A mathematical model of vibrissa motoneurons (vMN), which has been developed by Harish and Golomb, can show repetitive spiking in response to a transient external stimulation. The vMN model is described by a system of...A mathematical model of vibrissa motoneurons (vMN), which has been developed by Harish and Golomb, can show repetitive spiking in response to a transient external stimulation. The vMN model is described by a system of nonlinear ordinary differential equations based on the Hodgkin-Huxley scheme. The vMN model is regulated by various types of ionic conductances, such as persistent sodium, transient sodium, delayed-rectifier potassium, and slow ionic conductances (e.g., slowly activating potassium afterhyperpolarization (AHP) conductance and h conductance). In the present study, a numerical simulation analysis of the vMN model was performed to investigate the effect of variations in the transient sodium and the slow ionic conductance values on the response of the vMN model to a transient external stimulation. Numerical simulations revealed that when both the transient sodium and the AHP conductances are eliminated, the vMN model shows a bistable behavior (i.e., a stimulation-triggered transition between dynamic states). In contrast, none of the following induce the transition alone: 1) elimination of the transient sodium conductance;2) elimination of the AHP conductance;3) elimination of the h conductance;or 4) elimination of both the transient sodium and the h conductances.展开更多
A previous study proposed a mathematical model of A-type horizontal cells in the rabbit retina. This model, which was constructed based on the Hodgkin-Huxley model, was described by a system of nonlinear ordinary diff...A previous study proposed a mathematical model of A-type horizontal cells in the rabbit retina. This model, which was constructed based on the Hodgkin-Huxley model, was described by a system of nonlinear ordinary differential equations. The model contained five types of voltage-dependent ionic conductances: sodium, calcium, delayed rectifier potassium, transient outward potassium, and anomalous rectifier potassium conductances. The previous study indicated that when the delayed rectifier potassium conductance had a small value, depolarizing stimulation could change the dynamic state of the model from a hyperpolarized steady state to a depolarized steady state. However, how this change was affected by variations in the ionic conductance values was not clarified in detail in the previous study. To clarify this issue, in the present study, we performed numerical simulation analysis of the model and revealed the differences among the five types of ionic conductances.展开更多
A previous study has proposed a mathematical model of type-A medial vestibular nucleus neurons (mVNn). This model is described by a system of nonlinear ordinary differential equations, which is based on the Hodgkin-Hu...A previous study has proposed a mathematical model of type-A medial vestibular nucleus neurons (mVNn). This model is described by a system of nonlinear ordinary differential equations, which is based on the Hodgkin-Huxley formalism. The type-A mVNn model contains several ionic conductances, such as the sodium conductance, calcium conductance, delayed-rectifier potassium conductance, transient potassium conductance, and calcium-dependent potassium conductance. The previous study revealed that spontaneous repetitive spiking in the type-A mVNn model can be suppressed by hyperpolarizing stimulation. However, how this suppression is affected by the ionic conductances has not been clarified in the previous study. The present study performed numerical simulation analysis of the type-A mVNn model to clarify how variations in the different ionic conductance values affect the suppression of repetitive spiking. The present study revealed that the threshold for the transition from a repetitive spiking state to a quiescent state is differentially sensitive to variations in the ionic conductances among the different types of ionic conductance.展开更多
The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state ...The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state thin-film microbatteries(TFMBs),distinguished by their intrinsicsafety,compact design,and compatibility with microfabrication techniques,have emerged as promisingcandidates to power next-generation IoT devices.Nevertheless,in contrast to the well-establisheddevelopment of conventional lithium-ion batteries,the advancement of TFMBs remains at an earlystage,facing persistent challenges in materials innovation,interface optimization,and scalable manufacturing.This review critically examines the pivotal role of vapor deposition technologies,includingmagnetron sputtering,pulsed laser deposition,thermal/electron-beam evaporation,chemical vapordeposition,and atomic layer deposition,in the fabrication and performance modulation of TFMBs.We systematically summarize recent progress in thin-film electrodes and solid-state electrolytes,withparticular emphasis on how deposition parameters dictate crystallinity,lattice orientation,and ionictransport in functional layers.Furthermore,we highlight strategies for solid-solid interface engineering,three-dimensional structural design,andmultifunctional integration to enhance capacity retention,cycling stability,and interfacial compatibility.Looking ahead,TFMBs are expectedto evolve toward multifunctional platforms,exhibiting mechanical flexibility,optical transparency,and hybrid energy-harvesting compatibility,thereby meeting the heterogeneous energy requirements of future IoT ecosystems.Overall,this review provides a comprehensive perspective onvapor-phase-enabled TFMB technologies,delivering both theoretical insights and technological guidelines for the scalable realization of highperformancemicroscale power sources.展开更多
Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storag...Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.展开更多
Solid electrolytes face challenges in solid-state sodium batteries(SSSBs)because of limited ionic conductivity,increased interfacial resistance,and sodium dendrite issues.In this study,we adopted a unique Sn4+doping s...Solid electrolytes face challenges in solid-state sodium batteries(SSSBs)because of limited ionic conductivity,increased interfacial resistance,and sodium dendrite issues.In this study,we adopted a unique Sn4+doping strategy for Na_(3.2)Zr_(2)Si_(2.2)P_(0.8)O_(12)(NZSP)that caused a partial structural transition from the monoclinic(C2/c)phase to the rhombohedral(R-3c)phase in Na_(3.2)Zr_(1.9)Sn_(0.1)Si_(2.2)P_(0.8)O_(12)(NZSnSP1).X-ray diffraction(XRD)patterns and high-resolution transmission electron microscopy analyses were used to confirm this transition,where rhombohedral NZSnSP1 showed an increase in the Na2-O bond length compared with monoclinic NZSnSP1,increasing its triangular bottleneck areas and noticeably enhancing Na+ionic conductivity,a higher Na transference number,and lower electronic conductivity.NZSnSP1 also showed exceptionally high compatibility with Na metal with an increased critical current density,as evidenced by symmetric cell tests.The SSSB,fabricated using Na_(0.9)Zn_(0.22)Fe_(0.3)Mn_(0.48)O_(2)(NZFMO),Na metal,and NZSnSP1 as the cathode,anode,and the solid electrolyte and separator,respectively,maintains 65.86%of retention in the reversible capacity over 300 cycles within a voltage range of 2.0-4.0 V at 25℃ at 0.1 C.The in-situ X-ray diffraction and X-ray absorption analyses of the P and Zr K-edges confirmed that NZSnSP1 remained highly stable before and after electrochemical cycling.This crystal structure modification strategy enables the synthesis of ideal solid electrolytes for practical SSSBs.展开更多
