Lanthanum Zirconium Oxide Research Articles

A single-ion transport interfacial layer for solid-state lithium batteries

All-solid-state batteries possess several advantages including high safety, flexibility to use high-capacity metal anodes and are projected to be the next generation energy storage devices. Garnet-type cubic Li7La3Zr2O12 (LLZO) solid electrolyte is of particular interest due to its high ionic conductivity under ambient conditions and compatibility with Li metal. However, large electrode/electrolyte interfacial resistance constraints their development. Herein, the use of a highly lithium ion conducting dilithium phthalocyanine (Li2Pc) in ionic liquid as an interlayer is proposed to effectively suppress the high impedance at the interface thus improving the electrode-electrolyte contact. Fast Li+ mobility and high dielectric constant of dilithium phthalocyanine enhance the kinetics of Li+ transport across the interface. A significant reduction in overpotential and very stable stripping/plating cycling are observed in lithium symmetric cells upon introducing Li2Pc interlayer as compared to the use of bare tantalum doped lithium lanthanum zirconium oxide (LLZTO) electrolyte. Cells comprising interlayer-modified Li|LLZTO|LiFePO4 show high capacity with excellent cycling and rate capability. The performance of full cells using lithiated graphite and lithium titanate anodes has also been evaluated. This study presents a promising application of garnet electrolytes towards the advancement of solid-state lithium batteries.

Decoupling the roles of grain boundary strength and grain size hidden in grain-level electro-chemo-mechanical failure of solid-state electrolyte

Garnet lithium lanthanum zirconium oxide (Li7La3Zr2O12, LLZO) is a benchmark solid-state electrolyte material receiving considerable attention owing to its high conductivity and chemical stability against Li metal. Although its electro-chemo-mechanical failure mechanisms have been much investigated, the equivocal roles of grain boundary strength and grain size of LLZO remain under-explored, hindering further performance improvements. Here we decoupled the effects of grain size and grain boundary strength of polycrystalline LLZO via the combination of electrochemical kinetics and the cohesive zone model. We discovered that the disintegration of LLZO is initiated by the accumulation of local displacements, which strongly relates to the changes in both grain size and grain boundary strength. However, variations in grain boundary strength affect the diffusion and propagation pathways of damage, while the failure of LLZO is determined by the grain size. Large LLZO grains facilitate transgranular damage under low grain boundary strength, which can alter local chemo-mechanics within the bulk of LLZO, leading to more extensive damage propagation. The results showcase the structure optimization pathways by preferentially controlling the growth of lithium dendrites at grain boundaries and their penetration in garnet-type SSE.

A multiscale model to understand the interface chemistry, contacts, and dynamics during lithium stripping

A reversible Li-metal electrode, paired with a solid electrolyte, is critical for attaining higher energy density and safer batteries beyond the current lithium-ion cells. A stable stripping process may be even harder to attain as the stripping process will remove Li-atoms from the surface, and naturally reduce surface contact area, if not self-corrected by other mechanisms, such as diffusion and plastic deformation under an applied external stack pressure. Here, we capture these mechanisms occurring at multiple length- and time- scales, i.e., interface interactions, vacancy hopping, and plastic deformation, by integrating density functional theory (DFT) simulations, kinetic Monte Carlo (KMC), and continuum finite element method (FEM). By assuming the self-affine nature of multiscale contacts, we predict the steady-state contact area as a function of stripping current density, interface wettability, and stack pressure. We further estimate the exponential increase of overpotential due to contact area loss to maintain the same stripping current density. We demonstrate that a lithiophilic interface requires less stack pressure to reach the same steady-state contact area fraction than a lithiophobic interface. A “tolerable steady-state” contact area loss for maintaining stable stripping is estimated at 20 %, corresponding to a 10 % increase in overpotential. To constrain contact loss within the tolerance, the required stack pressure is 0.1, 0.5, and 2 times the yield strength of lithium metal for three distinct interfaces, lithiophilic Li/lithium oxide(Li2O), Li/lithium lanthanum zirconium oxide(LLZO), and lithiophoblic Li/lithium fluoride(LiF), respectively. The modeling results agree with experiments on the impact of the stack pressure quantitatively, while the discrepancy in stripping rate sensitivity is attributed to the simplifying interface interaction in our simulations. Overall, this multiscale simulation framework demonstrates the importance of electrochemical-mechanical coupling in understanding the dynamics of the Li/SE interface during stripping.

