Ceramic Composite Electrolytes Research Articles

Enhanced ionic conductivity of NASICON-type NaTi2(PO4)3 solid electrolytes with sodium-ion conduction: based on NaF-assisted synthesis

The ceramic composite electrolytes in the NaTi2(PO4)3–NaF system were characterised by thermal analysis, X-ray diffraction, Fourier infrared absorption spectroscopy, scanning electron microscope, and impedance spectroscopy. X-ray diffraction confirmed that the ceramic composites have a Na Super Ionic Conductor (NASICON) structure. The scanning electron images showed that the addition of NaF significantly improved the microscopic morphology of the NaTi2(PO4)3 crystals and made the packing of crystal grains closer. The addition of NaF in a certain proportion is beneficial to the growth of crystals, making the crystal grains more compact and improving the density of the solid electrolytes. The ionic conductivity analysis was carried out by alternating current (AC) impedance spectroscopy. The conductivity can be effectively improved when a certain proportion of NaF is added to the ceramic composites. The maximum total conductivity is about 1.50 × 10−5 S·cm−1 obtained when the molar ratio of NaF to NaTi2(PO4)3 reaches 0.4.

Surface modification strategies for an improved interfacial compatibility between LLZO and a polymer substrate for applications in high-performance solid-state Li-metal batteries

The interfacial compatibility between inorganic powder and polymeric matrix is one of the most important key factors for the applications of polymer ceramic composite electrolytes (PCCEs). In the present study, a surface modification strategy has been proposed by using three different terminating groups of silane coupling agents in the modification of the interfacial compatibility between LLZO and PEO in PEO/LLZO composite electrolyte. Experiments and density functional theory (DFT) calculations have been performed in studying the effect of different silane coupling agents on interfacial properties. Especially, the interface compatibility is found to be improved when using amino-terminated silane coupling agent KH550, which is due to hydrogen bond interactions between amino groups and PEO. In addition, the mechanical strength and conductivity are significantly increased by increasing the interaction energy and by decreasing the crystallinity, and the values of 1.39 MPa and 0.22 mS cm−1 at 30 °C are then successfully achieved. As a result, the solid-state LiFePO4|PCCE|Li battery demonstrates a high discharge specific capacity of 157 mAh g−1 at 60 °C and 1C. And it has a cycle capacity decay rate of only 0.034 % for 380 cycles. These results pave the way for future developments of high-performance PCCEs.

(Invited) Ion Transport and Interface Resistance in Polymer-Based Composite Electrolytes and Composite Cathode

Solid-state electrolytes are promising to enable the next generation batteries with higher energy density and improved safety. However, each major class of solid electrolytes has intrinsic weaknesses. By combining different classes of solid electrolytes, such as a polymer electrolyte and an oxide ceramic electrolyte, one can potentially overcome the intrinsic weaknesses of each component and develop a composite electrolyte to achieve high ionic conductivity, good mechanical properties, good chemical stability, and adhesion with the electrodes.In this presentation, we show that the interfacial resistance strongly affects the ionic conductivity of polymer/oxide ceramic composite electrolytes, in both the ceramic-in-polymer design where ceramic particles are dispersed within the polymer electrolyte matrix as well as the polymer-in-ceramic design where a three dimensionally interconnected ceramic scaffold is developed. The quantification of the interfacial resistance, the origin of this resistance, as well as the strategies to minimize it are discussed.In a second case, we examine the effect of interfaces on ion transport in a polymer based composite cathode consisting of LiFePO4 (LFP), carbon and poly(ethylene oxide) (PEO) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The structure and dynamics of PEO and lithium ion mobility are studied by small angle neutron scattering and quasi-elastic neutron scattering. The results show that Li ion mobility in PEO/LiTFSI in the composite cathode is only 30% of the bulk electrolyte. This suggests a key bottleneck that limits the rate performance of polymer-based solid-state batteries originates from the sluggish ion transport in the polymer electrolyte confined in the cathode.

Phase Structure and Conductivity of Polymer Ceramic Composite Electrolytes Studied by Solid-State NMR

The influences of nano-Al2O3 on the phase structure and conductivity of PEO/LiCF3SO3 polymer electrolyte complex are discussed in this work. The addition amount of Al2O3 is 0-30wt%. The phase structure of the complex shows complicated changes with the addition of Al2O3. The crystallinity of the complex first decreases when Al2O3 content less than 15wt% then increases when Al2O3 content more than 15wt%. As the addition amount of Al2O3 is 15wt%, the 13C NMR signals from PEO3/LiCF3SO3 crystalline complex and neat crystalline PEO can hardly be seen. The complex obtains the highest ionic conductivity at room temperature when the content of Al2O3 is 15wt% (3.822x10-5 S/cm).

