Construction of a High‑Performance Composite Solid Electrolyte Through In‑Situ Polymerization within a Self‑Supported Porous Garnet Framework

Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for SSLMBs.To overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the CSE.The synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room temperature.Furthermore,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode interface.The synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V vs.Li/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.

Composite solid electrolyte of Na3PS4-PEO for all-solid-state SnS2/Na batteries with excellent interfacial compatibility between electrolyte and Na metal

High ionic conductivity and superior interfacial stability of solid electrolytes at the electrodes are crucial factors for high-performance all-solid-state sodium batteries. Herein, a composite solid electrolyte Na3PS4-polyethylene oxide is synthesized by the solution-phase reaction method with an improved ionic conductivity up to 9.4 × 10-5 S/cm at room temperature. Moreover, polyethylene oxide polymer layer is wrapped homogeneously on the surface of Na3PS4 particles, which could effectively avoid the direct contact between Na3PS4 electrolyte and sodium metal, thus alleviate their side reactions. We demonstrate that all-solid-state battery SnS2/Na with the composite solid electrolyte Na3PS4-polyethylene oxide delivers an enhanced electrochemical performance with 230 m Ah/g after 40 cycles.

Li4-xSbxSn1-xS4 solid solutions for air-stable solid electrolytes

The sulfide solid electrolytes have the characteristics of high ionic conductivity and low grain boundary resistance, which make them suitable for bulk-type all-solid-state batteries. However, most of them suffer from poor stability in air. Here, we explore the air stable sulfide solid electrolytes in Li4-xSbxSn1-xS4 system. The solid solutions of Li4-xSbxSn1-xS4(0 ≤ x ≤ 0.5) can be formed in Li4-xSbxSn1-xS4 system. Li3.8 Sb0.2 Sn0.8 S4 achieves the highest ionic conductivity of 3.5 × 10-4 S cm-1 in this system,which is 5 times as that of Li4 Sn S4 and 3 orders of magnitude higher than that of Li3 Sb S4, respectively. Li3.8 Sb0.2 Sn0.8 S4 crystallizes into the same structure with high ionic conductivity phase of β-Li3 PS4. Moreover, Li3.8 Sb0.2 Sn0.8 S4 owns good stability in humid air. Matching with LiCoO2 and Li4 Ti5 O12,Li3.8 Sb0.2 Sn0.8 S4 exhibits the potential to be applied in all-solid-state batteries.

Engineering a flexible and mechanically strong composite electrolyte for solid-state lithium batteries

Lithium-ion batteries(LIBs)have greatly facilitated our daily lives since 1990s[1,2].To meet the ever-increasing demand on energy density,Li metal is seen as the ultimate anode because of its ultra-high specific capacity(3860 m Ah/g)and the lowest electrochemical potential(-3.04 V vs.the standard hydrogen electrode)[3–6].However,issues of Li metal anode,such as Li dendrite formation and large volume change during plating/stripping。

Preparation and characterization of poly(lithium acrylate-arcylonitrile)/LiClO_4-LiNO_3-LiBr solid polymer electrolytes

Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n（LiClO4）∶n（LiNO3）∶n（LiBr）=1.6∶3.8∶1.0 was prepared. The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes were prepared with poly（lithium acrylate-acrylonitrile） and （LiClO4-LiNO3-LiBr） eutectic salts. The effect of LiClO4-LiNO3-LiBr eutectic salts content on the conductivity of solid polymer electrolytes was studied by alternating current impedance method, and the structures of eutectic salts and solid polymer electrolytes were characterized by differential thermal analysis, infrared spectroscopy and X-ray diffractometry. The results show that the room temperature conductivity of LiClO4-LiNO3-LiBr eutectic salts reaches (3.11×10-4 S·cm-1.) The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes possess the highest room temperature conductivity at 70% LiClO4-LiNO3-LiBr eutectic salts content, and exhibit lower glass transition temperature of 75 ℃ compared with that of poly（lithium acrylate-acrylonitrile） of 105 ℃. A complex may be formed in the solid polymer electrolytes from the differential thermal analysis and infrared spectroscopy analysis. X-ray diffraction results show that the poly（lithium acrylate-acrylonitrile） can suppress the crystallization of eutectic salts in this system.

