Revealing the specific role of sulfide and nano-alumina in composite solid-state electrolytes for performance-reinforced ether-nitrile copolymers

Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design.

Data-Driven Viewpoint for Developing Next-Generation Mg-Ion Solid-State Electrolytes

Magnesium(Mg)is a promising alternative to lithium(Li)as an anode material in solid-state batteries due to its abundance and high theoretical volumetric capacity.However,the sluggish Mg-ion conduction in the lattice of solidstate electrolytes(SSEs)is one of the key challenges that hamper the development of Mg-ion solid-state batteries.Though various Mg-ion SSEs have been reported in recent years,key insights are hard to be derived from a single literature report.Besides,the structure-performance relationships of Mg-ion SSEs need to be further unraveled to provide a more precise design guideline for SSEs.In this viewpoint article,we analyze the structural characteristics of the Mg-based SSEs with high ionic conductivity reported in the last four decades based upon data mining-we provide big-data-derived insights into the challenges and opportunities in developing next-generation Mg-ion SSEs.

Comparative study of nudged elastic band and molecular dynamics methods for diffusion kinetics in solid-state electrolytes

Considerable efforts are being made to transition current lithium-ion and sodium-ion batteries towards the use of solid-state electrolytes.Computational methods,specifically nudged elastic band(NEB)and molecular dynamics(MD)methods,provide powerful tools for the design of solid-state electrolytes.The MD method is usually the choice for studying the materials involving complex multiple diffusion paths or having disordered structures.However,it relies on simulations at temperatures much higher than working temperature.This paper studies the reliability of the MD method using the system of Na diffusion in MgO as a benchmark.We carefully study the convergence behavior of the MD method and demonstrate that total effective simulation time of 12 ns can converge the calculated diffusion barrier to about 0.01 eV.The calculated diffusion barrier is 0.31 eV from both methods.The diffusion coefficients at room temperature are 4.3×10^(-9) cm^(2)⋅s^(−1) and 2.2×10^(-9) cm^(2)⋅s^(−1),respectively,from the NEB and MD methods.Our results justify the reliability of the MD method,even though high temperature simulations have to be employed to overcome the limitation on simulation time.

A leap by the rise of solid-state electrolytes for Li-air batteries

Li-air batteries have attracted extensive attention because of their ultrahigh theoretical energy density. However, the potential safety hazard of flammable organic liquid electrolytes hinders their practical applications. Replacing liquid electrolytes with solidstate electrolytes(SSEs) is expected to fundamentally overcome the safety issues. In this work, we focus on the development and challenge of solid-state Li-air batteries(SSLABs). The rise of different types of SSEs, interfacial compatibility and verifiability in SSLABs are presented. The corresponding strategies and prospects of SSLABs are also proposed. In particular, combining machine learning method with experiment and in situ(or operando)techniques is imperative to accelerate the development of SSLABs.

Deep dive into anionic metal-organic frameworks based quasi-solid-state electrolytes

The development and application of high-capacity energy storage has been crucial to the global transition from fossil fuels to green energy.In this context,metal-organic frameworks(MOFs),with their unique 3D porous structure and tunable chemical functionality,have shown enormous potential as energy storage materials for accommodating or transporting electrochemically active ions.In this perspective,we specifically focus on the current status and prospects of anionic MOF-based quasi-solid-state-electrolytes(anionic MOF-QSSEs)for lithium metal batteries(LMBs).An overview of the definition,design,and properties of anionic MOF-QSSEs is provided,including recent advances in the understanding of their ion transport mechanism.To illustrate the advantages of using anionic MOF-QSSEs as electrolytes for LMBs,a thorough comparison between anionic MOF-QSSEs and other well-studied electrolyte systems is made.With these in-depth understandings,viable techniques for tuning the chemical and topological properties of anionic MOF-QSSEs to increase Li+conductivity are discussed.Beyond modulation of the MOFs matrix,we envisage that solvent and solid-electrolyte interphase design as well as emerging fabrication techniques will aid in the design and practical application of anionic MOF-QSSEs.

