Ceramic Separator Research Articles

Sputtered Zero‐Excess Electrodes with Metallic Seed Layers for Solid‐State Sodium Batteries

Zero‐excess sodium metal solid‐state batteries offer improved safety, lower cost, higher energy density, and reduced resource dependency compared to today’s lithium‐ion technology. This study demonstrates the fabrication of zero‐excess electrodes with unprecedented stability during plating/stripping cycles. The fabrication process involves the sputter deposition of 20 nm metallic seed layers – zinc, silver, indium, or tin – onto NASICON (Na3.4Zr2Si2.4P0.6O12) ceramic separators, followed by the sputter deposition of a 30 µm copper current collector. The favorable influence of these seed layers on the in‐situ formation of the sodium|NASICON interface is examined through nucleation and cycling experiments, with a sodium metal reservoir serving as the non‐limiting counter electrode. Due to alloy formation the seed layers – particularly tin – stabilize sodium nucleation and cycling substantially and reduce dendrite formation compared to reference cells with bare copper current collectors. Sodium loss during cycling is primarily attributed to local cracking of the current collector and its partial delamination from the NASICON. Compared to polished NASICON, a roughened surface reduces the resistance e.g. of the counter electrode 200‐fold to approx. 1 Ωcm² at 3 MPa and suppresses delamination further.

Ga-ion migration during co-sintering of heterogeneous Ta- and Ga-substituted LLZO solid-state electrolytes

Li7La3Zr2O12 (LLZO) is an attractive solid-state electrolyte for next-generation lithium solid-state batteries (SSB) because of its high ionic conductivity, and safety properties. Only the cubic LLZO phase has sufficient ionic conductivity, which is stabilized by substitution with elements like Ta or Ga. Ga-substituted LLZO has the highest ionic conductivity but is not stable towards metallic Li anodes, while Ta-substituted LLZO has a slightly lower conductivity but excellent reduction stability towards Li anodes. The combination of LLZO:Ga as a catholyte and LLZO:Ta as a ceramic separator for Li anodes would significantly enhance the performance of SSBs, but both materials have different processing parameters. In this work, the possibility of co-sintering LLZO:Ga|LLZO:Ta components is investigated with varying Li-excess of the LLZO:Ta phase, while the results are compared with pure references. The experiments showed a changed sintering activity, secondary phase formation, Ta- and Ga-ion diffusion, and a changed ionic conductivity when co-sintering LLZO:Ga|LLZO:Ta.

Prolonging rechargeable aluminum batteries life with flexible ceramic separator

Rechargeable aluminum batteries (RABs) are attracting significant attention for their high theoretical capacity and abundant reserves. However, the poor mechanical performance of glass fiber (GF) separators and the formation of Al dendrite severely hinder the practical cycle life of these batteries. Herein, a flexible ceramic separator was developed with simple coating technique, effectively improving the cycling stability of RABs. Compared with the commercial GF separator, this flexible ceramic separator has less thickness and superior electrolyte wettability, resulting in improved interfacial compatibility and minimized interfacial resistance. Moreover, its exceptional flexibility and toughness (stress of 39.34 MPa) coupled with uniform nanopore structure, which can effectively resist the penetration of dendrites. As expected, this ceramic flexible separator facilitates stable cycling of the symmetric battery for over 1762 h at 2 mA/cm2 and 2 mAh/cm2. It also permits the pouch Al//flake graphite full battery to achieve a coulombic efficiency of up to 90% even after 115 cycles. Apparently, this work developed the simple separator manufacturing strategy that provides an effective method to improve the cycling stability of RABs and extends the application to other types of batteries.

HE3DA Thick Tablet Electrode Architecture - Large Lithium Cells for Energy Storage

Large energy storage applications require ultimate safety, economical manufacturing and full recyclability of the batteries. HE3DA lithium battery technology platform with 3-D electrode architecture meets all these demands. The 3D cell construction, together with ceramic composite separator increases battery safety by orders of magnitude. Easy disassembling and separating of the materials after the life end of the battery makes recycling a profitable secondary source of battery materials. Recycling of this type of battery already meets parametres set for 2050.Main features of this technology and 3D cell parameters produced in the commercial production will be discussed. Advantages of these cells in large energy storage units will be demonstrated. Figure 1