3D flame-retardant skeleton reinforced polymer electrolyte for solid-state dendrite-free lithium metal batteries

For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton(3DPA)and adding nano-multifunctional fillers(Li-ILs@ZIF-8).In addition to providing mechanical support for the polyethylene oxide(PEO)matrix,3DPA also has further contributed to the system’s flame retardancy and further improved the safety.Simultaneously,the electrochemical performance is fully guaranteed by rigid Li-ILs@ZIF-8,which provides fast migration channels forLi^(+),reduces the crystallinity of PEO and effectively inhibits lithium dendrites.The limiting oxygen index of the optimal sample(PL3Z/PA)is as high as 20.5%,and the ionic conductivity reaches 2.89×10^(-4) and 0.91×10^(-3) S cm^(-1) at 25 and 55°C,respectively.The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 m A cm^(-2) without short circuit being pierced by lithium dendrites.The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 m Ah g^(-1) under a current density of 0.5 C,and the capacity retention rate was 90.0%after 300 cycles.

Al-incorporation into Li7La3Zr2O12 solid electrolyte keeping stabilized cubic phase for all-solid-state Li batteries

We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 （LLZO）. A direct incorporation of AI is first promoted in a Li-insufficient garnet solid electrolyte during the calcination process of 850 ℃ and then the cubic phase of LLZO is obtained after successive annealing step of 1000 ℃. Comparing to pristine LLZO, AI incorporated LLZO shows less formation of Li_2CO_3, keeping crystallographic and physicochemical properties. This AI incorporation im- proves both the ionic conductivity and interfacial resistance to poisoning procedure.

Enhancing interfacial stability in solid-state lithium batteries with polymer/garnet solid electrolyte and composite cathode framework

The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium battery.Here,a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide),poly(vinylidene fluoride),Li6.75La3 Zr1.75Ta0.25O12,lithium bis(trifluoromethanesulfonyl)imide and oxalate,which exhibits an ionic conductivity of 2.0 ×10^(-4) S cm^(-1) at 55℃,improved mechanical property,wide electrochemical window(4.8 V vs.Li/Li+),enhanced thermal stabilities.Tiny acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3 Zr1.75Ta0.25O12 and poly(vinylidene fluoride).In order to improve the interfacial stability between cathode and electrolyte,an Al2 O3@LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as additives.The solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g^(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55℃,which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries.

Investigation on pumping oxygen characteristics of (Bi_2O_3)_(0.73)(Y_2O_3)_(0.27) solid electrolyte

（Bi2O3）0.73（Y2O3）0.27 fine powders prepared by wet chemical precipitation method were cold isostatically pressed to form solid electrolyte tubes, and sintered at 900 ℃ for 10 h in the air. Their pumping oxygen characteristics in non-dehydrated Ar gas were investigated, where a ZrO2 （Y2O3 stabilized） oxygen sensor was used to measure the oxygen partial pressure Po2. The results showed that the Po2 value reached magnitudes of 1×10^-2-1×10^-10 Pa at the applied pumping oxygen voltage of 0.5 V, 1×10^-37-1×10^-27 Pa at 1.0 V and 1×10^-53-1×10^47 Pa at 2.0 V within the temperature range from 550 to 650 ℃. Moreover, no cracks were found in the tested solid electrolyte tubes. Thus, the Bi2O3-Y2O3 system might be used in solid electrolyte oxygen pump for purifying gases.

In situ formed LiF-Li_(3)N interface layer enables ultra-stable sulfide electrolyte-based all-solid-state lithium batteries