Composite solid electrolyte based on (Ca2+, Al3+)-infiltrated ZrO2(MgO) for direct sulfur determination in the liquid iron

Magnesium-stabilized zirconia [ZrO2(MgO)] with calcium aluminate (CaO–Al2O3) ceramic composite electrolyte based on (calcium ion [Ca2+], aluminum ion [Al3+])-infiltrated zirconia-magnesia [ZrO2(MgO)] porous backbone was prepared for direct sulfur ([S]) determination in the liquid iron. Effect of amylum content on the phase composition, microstructures and mechanical properties of the composite electrolyte was detected and correlated to the electrochemical performance. The results indicated that the ZrO2(MgO)-(CaO–Al2O3) composite electrolyte simultaneously inherited the mechanical and electrochemical properties of ZrO2(MgO), and unique physical and chemical properties of CaO–Al2O3. The compressive strength of the composite electrolyte reached above 250 MPa and the conductivity reached up to 0.003 S/cm-, meeting the requirements of the sensor for the electrolyte. The assembled sensor could respond to sulfur activity and showed fine response characteristics. Among the tested compositions, the composite electrolyte with 6.0 wt% of amylum added in ZrO2(MgO) porous backbone exhibited the best properties and was more suitable for application in sulfur determination.

Ion dynamics and positron annihilation studies on polymer ceramic composite electrolyte system (PVA/NaClO4/Y2O3): Application in electrochemical devices

This study aimed to develop a framework to investigate the structural, dielectric, and transport properties of a sequence-based PVA matrix polymer ceramic composite electrolyte system with sodium perchlorate (NaClO4) and yttrium oxide (Y2O3) as nanofillers. The XRD results revealed a change in crystallinity. Chemical interactions between the PVA/NaClO4 matrix and yttrium ions were revealed using FTIR studies. From SEM studies, the morphology was observed to be smoother, homogeneous, and coherent for the pure+salt PCCE system after addition of Y2O3 nanoparticles to the matrix. In Py3% system, the nanoparticles were randomly linearly aligned due to inter- and intramolecular bonding. The elemental composition and mapping were confirmed by the presence of Y2O3 and NaClO4 particles. For 7 wt%, 1 wt% Y2O3 nanoparticle loading (Py7%, Py1%) in the PCCE matrix, the positron lifetime parameters o-Ps lifetime (τ3) and free volume size (Vf) showed a minimum (Py7%) and maximum value (Py1%). Between these two values, the value for Py3% was ascertained. It was found that Py3% was least crystalline with highest ionic conductivity 3.25 × 10−4 S/cm which is strongly influenced by the highest charge concentration (n), not its mobility (μ). The highest conducting sample (Py3%) had an ion transference number (tion) of 0.919, indicating that the current system was ion-dominant with a small amount of electron participation. The LSV technique determined the potential window for the Py3% PCCE system to be 3 V, indicating that it could be used in energy storage applications. The proposed PCCE system's open circuit voltage was 1.7 V, and the discharge characteristics of a primary sodium battery built with a high-conductivity electrolyte system (Py3%) were thoroughly examined. To ensure the safety of our prepared energy storage systems, we tested films for flame retardancy and dimensional stability. Py3% film demonstrated considerable flame retardation that was stable over several ignitions. Self-extinguishing time for pure+salt displays ⁓ 41 s g−1 whereas in the case of Py3% PCCE it has a value ⁓ 6 s g−1.

Polymer–Ceramic Composite Electrolytes for Lithium Batteries: A Comparison between the Single-Ion-Conducting Polymer Matrix and Its Counterpart

Single-ion-conducting polymer electrolytes are attractive to use in lithium batteries as the transference number of the lithium cation approaches unity. This helps prevent concentration gradients a...