Boron Surface Treatment of Li7La3Zr2O12 Enabling Solid Composite Electrolytes for Li-metal Battery Applications.

Despite being promoted as a superior Li-ion conductor, lithium lanthanum zirconium oxide (LLZO) still suffers from a number of shortcomings when employed as an active ceramic filler in composite polymer-ceramic solid electrolytes for rechargeable all-solid-state lithium metal batteries. One of the main limitations is the detrimental presence of Li2CO3 on the surface of LLZO particles, restricting Li-ion transport at the polymer-ceramic interfaces. In this work, a facile way to improve this interface is presented, by purposely engineering the LLZO particle surfaces for better compatibility with a PEO:LiTFSI solid polymer electrolyte matrix. It is shown that an surface treatment based on immersing LLZO particles in a boric acid solution can improve the LLZO surface chemistry, resulting in an enhancement in the ionic conductivity and cation transference number of the CPE with 20 wt.% of boron-treated LLZO particles compared to the analogous CPE with non-treated LLZO. Ultimately, an improved cycling performance and stability in Li // LiFePO4 cells was also demonstrated for the modified material.

Cross-Linked Composite Solid Polymer Electrolyte Doped with Li6.4La3Zr1.4Ta0.6O12 for High Voltage Lithium Metal Batteries.

Composite solid polymer electrolytes (CSPEs) are safer alternatives to liquid electrolytes and excellent candidates for high-voltage solid-state batteries. However, interfacial instabilities between the electrodes and CSPEs are one of the bottlenecks in pursuing these systems. In this study, a cross-linked CSPE was synthesized based on polypropylene carbonate, polyethylene glycol methyl ether acrylate, polyethylene glycol diacrylate with additives including lithium bis(trifluoromethane)sulfonimide salt, and tantalum-doped lithium lanthanum zirconium oxide (LLZTO). Mass fractions of 10, 20, and 40% LLZTO were added to the CSPE matrix. In a symmetric cell, lithium plating and stripping revealed that the interface between the lithium metal anode and CSPE with 10% of the LLZTO (CSPE-10LLZTO) shows the most stable interface. The CSPE-10LLZTO sample demonstrated high flexibility and showed no degradation over 800 h of cycling at varying current densities. The ionic conductivity for the CSPE-10LLZTO sample at 40 °C was 6.4 × 10-4 S/cm. An all-solid-state full cell was fabricated with LiNi0.5Mn0.3Co0.2O2 as the cathode, CSPE-10LLZTO as the electrolyte and separator, and Li metal as the anode, delivering approximately 140 mAh/g of capacity. Differential scanning calorimetry measurements on CSPE-xLLZTO showed high miscibility and the elimination of crystallinity. Raman spectroscopy revealed uniformity in the structure. These findings demonstrate the capability of the CSPEs to develop high-voltage solid-state lithium metal batteries.

Electrochemical Embrittlement Accelerates Dendrite Growth in Ceramic Electrolytes

Although solid-state batteries with metal anodes promise to enable safer, higher energy density batteries, metal protrusions (dendrites) grow when charging faster than a critical current density[1,2]. It is generally believed that dendrites grow when plating-induced stresses exceed that required for fracture of the solid-electrolyte[2–4]. Although the electrolyte's fracture toughness is commonly taken as a constant[2–4], here we show that the effective fracture toughness depends markedly upon the metal deposition current density. Based upon operando birefringence microscopy[5], we directly measure dendrite-induced stresses and obtain the mechanical driving force for failure, as well as the electrolyte fracture toughness. We find that increasing current densities embrittle the solid electrolyte—diminishing the fracture toughness by as much as 70%. Cryogenic Scanning Transmission Electron Microscopy (Cryo-STEM) reveals decomposed electrolyte phases at the dendrite tip. This decomposition is associated with a volume contraction consistent with embrittlement of the electrolyte. All experiments were conducted on the most electrochemically stable Li-ion conducting solid electrolyte (tantalum-doped lithium lanthanum zirconium oxide); the fracture toughness of less stable electrolytes (e.g., agryodites) may be even more susceptible to such embrittlement. The collective results indicate that “electrochemical embrittlement” markedly weakens the electrolyte, enabling dendrite growth—even when such degradation has negligible effect on bulk electrochemical properties.