To study the behavior of structural dynamics,ionic conductivity and ion transport properties,the gel polymer electrolytes(GPEs)was developed using polyvinyl alcohol in combination with potassium iodide,dimethyl sulfox...To study the behavior of structural dynamics,ionic conductivity and ion transport properties,the gel polymer electrolytes(GPEs)was developed using polyvinyl alcohol in combination with potassium iodide,dimethyl sulfoxide,ethylene carbonate,propylene carbonate and tetra-N-propylammonium iodide(C12H28IN),The GPEs were synthesized via a solution mixing technique,systematically varying the tetra-N-propylammonium iodide concentration to optimize ionic transport properties.The gel polymer electrolytes(GPEs)preparation was initially dissolving the potassium iodide and tetra-N-propylammonium iodide in a measured combination of ethylene carbonate,propylene carbonate,and dimethyl sulfoxide within a glass container.Subsequently,polyvinyl alcohol(PVA)was introduced into the salt solution and continuously stirred at 100℃until a uniform mixture was formed.The solution was then allowed to cool to 30℃and resulting GPE exhibited a gel-like consistency.Electrochemical impedance spectroscopy(EIS)was employed to evaluate ionic conductivity,dielectric behavior,and ion transport properties at the temperature of 25℃.X-ray diffraction(XRD)was utilized to investigate the structure of the gel polymer electrolyte.Fourier-transform infrared(FTIR)spectroscopy was applied to describe the structural interactions between salts and polymer in the GPEs.Notably,the gel polymer electrolytes containing 30 wt.%tetra-N-propylammonium iodides exhibited a remarkable ionic conductivity of approximately 9.70 mS cm^(-1)at the temperature of 25℃.展开更多
Fiber-shaped energy storage devices(FSESDs)with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during defo...Fiber-shaped energy storage devices(FSESDs)with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during deformation.Among the solid options,polymer electrolytes are particularly preferred due to their robustness and flexibility,although their low ionic conductivity remains a significant challenge.Here,we present a redox polymer electrolyte(HT_RPE)with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl(HT)as a multi-functional additive.HT acts as a plasticizer that transforms the glassy state into the rubbery state for improved chain mobility and provides distinctive ion conduction pathway by the self-exchange reaction between radical and oxidized species.These synergetic effects lead to high ionic conductivity(73.5 mS cm−1)based on a lower activation energy of 0.13 eV than other redox additives.Moreover,HT_RPE with a pseudocapacitive characteristic by HT enables an outstanding electrochemical performance of the symmetric FSESDs using carbon-based fiber electrodes(energy density of 25.4 W h kg^(−1) at a power density of 25,000 W kg^(−1))without typical active materials,along with excellent stability(capacitance retention of 91.2%after 8,000 bending cycles).This work highlights a versatile HT_RPE that utilizes the unique functionality of HT for both the high ionic conductivity and improved energy storage capability,providing a promising pathway for next-generation flexible energy storage devices.展开更多
In recent years,flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors.However,most of these materials still face challenges such as the difficult trade-of...In recent years,flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors.However,most of these materials still face challenges such as the difficult trade-off between stretchability and high mechanical strength,as well as insufficient ionic conductivity.Among them,polymerizable deep eutectic solvents(PDES),which possess both hydrogen bond network construction capabilities and ionic conduction properties,have demonstrated great advantages in the synthesis of flexible ionic conductors.Herein,we report an ionic conductive elastomer(ICE)named PCHS-X based on PDES composed of 2-(methacryloyloxy)-N,N,N-trimethylammonium methyl sulfate(MA-MS),choline chloride(ChCl),and 2-hydroxyethyl acrylate(HEA).The introduction of MA-MS enabled the polymer network to form abundant hydrogen bonds,endowing PCHS-X with excellent mechanical strength,high transparency,favorable ionic conductivity,self-adhesiveness,and self-healing efficiency.When used as a strain sensor,the PCHS-X exhibits highly sensitive strain response,along with good stability and durability,allowing it to accurately monitor the movement of human body parts such as fingers,wrists,elbows,and knees.Additionally,owing to the enhanced ionic mobility at higher temperatures,this material also possesses excellent temperature sensing performance,enabling the fabrication of simple temperature sensors that can sensitively respond to temperature changes.This research provides new strategies for the practical applications of flexible electronic devices in fields such as wearable health monitoring and intelligent human-machine interaction.展开更多
Conventional liquid electrolytes in lithium-ion batteries(LIBs)pose significant safety risks and interfacial instability,hindering the development of high-energy-density systems.Solid polymer electrolytes(SPEs),partic...Conventional liquid electrolytes in lithium-ion batteries(LIBs)pose significant safety risks and interfacial instability,hindering the development of high-energy-density systems.Solid polymer electrolytes(SPEs),particularly polyethylene oxide(PEO)-based systems,offer enhanced safety but suffer from low room-temperature ionic conductivity due to high crystallinity,alongside limitations such as poor lithium-ion transference numbers and dendrite growth.To address these challenges,this study develops a novel composite solid electrolyte(PSPH)by synthesizing a polystyrene-polyethylene oxide-polystyrene(PSPEO-PS)triblock copolymer and blending it with poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and lithium bis(trifluoromethylsulfonyl)imide(LiTFSI).The rigid PS segments suppress PEO crystallization,while PVDF-HFP enhances amorphous domain content,promotes LiTFSI dissociation via its high dielectric constant,and improves mechanical strength.The optimized PSPH composition(M_(w,PEO)=35 kg·mol^(-1),w_(PS)=15%,w_(PVDF-HFP)=30%)exhibits a high ionic conductivity of 1.05×10^(-4) S·cm^(-1)at 25℃,a Li^(+)transference number of 0.46,and an extended electrochemical stability window up to 4.8 V.PSPH demonstrates excellent thermal stability(decomposition onset at about 340℃),flexibility,and interfacial compatibility.LiFePO_(4)/PSPH/Li cells delivere a high discharge capacity of 163.7 mAh·g^(-1) at 0.1 C,with 96.2%capacity retention and 99.83%average coulombic efficiency after 200 cycles.Furthermore,Li/PSPH/Li symmetric cells exhibit stable cycling for over 1500 h at 0.05 mA·cm^(-2) with low overpotential(about 0.15 V).These results demonstrate that PSPH is a highly promising electrolyte for enhancing the safety and electrochemical performance of all-solid-state lithium-metal batteries(LMBs).展开更多
Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,per...Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.展开更多
The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sa...The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sample was investigated by alternating current impedance spectroscopy and gas concentration cell methods under different gases atmospheres in the temperature range of 500-900 ℃. The performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured. In wet hydrogen, the sample is a pure protonic conductor with the protonic transport number of 1 in the range of 500-600 ℃, a mixed conductor of proton and electron with the protonic transport number of 0.945-0.933 above 600 ℃. In wet air, the sample is a mixed conductor of proton, oxide ion, and electronic hole. The protonic transport numbers are 0.010-0.021, and the oxide ionic transport numbers are 0.471-0.382. In hydrogen-air fuel cell, the sample is a mixed conductor of proton, oxide ion and electron, the ionic transport numbers are 0.942 0.885. The fuel cell using Ba0.98Ce0.8Tm0.2O3-α as solid electrolyte can work stably. At 900 ℃, the maximum power output density is 110,2 mW/cm2, which is higher than that of our previous cell using Ba0.98Ce0.8Tm0.2O3-α （x〈≤1, RE=Y, Eu, Ho） as solid electrolyte.展开更多
The global energy crisis and electricity shortage pose unprecedented challenges.Bio-based solar-driven ionic power generation devices with flexibility,photothermal self-healing and scalability hold great promise for s...The global energy crisis and electricity shortage pose unprecedented challenges.Bio-based solar-driven ionic power generation devices with flexibility,photothermal self-healing and scalability hold great promise for sustainable electricity and alleviating energy crisis.Here,inspired by plant transpiration,a multifunctional bio-based ion conductive elastomer with solar power generation capability was designed by engineered synergy among epoxy natural rubber,cellulose nanofibrils,lithium bis(trifluoromethane)sulfonimide and eumelanin.The film exhibits an outstanding stretchability(1072%)and toughness(22.7 MJ m^(-3)).The favorable synergy of low thermal conductivity,high hygroscopicity and photothermal conversion performance endowed the film with a large thermal gradient under light illumination,driving efficient water transpiration.Furthermore,the excellent interfacial compatibility between eumelanin and matrix facilitates the formation of space charge regions,which further enhances Li^(+)transport.The film demonstrates excellent evaporation rate(2.83 kg m^(-2)h^(-1)),output voltage(0.47 V)and conductivity(5.11×10^(-2)S m^(-1)).Notably,the film exhibits remarkable photothermal self-healing performance even in saline environment,achieving 99.6%healing efficiency of output voltage.Therefore,the film demonstrates significant prospects for applications in photo-thermoelectric generation and solar-driven ionic power generation.展开更多
Electrosensory pyramidal neurons in weakly electric fish can generate burst firing. Based on the Hodgkin-Huxley scheme, a previous study has developed a mathematical model that reproduces this burst firing. This model...Electrosensory pyramidal neurons in weakly electric fish can generate burst firing. Based on the Hodgkin-Huxley scheme, a previous study has developed a mathematical model that reproduces this burst firing. This model is called the ghostbursting model and is described by a system of non-linear ordinary differential equations. Although the dynamic state of this model is a quiescent state during low levels of electrical stimulation, an increase in the level of electrical stimulation transforms the dynamic state first into a repetitive spiking state and finally into a burst firing state. The present study performed computer simulation analysis of the ghostbursting model to evaluate the sensitivity of the three dynamic states of the model (i.e., the quiescent, repetitive spiking, and burst firing states) to variations in sodium and potassium conductance values of the model. The present numerical simulation analysis revealed the sensitivity of the electrical stimulation threshold required for eliciting the burst firing state to variations in the values of four ionic conductances (i.e., somatic sodium, dendritic sodium, somatic potassium, and dendritic potassium conductances) in the ghostbursting model.展开更多
Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so ...Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so as to obtain homogeneous nano-sized precursor powders. The X-ray diffraction （XRD） and the scan electron microscope （SEM） are used to investigate the phases and microstructures. The measurements and analyses of oxygen ionic conductivity of SDC-LSGM are carried out through the four-terminal direct current （DC） method and the electrochemical impendence spectroscopy, respectively. The optimum weight ratio of SDC-LSGM is 8∶2, of which the ionic conductivity is 0.113 S/cm at 800℃ and the conductivity activation energy is 0.620 eV. The impendence spectra shows that the grain boundary resistance becomes the main barrier for the ionic conductivity of electrolyte at lower temperatures. The appropriate introduction of LSGM to the electrolyte SDC can not only decrease the electronic conductivity but also improve the conditions of the grain and grain boundary, which is advantageous to cause an increase in oxygen ionic conductivity.展开更多
