Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “ceramic electrolyte”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

A self-healing plastic ceramic electrolyte by an aprotic dynamic polymer network for lithium metal batteries

Abstract Oxide ceramic electrolytes (OCEs) have great potential for solid-state lithium metal (Li 0 ) battery applications because, in theory, their high elastic modulus provides better resistance to Li 0 dendrite growth. However, in practice, OCEs can hardly survive critical current densities higher than 1 mA/cm 2 . Key issues that contribute to the breakdown of OCEs include Li 0 penetration promoted by grain boundaries (GBs), uncontrolled side reactions at electrode-OCE interfaces, and, equally importantly, defects evolution (e.g., void growth and crack propagation) that leads to local current concentration and mechanical failure inside and on OCEs. Here, taking advantage of a dynamically crosslinked aprotic polymer with non-covalent –CH 3 ⋯CF 3 bonds, we developed a plastic ceramic electrolyte (PCE) by hybridizing the polymer framework with ionically conductive ceramics. Using in-situ synchrotron X-ray technique and Cryogenic transmission electron microscopy (Cryo-TEM), we uncover that the PCE exhibits self-healing/repairing capability through a two-step dynamic defects removal mechanism. This significantly suppresses the generation of hotspots for Li 0 penetration and chemomechanical degradations, resulting in durability beyond 2000 hours in Li 0 -Li 0 cells at 1 mA/cm 2 . Furthermore, by introducing a polyacrylate buffer layer between PCE and Li 0 -anode, long cycle life >3600 cycles was achieved when paired with a 4.2 V zero-strain cathode, all under near-zero stack pressure.

36 MATERIALS SCIENCE↗

A review of composite polymer-ceramic electrolytes for lithium batteries

All solid-state lithium batteries are garnering attention in both academia and industry. Lithium-ion conductive polymers and lithium-ion conductive ceramics are the two major classes of solid electrolytes that have prevalently been pursued for many years. However, each of them has its own advantages and disadvantages. One approach to overcome the disadvantages and get the best out of each of those materials is a solid composite electrolyte that combines the advantages of inorganic ceramic electrolytes and solid polymer electrolytes. Such composite electrolytes can offer acceptable ionic conductivity, high mechanical strength, and favorable interfacial contact with electrodes, which can greatly improve the electrochemical performance of all-solid-state batteries compared to cells based on a polymer electrolyte alone or a ceramic electrolyte alone. We present in this review the state-of-the-art composite polymer-ceramic electrolytes in view of their electrochemical and physical properties for the applications in lithium batteries. The review mainly encompasses the polymer matrices, various ceramic filler materials, and the polymer/ceramics composite systems. Specifically, the structures, ionic conductivities, electrochemical/chemical stabilities, and fabrications of solid composite electrolytes are discussed in-depth. On the basis of previous work, a perspective on future research directions is highlighted for developing high-performance composite polymer-ceramic electrolytes.

25 ENERGY STORAGE↗

High-Energy All-Solid-State Organic–Lithium Batteries Based on Ceramic Electrolytes

Recent studies have identified unique properties of organic battery electrode materials such as moderate redox potentials and mechanical softness which are uniquely beneficial for all-solid-state batteries based on ceramic electrolytes. Here, we further explore the promise of organic materials and demonstrate a sulfide electrolyte- based organic-lithium battery with a specific energy of 828 Wh kg –1 , rivaling the state-of- the-art of all-solid-state batteries. Two innovation steps are responsible for the accomplishment. First, the combination of lithium anode and the high-capacity cathode material pyrene-4,5,9,10-tetraone ensures a high theoretical specific energy. Second, the microstructure of the organic cathode is optimized with the introduction of cryomilling, a technique common to processing soft materials but not familiar to electrode fabrication. The cathode material utilization increases to 99.5% as a result, up from the 55–89% previously reported for ceramic electrolyte-based solid-state organic batteries. In conclusion, the improvement highlights the special requirements of solid-state organic electrodes for microstructural engineering while preserving the chemical integrity of components.

