlights the great potential of the intergrown structure to inspire the design of advanced cathode materials for lithium-ion batteries.展开更多
The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate(SDS) and cetyl trimethyl ammonium bromide(CTAB) was investigated under various conditions such as concentrations and molar ratios of the tw...The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate(SDS) and cetyl trimethyl ammonium bromide(CTAB) was investigated under various conditions such as concentrations and molar ratios of the two surfactants, the addition of sodium chloride and temperature. Vesicles formation was found in the both phases by TEM image.展开更多
The physico-chemical properties of organized assemblies (micelle or vesicle ) from sodium alkylcarboxylate - alkyltrimethyl -ammonium bromide mixture have been investigated systematically. In different mixed cationic-...The physico-chemical properties of organized assemblies (micelle or vesicle ) from sodium alkylcarboxylate - alkyltrimethyl -ammonium bromide mixture have been investigated systematically. In different mixed cationic-anionic surfactant systems, micelles and vesicles can coexist or be transformed into each other on different conditions. The experimental results are explained prelimilarily from the viewpoint of molecular packing geometry. The solubilization of organic compound in the mixed surfactant system was also studied in detail.展开更多
基金supported by the National Key R&D Program of China(2021YFB2401800)the National Natural Science Foundation of China(22179008,21875022)+2 种基金the Natural Science Foundation of Chongqing,China(cstc2020jcyj-msxmX0589,cstc2020jcyjmsxmX0654)the support from Beijing Institute of Technology Research Fund Program for Young Scholarsthe 4B7B beamlines radiation equipment of Beijing Synchrotron Radiation Facility(2021-BEPC-PT-005924,2021-BEPC-PT-005967)。
文摘Cation-disordered rocksalt oxides(DRX)have been identified as promising cathode materials for high energy density applications owing to their variable elemental composition and cationic-anionic redox activity.However,their practical implementation has been impeded by unwanted phenomena such as irrepressible transition metal migration/dissolution and O_(2)/CO_(2)evolution,which arise due to parasitic reactions and densification-degradation mechanisms during extended cycling.To address these issues,a micron-sized DRX cathode Li_(1.2)Ni_(1/3)Ti_(1/3)W_(2/15)O_(1.85)F_(0.15)(SLNTWOF)with F substitution and ultrathin LiF coating layer is developed by alcohols assisted sol-gel method.Within this fluorination-induced integrated structure design(FISD)strategy,in-situ F substitution modifies the activity/reversibility of the cationic-anionic redox reaction,while the ultrathin LiF coating and single-crystal structure synergistically mitigate the cathode/electrolyte parasitic reaction and densification-degradation mechanism.Attributed to the multiple modifications and size effect in the FISD strategy,the SLNTWOF sample exhibits reversible cationic-anionic redox chemistry with a meliorated reversible capacity of 290.3 mA h g^(-1)at 0.05C(1C=200 mA g^(-1)),improved cycling stability of 78.5%capacity retention after 50 cycles at 0.5 C,and modified rate capability of 102.8 mA h g^(-1)at 2 C.This work reveals that the synergistic effects between bulk structure modification,surface regulation,and engineering particle size can effectively modulate the distribution and evolution of cationic-anionic redox activities in DRX cathodes.
文摘Unilamellar vesicles from the mixtures of 1:1 sodium 10-undecenoate and trimethyl[2-(10-undecenoyloxy)ethyl]ammonium iodide in the mixed solvents of ethanol and heptane can be formed spontaneously or by sonication. They can exist in the variation of concentrations and volume ratios of ethanol to heptane, which indicates to some extent the high capability of vesicle formation in such mixed systems.
文摘In a previous paper, we have showed that, when aqueous solutions of cationicand anionic surfactants at certain concentrations were mixed, the solution separatedspontaneously into two immiscible phases (aqueous two-phases), one phase was rich,and the other was poor in the mixed surfactants. A clear interfacial boundary existsbetween two phases.
基金sponsored by National Natural Science Foundation of China(No.22109010)National Key R&D Program of China(No.2021YFC2902905)+4 种基金Beijing Nova Program,Chongqing Outstanding Youth Fund(No.2022NSCQ-JQX3895)Chongqing Talents Plan for Young Talents(No.CQYC202005032)The Key Project of Chongqing Technology Innovation and Application Development(No.2022TIAD-DEX0024)the support from Beijing Institute of Technology Research Fund Program for Young Scholarsthe support by the Shanghai Sailing Program(No.2023×0308–103–01)。
文摘The prototype material,Li_(1.23)Ru_(0.41)Ni_(0.36)O_(2),is proposed to gain the deep and comprehensive understanding of chemical and structural changes of the novel layered/rocksalt intergrown cathodes.Synchrotronbased X-ray absorption spectra and resonant inelastic X-ray scattering reveal that both cationic and anionic redox evolves in the charge compensation process of the intergrown material,while synchrotronbased extended X-ray fine structure spectra and in situ X-ray diffraction measurements demonstrates that the intergrown material undergoes minimal local-and long-range structural variations at deep de/lithiation.This work highlights the great potential of the intergrown structure to inspire the design of advanced cathode materials for lithium-ion batteries.
文摘The phenomenon of two dilute aqueous phases composed of sodium dodecylsulfate(SDS) and cetyl trimethyl ammonium bromide(CTAB) was investigated under various conditions such as concentrations and molar ratios of the two surfactants, the addition of sodium chloride and temperature. Vesicles formation was found in the both phases by TEM image.
基金Project supported by the National Natural Science Foundation of China (Nos. 29992590-4, 29773004).
文摘The physico-chemical properties of organized assemblies (micelle or vesicle ) from sodium alkylcarboxylate - alkyltrimethyl -ammonium bromide mixture have been investigated systematically. In different mixed cationic-anionic surfactant systems, micelles and vesicles can coexist or be transformed into each other on different conditions. The experimental results are explained prelimilarily from the viewpoint of molecular packing geometry. The solubilization of organic compound in the mixed surfactant system was also studied in detail.