Sodium-ion batteries are expected to be more affordable for stationary applications than lithium-ion batteries,while still offering sufficient energy density and operational capacity to power a significant segment of ...Sodium-ion batteries are expected to be more affordable for stationary applications than lithium-ion batteries,while still offering sufficient energy density and operational capacity to power a significant segment of the battery market.Despite this,thermal runaway explosions associated with organic electrolytes have led to concerns regarding the safety of sodium-ion batteries.Among electrolytes,ionic liquids are promising because they have negligible vapor pressure and show high thermal and electrochemical stability.This review discusses the safety contributions of these electrolyte properties for high-temperature applications.The ionic liquids provide thermal stability while at the same time promoting high-voltage window battery operations.Moreover,apart from cycle stability,there is an additional safety feature attributed to modified ultra-concentrated ionic liquid electrolytes.Concerning these contributions,the following have been discussed,heat sources and thermal runaway mechanisms,thermal stability,the electrochemical decomposition mechanism of stable cations,and the ionic transport mechanism of ultra-concentrated ionic liquid electrolytes.In addition,the contributions of hybrid electrolyte systems consisting of ionic liquids with either organic carbonate or polymers are also discussed.The thermal stability of ionic liquids is found to be the main contributor to cell safety and cycle stability.For high-temperature applications where electrolyte safety,capacity,and cycle stability are important,highly concentrated ionic liquid electrolyte systems are potential solutions for sodium-ion battery applications.展开更多
Ionic conductivity is one of the crucial parameters for inorganic solid-state electrolytes.To explore the relationship between porosity and ionic conductivity,a series of Li_(6.4)Ga_(0.2)La_(3)Zr_(2)O_(12)garnet type ...Ionic conductivity is one of the crucial parameters for inorganic solid-state electrolytes.To explore the relationship between porosity and ionic conductivity,a series of Li_(6.4)Ga_(0.2)La_(3)Zr_(2)O_(12)garnet type solid-state electrolytes with different porosities were prepared via solid-state reaction.Based on the quantified data,an empirical decay relationship was summarized and discussed by means of mathematical model and dimensional analysis method.It suggests that open porosity causes ionic conductivity to decrease exponentially.The pre-exponential factor obeys the Arrhenius Law quite well with the activation energy of 0.23 eV,and the decay constant is averaged to be 2.62%.While the closed porosity causes ionic conductivity to decrease linearly.The slope and intercept of this linear pattern also obey the Arrhenius Law and the activation energies are 0.24 and 0.27 eV,respectively.Moreover,the total porosity is linearly dependent on the open porosity,and different sintering conditions will lead to different linear patterns with different slopes and intercepts.展开更多
Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33 2x/3MxSi6O26 （M=Mg, Ca, Sr） is prepa...Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33 2x/3MxSi6O26 （M=Mg, Ca, Sr） is prepared by the sol-gel method with sintering at 1000℃. The powder is characterized by X-ray diffraction （XRD） and scanning electron micrograph （SEM）. The apatite can be obtained at relatively low temperature as compared to the conventional solid-state reaction method. The measurements of conductivity of a series of doped samples La9.33-2x/3MxSi6O26 （M=Ca, Mg, Sr） indicate that the type of dopant and the amount have a significant effect on the conductivity. The greatest decrease in conductivity is observed for Mg doping, following the Ca and the Sr doped apatites. The effect is ultimately attributed to the amount of oxygen interstitials, which is affected by the crystal lattice distortion arising from cation vacancies.展开更多
As a promising solid electrolyte for thin-film lithium batteries,the amorphous Li_(0.33)La_(0.56)TiO_(3)(LLTO)thin film has gained great interest.However,enhancing ionic conductivity remains challenging in the field.H...As a promising solid electrolyte for thin-film lithium batteries,the amorphous Li_(0.33)La_(0.56)TiO_(3)(LLTO)thin film has gained great interest.However,enhancing ionic conductivity remains challenging in the field.Here,a systematical study was performed to improve the ionic conductivity of sputter-deposited LLTO thin films via the optimization of processing atmosphere and temperature.By combining the optimized oxygen partial pressure(30%),annealing temperature(300℃),and annealing atmosphere(air),an amorphous LLTO thin film with an ionic conductivity of 5.32910^(-5)·S·cm^(-1) at room temperature and activation energy of 0.26 eV was achieved.The results showed that,first,the oxygen partial pressure should be high enough to compensate for the oxygen loss,but low enough to avoid the abusive oxygen scattering effect on lithium precursors that results in a lithium-poor composition.The oxygen partial pressure needs to achieve a balance between lithium loss and oxygen defects to improve the ionic conductivity.Second,a proper annealing temperature reduces the oxygen defects of LLTO thin films while maintaining its amorphous state,which improves the ionic conductivity.Third,the highest ionic conductivity for the LLTO thin films that were annealed in air(a static space without a gas stream)occurs because of the decreased lithium loss and oxygen defects during annealing.These findings show that the lithium-ion concentration and oxygen defects affect the ionic conductivity for amorphous LLTO thin films,which provides insight into the optimization of LLTO thin-film solid electrolytes,and generates new opportunities for their application in thinfilm lithium batteries.展开更多
Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane （WPU） and 1-butyl-3-methylimidazolium bis[（trifluoromethyl）sulfonyl]imide （BMImTFSI） have been prepared and characterized. The ...Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane （WPU） and 1-butyl-3-methylimidazolium bis[（trifluoromethyl）sulfonyl]imide （BMImTFSI） have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration （BMImTFSI/WPU = 3 in weight ratio）, the ionic conductivity reaches 4.27 × 10^-3 S/cm at 30 ℃. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.展开更多
文摘A mathematical model of vibrissa motoneurons (vMN), which has been developed by Harish and Golomb, can show repetitive spiking in response to a transient external stimulation. The vMN model is described by a system of nonlinear ordinary differential equations based on the Hodgkin-Huxley scheme. The vMN model is regulated by various types of ionic conductances, such as persistent sodium, transient sodium, delayed-rectifier potassium, and slow ionic conductances (e.g., slowly activating potassium afterhyperpolarization (AHP) conductance and h conductance). In the present study, a numerical simulation analysis of the vMN model was performed to investigate the effect of variations in the transient sodium and the slow ionic conductance values on the response of the vMN model to a transient external stimulation. Numerical simulations revealed that when both the transient sodium and the AHP conductances are eliminated, the vMN model shows a bistable behavior (i.e., a stimulation-triggered transition between dynamic states). In contrast, none of the following induce the transition alone: 1) elimination of the transient sodium conductance;2) elimination of the AHP conductance;3) elimination of the h conductance;or 4) elimination of both the transient sodium and the h conductances.