Sulfide solid electrolytes are promising for high energy density and safety in all-solid-state batteries due to their high ionic conductivity and good mechanical properties.However,the application of sulfide solid electrolytes in all-solid-state batteries with lithium anode is restricted by the side reactions at lithium/electrolytes interfaces and the growth of lithium dendrite caused by nonuniform lithium deposition.Herein,a homogeneous LiF-Li_(3)N composite protective layer is in situ formed via a manipulated reaction of pentafluorobenzamide with Li metal.The LiF-Li_(3)N layer with both high interfacial energy and interfacial adhesion energy can synergistically suppress side reactions and inhibit the growth of lithium dendrite,achieving uniform deposition of lithium.The critical current densities of Li_(10)GeP_(2)S_(12)and Li_(6)PS_(5)Cl are increased to 3.25 and 1.25 mA cm^(-2)with Li@LiF-Li_(3)N layer,which are almost triple and twice as those of Li-symmetric cells in the absence of protection layer,respectively.Moreover,the Li@LiF-Li_(3)N/Li10GeP2S12/Li@LiF-Li_(3)N cell can stably cycle for 9000 h at 0.1 mA cm^(-2)under 0.1 mA h cm^(-2),and Li@LiF-Li_(3)N/Li_(6)PS_(5)Cl/Li@LiF-Li_(3)N cell achieves stable Li plating/stripping for 8000 h at 0.1 mA cm^(-2)under10 m A h cm^(-2).The improved dynamic stability of lithium plating/stripping in Li@LiF-Li_(3)N/Li_(10)GeP_(2)S_(12)or Li_(6)PS_(5)Cl interfaces is proved by three-electrode cells.As a result,LiCoO_(2)/electrolytes/Li@LiF-Li_(3)N batteries with Li_(10)GeP_(2)S_(12)and Li_(6)PS_(5)Cl exhibit remarkable cycling stability of 500 cycles with capacity retentions of 93.5%and 89.2%at 1 C,respectively.

A low cost composite quasi-solid electrolyte of LATP, TEGDME,and LiTFSI for rechargeable lithium batteries

The composite quasi solid state electrolytes（CQSE） is firstly synthesized with quasi solid state electrolytes（QSE） and lithium-ion-conducting material Li1.4Al0.4Ti1.6（PO4）3（LATP）, and the QSE consists of [LiG4][TFSI] with fumed silica nanoparticles. Compared with LATP, CQSE greatly improves the interface conductance of solid electrolytes. In addition,it has lower liquid volume relative to QSE. Although the liquid volume fraction of CQSE is droped to 60%, its conductivity can also reach 1.39 × 10^-4S/cm at 20℃. Linear sweep voltammetry（LSV） is conducted on each composite electrolyte.The results show the possibility that CQSE has superior electrochemical stability up to 5.0 V versus Li/Li^＋1. TG curves also show that composite electrolytes have higher thermal stability. In addition, the performance of Li/QSE/Li Mn2O4 and Li/CQSE/Li Mn2O4 batteries is evaluated and shows good electrochemical characteristics at 60℃.

Insights on“nitrate salt”in lithium anode for stabilized solid electrolyte interphase

A Li/KNO_(3) composite(LKNO),with KNO_(3) uniformly implanted in bulk metallic Li,is fabricated for battery anode via a facile mechanical kneading approach,which exhibits high Coulombic efficiency and prolonged cycle life.The mechanism behind the enhanced electrochemical performance of the“salt-in-metal”composite is investigated,where KNO_(3) in metallic Li composite electrode would be sustainably released into the electrolyte.The presence of NO_(3)-stabilizes the solid electrolyte interphase by producing functional Li_(3)N,LiNxOy,and Li_(2)O species.K^(+)from KNO_(3) also helps to form an electrostatic shield after its adsorption on the electrode protrusions,which suppresses the dendritic growth of metallic Li.With the above advantages,uniform Li plating with dense and planar structure is realized for the LKNO electrode.These findings reveal a deep understanding of the effect of the“saltin-metal”anode and provide new insights into the use of nitrate additives for high-energy-density Li metal batteries.

From protonation & Li-rich contamination to grain-boundary segregation: Evaluations of solvent-free vs. wet routes on preparing Li_(7)La_(3)Zr_(2)O_(12) solid electrolyte

Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO) has been recognized as a candidate solid electrolyte for high-safety Lianode based solid-state batteries because of its electro-chemical stability against Li-metal and high ionic conductivity. Solvent(e.g., isopropanol(IPA)) has been commonly applied for preparing LLZO powders and ceramics. However, the deterioration of the proton-exchange between LLZO and IPA/absorbed moisture during the mixing and tailoring route has aroused less attention. In this study, a solvent-free dry milling route was developed for preparing the LLZO powders and ceramics. For orthogonal four categories of samples prepared using solvent-free and IPA-assisted routes in the mixing and tailoring processes, the critical evaluation was conducted on the crystallinity, surficial morphology, and contamination of ascalcinated and as-tailored particles, the cross-sectional microstructure of green and sintered pellets,the morphology and electro-chemical properties of grain boundaries in ceramics, as well as the interfacial resistance and performance of Li anode based symmetric batteries. The wet route introduced Li-rich contaminations(e.g., Li OH·H)_(2)O and Li)_(2)CO)_(3)) onto the surfaces of LLZO particles and Li-Ta-O segregations at the adjacent and triangular grain boundaries. The LLZO solid electrolytes prepared through dry mixing in combination with the dry tailoring route without the use of any solvent were found to the optimal performance. The fundamental material properties in the whole LLZO preparation process were found, which are of guiding significance to the development of LLZO powder and ceramic production craft.