Research progress in electrospinning engineering for all-solid-state electrolytes of lithium metal batteries

Owing to safety issue and low energy density of liquid lithium-ion batteries(LIBs),all-solid-state lithium metal batteries(ASLMBs)with unique all-solid-state electrolytes(SEs)have attracted wide attentions.This arises mainly from the advantages of the SEs in the suppression of lithium dendrite growth,long cycle life,and broad working temperature range,showing huge potential applications in electronic devices,electric vehicles,smart grids,and biomedical devices.However,SEs suffer from low lithiumion conductivity and low mechanical integrity,slowing down the development of practical ASLMBs.Nanostructure engineering is of great efficiency in tuning the structure and composition of the SEs with improved lithium-ion conductivity and mechanical integrity.Among various available technologies for nanostructure engineering,electrospinning is a promising technique because of its simple operation,cost-effectiveness,and efficient integration with different components.In this review,we will first give a simple description of the electrospinning process.Then,the use of electrospinning technique in the synthesis of various SEs is summarized,for example,organic nanofibrous matrix,organic/inorganic nanofibrous matrix,and inorganic nanofibrous matrix combined with other components.The current development of the advanced architectures of SEs through electrospinning technology is also presented to provide references and ideas for designing high-performance ASLMBs.Finally,an outlook and further challenges in the preparation of advanced SEs for ASLMBs through electrospinning engineering are given.

Solid-state electrolytes for solid-state lithium-sulfur batteries:Comparisons,advances and prospects

Compared with other secondary batteries,lithium-sulfur batteries(LSBs)have unparalleled advantages such as high energy density,low cost,etc.In liquid LSB systems,it is extremely easy to cause severe‘‘shuttle effecto and safety issues.Hence,the development of solid-state LSBs(SSLSBs)has been attracting much more attention.As the most essential part of the SSLSBs,the solid-state electrolyte(SSE)has received significant attention from researchers.In this review,we concentrate on discussing the core of SSLSBs,which is the SSE.Moreover,we also highlight the differences in the properties of the different SSEs,which are polymer-based electrolytes and ceramic-based electrolytes.In addition,the challenges and advances in different types of SSEs are also compared and described systematically.Furthermore,the prospects for new SSE systems and the design of effective SSE structures to achieve highperformance SSLSBs are also discussed.Thus,this review is expected to give readers a comprehensive and systematic understanding of SSEs for SSLSBs.

Empirical decay relationship between ionic conductivity and porosity of garnet type inorganic solid-state electrolytes

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.

Development of solid-state electrolytes for sodium-ion battery–A short review

All-solid-state sodium-ion battery is regarded as the next generation battery to replace the current commercial lithium-ion battery, with the advantages of abundant sodium resources, low price and high-level safety. As one critical component in sodium-ion battery, solid-state electrolyte should possess superior operational safety and design simplicity, yet reasonable high room-temperature ionic conductivity. This paper gives a comprehensive review on the recent progress in solid-state electrolyte materials for sodium-ion battery, including inorganic ceramic/glass-ceramic, organic polymer and ceramic-polymer composite electrolytes, and also provides a comparison of the ionic conductivity in various solid-state electrolyte materials. The development of solid-state electrolytes suggests a bright future direction: all solid-state sodium-ion battery could be fully used to power all electric road vehicles, portable electronic devices and large-scale grid support.

Solid-State Electrolytes for Lithium-Sulfur Batteries

Secondary lithium-sulfur batteries have attracted extensive attention due to their high energy density,low cost and environment friendly.However,the"shuttle effect"of polysulfides dissolved in liquid electrolytes leads to a decrease of the cell Coulomb efficiency(CE).Therefore,researchers have used solid electrolytes instead of traditional liquid electrolytes and separators to suppress the"shuttle effect"of polysulfides and the growth of lithium dendrites.The progress in electrolytes for solid-state lithium-sulfur batteries including solid-state polymer,inorganic,and composite electrolytes to solve the issues is summarized.