Innovative Nanoscale Ceramic Separators to Boost Cycle Life and Cycle Efficiency of Lithium Metal Batteries

In the pursuit of advancing energy storage, the extraordinary theoretical specific capacity of lithium metal at 3,860 mAh/g significantly outperforms traditional graphite anodes, which offer a capacity of around 372 mAh/g. This disparity underscores the potential of lithium metal batteries to facilitate a leap in energy density, heralding a new age of high-performance batteries. Yet, the evolution of lithium metal batteries is hindered by the formation of dendritic structures during repetitive cycling, posing serious risks, including the likelihood of short circuits that underscore severe safety concerns. To mitigate these risks and enhance the longevity of lithium metal anodes, extensive research has been dedicated to various strategies, including surface modifications of lithium metal and the application of innovative coatings on separators. These strategies, however, often compromise energy density and ionic conductivity due to the addition of ceramic materials and binders. Our study introduces a groundbreaking approach that utilizes nanoscale ceramic-coated separators, created via electron beam deposition. This method achieves a consistent nanoscale spread of metal oxide particles on conventional polyethylene (PE) separators. Crucially, this technique ensures even lithium-ion flow and greatly reduces dendrite growth. The effectiveness of this innovative approach was confirmed in comprehensive LiFePO4-Li cell tests, where cells with these ceramic-coated separators showed notable improvements in both cycle life and Coulombic efficiency, representing a significant advancement over traditional methods.

Development of High-Performance LLZO Separators for Solid-State Batteries: Balancing Li Loss, Stability, and Morphology in a Tape Casting Process

Ceramic solid-state batteries (SSBs) are considered a viable alternative to lithium-ion batteries with liquid electrolytes, as they offer greater safety at the cell level. The Li7La3Zr2O12 garnet (LLZO) is a promising solid electrolyte for SSBs due to its stability with lithium metal anode and its good ionic conductivity of up to 2 mS cm-1. However, scalable and economically feasible techniques for producing LLZO-based batteries are required to make them competitive in the market.Tape casting is an industrially scalable process for producing customizable ceramic components. Successful implementation of this method requires a deep understanding of the transformation of the LLZO powder during the whole process chain, especially the effects of Li loss due to air and protic solvents interaction as well as Li evaporation during sintering.In this talk, a novel approach for fabricating thin LLZO ceramic separators by tape casting will be presented, in which lithium saltis used as a lithium mediator source in different process steps to optimize the separator properties. Using XRD, Raman spectroscopy, NMR spectroscopy, and SEM, we systematically investigate the effects of material composition and process conditions on the compositional and electrochemical performance of tape-cast LLZO separators in symmetric cells. This research provides important insights for optimizing the manufacturing process and enables the development of high-performance LLZO ceramic separators for all-solid-state batteries.

Flexible ceramic based ‘paper separator’ with enhanced safety for high performance lithium-ion batteries: Probing the effect of ceramics impregnation on electrochemical performances

Cellulose is now considered as an appealing environment friendly material for the development of sustainable separators for rechargeable batteries. This study thus aims to develop high performance paper based ceramic separators with superior electrolyte wettability (>170 %), high thermal stability (>200 °C) and excellent flame safety. While developing paper based ceramic separator, extensive studies are carried out to understand thenature and functionality of different nano-structured ceramic materials (Al2O3, BaTiO3 and ZrO2) impregnated in paper matrix. Nano-ZrO2 facilitates an effective pathway for Li +-ion transport (tLi+ = 0.51), whereas BaTiO3 and Al2O3 ceramics show moderate Li +-ion transport properties (tLi+ of 0.29 and 0.30 respectively). Electrochemical Impedance Spectroscopy (EIS) measurement clearly reveals that ZrO2 exhibits more interfacial compatibility with the electrodes (MCMB and LiNi1/3Mn1/3Co1/3O2) compared to the other two ceramic separators during full cell operation. The developed paper separators show excellent electrochemical properties in terms of cycling (tested 300 cycles), multi-electrode compatibility and rate capabilities at different current densities of 0.1–1.2 mAcm−2. The pre- and post-electrochemical EIS data reveal that ZrO2 based impregnation offers significantly lower charge transfer resistance compared to the other two separators. The study thus demonstrates a real promise for its successful application in Li-ion battery towards achieving sustainability and safety.

