Bridge polycarboxylate superplasticizers（PCs） with crosslink structure were synthesized by using polyethyleneglycol di-acrylate（PEGdA）, replacing partial polyethyleneglycol mono-acrylate （PEGmA） as crosslinking ...Bridge polycarboxylate superplasticizers（PCs） with crosslink structure were synthesized by using polyethyleneglycol di-acrylate（PEGdA）, replacing partial polyethyleneglycol mono-acrylate （PEGmA） as crosslinking agent. Structures of bridge PCs were analyzed by gel permeation chromatography, and dispersion ability was evaluated by cement paste dispersity variation on time and rheology test. The experimental results showed that, molecular weight（MW） of bridge PCs increased with increase of PEGdA proportion, and MW distribution curve changed from Gaussian to fiat like, which meant notable increase of highly crosslinked copolymer. Bridge PCs led to decreased initial cement paste dispersity and better dispersity retention due to slow releasing. Further research showed that, PEGdA proportion had slight effect on polymerization degree of backbone, MW distribution of backbone deviated from Gaussian distribution and shoulder peaks appeared on distribution curve when PEGdA increased.展开更多
Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a ...Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a simple and residue-free preparation process,resulting in a stable interface between electrolyte and electrode,is still a great challenge for practical applications.Herein,we report a self-crosslinked polymer electrolyte(SCPE)for high-performance lithium batteries,prepared by a one-step method based on 3-methoxysilyl-terminated polypropylene glycol(SPPG,a liquid oligomer).It is worth noting that lithium bis(oxalate)borate(Li BOB)can react with SPPG to form a crosslinked structure via a curing reaction.This self-formed polymer electrolyte exhibits excellent properties,including high roomtemperature ionic conductivity(2.6×10^(-4) S cm^(-1)),wide electrochemical window(4.7 V),and high Li ion transference number(0.65).The excellent cycling stability(500 cycles,83%)further highlights the improved interfacial stability after the in situ formation of SCPE on the electrode surface.Moreover,this self-formation strategy enhances the safety of the battery under mechanical deformation.Therefore,the present self-crosslinked polymer electrolyte shows great potential for applications in high-performance lithium batteries.展开更多
In this study,the authors proposed a promising structure design,the micro-crosslinked polypropylene(PP),to enhance the high-temperature energy storage density.With the grafting of 1,6,7,12-tetrachlorinated perylene-N-...In this study,the authors proposed a promising structure design,the micro-crosslinked polypropylene(PP),to enhance the high-temperature energy storage density.With the grafting of 1,6,7,12-tetrachlorinated perylene-N-2-aminoethyl acrylate-Nʹ-dodecylamine-3,4,9,10-tetracarboxylic bisimide(PTCDA)onto PP molecules,the obtained PP-g-PTCDA achieved a superior energy storage density of 2.34 J/cm^(3)at 120℃ with the discharge efficiency above 90%,which was 585%higher than that of neat PP.The great enhancement,on the one hand,originated from the micro-crosslinked structure,since the restricted molecular motion can lead to the suppression of electrons'hopping across the molecular chains.On the other hand,deep traps were also introduced in PP-g-PTCDA,which restricted the electrons'hopping along the molecular chains simultaneously.This work provided an orientation to enhance the energy storage density at an elevated temperature of 120℃.展开更多
The mechanics of structural ceramics,especially the toughness,are crucial to their service reliability and need to be continuously optimized.Inspired by the“brick-mortar”structure and further adjusting the microstru...The mechanics of structural ceramics,especially the toughness,are crucial to their service reliability and need to be continuously optimized.Inspired by the“brick-mortar”structure and further adjusting the microstructure of“mortar”on the interface,ceramic with strength and toughness up to 444.16 MPa and 13.79 MPa⋅m^(1/2) is constructed by hot pressed sintering with alumina(Al_(2)O_(3))as brick and vertical graphene(VG)with active atomic edges as mortar.Relying on the covalent interface between VG grown in-situ and Al_(2)O_(3),the sliding of Al_(2)O_(3)links the shear-deformation process of the crosslinked and interlocked nanointerface formed by VG,making the VG-enhanced Al_(2)O_(3)ceramics(AVG)obtain super toughness.Moreover,the structure of interlocked VG-nanointerface exhibits an excellent high-temperature resistance,which makes AVG still show the excellent strength of 437.66 MPa and toughness of 11.16 MPa⋅m^(1/2)after heat treatment at 1500℃for 100 h and they are respective 2.51 times and 3.18 times higher than Al_(2)O_(3)in the same condition.This work provides a new thought for the preparation of high-strength,ultra-tough and high-temperature mechanical stable ceramics.展开更多