25 ENERGY STORAGE↗

Probing the proton exchange kinetics of BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3− δ ceramic electrolyte by operando diffuse reflectance infrared Fourier transform spectroscopy

Proton exchange kinetics plays an important role in governing the performance of intermediate-temperature protonic ceramic electrolysis cells (PCECs) for hydrogen production. Our understanding of the nature of the surface hydration reaction at the single-cell level, however, remains very limited, hampering further efficiency improvements. Here, in this study, we developed a custom operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) platform that operates under high temperature and steam conditions with applied bias. Quantitative investigations of surface H 2 O/D 2 O isotope exchange in a BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3−δ (BZCYYb1711) protonic electrolyte-based single cell were conducted under different applied voltages using this DRIFTS platform, to gain molecular-level insight into hydration kinetics. The findings show that the application of an external voltage significantly enhances the surface proton exchange rate, decreasing the apparent activation energy from 29.1 kJ mol −1 at open-circuit voltage (OCV) to 6.8 kJ mol −1 at 1.3 V. In addition, distinct voltage-induced spectral shifts in O–D vibrations point to dynamic changes in surface hydration. These findings demonstrate a sensitive spectroscopic platform for probing interfacial proton processes and reveal strong electrochemical control over surface proton kinetics, offering new opportunities for probing electrolyte hydration behavior in PCECs.

36 - MATERIALS SCIENCE↗

Characterization of hot-pressed von Alpen type NASICON ceramic electrolytes

The Na-ion conducting solid electrolyte NASICON is a promising solid state electrolyte (SSE) for use in Na based electrochemical systems. The effects of particle morphology and synthesis of von Alpen type NASICON via hot-pressing were investigated. Spray dried particles were shown to improve mechanical and electrochemical properties. X-ray diffraction, scanning electron microscopy, impulse excitation measurements, Vickers hardness, and impedance spectroscopy were used to correlate relationships between phase purity, microstructure, mechanical properties, and electrochemical properties. Scanning electron microscopy showed the presence of a glass phase as between 19.08% and 28.23% area percentage and a ZrO 2 phase between 0.46% and 3.51% area percentage in the hot-pressed samples. Impulse excitation showed elastic modulus varying from 83.65 to 97.65 GPa. The first values of Poisson's ratio and shear modulus of NASICON are reported as between 0.23 and 0.26 and 33.87 to 38.79 GPa, respectively. Vickers hardness and fracture toughness measurements showed Vickers hardness ranging from 4.30 to 4.68 GPa and fracture toughness ranging from 1.05 to 1.09 MPa m ½ . Impedance spectroscopy showed grain conductivities ranging from 1.023 to 1.287 mS/cm, with grain boundary resistance percentages between 73.22 and 47.5%. Total conductivities ranged from 0.292 to 0.596 mS/cm, with 0.596 mS/cm being achieved at room temperature for the spray dried powders with lower grain boundary resistance percentages.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Physical and Mechano-Electrochemical Phenomena of Thin Film Lithium-Ceramic Electrolyte Constructs

While a small number of solid electrolytes exhibit high ionic conductivity (~1mS cm at 298K), few are stable against Li metal. The garnet-type solid electrolyte, based on the nominal formula Li 7 La 3 Zr 2 O 12 (LLZO), is unique in that it is a fast ion conductor and – as we demonstrated in our recent project (DE-EE-00006821) – is stable against Li. Moreover, our former project successfully demonstrated a decrease in Li-LLZO interface resistance from 12,000 to 2 Ohms cm 2 and stable cycling at 1 mA cm 2 for 100 cycles (+/- 15 µm Li per cycle). Although the past project (DE-EE-00006821) demonstrated LLZO is a viable solid electrolyte for enabling batteries using metallic Li, the studies used thick pellets (1mm) and thick anodes (~500 µm). We believe that to achieve a step increase in technology readiness level (TRL), the same performance characteristics previously shown should be demonstrated in technologically relevant cells, e.g. thin LLZO and thin Li. The goal of this project is to acquire a deep fundamental understanding of the physical and mechano-electrochemical phenomena that control the performance of cells consisting of thin LLZO (~10 µm), thin Li anodes (~20 µm) and thin solid-state composite cathodes. If successful, the knowledge gained in this project will guide closely related commercialization efforts to scale the production of LLZO-based solid-state batteries.

25 ENERGY STORAGE↗

Improved Stability and Cyclability of Ceramic Solid Electrolyte by Coating Polymer

Rechargeable all-solid-state lithium (Li) metal batteries show better safety and energy density compared to commercial Li-ion batteries using liquid electrolyte. As the key component of Li metal batteries, ceramic solid-state electrolyte has attracted great interest because of its high ion conductivity and great potential in interfacing with Li metal. Ceramic electrolyte has a more stable interface with Li metal than liquid electrolyte, but chemical reaction and Li dendrite growth at the electrolyte/Li interface are still significant, which causes device degradation and failure by cycling of Li plating and stripping. Unlike ceramic electrolyte, polymer electrolyte has a relatively stable interface with Li metal and better mechanical flexibility. Therefore, we introduced a polymer electrolyte coating to protect the ceramic electrolyte from direct contact with Li metal. The galvanotactic cycling Li plating/striping data on the devices with (without) the coating illustrates increased (decreased) overall conductivity and cyclability of the test cell by the cycling. Nanometer-scale ionic-transport imaging, based on atomic force microscopy, shows that cycling degrades the ceramic-only electrolyte by partially blocking ionic transport in areas; in contrast, cycling on the polymer-coated electrolyte improves ionic conductivity. Compared with the ceramic-only electrolyte, this novel polymer electrolyte coating on ceramic electrolyte shows less degradation when in contact with Li metal.