Recent advances on quasi-solid-state electrolytes for supercapacitors

Solid-state and quasi-solid-state electrolytes have been attracting the scientific community’s attention in the last decade. These electrolytes provide significant advantages, such as the absence of leakage and separators for devices and safety for users. They also allow the assembly of stretchable and bendable supercapacitors. Comparing solid-state to quasi-solid-states, the last provides the most significant energy and power densities due to the better ionic conductivity. Our goal here is to present recent advances on quasisolid-state electrolytes, including gel-polymer electrolytes. We reviewed the most recent literature on quasi-solid-state electrolytes with different solvents for supercapacitors. Organic quasi-solid-state electrolytes need greater attention once they reach an excellent working voltage window greater than 2.5 V.Meanwhile, aqueous-based solid-state electrolytes have a restricted voltage window to less than 2 V. On the other hand, they are easier to handle, provide greater ionic conductivity and capacitance. Recent water-in-salt polymer-electrolytes have shown stability as great as 2 V encouraging further development in aqueous-based quasi-solid-state electrolytes. Moreover, hydrophilic conductive polymers have great commercial appeal for bendable devices. Thus, these electrolytes can be employed in flexible and bendable devices, favoring the improvement of portable electronics and wearable devices(376 references were evaluated and summarized here).

Recent research progress on quasi-solid-state electrolytes for dye-sensitized solar cells

Dye-sensitized solar cells （DSSCs） are the most promising, low cost and most extensively investigated solar cells. They are famous for their clean and efficient solar energy conversion. Nevertheless this, long-time sta- bility is still to be acquired. In recent years research on solid and quasi-solid state electrolytes is extensively in- creased. Various quasi-solid electrolytes, including composites polymer electrolytes, ionic liquid electrolytes, thermoplastic polymer electrolytes and thermosetting polymer electrolytes have been used. Performance and stability of a quasi-solid state electrolyte are between liquid and solid electrolytes. High photovoltaic performances of QS-DSSCs along better long-term stability can be obtained by designing and optimizing quasi-solid electrolytes. It is a prospective candidate for highly efficient and stable DSSCs.

Pancake-Like MOF Solid-State Electrolytes with Fast Ion Migration for High-Performance Sodium Battery

Solid-state electrolyte(SSE)of the sodium-ion battery have attracted tremendous attention in the next generation energy storage materials on account of their wide electrochemical window and thermal stability.However,the high interfacial impedance,low ion transference number and complex preparation process restrict the application of SSE.Herein,inspired by the excellent sieving function and high specific surface area of red blood cells,we obtained a solid-like electrolyte(SLE)based on the combination of the pancake-like metal-organic framework(MOF)with liquid electrolyte,possessing a high ionic conductivity of 6.60×10^(-4) S cm^(−1),and excellent sodium metal compatibility.In addition,we investigated the ion restriction effect of MOF’s apertures size and special functional groups,and the ion transference number increased from 0.16 to 0.33.Finally,the assembled Na_(0.44)MnO_(2)//SLE//Na full batteries showed no obvious capacity decrease after 160 cycles.This material design of SLE in our work is an important key to obtain fast ion migration SLE for high-performance sodium-ion batteries.

Self-Assembled in-Plane-Gate Thin-Film Transistors Gated by WOx Solid-State Electrolytes

Low-voltage WOx gated indium-zinc-oxide thin-film transistors(TFTs)with in-plane-gate structures are fabricated by using an extremely simplified one-shadow mask method at room temperature.The proton conductive WOx solid-state electrolyte is demonstrated to form an electric-double-layer(EDL)effect associated with a huge capacitance of 0.51μF/cm^(2).The special EDL capacitance of the WOx electrolyte is also extended to novel in-plane-gate structure TFTs as the gate dielectric,reducing the operating voltage to 1.8 V.Such TFTs operate at n-type depletion mode with a threshold voltage of -0.5 V,saturation electron mobility of 13.2 cm^(2)/V·s,ON/OFF ratio of 1.7×10^(6),subthreshold swing of 110 mV/dec,and low leakage current less than 7 nA.The hysteresis window of the transfer curves is also explained by an unique reaction within the WOx electrolyte.