文摘A previous study proposed a mathematical model of A-type horizontal cells in the rabbit retina. This model, which was constructed based on the Hodgkin-Huxley model, was described by a system of nonlinear ordinary differential equations. The model contained five types of voltage-dependent ionic conductances: sodium, calcium, delayed rectifier potassium, transient outward potassium, and anomalous rectifier potassium conductances. The previous study indicated that when the delayed rectifier potassium conductance had a small value, depolarizing stimulation could change the dynamic state of the model from a hyperpolarized steady state to a depolarized steady state. However, how this change was affected by variations in the ionic conductance values was not clarified in detail in the previous study. To clarify this issue, in the present study, we performed numerical simulation analysis of the model and revealed the differences among the five types of ionic conductances.
文摘A previous study has proposed a mathematical model of type-A medial vestibular nucleus neurons (mVNn). This model is described by a system of nonlinear ordinary differential equations, which is based on the Hodgkin-Huxley formalism. The type-A mVNn model contains several ionic conductances, such as the sodium conductance, calcium conductance, delayed-rectifier potassium conductance, transient potassium conductance, and calcium-dependent potassium conductance. The previous study revealed that spontaneous repetitive spiking in the type-A mVNn model can be suppressed by hyperpolarizing stimulation. However, how this suppression is affected by the ionic conductances has not been clarified in the previous study. The present study performed numerical simulation analysis of the type-A mVNn model to clarify how variations in the different ionic conductance values affect the suppression of repetitive spiking. The present study revealed that the threshold for the transition from a repetitive spiking state to a quiescent state is differentially sensitive to variations in the ionic conductances among the different types of ionic conductance.
基金supported by the National Key Research and Development Program of China (2023YFA1608800)Guangdong Basic and Applied Basic Research Foundation (2024A1515012385, 2024B1515120042)+6 种基金Shenzhen Foundation Research Fund (JCYJ20240813095004006)the National Natural Science Foundation of China (12426301, 12275119, 52227802)Shenzhen Science and Technology Program (KQTD20200820113047086)Shenzhen Key Laboratory of Solid State Batteries (SYSPG20241211173726011)Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices (2019B121205001)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power (2018B030322001)the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by the Municipal Development and Reform Commission of Shenzhen
文摘The rapid proliferation of microelectronics,coupled with the advent of the internet ofthings(IoT)era,has created an urgent demand for miniaturized,integrable,and reliable on-chip energystorage systems.All-solid-state thin-film microbatteries(TFMBs),distinguished by their intrinsicsafety,compact design,and compatibility with microfabrication techniques,have emerged as promisingcandidates to power next-generation IoT devices.Nevertheless,in contrast to the well-establisheddevelopment of conventional lithium-ion batteries,the advancement of TFMBs remains at an earlystage,facing persistent challenges in materials innovation,interface optimization,and scalable manufacturing.This review critically examines the pivotal role of vapor deposition technologies,includingmagnetron sputtering,pulsed laser deposition,thermal/electron-beam evaporation,chemical vapordeposition,and atomic layer deposition,in the fabrication and performance modulation of TFMBs.We systematically summarize recent progress in thin-film electrodes and solid-state electrolytes,withparticular emphasis on how deposition parameters dictate crystallinity,lattice orientation,and ionictransport in functional layers.Furthermore,we highlight strategies for solid-solid interface engineering,three-dimensional structural design,andmultifunctional integration to enhance capacity retention,cycling stability,and interfacial compatibility.Looking ahead,TFMBs are expectedto evolve toward multifunctional platforms,exhibiting mechanical flexibility,optical transparency,and hybrid energy-harvesting compatibility,thereby meeting the heterogeneous energy requirements of future IoT ecosystems.Overall,this review provides a comprehensive perspective onvapor-phase-enabled TFMB technologies,delivering both theoretical insights and technological guidelines for the scalable realization of highperformancemicroscale power sources.
基金supported by the National Natural Science Foundation of China(Nos.22171102 and 22090044)the National Key R&D Program of China(Nos.2021YFF0500502 and 2023YFA1506304)+2 种基金the Jilin Province Science and Technology Development Plan(No.20230101024JC)the"Medicine+X"crossinnovation team of Bethune Medical Department of Jilin University"Leading the Charge with Open Competition"construction project(No.2022JBGS04)the Jilin University Graduate Training Office(Nos.2021JGZ08 and 2022YJSJIP20).
文摘Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.
基金supported by the National Research Foundation of Korea(RS-2024-00404414)the National Research Council of Science&Technology(NST,No.GTL24011-000)funded by the Ministry of Science and ICTsupported by the KIST Institutional Program(Project No.2E33270).