Lithium metal batteries(LMBs)with extremely high energy densities have several advantages among energy storage equipment.However,the uncontrolled growth of dendrites and the flammable liquid electrolytes(LEs)often cau...Lithium metal batteries(LMBs)with extremely high energy densities have several advantages among energy storage equipment.However,the uncontrolled growth of dendrites and the flammable liquid electrolytes(LEs)often cause safety accidents.All solid-state batteries seem to be the ultimate choice,but solvent-free electrolytes usually fail in terms of conductivity at room temperature.Therefore,gel polymer electrolytes(GPEs)with a simple manufacturing process and high ionic conductivity are considered as the most competitive candidates to resolve the present difficulties.Herein,we design a polymeric network structure via esterification and amidation reactions between polyethylene glycol(PEG)and carbon dots(CDs).After incorporation with polyvinylidene fluoride and some LEs,the as-prepared PEG-CDs composite electrolytes(PCCEs)show a high ionic conductivity of 5.5 mS/cm and an ion transference number of 0.71 at room temperature,as well as good flexibility and thermostability.When the PCCEs are assembled with lithium metal anodes and LiFePO4 or LiCoO2 cathodes,both the cycling stability and the retention rate of these LMBs show excellent performance at room temperature.展开更多
基金Funded by the Western Region Traffic Construction Technology Program of the Ministry of Transport of China(No.2007319811130)
文摘Bridge polycarboxylate superplasticizers（PCs） with crosslink structure were synthesized by using polyethyleneglycol di-acrylate（PEGdA）, replacing partial polyethyleneglycol mono-acrylate （PEGmA） as crosslinking agent. Structures of bridge PCs were analyzed by gel permeation chromatography, and dispersion ability was evaluated by cement paste dispersity variation on time and rheology test. The experimental results showed that, molecular weight（MW） of bridge PCs increased with increase of PEGdA proportion, and MW distribution curve changed from Gaussian to fiat like, which meant notable increase of highly crosslinked copolymer. Bridge PCs led to decreased initial cement paste dispersity and better dispersity retention due to slow releasing. Further research showed that, PEGdA proportion had slight effect on polymerization degree of backbone, MW distribution of backbone deviated from Gaussian distribution and shoulder peaks appeared on distribution curve when PEGdA increased.
基金supported by funding from the Shandong Natural Science Excellent Youth Fund(ZR2019YQ22)the Research Initiation Fund of Qingdao University of Science and Technology。
文摘Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a simple and residue-free preparation process,resulting in a stable interface between electrolyte and electrode,is still a great challenge for practical applications.Herein,we report a self-crosslinked polymer electrolyte(SCPE)for high-performance lithium batteries,prepared by a one-step method based on 3-methoxysilyl-terminated polypropylene glycol(SPPG,a liquid oligomer).It is worth noting that lithium bis(oxalate)borate(Li BOB)can react with SPPG to form a crosslinked structure via a curing reaction.This self-formed polymer electrolyte exhibits excellent properties,including high roomtemperature ionic conductivity(2.6×10^(-4) S cm^(-1)),wide electrochemical window(4.7 V),and high Li ion transference number(0.65).The excellent cycling stability(500 cycles,83%)further highlights the improved interfacial stability after the in situ formation of SCPE on the electrode surface.Moreover,this self-formation strategy enhances the safety of the battery under mechanical deformation.Therefore,the present self-crosslinked polymer electrolyte shows great potential for applications in high-performance lithium batteries.