25 ENERGY STORAGE↗

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-dependent 7 Li and 19 F NMR to examine the chemical environment and the dynamics of Li + cation and triflate anion in poly(ethylene oxide) (PEO)–lithium triflate (LiTf) polymer electrolyte and a composite electrolyte containing 55 vol % doped lithium aluminum titanium phosphate (LICGC). The line shape analysis and spin–lattice relaxation (T 1 ) measurements suggest both the Li + cations and the Tf – anions reside in two distinct environment: a mobile environment and an immobile environment. In the semicrystalline state, a large ratio (>70%) of immobile Li + and Tf – is observed. In the melt state, the ratio of mobile cations and anions significantly increases. With the presence of LICGC ceramic, an increased ratio of immobile Li + and Tf – and reduced mobility of the mobile components are observed, indicating that the ceramic negatively impacts the transport of both the cations and the anions. NMR characterizations are corroborated by conductivity results, which reveal that the intrinsic ionic conductivity of the polymer phase of the composite electrolyte was only 0.15 of the ceramic-free polymer electrolyte at room temperature. These results shed light on the challenges inherent to composite electrolytes with the goal of achieving both enhanced Li + transference number and ionic conductivity.

25 ENERGY STORAGE↗

Orientation microscopy–assisted grain boundary analysis for protonic ceramic cell electrolytes

Abstract Grain boundaries in protonic ceramic cell (PCC) electrolytes hinder proton transport, reducing interfacial conductivity. In multicomponent PCC electrolytes, the inclusion of sintering aids further accentuates the complexity of grain boundaries. In this study, we synthesize nanocrystalline BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3− δ thin films via pulsed laser deposition and analyze their grain boundary character distributions using orientation data collected by precession electron diffraction technique. The results reveal an anisotropic distribution of grain boundary characters, with notably high populations of 180°‐tilt and twist grain boundaries. These findings provide critical insights into identifying the predominant grain boundaries in this PCC electrolyte material, assessing the vast five‐dimensional grain boundary space.

Patel, Sooraj [School of Aerospace and Mechanical ↗

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 across the electrolyte, which can result in dendrite formation. The addition of ceramic particles to polymer electrolytes at high loadings can increase the mechanical strength of the polymer, which can also help suppress dendrite formation. Here, a single-ion-conducting polymer electrolyte is blended with lithium-conducting oxide ceramic particles to make a composite electrolyte. This electrolyte is studied in comparison to a composite electrolyte containing freely dissolved lithium salt. It is found that the addition of ceramic particles to the single-ion-conducting polymer can result in increased cation dissociation and consequent increased ionic conductivity. The electrolytes are cycled in lithium symmetrical cells, and it is found that the ceramic-containing electrolytes show increased interfacial stability with the lithium metal compared to the pristine polymer electrolytes. Our findings shed light on how to optimize the polymer host chemistry to form composite electrolytes that can meet the challenging requirements to stabilize the lithium metal anode.

25 ENERGY STORAGE↗

Highly Loaded Sulfur Cathode, Coated Separator and Gel Electrolyte for High Rate Li-Sulfur Batteries