文摘Solid electrolytes face challenges in solid-state sodium batteries(SSSBs)because of limited ionic conductivity,increased interfacial resistance,and sodium dendrite issues.In this study,we adopted a unique Sn4+doping strategy for Na_(3.2)Zr_(2)Si_(2.2)P_(0.8)O_(12)(NZSP)that caused a partial structural transition from the monoclinic(C2/c)phase to the rhombohedral(R-3c)phase in Na_(3.2)Zr_(1.9)Sn_(0.1)Si_(2.2)P_(0.8)O_(12)(NZSnSP1).X-ray diffraction(XRD)patterns and high-resolution transmission electron microscopy analyses were used to confirm this transition,where rhombohedral NZSnSP1 showed an increase in the Na2-O bond length compared with monoclinic NZSnSP1,increasing its triangular bottleneck areas and noticeably enhancing Na+ionic conductivity,a higher Na transference number,and lower electronic conductivity.NZSnSP1 also showed exceptionally high compatibility with Na metal with an increased critical current density,as evidenced by symmetric cell tests.The SSSB,fabricated using Na_(0.9)Zn_(0.22)Fe_(0.3)Mn_(0.48)O_(2)(NZFMO),Na metal,and NZSnSP1 as the cathode,anode,and the solid electrolyte and separator,respectively,maintains 65.86%of retention in the reversible capacity over 300 cycles within a voltage range of 2.0-4.0 V at 25℃ at 0.1 C.The in-situ X-ray diffraction and X-ray absorption analyses of the P and Zr K-edges confirmed that NZSnSP1 remained highly stable before and after electrochemical cycling.This crystal structure modification strategy enables the synthesis of ideal solid electrolytes for practical SSSBs.
基金funding from Universiti Sains Malaysia under the Bridging Grant(Project No:R501-LR-RND003-0000002095-0000)to support this study.
文摘To study the behavior of structural dynamics,ionic conductivity and ion transport properties,the gel polymer electrolytes(GPEs)was developed using polyvinyl alcohol in combination with potassium iodide,dimethyl sulfoxide,ethylene carbonate,propylene carbonate and tetra-N-propylammonium iodide(C12H28IN),The GPEs were synthesized via a solution mixing technique,systematically varying the tetra-N-propylammonium iodide concentration to optimize ionic transport properties.The gel polymer electrolytes(GPEs)preparation was initially dissolving the potassium iodide and tetra-N-propylammonium iodide in a measured combination of ethylene carbonate,propylene carbonate,and dimethyl sulfoxide within a glass container.Subsequently,polyvinyl alcohol(PVA)was introduced into the salt solution and continuously stirred at 100℃until a uniform mixture was formed.The solution was then allowed to cool to 30℃and resulting GPE exhibited a gel-like consistency.Electrochemical impedance spectroscopy(EIS)was employed to evaluate ionic conductivity,dielectric behavior,and ion transport properties at the temperature of 25℃.X-ray diffraction(XRD)was utilized to investigate the structure of the gel polymer electrolyte.Fourier-transform infrared(FTIR)spectroscopy was applied to describe the structural interactions between salts and polymer in the GPEs.Notably,the gel polymer electrolytes containing 30 wt.%tetra-N-propylammonium iodides exhibited a remarkable ionic conductivity of approximately 9.70 mS cm^(-1)at the temperature of 25℃.
基金supported by Korea Institute of Science and Technology(KIST)Institutional Program and Open Research Program(ORP)This work was also supported by grant from the National Research Foundation(NRF)of Korea government(RS-2024-00433159 and RS-2023-00208313)from ITECH R&D program of MOTIE/KEIT(RS-2023-00257573).
文摘Fiber-shaped energy storage devices(FSESDs)with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during deformation.Among the solid options,polymer electrolytes are particularly preferred due to their robustness and flexibility,although their low ionic conductivity remains a significant challenge.Here,we present a redox polymer electrolyte(HT_RPE)with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl(HT)as a multi-functional additive.HT acts as a plasticizer that transforms the glassy state into the rubbery state for improved chain mobility and provides distinctive ion conduction pathway by the self-exchange reaction between radical and oxidized species.These synergetic effects lead to high ionic conductivity(73.5 mS cm−1)based on a lower activation energy of 0.13 eV than other redox additives.Moreover,HT_RPE with a pseudocapacitive characteristic by HT enables an outstanding electrochemical performance of the symmetric FSESDs using carbon-based fiber electrodes(energy density of 25.4 W h kg^(−1) at a power density of 25,000 W kg^(−1))without typical active materials,along with excellent stability(capacitance retention of 91.2%after 8,000 bending cycles).This work highlights a versatile HT_RPE that utilizes the unique functionality of HT for both the high ionic conductivity and improved energy storage capability,providing a promising pathway for next-generation flexible energy storage devices.
基金financially supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJA150009)a Project Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘In recent years,flexible ionic conductors have made remarkable progress in the fields of energy storage devices and flexible sensors.However,most of these materials still face challenges such as the difficult trade-off between stretchability and high mechanical strength,as well as insufficient ionic conductivity.Among them,polymerizable deep eutectic solvents(PDES),which possess both hydrogen bond network construction capabilities and ionic conduction properties,have demonstrated great advantages in the synthesis of flexible ionic conductors.Herein,we report an ionic conductive elastomer(ICE)named PCHS-X based on PDES composed of 2-(methacryloyloxy)-N,N,N-trimethylammonium methyl sulfate(MA-MS),choline chloride(ChCl),and 2-hydroxyethyl acrylate(HEA).The introduction of MA-MS enabled the polymer network to form abundant hydrogen bonds,endowing PCHS-X with excellent mechanical strength,high transparency,favorable ionic conductivity,self-adhesiveness,and self-healing efficiency.When used as a strain sensor,the PCHS-X exhibits highly sensitive strain response,along with good stability and durability,allowing it to accurately monitor the movement of human body parts such as fingers,wrists,elbows,and knees.Additionally,owing to the enhanced ionic mobility at higher temperatures,this material also possesses excellent temperature sensing performance,enabling the fabrication of simple temperature sensors that can sensitively respond to temperature changes.This research provides new strategies for the practical applications of flexible electronic devices in fields such as wearable health monitoring and intelligent human-machine interaction.
基金supported by the 2024 Capital Construction Funds within the Provincial Budget of Jilin Provincial Development and Reform Commission[2024C018-2].