基金National Natural Science Foundation of China,Grant/Award Numbers:52077163,52107025。
文摘In this study,the authors proposed a promising structure design,the micro-crosslinked polypropylene(PP),to enhance the high-temperature energy storage density.With the grafting of 1,6,7,12-tetrachlorinated perylene-N-2-aminoethyl acrylate-Nʹ-dodecylamine-3,4,9,10-tetracarboxylic bisimide(PTCDA)onto PP molecules,the obtained PP-g-PTCDA achieved a superior energy storage density of 2.34 J/cm^(3)at 120℃ with the discharge efficiency above 90%,which was 585%higher than that of neat PP.The great enhancement,on the one hand,originated from the micro-crosslinked structure,since the restricted molecular motion can lead to the suppression of electrons'hopping across the molecular chains.On the other hand,deep traps were also introduced in PP-g-PTCDA,which restricted the electrons'hopping along the molecular chains simultaneously.This work provided an orientation to enhance the energy storage density at an elevated temperature of 120℃.
基金supported by the National Natural Science Foundation of China under Grant Nos.52222204,52172103,52293371,52072304,and Natural Science Basic Research Program in Shaanxi(2022JC-25).
文摘The mechanics of structural ceramics,especially the toughness,are crucial to their service reliability and need to be continuously optimized.Inspired by the“brick-mortar”structure and further adjusting the microstructure of“mortar”on the interface,ceramic with strength and toughness up to 444.16 MPa and 13.79 MPa⋅m^(1/2) is constructed by hot pressed sintering with alumina(Al_(2)O_(3))as brick and vertical graphene(VG)with active atomic edges as mortar.Relying on the covalent interface between VG grown in-situ and Al_(2)O_(3),the sliding of Al_(2)O_(3)links the shear-deformation process of the crosslinked and interlocked nanointerface formed by VG,making the VG-enhanced Al_(2)O_(3)ceramics(AVG)obtain super toughness.Moreover,the structure of interlocked VG-nanointerface exhibits an excellent high-temperature resistance,which makes AVG still show the excellent strength of 437.66 MPa and toughness of 11.16 MPa⋅m^(1/2)after heat treatment at 1500℃for 100 h and they are respective 2.51 times and 3.18 times higher than Al_(2)O_(3)in the same condition.This work provides a new thought for the preparation of high-strength,ultra-tough and high-temperature mechanical stable ceramics.
基金supported by the National Natural Science Foundation of China(Nos.21975048 and 21771039)the Shanghai Science and Technology Committee(No.19DZ2270100).
文摘Lithium metal batteries(LMBs)with extremely high energy densities have several advantages among energy storage equipment.However,the uncontrolled growth of dendrites and the flammable liquid electrolytes(LEs)often cause safety accidents.All solid-state batteries seem to be the ultimate choice,but solvent-free electrolytes usually fail in terms of conductivity at room temperature.Therefore,gel polymer electrolytes(GPEs)with a simple manufacturing process and high ionic conductivity are considered as the most competitive candidates to resolve the present difficulties.Herein,we design a polymeric network structure via esterification and amidation reactions between polyethylene glycol(PEG)and carbon dots(CDs).After incorporation with polyvinylidene fluoride and some LEs,the as-prepared PEG-CDs composite electrolytes(PCCEs)show a high ionic conductivity of 5.5 mS/cm and an ion transference number of 0.71 at room temperature,as well as good flexibility and thermostability.When the PCCEs are assembled with lithium metal anodes and LiFePO4 or LiCoO2 cathodes,both the cycling stability and the retention rate of these LMBs show excellent performance at room temperature.