Investigation of Lithium Deposition in Tri-Layer Llzo Garnet Structure As a Function of Cell Cycling Using Nuclear Reaction Analysis Method

A key challenge of lithium metal batteries is the volumetric expansion of battery after several charging cycles due to the non-uniform deposition of lithium on anode. This leads to lithium dendrite formation compromising battery safety, and poor lifetime. We adapted tri-layer (porous-dense-porous) Al-doped Lithium Lanthanum Zirconium Oxide (LLZO) host (separator) via tape casting. During cycling lithium is deposited in the porous structure preventing dendrite formation. XRD analysis of annealed host structure confirmed presence of cubic phase LLZO which provides higher ionic conductivity. We measured Li distribution on LLZO host structure before and after different cell cycling conditions and investigated the failure mechanism. We performed concentration depth profiles of 7Li and 6Li isotopes by Nuclear Reaction Analysis (NRA) using two different methods: Proton Induced Gamma-ray Emission (PIGE) and Proton Induced Alpha-particle Reaction (Particle-Particle reaction) and compared the results for accuracy. Depth profile of 7Li confirmed 33 at % Li at 0.44µm thickness before cycling which was increased after cycling. The Gaussian distribution of NRA data indicated a uniform Li depth profile in the dense layer. Through electrochemical testing, we measured that Li capacity loss after 5 and 25 charging cycles with 0.1C rate, 1.51mAh and 2.89mAh, respectively, in tri layered LLZO separator.

Development of Efficient Ink Dispersion Process for Solid-State Electrolyte and Electrode Manufacturing

All-solid-state lithium batteries (ASSBs) have several advantages over lithium-ion batteries (LIBs) such as higher safety thresholds associated with solid electrolytes (SEs) and the possibility of using lithium metal or silicon anodes to achieve comparatively higher energy and power density. The SE can also prevent chemical interactions with dissolved active materials, and thus solve the issue of long-term instability of LIBs. However, there are also challenges associated with ASSBs manufacturing, such as local stress and contact-loss between SE and active materials in cathodes due to active material “breath”, poor contact and high ionic resistance at the SE-cathode interface, difficulty in fabricating thin SEs, and the absence of scalable and cost-effective manufacturing processes (J. Janek and W.G. Zeier, Nature Energy 8 (2023): 230-240). A key to tackling these issues begins with ink formulation for electrolyte and cathode coating, including ink compositions and rheological properties.In this study, we report the influence of ink preparation methods and conditions on the solid-state electrolyte and cathode coating qualities, where lithium lanthanum zirconium oxide (LLZO) and lithium nickel manganese cobalt oxide (NMC) are used as model systems. Various mixing methods, such as acoustic wave mixing, high-speed off-axis mixing, and thin film mixing, are compared. Their influence on ink viscosity and particle dispersion, coating thickness and microstructure uniformity, and electrolyte and electrode electrochemical properties will be discussed.

Investigations on structure and optical properties of neutron irradiated nanocrystalline La2Zr2O7 pyrochlores

This research work investigates the response of nanocrystalline lanthanum zirconium oxide (LZO) under neutron irradiation, emphasizing grain size-dependent structural stability. LZO samples were synthesized with the chemical precipitation method and the LZO pellets were annealed at two different temperatures (1200 °C and 1400 °C) to obtain two different grain size samples, namely LZO-1200 and LZO-1400. The samples were exposed to neutrons at different doses (ranging from 1.63 × 1012 n/cm2 to 5.68 × 1014 n/cm2) and the effects were studied with X-ray diffraction, scanning electron microscopy, Raman scattering and optical characterization. The structural characterization results reveal that, the grain size and strain are significantly modified in LZO-1400 samples, and such changes are absent inLZO-1200 samples. The band gap and photoluminescence intensity are reduced significantly in LZO-1400 samples, however, this effect is not observed in LZO-1200 samples. The experimental results reveal that in LZO-1200 samples, the grain boundaries act as a sink for irradiation-induced defects and there is no significant change in the grain size, strain and band gap. However, in the case of the LZO-1400 sample, the grain size is larger than the cascades induced by primary knock-on atoms (PKAs) and it results in disorder-driven fast grain growth and changes in band gap and PL intensity. The LZO-1200 samples with small grain sizes are radiation resistant.