文摘Conventional liquid electrolytes in lithium-ion batteries(LIBs)pose significant safety risks and interfacial instability,hindering the development of high-energy-density systems.Solid polymer electrolytes(SPEs),particularly polyethylene oxide(PEO)-based systems,offer enhanced safety but suffer from low room-temperature ionic conductivity due to high crystallinity,alongside limitations such as poor lithium-ion transference numbers and dendrite growth.To address these challenges,this study develops a novel composite solid electrolyte(PSPH)by synthesizing a polystyrene-polyethylene oxide-polystyrene(PSPEO-PS)triblock copolymer and blending it with poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and lithium bis(trifluoromethylsulfonyl)imide(LiTFSI).The rigid PS segments suppress PEO crystallization,while PVDF-HFP enhances amorphous domain content,promotes LiTFSI dissociation via its high dielectric constant,and improves mechanical strength.The optimized PSPH composition(M_(w,PEO)=35 kg·mol^(-1),w_(PS)=15%,w_(PVDF-HFP)=30%)exhibits a high ionic conductivity of 1.05×10^(-4) S·cm^(-1)at 25℃,a Li^(+)transference number of 0.46,and an extended electrochemical stability window up to 4.8 V.PSPH demonstrates excellent thermal stability(decomposition onset at about 340℃),flexibility,and interfacial compatibility.LiFePO_(4)/PSPH/Li cells delivere a high discharge capacity of 163.7 mAh·g^(-1) at 0.1 C,with 96.2%capacity retention and 99.83%average coulombic efficiency after 200 cycles.Furthermore,Li/PSPH/Li symmetric cells exhibit stable cycling for over 1500 h at 0.05 mA·cm^(-2) with low overpotential(about 0.15 V).These results demonstrate that PSPH is a highly promising electrolyte for enhancing the safety and electrochemical performance of all-solid-state lithium-metal batteries(LMBs).
基金supported by the National Key Research and Development Program of China (2022YFE0138900)the “Scientific and Technical Innovation Action Plan” Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)。
文摘Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.
文摘The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sample was investigated by alternating current impedance spectroscopy and gas concentration cell methods under different gases atmospheres in the temperature range of 500-900 ℃. The performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured. In wet hydrogen, the sample is a pure protonic conductor with the protonic transport number of 1 in the range of 500-600 ℃, a mixed conductor of proton and electron with the protonic transport number of 0.945-0.933 above 600 ℃. In wet air, the sample is a mixed conductor of proton, oxide ion, and electronic hole. The protonic transport numbers are 0.010-0.021, and the oxide ionic transport numbers are 0.471-0.382. In hydrogen-air fuel cell, the sample is a mixed conductor of proton, oxide ion and electron, the ionic transport numbers are 0.942 0.885. The fuel cell using Ba0.98Ce0.8Tm0.2O3-α as solid electrolyte can work stably. At 900 ℃, the maximum power output density is 110,2 mW/cm2, which is higher than that of our previous cell using Ba0.98Ce0.8Tm0.2O3-α （x〈≤1, RE=Y, Eu, Ho） as solid electrolyte.
基金financially supported by the National Natural Science Foundation of China(22175044)the Guangxi Natural Science Foundation(2023GXNSFDA026049)the Guangxi Major Talents Program(GXR-1BGQ2424023)。
文摘The global energy crisis and electricity shortage pose unprecedented challenges.Bio-based solar-driven ionic power generation devices with flexibility,photothermal self-healing and scalability hold great promise for sustainable electricity and alleviating energy crisis.Here,inspired by plant transpiration,a multifunctional bio-based ion conductive elastomer with solar power generation capability was designed by engineered synergy among epoxy natural rubber,cellulose nanofibrils,lithium bis(trifluoromethane)sulfonimide and eumelanin.The film exhibits an outstanding stretchability(1072%)and toughness(22.7 MJ m^(-3)).The favorable synergy of low thermal conductivity,high hygroscopicity and photothermal conversion performance endowed the film with a large thermal gradient under light illumination,driving efficient water transpiration.Furthermore,the excellent interfacial compatibility between eumelanin and matrix facilitates the formation of space charge regions,which further enhances Li^(+)transport.The film demonstrates excellent evaporation rate(2.83 kg m^(-2)h^(-1)),output voltage(0.47 V)and conductivity(5.11×10^(-2)S m^(-1)).Notably,the film exhibits remarkable photothermal self-healing performance even in saline environment,achieving 99.6%healing efficiency of output voltage.Therefore,the film demonstrates significant prospects for applications in photo-thermoelectric generation and solar-driven ionic power generation.
文摘Electrosensory pyramidal neurons in weakly electric fish can generate burst firing. Based on the Hodgkin-Huxley scheme, a previous study has developed a mathematical model that reproduces this burst firing. This model is called the ghostbursting model and is described by a system of non-linear ordinary differential equations. Although the dynamic state of this model is a quiescent state during low levels of electrical stimulation, an increase in the level of electrical stimulation transforms the dynamic state first into a repetitive spiking state and finally into a burst firing state. The present study performed computer simulation analysis of the ghostbursting model to evaluate the sensitivity of the three dynamic states of the model (i.e., the quiescent, repetitive spiking, and burst firing states) to variations in sodium and potassium conductance values of the model. The present numerical simulation analysis revealed the sensitivity of the electrical stimulation threshold required for eliciting the burst firing state to variations in the values of four ionic conductances (i.e., somatic sodium, dendritic sodium, somatic potassium, and dendritic potassium conductances) in the ghostbursting model.
基金The National Basic Research Program of China (973 Program) (No.2007CB936300)the Natural Science Foundation of Jiangsu Province (No.BK2009293)
文摘Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so as to obtain homogeneous nano-sized precursor powders. The X-ray diffraction （XRD） and the scan electron microscope （SEM） are used to investigate the phases and microstructures. The measurements and analyses of oxygen ionic conductivity of SDC-LSGM are carried out through the four-terminal direct current （DC） method and the electrochemical impendence spectroscopy, respectively. The optimum weight ratio of SDC-LSGM is 8∶2, of which the ionic conductivity is 0.113 S/cm at 800℃ and the conductivity activation energy is 0.620 eV. The impendence spectra shows that the grain boundary resistance becomes the main barrier for the ionic conductivity of electrolyte at lower temperatures. The appropriate introduction of LSGM to the electrolyte SDC can not only decrease the electronic conductivity but also improve the conditions of the grain and grain boundary, which is advantageous to cause an increase in oxygen ionic conductivity.