“Polymer-in-ceramic” based poly(Ɛ-caprolactone)/ceramic composite electrolyte for all-solid-state batteries

Inspired by the concept of “polymer-in-ceramic”, a composite poly(Ɛ-caprolactone) (PCL)/ceramic containing LiTFSI is prepared and investigated as a solid electrolyte for all-solid-state batteries. The composite with the optimum concentration of 45 wt% LiTFSI and 75 wt% Li1.5Al0.5Ge1.5(PO4)3 (LAGP, NASICON-type structure) exhibits a high ionic conductivity (σi= 0.17 mS cm−1) at 30 °C, a transference number of 0.30, and is stable up to 5.0 V. The composite electrolyte is a flexible and self-standing membrane. Solid-state LiFePO4//Li batteries with this composite electrolyte demonstrate excellent cycling stability with high discharge capacity of 157 mA h g−1, high capacity retention of 96% and coulombic efficiency of 98.5% after 130 cycles at 30 °C and 0.1 C rate. These electrochemical properties are better than other PCL-based all-solid-lithium batteries, and validate the concept of “polymer-in-ceramic” by avoiding the drawback of lower conductivity in prior “polymer-in-ceramic” electrolyte at high concentration of the ceramic.

A Nuclear Magnetic Resonance Study of Cation and Anion Dynamics in Polymer–Ceramic Composite Solid Electrolytes

Polymer–ceramic composite electrolytes are promising for the application of all-solid-state lithium-ion batteries with high energy density and improved safety. In this work, we employ temperature-d...

Rational Design of a Laminated Dual-Polymer/Polymer–Ceramic Composite Electrolyte for High-Voltage All-Solid-State Lithium Batteries

We present a multi-layer approach to design a laminated dual-polymer/polymer–ceramic composite electrolyte (LDPPCCE) for high-voltage all-solid-state lithium batteries. An anode friendly poly(ethyl...

Lithiated Nafion-garnet ceramic composite electrolyte membrane for solid-state lithium metal battery

Abstract Single-ion conducting solid polymer electrolytes are expected to play a vital role in the realization of solid-state Li metal batteries. In this work, a lithiated Nafion (Li-Nafion)-garnet ceramic Li6.25La3Zr2Al0.25O12 (LLZAO) composite solid electrolyte (CSE) membrane with 30 µm thickness was prepared for the first time. By employing X-ray photoelectron spectroscopy and transmission electron microscope, the interaction between LLZAO and Li-Nafion was investigated. It is found that the LLZAO interacts with the Li-Nafion to form a space charge layer at the interface between LLZAO and Li-Nafion. The space charge layer reduces the migration barrier of Li-ions and improves the ionic conductivity of the CSE membrane. The CSE membrane containing 10 wt% LLZAO exhibits the highest ionic conductivity of 2.26 × 10−4 S cm−1 at 30 °C among the pristine Li-Nafion membrane, the membrane containing 5 wt%, 20 wt%, and 30 wt% LLZAO, respectively. It also exhibits a high Li-ion transference number of 0.92, and a broader electrochemical window of 0–+4.8 V vs. Li+/Li than that of 0–+4.0 V vs. Li+/Li for the pristine Li-Nafion membrane. It is observed that the CSE membrane not only inhibits the growth of Li dendrites but also keeps excellent electrochemical stability with the Li electrode. Benefitting from the above merits, the solid-state LiFePO4/Li cell fabricated with the CSE membrane was practically charged and discharged at 30 °C. The cell exhibits an initial reversible discharge specific capacity of 160 mAh g−1 with 97% capacity retention after 100 cycles at 0.2 C, and maintains discharge specific capacity of 126 mAh g−1 after 500 cycles at 1 C. The CSE membrane prepared with Li-Nafion and LLZAO is proved to be a promising solid electrolyte for advanced solid-state Li metal batteries.

The Cathode Composition, A Key Player in the Success of Li-Metal Solid-State Batteries

Polymer–ceramic composite electrolytes are major contenders for applications in commercial Li-metal solid-state batteries. However, the cycling performance and energy density of such batteries are ...

Correction: Study of segmental dynamics and ion transport in polymer–ceramic composite electrolytes by quasi-elastic neutron scattering

Correction for ‘Study of segmental dynamics and ion transport in polymer–ceramic composite electrolytes by quasi-elastic neutron scattering’ by X. Chelsea Chen et al., Mol. Syst. Des. Eng., 2019, 4, 379–385.

Study of segmental dynamics and ion transport in polymer–ceramic composite electrolytes by quasi-elastic neutron scattering

This work elucidates the effects of Li+ conducting ceramic on the segmental dynamics and ionic conductivity of polymer electrolyte using quasi-elastic neutron scattering.