Thermodynamic and structural characterization of high-entropy garnet electrolytes for all-solid-state battery

This study explores multi-component garnet-based materials as solid electrolytes for all-solid-state lithium batteries. Through a combination of computational and experimental approaches, we investigate the thermodynamic and structural properties of lithium lanthanum zirconium oxide garnets doped with various elements. Applying density functional theory, the influence of dopants on the thermodynamic stability of these garnets was studied. Probable atomic configurations and their impact on materials’ properties were investigated with the focus on understanding the influence of these configurations on structural stability, phase preference, and ionic conductivity. In addition to the computational study, series of cubic-phase garnet compounds were synthesized and their electrochemical performance was evaluated experimentally. Our findings reveal that the stability of cubic phase in doped Li-garnets is primarily governed by enthalpy, with configurational entropy playing a secondary role. Moreover, we establish that the increased number of doping elements significantly enhances the cubic phase’s stability. This in-depth understanding of materials’ properties at atomic level establishes the basis for optimizing high-entropy ceramics, contributing significantly to the advancement of solid-state lithium batteries and other applications requiring innovative material solutions.

Effect of La2O3 as sintering aid on the structural, mechanical & electrical properties of Y2O3

Yttrium oxide (Y2O3) is a potential material in the development of transparent polycrystalline ceramics (PTCs). PTCs have possible applications in laser-materials, scintillators, Infrared windows, opto-electronic devices, displays etc. To obtain these, the ceramic must have a symmetric crystal structure, high purity and density. Highly dense ceramics require sophisticated sintering procedures as well as optimum sintering additives such as Lanthanum Oxide (La2O3) and Zirconium Oxide (ZrO2). In this manuscript, La2O3 is used as a sintering to embrace the sintering of Y2O3 with the aim to bring down the sintering temperature and systematically study the opto-electrical properties. La2O3 substituted Y2O3 (LaxY2−xO3, where, x = 0, 3, 6 and 9 at.%) ceramics are made, using co-precipitation method were examined for structural, morphological, physico-chemical and electrical properties by using XRD, SEM, TGA-DSC, and dielectric measurements. The obtained results serve as guidelines for the use of Y2O3 as a pathway to new dimensions opto-electronic applications.

Protective shielding films for atomic-level evaluation of lithium lanthanum zirconium oxide at room temperature

Protective shielding films for atomic-level evaluation of lithium lanthanum zirconium oxide at room temperature

Surface Reconditioning of Lithium Metal Electrodes by Laser Treatment for the Industrial Production of Enhanced Lithium Metal Batteries

AbstractIncorporating lithium metal anodes in next‐generation batteries promises enhanced energy densities. However, lithium's reactivity results in the formation of a native surface film, affecting battery performance. Therefore, precisely controlling the chemical and morphological surface condition of lithium metal anodes is imperative for producing high‐performance lithium metal batteries. This study demonstrates the efficacy of laser treatment for removing superficial contaminants from lithium metal substrates. To this end, picosecond‐pulsed laser radiation is proposed for modifying the surface of lithium metal substrates. Scanning electron microscopy (SEM) revealed that different laser process regimes can be exploited to achieve a wide spectrum of surface morphologies. Energy‐dispersive X‐ray spectroscopy (EDX) confirmed substantial reductions of ≈80% in oxidic and carbonaceous surface species. The contamination layer removal translated into interfacial resistance reductions of 35% and 44% when testing laser‐cleaned lithium metal anodes in symmetric all‐solid‐state batteries (ASSBs) with lithium phosphorus sulfur chloride (LPSCl) and lithium lanthanum zirconium oxide (LLZO) solid electrolytes, respectively. Finally, a framework for integrating laser cleaning into industrial battery production is suggested, evidencing the industrial feasibility of the approach. In summary, this work advances the understanding of lithium metal surface treatments and serves as proof of principle for its industrial applicability.

Dendrite Growth—Microstructure—Stress—Interrelations in Garnet Solid‐State Electrolyte

AbstractThis study illustrates how the microstructure of garnet solid‐state electrolytes (SSE) affects the stress‐state and dendrite growth. Tantalum‐doped lithium lanthanum zirconium oxide (LLZTO, Li6.4La3Zr1.4Ta0.6O12) is synthesized by powder processing and sintering (AS), or with the incorporation of intermediate‐stage high‐energy milling (M). The M compact displays higher density (91.5% vs 82.5% of theoretical), and per quantitative stereology, lower average grain size (5.4 ± 2.6 vs 21.3 ± 11.1 µm) and lower AFM‐derived RMS surface roughness contacting the Li metal (45 vs 161 nm). These differences enable symmetric M cells to electrochemically cycle at constant capacity (0.1 mAh cm−2) with enhanced critical current density (CCD) of 1.4 versus 0.3 mA cm−2. It is demonstrated that LLZTO grain size distribution and internal porosity critically affect electrical short‐circuit failure, indicating the importance of electronic properties. Lithium dendrites propagate intergranularly through regions where LLZTO grains are smaller than the bulk average (7.4 ± 3.8 µm for AS in a symmetric cell, 3.1 ± 1.4 µm for M in a half‐cell). Metal also accumulates in the otherwise empty pores of the sintered compact present along the dendrite path. Mechanistic modeling indicates that reaction and stress heterogeneities are interrelated, leading to current focusing and preferential plating at grain boundaries.