As one of DOE Battery 500 Seedling projects, Cornell University and EIC Labs investigated and developed i) highly loaded sulfur cathodes (> 3 mg/cm 2 ), ii) hybrid separators, and iii) gel ceramic electrolytes (GCE) to mitigate the low rate capability, shuttling effect and limited cycle life in high performance Li-Sulfur batteries. Scalable nanomanufacturing processes such as air-controlled electrospray (ACES) and gas-assisted electrospinning (GAES) have been utilized to develop directly deposited electrodes and polymer/ceramic hybrid separators. First, in the development of highly loaded cathodes, alternating layers of sulfur impregnated mesoporous carbon and graphene were fabricated via ACES and the resulting layered cathodes and coated separators exhibit higher capacity and capacity retention (about 1,000 mAh/g capacity with less than 0.02% fade/cycles) than single layer cathode or cathode prepared by conventional slurry cast. Alternating layer approach via ACES has been applied to high loading systems (3 - 5 mg S/cm 2 ), demonstrating the potential to increase sulfur utilization and capacity retention. We have also incorporated iron oxides (Fe 3 O 4 ) into S/mesoporous carbon/graphene cathodes to enhance sulfur utilization and mitigation of polysulfide shuttling. and the effect of Fe 3 O 4 in mesoporous carbon and Gr is highly pronounced at high C rates of 1C and 2C cycling performance. To further improve the cathodes at high rates, graphene nanoribbons (GNR) which can promote ion transport were incorporated in the cathode, resulting in 550 mAh/g at 5C/5C rates. Hybrid Li-ion/Li-S cathodes has also been explored to better engage unreacted polysulfides during charge/discharge. S/LFP hybrid cathodes offer higher sulfur utilization and enhanced rate capability, as well as higher areal loading. This study suggests inclusion of iron phosphide (Fe2P) which can chemically interact with polysulfides can further enhance sulfur utilization and mitigation of soluble polysulfides at high rates. Secondly, in the development of hybrid separators, we first employed graphene coating on the commercial polyolefin separators, which exhibits higher capability, better capacity retention and enhanced rate capability. To improve the rate capability with enhanced safety features such as thermal stability and nonflammability, we developed polymer/ceramic hybrids based on thermally stable polyimide (PI) and room temperature curable ceramic precursors such as organopolysilazane (OPSZ) or polysilsesquioxanes (PSSQ), which exhibit no shrinkages up to 300 ºC and non-flammability. To improve mechanical properties and electrochemical stability, polybenzimidazole (PBI) and alumina have been incorporated in polymer/ceramic hybrid separator, replacing PI and OPSZ/PSSQ, respectively. Finally, the gel ceramic electrolyte (GCE) based on ceramic cross linkers have been applied to make Li-S cells even safer and also to mitigate the polysulfide shuttling further. The resulting gel ceramic electrolyte offers improved capacity retention and rate capability, and also effectively mitigates polysulfide shuttling which was also confirmed by modeling. Inclusion of high ion conducting additives into GCE together with polymer/ceramic hybrid separators exhibit the higher ionic conductivity than liquid electrolyte with commercial polyolefin separator. We demonstrated that the developed highly loaded sulfur cathodes, polymer/ceramic hybrid separators and gel ceramic electrolyte can effectively mitigate the low rate capability, shuttling effect and limited cycle life in high performance Li-Sulfur batteries with improved safety.

25 ENERGY STORAGE↗

Polymer-ceramic composite electrolytes for all-solid-state lithium batteries: Ionic conductivity and chemical interaction enhanced by oxygen vacancy in ceramic nanofibers

Perovskite Li 3x La 2/3-x TiO3 (LLTO) nanofibers have been heat-treated in the hydrogen-containing atmosphere and then incorporated with the poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) polymer to form a composite electrolyte. Hydrogen treatment has created oxygen vacancies in the LLTO nanofibers, which has reduced the activation energy of Li ion transport along intra-grains and inter-grains, leading to improvement in the ion conductivity of LLTO nanofibers. Hydrogen treatment of the LLTO nanofibers has also enhanced the chemical interaction between the LLTO nanofibers and the polymer matrix in the composite electrolyte, and favored the Li ion transport at the nanofiber/polymer interface, improving the ion conductivity of the composite electrolyte to 3.4×10- 4 S/cm at room temperature. As a result, the Li|composite-electrolyte|Li half-cell exhibits good stability during lithium plating/stripping cycling at room temperature, showing an overpotential of ~91 mV at a constant current density of 0.5 mA/cm 2 . Finally, the full-cell battery with the composite electrolyte, lithium metal anode and lithium iron phosphate cathode shows excellent rate capacity and cycling performance.

25 ENERGY STORAGE↗

Design of High-Voltage Stable Hybrid Electrolyte with an Ultrahigh Li Transference Number

Considering the high energy consumption during processing, and the low compliance and adhesion of ceramic electrolytes, the integration of polymer into ceramic electrolytes provides a way to mitigate the interfacial issues. However, the severe ion concentration gradient, low ionic conductivity, and instability toward Li metal and high-voltage cathodes become the major concerns in applying hybrid electrolytes. In this work, we report a single-ionconducting hybrid electrolyte (SIE-LLZO) with 64 wt % Li 7 La 3 Zr 2 O 12 (LLZO) particles embedded in a fluoroboron-centered Li-conductive polymer framework (LiBFSIE). The SIE-LLZO electrolyte exhibited a high Li transference number of 0.94 and electrochemical stability up to 5.6 V vs Li/Li + . Promising averaged Coulombic efficiencies of 99.97% and 99.91% were achieved in cells with LiNi 0.8 Co 0.15 Al 0.05 O 2 and LiNi 0.6 Mn 0.2 Co 0.2 O2 cathodes for 400 and 200 cycles, respectively. Finally, the Li-conducting pathway in the hybrid electrolyte was further investigated by a 6 Li-to- 7 Li isotope replacement method, indicating that Li transport mainly relies on the LLZO and interface between LiBFSIE and LLZO.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Identifying Bounds of Inorganic Content in Solventless Processing of Hybrid Solid Electrolytes