A durable and safe solid-state lithium battery with a hybrid electrolyte membrane

Polymer–ceramic composite electrolytes are emerging as a promising solution to achieving high ionic conductivity, optimal mechanical properties, and good safety for developing high-performance all-solid-state rechargeable batteries. In this work, we report a garnet (Li7La3Zr2O12)-based hybrid solid electrolyte (HSE) membrane designed for high performance solid-state lithium batteries for the first time. The composite HSE membrane is composed of LLZO particles and PVDF–HFP polymer matrix. The solid-state lithium battery with this HSE membrane, Li metal anode and LiFePO4 cathode exhibits an initial reversible discharge capacity of 120mAhg−1 at a charge/discharge current density of 0.5C at room temperature. This solid-state battery is used to store the energy harvested by a TENG at different rotation rates. The solid state battery can efficiently store the pulsed energy, especially for output at high frequencies.

Integrative preparation of mesoporous epoxy resin–ceramic composite electrolytes with multilayer structure for dendrite-free lithium metal batteries

Multi-layered mesoporous epoxy resin–ceramic composite design simultaneously solves the problems of Li dendrites.

Lithium Ion Pathway within Li7La3Zr2O12‐Polyethylene Oxide Composite Electrolytes

AbstractPolymer–ceramic composite electrolytes are emerging as a promising solution to deliver high ionic conductivity, optimal mechanical properties, and good safety for developing high‐performance all‐solid‐state rechargeable batteries. Composite electrolytes have been prepared with cubic‐phase Li7La3Zr2O12 (LLZO) garnet and polyethylene oxide (PEO) and employed in symmetric lithium battery cells. By combining selective isotope labeling and high‐resolution solid‐state Li NMR, we are able to track Li ion pathways within LLZO‐PEO composite electrolytes by monitoring the replacement of 7Li in the composite electrolyte by 6Li from the 6Li metal electrodes during battery cycling. We have provided the first experimental evidence to show that Li ions favor the pathway through the LLZO ceramic phase instead of the PEO‐LLZO interface or PEO. This approach can be widely applied to study ion pathways in ionic conductors and to provide useful insights for developing composite materials for energy storage and harvesting.

Honeycomb-alumina supported garnet membrane: Composite electrolyte with low resistance and high strength for lithium metal batteries

Li-ion ceramic electrolyte material is considered the key for advanced lithium metal batteries, and garnet-type oxides are promising ceramic electrolyte materials. To disentangle the thinness-strength dilemma in garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) electrolyte, we designed and successfully synthesized a ceramic–ceramic composite electrolyte, i.e. a honeycomb-Al2O3 pellet supported LLZTO membrane. The honeycomb-Al2O3 pellet acts as a supporter to the thin LLZTO membrane and makes the whole composite electrolyte strong enough, while the straight holes in the Al2O3 supporter can be filled with liquid electrolyte and acts as channels for Li+ transportation. Such a composite design eliminates the concern over the LLZTO membrane's fragility, and keeps its good electrical property.

Preparation and Characterization of PEO-LATP/LAGP Ceramic Composite Electrolyte Membrane for Lithium Batteries

A PEO-LATP/LAGP composite electrolyte for lithium batteries was designed and prepared. Uniformly composite electrolyte membrane with thickness of 20 μm was obtained by assembling Li1.4Al0.4Ti1.6(PO4)3 (LATP) or Li1.5Al0.5Ge1.5(PO4)3 (LAGP) as ceramic substrate and PEO as binder. Highest room-temperature conductivities were achieved for the sample prepared with w(ceramics):w(PEO)=7:3. Electrochemical analysis showed that the conductivity reached 0.186 mS/cm for PEO-LATP and 0.111 mS/cm for PEO-LAGP. Cycling performances of 170 mAh/g was obtained for the first discharge capacity of the Li/composite electrolyte/LiCo1/3Ni1/3Mn1/3O2 cell. Sharp decrease of cycling capacity was observed for the cell using PEO-LATP membrane. The cycling performance of the PEO-LAGP based cell was greatly improved with 150 mAh/g remained after 10 cycles.

Polymer–ceramic composite electrolytes: conductivity and thermal history effects

This paper reports the conductivity and DSC measurements of composite electrolytes containing the PEO:LiBF 4 complex, and TiO 2 and ZrO 2 nanosized particles. Below the melting temperature of PEO, conductivity is strongly dependent upon thermal history. The roles of the ceramic phase are to depress the melting temperature and retard the kinetics of crystallization of PEO. This results in a conductivity relaxation below the melting temperature of PEO which appears to be a characteristic of these composite electrolytes.