Extremely stable Li-metal battery enabled by piezoelectric polyacrylonitrile quasi-solid-state electrolytes

Polymer solid-state electrolytes(PSSEs)are promising for solving the safety problem of Lithium(Li)metal batteries(LMBs).However,PSSEs with low modulus in nature are prone to be penetrated by lithium dendrites,resulting in short circuit of LMBs.Here,we design and prepare piezoelectric BaTiO_(3)doped polyacrylonitrile(PAN@BTO)quasi-solid-state electrolytes(PQSSEs)by electrostatic spinning method to suppress dendritic growth.The piezoelectric polymer electrolytes are squeezed by nucleation and growth processes of Li dendrites,which can generate a piezoelectric electric field to regulate the deposition of Li^(+)ions and eliminate lithium bud.Consequently,piezoelectric PAN@BTO PQSSEs enables highly stable Li plating/stripping cycling for over 2000 h at 0.15 mA/cm^(2)at room temperature(RT,25℃).Also,LiFePO_(4)|PAN@BTO|Li full cells demonstrate excellent cycle performance(136.9 mA·h/g and 78%retention after 600 cycles at 0.5 C)at RT.Moreover,LiFePO_(4)|PAN@BTO|Li battery show extremely high safety and can still work normally under high-speed impact(2 Hz,∼30 kPa).We construct an in-situ cell monitoring system and disclose that the mechanism of suppressed lithium dendrite is originated from the generation of opposite piezoelectric potential and the feedback speed of intermittent piezoelectric potential signals is extremely fast.

Ferroelectric Ceramic Materials Enable High-Performance Organic-Inorganic Composite Electrolytes in Solid-State Lithium Metal Batteries

Compared to commercial lithium-ion batteries, all-solid-state batteries can greatly increase the energy density, safety, and cycle life of batteries. The development of solid-state electrolyte with high lithium-ion conductivity and wide electrochemical window is the key for all-solid-state batteries. In this work, we report on the achievement of high ionic conductivity in the PAN/LiClO_(4)/BaTiO_(3) composite solid electrolyte (CSE) prepared by solution casting method. Our experimental results show that the PAN-based composite polymer electrolyte with 5 wt% BaTiO_(3) possesses a high room-temperature lithium-ion conductivity (9.85 × 10^(−4) S⋅cm^(−1)), high lithium-ion transfer number (0.63), wide electrochemical window (4.9 V vs Li+/Li). The Li|Li symmetric battery assembled with 5 wt% BaTiO_(3) can be stably circulated for 800 h at 0.1 mA⋅cm^(−2), and the LiFePO_(4)|CSE|Li battery maintains a capacity retention of 86.2% after 50 cycles at a rate of 0.3 C. The influence of BaTiO_(3) ceramic powder on the properties of PAN-based polymer electrolytes is analyzed. Our results provide a new avenue for future research in the all-solid-state lithium battery technology.

Sandwich-type composited solid polymer electrolytes to strengthen the interfacial ionic transportation and bulk conductivity for all-solid-state lithium batteries from room temperature to 120℃

The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point,dominantly limits their applications in solid-state batteries(SSBs).Although the inorganic filler such as CeO_(2)nanoparticle content of composite solid polymer electrolytes(CSPEs)can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface,we found that the required content of CeO_(2)nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs.In this regard,a sandwich-type composited solid polymer electrolyte with a 10%CeO_(2)CSPEs interlayer sandwiched between two 50%CeO_(2)CSPEs thin layers(sandwiched CSPEs)is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30℃.The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm^(-2)and 30℃.In addition,the LiFePO_(4)/Sandwiched CSPEs/Li cell also exhibits exceptional cycle performance at 30℃and even elevated120℃without short circuits.Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.