FREE ENERGY OF FORMATION OF Na_2SnO_3 BY EMF MEASUREMENT USING β-ALUMINA SOLID ELECTROLYTE CELL

A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in temperature range of 912—1223 K:E=652.1— 0.2092 T+2.3(mV).Using this equation and cited free energies of formation of NaCrO_2, Cr_2O_3 and SnO_2,the molar free energy of formation of Na_2 SnO_3 may be calculated by ΔG°=-1050+0.2544 T±5.4(kJ mol^(-1)).

A panoramic view of Li_(7)P_(3)S_(11) solid electrolytes synthesis, structural aspects and practical challenges for all-solid-state lithium batteries

The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries(ASSLBs).Because of their advantages in safety,working temperature,high energy density,and packaging,ASSLBs can develop an ideal energy storage system for modern electric vehicles(EVs).A solid electrolyte(SE)model must have an economical synthesis approach,exhibit electrochemical and chemical stability,high ionic conductivity,and low interfacial resistance.Owing to its highest conductivity of 17 mS·cm^(-1),and deformability,the sulfide-based Li_(7)P_(3)S_(11) solid electrolyte is a promising contender for the high-performance bulk type of ASSLBs.Herein,we present a current glimpse of the progress of synthetic procedures,structural aspects,and ionic conductivity improvement strategies.Structural elucidation and mechanistic approaches have been extensively discussed by using various characterization techniques.The chemical stability of Li_(7)P_(3)S_(11) could be enhanced via oxide doping,and hard and soft acid/base(HSAB)concepts are also discussed.The issues to be undertaken for designing the ideal solid electrolytes,interfacial challenges,and high energy density have been discoursed.This review aims to provide a bird’s eye view of the recent development of Li_(7)P_(3)S_(11)-based solid-state electrolyte applications and explore the strategies for designing new solid electrolytes with a target-oriented approach to enhance the efficiency of high energy density allsolid-state lithium batteries.

Highly Efficient Aligned Ion‑Conducting Network and Interface Chemistries for Depolarized All‑Solid‑State Lithium Metal Batteries

Improving the long-term cycling stability and energy density of all-solid-state lithium(Li)-metal batteries(ASSLMBs)at room temperature is a severe challenge because of the notorious solid–solid interfacial contact loss and sluggish ion transport.Solid electrolytes are generally studied as two-dimensional(2D)structures with planar interfaces,showing limited interfacial contact and further resulting in unstable Li/electrolyte and cathode/electrolyte interfaces.Herein,three-dimensional(3D)architecturally designed composite solid electrolytes are developed with independently controlled structural factors using 3D printing processing and post-curing treatment.Multiple-type electrolyte films with vertical-aligned micro-pillar(p-3DSE)and spiral(s-3DSE)structures are rationally designed and developed,which can be employed for both Li metal anode and cathode in terms of accelerating the Li+transport within electrodes and reinforcing the interfacial adhesion.The printed p-3DSE delivers robust long-term cycle life of up to 2600 cycles and a high critical current density of 1.92 mA cm^(−2).The optimized electrolyte structure could lead to ASSLMBs with a superior full-cell areal capacity of 2.75 mAh cm^(−2)(LFP)and 3.92 mAh cm^(−2)(NCM811).This unique design provides enhancements for both anode and cathode electrodes,thereby alleviating interfacial degradation induced by dendrite growth and contact loss.The approach in this study opens a new design strategy for advanced composite solid polymer electrolytes in ASSLMBs operating under high rates/capacities and room temperature.