The effect of iron ion irradiation on the ionic conductivity of lithium lanthanum zirconium oxide garnet thin films

The ionic conductivity of most lithium lanthanum zirconium oxide (LLZO, Li7La3Zr2O12) solid electrolytes requires improvement. In this study, LLZO thin films were fabricated through sputtering, and various doses of iron ion irradiation (Fe11+) were employed. As the irradiation dose increased from 1014 ions cm−2 to 1016 ions cm−2, the half-height width of the X-ray diffraction peak gradually broadened. Concurrently, the ionic conductivity increased from 2.3 × 10−9 S cm−1 to 2.4 × 10−5 S cm−1, while the activation energy decreased from 0.37 eV to 0.18 eV. The improved ionic conductivity can be attributed to the introduction of point defects in the microstructure of the LLZO thin film upon irradiation. Overall, the findings demonstrate the effective enhancement of the ionic conductivity of LLZO solid electrolytes through iron ion irradiation.

Nanoscale Ion Transport Enhances Conductivity in Solid Polymer-Ceramic Lithium Electrolytes.

The predictive design of flexible and solvent-free polymer electrolytes for solid-state batteries requires an understanding of the fundamental principles governing the ion transport. In this work, we establish a correlation among the composite structures, polymer segmental dynamics, and lithium ion (Li+) transport in a ceramic-polymer composite. Elucidating this structure-property relationship will allow tailoring of the Li+ conductivity by optimizing the macroscopic electrochemical stability of the electrolyte. The ion dissociation from the slow polymer segmental dynamics was found to be enhanced by controlling the morphology and functionality of the polymer/ceramic interface. The chemical structure of the Li+ salt in the composite electrolyte was correlated with the size of the ionic cluster domains, the conductivity mechanism, and the electrochemical stability of the electrolyte. Polyethylene oxide (PEO) filled with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium bis(fluorosulfonyl) imide (LiFSI) salts was used as a matrix. A garnet electrolyte, aluminum substituted lithium lanthanum zirconium oxide (Al-LLZO) with a planar geometry, was used for the ceramic nanoparticle moieties. The dynamics of the strongly bound and highly mobile Li+ were investigated using dielectric relaxation spectroscopy. The incorporation of the Al-LLZO platelets increased the number density of more mobile Li+. The structure of the nanoscale ion-agglomeration was investigated by small-angle X-ray scattering, while molecular dynamics (MD) simulation studies were conducted to obtain the fundamental mechanism of the decorrelation of the Li+ in the LiTFSI and LiFSI salts from the long PEO chain.

Effects of Al concentration on the structure and conductivity of lithium lanthanum zirconium oxide

New structural contributions to conductivity in cubic Li7−3xAlxLa3Zr2O12 and differences in conductivity controlling mechanisms between different substitution types are revealed.

Performance Enhancement of Nickel Manganese Cobalt Oxide Cathodic Material for Solid-State Battery Technology by Surface Engineering