A gel polymer electrolyte based on IL@NH_(2)-MIL-53(Al)for high-performance all-solid-state lithium metal batteries

Solid polymer composite electrolytes possess the benefits of superior compatibility with electrodes and good thermal characteristics for more secure energy storage equipment.Herein,a new gel polymer electrolyte(GPE)containing NH_(2)-MIL-53(Al),[PP_(13)][TFSI],LiTFSI,and PVDF-HFP was prepared using a simple method of solution casting.The effects of encapsulating different ratios of ionic liquid([PP_(13)][TFSI])into the micropores of functionalized metal-organic frameworks(NH_(2)-MIL-53(Al))on the electrochemical properties were compared.XRD,SEM,nitrogen adsorption-desorption isotherms,and electrochemical measurements were conducted.This GPE demonstrates a superior ionic conductivity of 8.08×10^(-4)S·cm^(-1)at 60℃and can sustain a discharge specific capacity of 156.6 mA·h·g^(-1)at 0.2 C for over 100 cycles.This work might offer a potential approach to alleviate the solid-solid contact with the solid-state electrolyte and electrodes and broaden a new window for the creation of all-solid-state batteries.

Elucidating Ion Transport Phenomena in Sulfide/Polymer Composite Electrolytes for Practical Solid-State Batteries

Despite the enormous interest in inorganic/polymer composite solid-state electrolytes(CSEs)for solid-state batteries(SSBs),the underlying ion transport phenomena in CSEs have not yet been elucidated.Here,we address this issue by formulating a mechanistic understanding of bi-percolating ion channels formation and ion conduction across inorganic-polymer electrolyte interfaces in CSEs.A model CSE is composed of argyrodite-type Li_6PS_5Cl(LPSCl)and gel polymer electrolyte(GPE,including Li~+-glyme complex as an ion-conducting medium).The percolation threshold of the LPSCl phase in the CSE strongly depends on the elasticity of the GPE phase.Additionally,manipulating the solvation/desolvation behavior of the Li~+-glyme complex in the GPE facilitates ion conduction across the LPSCl-GPE interface.The resulting scalable CSE(area=8×6(cm×cm),thickness~40μm)can be assembled with a high-mass-loading LiNi_(0.7)Co_(0.15)Mn_(0.15)O_(2)cathode(areal-mass-loading=39 mg cm~(-2))and a graphite anode(negative(N)/positive(P)capacity ratio=1.1)in order to fabricate an SSB full cell with bi-cell configuration.Under this constrained cell condition,the SSB full cell exhibits high volumetric energy density(480 Wh L_(cell)~(-1))and stable cyclability at 25℃,far exceeding the values reported by previous CSE-based SSBs.

Garnet-type solid-state electrolytes:crystal structure,interfacial challenges and controlling strategies

All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,the use of solid-state electrolytes(SSEs) instead of liquid ones meanwhile brings serious concerns related to the point-to-point contact between SSEs and electrodes,which is known to result in high interface resistance and inhomogeneous distribution of charges during the Li^(+)plating/stripping process,eventually leading to a premature failure of ASSBs.This review focuses on the garnet-type SSEs in the formula of Li_(7)La_(3)Zr_(2)O_(12)(LLZO),and discusses the structure-performance relationship of this ceramic electrolyte in detail to achieve a clear understanding of its Li^(+)transmission mechanism.Meanwhile,the challenges of cubic phase LLZO(c-LLZO) for their application in solidstate batteries(SSBs) are demonstrated by the Li/LLZO interface,which features the importance of Li metal wettability and dendrite suppression for sustainable performance.Furthermore,this review summarizes the recent research strategies to combat these contact issues at the Li/LLZO interface,highlighting the essential role played by surface modification of LLZO electrolytes.Following the obtained insights,perspectives for future research on LLZO to accelerate its potential development of SSBs in commercialized applications are also provided.