Solid-state lithium batteries require safe, robust electrolytes to enable higher energy densities and improved safety over conventional cells. Hybrid polymer–ceramic electrolytes are a promising solution, combining the processability of polymers with the high ionic conductivity and mechanical strength of inorganic fillers. In this work, we demonstrate a solventless, UV-curing method to produce hybrid solid electrolytes using a poly(ethylene glycol) dimethyl ether (PEGDME)-based photocurable matrix incorporating Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) or Li 7 La 3 Zr 2 O 12 (LLZO) ceramic electrolyte. Inorganic filler loadings up to ∼55 wt.% could be successfully incorporated via this process which was the highest inorganic content at which the slurry remains processable and cured into a uniform film. The resulting UV-cured composite electrolytes remain flexible and exhibit room-temperature ionic conductivities on the order of 10 −4 S·cm −1 , along with notably improved lithium-ion transference numbers compared to conventional polymer electrolytes. Similar performance and processing limits were observed for both LAGP and LLZO, indicating that ceramic filler chemistry does not significantly affect the UV-curing process or the electrolyte's ion transport properties in this regime. Eliminating solvents from fabrication not only simplifies processing and mitigates environmental concerns but also enables higher solid contents that enhance mechanical strength and help suppress lithium dendrite formation. In conclusion, this scalable approach thus paves the way for manufacturing robust composite solid electrolytes for next-generation solid-state batteries (SSBs).

Batteries↗

Exploring the structural uniformity and integrity of protonic ceramic thin film electrolyte using wet powder spraying

Thin protonic ceramic electrolyte contributes to lower ohmic resistance and enhances electrochemical performance of protonic ceramic electrochemical cells. However, manufacturing of large-scale thin electrolyte remains a challenge. Wet powder spraying is an attractive technique to deposit <10 µm thin electrolyte when advanced atomizing techniques and optimized spraying process are integrated. Here ultrasonic atomization is integrated in the wet powder spray technique to reduce the thickness of electrolyte. Moreover, a parametric study is conducted to optimize the wet powder spray process to deposit uniform and crack-free electrolyte film. It is illustrated that tuning of solid loading rates and spray passes can affect the morphology of the as-sprayed electrolyte film, enabling the structural compactness of the sintered electrolyte layer. To maintain chemical stability of the electrolyte layer during sintering, effect of sintering temperature is further investigated to produce a physically thin, structurally dense, and chemically homogeneous electrolyte layer. The protonic ceramic electrochemical cells fabricated with optimized spraying and sintering parameters demonstrate excellent performance under both fuel cell and electrolysis modes. In addition, the cells exhibit remarkable structural integrity during redox and long-term stability tests.

36 MATERIALS SCIENCE↗

LiAlO 2 /LiAl 5 O 8 Membranes Derived from Flame-Synthesized Nanopowders as a Potential Electrolyte and Coating Material for All-Solid-State Batteries

Recently, γ-LiAlO 2 has attracted considerable attention as a coating in Li-ion battery electrodes. However, its potential as a Li + ceramic electrolyte is limited due to its poor ionic conductivity (<10 –10 S cm –1 ). Here, we demonstrate an effective method of processing LiAlO 2 membranes (<50 μm) using nanopowders (NPs) produced via liquid-feed flame spray pyrolysis (LF-FSP). Here, membranes consisting of selected mixtures of lithium aluminate polymorphs and Li contents were processed by conventional tape casting of NPs followed by thermocompression of the green films (100 °C/10 kpsi/10 min). The sintered green films (1100 °C/2 h/air) present a mixture of LiAlO 2 (~72 wt %) and LiAl 5 O 8 (~27 wt %) phases, offering ionic conductivities (>10 –6 S cm –1 ) at ambient with an activation energy of 0.5 eV. This greatly increases their potential utility as ceramic electrolytes for all-solid-state batteries, which could simplify battery designs, significantly reduce costs, and increase their safety. Furthermore, a solid-state Li/Li 3.1 AlO 2 /Li symmetric cell was assembled and galvanostatically cycled at 0.375 mA cm –2 current density, exhibiting a transference number ≈ 1.

25 ENERGY STORAGE↗