Study of Bi_2O_3-based Rare Earth Solid Electrolyte Used in Fuel Cell

Solid ceramic electrolyte materials (Bi_2O_3)_(0.75)(Y_2O_3)_(0.25) and(Bi_2O_3)_(0.65)(Gd_2O_3 )_(0.35)were synthesized.Their crystal structure, XPS spectra and the change of ionic conductivity versus temperature were measured.A Bi_2O_3-based rare earth solid electrolyte fuel cell with ZrO_2-Y_2O_3 protection film was made.

Relationship between CO_2 Sensor Voltage Response and Phase Equilibrium of Solid Electrolyte Na,K-β/β″-Al_2O_3

A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2, CO2| Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell lI: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt. (Na,K-β/β'-AI2O3 is named by NKBA). The sensor signal is consistent with the Nernstian slope within the region of phase equilibrium for Na, K-β/β'-AI2O3 material. The relationship between CO2 sensor voltage response and phase equilibrium of solid electrolyte Na, K-β/β-AI2O3 is discussed in this paper.

Preparing 3D Perovskite Li_(0.33)La_(0.557)TiO_(3)Nanotubes Framework Via Facile Coaxial Electro-Spinning Towards Reinforced Solid Polymer Electrolyte

It is of significance to construct continuous multiphase percolation channels with fast lithium-ion pathway in hybrid solid electrolytes.3D ceramic nanostructure frameworks have attracted great attention in this field.Herein,the three-dimensional perovskite Li_(0.33)La_(0.557)TiO_(3)nanotubes framework(3D-LLTO-NT)is fabricated via a facile coaxial electro-spinning process followed by a calcination process at 800°C.The hybrid polymer electrolyte of 3DLLTO-NT framework and poly(ethylene carbonate)(3D-LLTO-NT@PEC)shows improved ionic conductivity of 1.73×10^(-4)S cm^(-1)at ambient temperature,higher lithium-ion transference number(t_(Li)^(+))of 0.78 and electrochemical stability window up to 5.0 V vs Li/Li^(+).The all-solid-state cell of LiFePO_(4)/3D-LLTO-NT@PEC/Li delivers a high specific capacity of 140.2 mAh g^(-1)at 0.1 C at ambient temperature.This outstanding performance is attributed to the 3D ceramic nanotubes frameworks which provide fast lithium ion transfer pathway and stable interfaces.

Novel sandwich structured glass fiber Cloth/Poly(ethylene oxide)-MXene composite electrolyte

Recently,poly(ethylene oxide)(PEO)-based solid polymer electrolytes have been attracting great attention,and efforts are currently underway to develop PEO-based composite electrolytes for next generation high performance all-solid-state lithium metal batteries.In this article,a novel sandwich structured solid-state PEO composite electrolyte is developed for high performance all-solid-state lithium metal batteries.The PEO-based composite electrolyte is fabricated by hot-pressing PEO,LiTFSI and Ti_(3)C_(2)T_(x) MXene nanosheets into glass fiber cloth(GFC).The as-prepared GFC@PEO-MXene electrolyte shows high mechanical properties,good electrochemical stability,and high lithium-ion migration number,which indicates an obvious synergistic effect from the microscale GFC and the nanoscale MXene.Such as,the GFC@PEO-1 wt%MXene electrolyte shows a high tensile strength of 43.43 MPa and an impressive Young's modulus of 496 MPa,which are increased by 1205%and 6048%over those of PEO.Meanwhile,the ionic conductivity of GFC@PEO-1 wt%MXene at 60℃ reaches 5.01×10^(-2) S m^(-1),which is increased by around 200%compared with that of GFC@PEO electrolyte.In addition,the Li/Li symmetric battery based on GFC@PEO-1 wt%MXene electrolyte shows an excellent cycling stability over 800 h(0.3 mA cm^(-2),0.3 mAh cm^(-2)),which is obviously longer than that based on PEO and GFC@PEO electrolytes due to the better compatibility of GFC@PEO-1 wt%MXene electrolyte with Li anode.Furthermore,the solid-state Li/LiFePO_(4) battery with GFC@PEO-1 wt%MXene as electrolyte demonstrates a high capacity of 110.2–166.1 mAh g^(-1) in a wide temperature range of 25–60C,and an excellent capacity retention rate.The developed sandwich structured GFC@PEO-1 wt%MXene electrolyte with the excellent overall performance is promising for next generation high performance all-solid-state lithium metal batteries.