Batteries as any other electronic devices are affected by parasitic phenomena including physical processes and chemical reactions occurring within the battery materials as well as their interfaces. The phenomena lead to degradation in performance, impose operation restrictions and potentially make devices unsafe.Solid-state, lithium-metal-based, batteries show promise to meet electric vehicle market requirements, but technical challenges to overcome rapid degradation and cost-effective processing remains. Cathode/electrolyte interfacial side reactions can lead to passivating layer formation, thus increasing cell resistance, unwanted additional overvoltage, and ultimately capacity loss. These phenomena are exacerbated in solid-to-solid contact between solid state electrolytes, active materials, and electronic conductive agents. Therefore, electrode manufacturing design is required to mitigate these issues.Within this work we have evaluated Spray Drying (SD) and Atomic Layer Deposition (ALD) coating processes to engineer the cathode/ electrolyte interface of SSBs, thus improving performance and overall cell cycle life. Cathode materials coating is utilised as an effective strategy to mitigate the degradation of the interface. SD is classically utilised in the food and pharma industries, and it has recently been expanded to include the synthesis/shaping of battery electrode materials as a versatile and robust methodology that can be easily scaled up. ALD is a widely exploited technique in the semiconductor (SC) industry based on self-limiting chemical reactions to deposit stoichiometrically-fixed, defect-free and nanometric-thick materials on surfaces. As such, the application of ALD to coat powders in the battery community is innovative and currently under development.Cathodic materials such as NMC (Nickel Manganese Cobalt Oxides) have been investigated, as the need for improving the capacity retention is strong for high-content (>80%) nickel cathodes. Indeed, ALD utilised to coat NMC powder provides a nanometric thick layer of a dielectric but ionic conductive metal oxide. Optimisation of aluminium oxide shell on a core of polycrystalline high nickel material has been investigated with surface engineering. In parallel, we have been exploring the benefit of SD to create an NMC811 powder showing a decorated structure using two different approaches. Indeed, we have either used preformed metal oxide nanoparticles dispersed in an NMC suspension or synthesised a metal oxide layer on top of the NMC in-situ by a chemical reaction during the spray process.Morphological and chemical characterisation of the products have been crucial to develop the coating processes. Electrochemical Impedance Spectroscopy (EIS) probed the engineered cathode/ electrolyte interface within half- and full-coin cell configuration. Rate performance and long-term cycling evaluation has driven the design of an oxide-based lithium metal solid state battery.Alumina coated powder NMC showed longer capacity retention than raw materials when tested in coin cell batteries. The cells were assembled using thin lithium metal anode, Lithium-Lanthanum Zirconium Oxide (LLZO) electrolyte, and surface-engineered NMC811 supported by aluminium current collector. Key words:Surface Engineering, Coatings, Solid-State Batteries (SSB), Spray Dry, Atomic Layer Deposition (ALD), Preformed Nanoparticles, Nickel Manganese Cobalt Oxide (NMC), NMC811, Lithium Lanthanum Zirconium Oxide (LLZO), Interfaces.

A Facile Two-Step Thermal Process for Producing a Dense, Phase-Pure, Cubic Ta-Doped Lithium Lanthanum Zirconium Oxide Electrolyte for Upscaling

An inorganic solid electrolyte is the most favorable candidate for replacing flammable liquid electrolytes in lithium batteries. Lithium lanthanum zirconium oxide (LLZO) is considered a promising solid electrolyte due to its safe operating potential window (0–5 V) combined with its good electrochemical stability. In this work, 250 g batches of pre-sintered Ta-doped LLZO (Li7La3Zr1.6Ta0.4O12, Ta-LLZO) were synthesized for bulk production of a dense LLZO electrolyte. A simple two-step thermal treatment process was developed. The first thermal step at 950 °C initiates nucleation of LLZO, with carefully controlled process parameters such as heating atmosphere, temperature, and dopant concentration. In the second thermal step at 1150 °C, sintered discs were obtained as solid electrolytes, with relative densities of 96%. X-ray diffraction analysis confirmed the phase purity of the sintered Ta-LLZO disc, and refined data were used to calculate the lattice parameter (12.944 Å). Furthermore, the presence of the Ta dopant in the disc was confirmed through X-ray photoelectron spectroscopy (XPS) analysis. The ionic and electronic conductivity values of the Ta-LLZO disc were 10−4 S cm−1 and 10−10 S cm−1, respectively. These values confirm that the prepared (Ta-LLZO) discs exhibit ionic conductivity while being electronically insulating, being suitable for use as solid electrolytes with the requisite electrical properties.

Enhanced electrochemical hydrogen storage performance of lanthanum zirconium oxide ceramic microstructures synthesized by a simple approach

Two rare-earth zirconate oxides RE2Zr2O7 (RE = La and Nd) with pyrochlore structures were fabricated, employing a simple and modified solid-state route. After confirmation of their microstructure, physicochemical features, and morphologies, the fabricated pyrochlores were applied for electrochemical hydrogen storage, and their capacity was compared in an alkaline medium. The La2Zr2O7 microstructure exhibited an enhanced electrochemical hydrogen storage performance (maximum discharge capacity = 2350 mAh/g) compared to the Nd2Zr2O7 structures. Having a higher specific surface, as well as a more favorable physical and chemical nature, could be responsible for this more suitable performance. Lanthanum zirconate ceramic microstructure could be introduced as an active material with an appropriate capacity for electrochemical hydrogen storage.