基金funded by CUA bursary,Ireland a project titled:Fabrication of solid-state electrolytes for batteries in smartphones and electric vehicles (EVs)。
文摘Sodium-ion batteries are expected to be more affordable for stationary applications than lithium-ion batteries,while still offering sufficient energy density and operational capacity to power a significant segment of the battery market.Despite this,thermal runaway explosions associated with organic electrolytes have led to concerns regarding the safety of sodium-ion batteries.Among electrolytes,ionic liquids are promising because they have negligible vapor pressure and show high thermal and electrochemical stability.This review discusses the safety contributions of these electrolyte properties for high-temperature applications.The ionic liquids provide thermal stability while at the same time promoting high-voltage window battery operations.Moreover,apart from cycle stability,there is an additional safety feature attributed to modified ultra-concentrated ionic liquid electrolytes.Concerning these contributions,the following have been discussed,heat sources and thermal runaway mechanisms,thermal stability,the electrochemical decomposition mechanism of stable cations,and the ionic transport mechanism of ultra-concentrated ionic liquid electrolytes.In addition,the contributions of hybrid electrolyte systems consisting of ionic liquids with either organic carbonate or polymers are also discussed.The thermal stability of ionic liquids is found to be the main contributor to cell safety and cycle stability.For high-temperature applications where electrolyte safety,capacity,and cycle stability are important,highly concentrated ionic liquid electrolyte systems are potential solutions for sodium-ion battery applications.
基金supported by the Innovation and Entrepreneurship Project of Hunan Province,China(No.2019GK5053)Program of Huxiang Young Talents,China(No.2019RS2002)+1 种基金the Natural Science Foundation for Distinguished Young Scholars of Hunan Province,China(No.2020JJ2047)the Fundamental Research Funds for the Central Universities of Central South University,China。
文摘Ionic conductivity is one of the crucial parameters for inorganic solid-state electrolytes.To explore the relationship between porosity and ionic conductivity,a series of Li_(6.4)Ga_(0.2)La_(3)Zr_(2)O_(12)garnet type solid-state electrolytes with different porosities were prepared via solid-state reaction.Based on the quantified data,an empirical decay relationship was summarized and discussed by means of mathematical model and dimensional analysis method.It suggests that open porosity causes ionic conductivity to decrease exponentially.The pre-exponential factor obeys the Arrhenius Law quite well with the activation energy of 0.23 eV,and the decay constant is averaged to be 2.62%.While the closed porosity causes ionic conductivity to decrease linearly.The slope and intercept of this linear pattern also obey the Arrhenius Law and the activation energies are 0.24 and 0.27 eV,respectively.Moreover,the total porosity is linearly dependent on the open porosity,and different sintering conditions will lead to different linear patterns with different slopes and intercepts.
基金Supported by the Natural Science Foundation of Guangdong PrOvince （06025657） and Guangdong Provincial Green Chemicals.
文摘Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33 2x/3MxSi6O26 （M=Mg, Ca, Sr） is prepared by the sol-gel method with sintering at 1000℃. The powder is characterized by X-ray diffraction （XRD） and scanning electron micrograph （SEM）. The apatite can be obtained at relatively low temperature as compared to the conventional solid-state reaction method. The measurements of conductivity of a series of doped samples La9.33-2x/3MxSi6O26 （M=Ca, Mg, Sr） indicate that the type of dopant and the amount have a significant effect on the conductivity. The greatest decrease in conductivity is observed for Mg doping, following the Ca and the Sr doped apatites. The effect is ultimately attributed to the amount of oxygen interstitials, which is affected by the crystal lattice distortion arising from cation vacancies.
基金This study was financially supported by the National Natural Science Funds of China(No.21905040)the Startup Funds from the University of Electronic Science and Technology of China,the National Key Research and Development Program of China(Nos.2017YFB0702802 and 2018YFB0905400)Shanghai Venus Project(No.18QB1402600).
文摘As a promising solid electrolyte for thin-film lithium batteries,the amorphous Li_(0.33)La_(0.56)TiO_(3)(LLTO)thin film has gained great interest.However,enhancing ionic conductivity remains challenging in the field.Here,a systematical study was performed to improve the ionic conductivity of sputter-deposited LLTO thin films via the optimization of processing atmosphere and temperature.By combining the optimized oxygen partial pressure(30%),annealing temperature(300℃),and annealing atmosphere(air),an amorphous LLTO thin film with an ionic conductivity of 5.32910^(-5)·S·cm^(-1) at room temperature and activation energy of 0.26 eV was achieved.The results showed that,first,the oxygen partial pressure should be high enough to compensate for the oxygen loss,but low enough to avoid the abusive oxygen scattering effect on lithium precursors that results in a lithium-poor composition.The oxygen partial pressure needs to achieve a balance between lithium loss and oxygen defects to improve the ionic conductivity.Second,a proper annealing temperature reduces the oxygen defects of LLTO thin films while maintaining its amorphous state,which improves the ionic conductivity.Third,the highest ionic conductivity for the LLTO thin films that were annealed in air(a static space without a gas stream)occurs because of the decreased lithium loss and oxygen defects during annealing.These findings show that the lithium-ion concentration and oxygen defects affect the ionic conductivity for amorphous LLTO thin films,which provides insight into the optimization of LLTO thin-film solid electrolytes,and generates new opportunities for their application in thinfilm lithium batteries.
基金financially supported by the National 863 Program(No.2007AA03Z226)the National Key Program for Basic Research of China(No.2002CB211800 and 2009CB220100).
文摘Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane （WPU） and 1-butyl-3-methylimidazolium bis[（trifluoromethyl）sulfonyl]imide （BMImTFSI） have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration （BMImTFSI/WPU = 3 in weight ratio）, the ionic conductivity reaches 4.27 × 10^-3 S/cm at 30 ℃. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.