The trend of changes in soil organic carbon content in Poland over recent years

The article analyzes soil organic carbon (SOC) content of in Poland from 2015 to 2021. The research aims to determine SOC levels and their dependence on soil agronomic categories and drought intensity. Soil samples from 1011 farms across 8 Polish voivodships were collected for analysis, all from the same agricultural plots. SOC determination was conducted using the Tiurin method. The results indicate a low SOC content nationwide (0.85-2.35%). Heavy soils exhibited higher SOC accumulation compared to light soils. Moreover, significant drought impact led to decreased SOC content in affected regions. Scientific evidence underscores a declining trend in organic carbon stock within agricultural soils, attributed to natural soil changes and unsustainable management practices. This decline is concerning given the crucial role of SOC in soil health, quality, and crop productivity. Therefore, it is imperative to monitor and address areas with low SOC levels to enhance SOC abundance. Furthermore, when used as a whole-cell biocatalyst in a low-cost upflow MFC, the Morganella morganii-rich SF11 consortium demonstrated the highest voltage and power density of 964.93±1.86 mV and 0.56±0.00 W/m3, respectively. These results suggest that the SF11 bacterial consortium has the potential for use in ceramic separator MFCs for the removal of penicillin and electricity generation.

Development of Moisture Absorbent Ceramic-Coated Separators for Advanced Lithium-Ion Batteries

In the present human life, various electric devices and machines are worked by lithium-ion batteries (LIBs). The batteries have still remained challenges such as, the low cycling stability due to side reactions during charge-discharge cycling and the weak thermal stability at high temperatures. Accordingly, research on improving resistance to high temperatures and impregnability by coating ceramic particles and polymer binders on the surface of the separator is being conducted. The ceramic coating separator is manufactured by connecting small-sized inorganic particles to each other using a small amount of binder. The inorganic particles have high hydrophilicity and high specific surface area, so the ceramic separator has excellent wettability to the electrolyte. As a ceramic coating, alumina is currently commercialized, and a slurry is prepared by mixing a binder, etc., and then coated on a separator and then dried. LG Energy Solutions has commercialized a ceramic composite separator called SRS (Safety-reinforcing separator) and is applying it to batteries. By introducing a ceramic layer on the surface of a polyolefin-based separator, the heat resistance and mechanical strength of the separator have been greatly improved, and it has been widely used in high-capacity and large-sized batteries. when the temperature of the LIBs rises and the separator shrinks or ruptures, a large amount of lithium ions may move, making control difficult and creating a risk of explosion. Therefore, shutdown occurs, but a separator with good shape retention at high temperature is required. Accordingly, research on improving resistance to high temperatures by coating ceramic particles and a polymer binder on the surface of the separator is being conducted. In this work, Ceramic-coated separator membrane film was fabricated using aluminum fluoride (AlF3) materials for a powerful moisture (H2O) scavenger. Accordingly, research on improving high temperature resistance and impregnation property by coating ceramic particles and a polymer binder on the surface of the separator is in progress. First of all, a-AlF₃ nanorods with an average length of 1.882 μm and a diameter of 320 nm were synthesized under low supersaturation conditions. Then, PVdF-HFP [Poly(vinylidene fluoride-co-hexafluoropropylene)]-acetone solution was mixed and coated on a polypropylene membrane. The AlF₃-coated separator exhibited thermal shrinkage of 4%, 8%, and 18% at 130, 140, and 150°C, respectively, confirming that thermal stability was improved. In addition, as a result of the impregnation test, it was confirmed that the impregnation property of the coated separator was improved compared to the existing polypropylene separator. In addition, it was confirmed that the full cell manufactured using the a-AlF₃-coated membrane film has improved cycle stability and high-speed, high-capacity compared to the full cell manufactured using the existing non-coated separator.

Electricity generation in a ceramic separator microbial fuel cell employing a bacterial consortium for penicillin removal

Electricity generation in a ceramic separator microbial fuel cell employing a bacterial consortium for penicillin removal

Batteries Worth Their Salt: Targeting Next Generation Stationary Storage with Molten Salt Electrolytes

There is an imminent need for batteries capable of meeting the evolving demands of a growing stationary storage landscape, one rich in renewable energy sources and challenged with unprecedented global electrification. Key to our future electrical grid, desirable large-scale, long-duration batteries must not only meet demands for high power and energy density, but they must be safe, cost-effective, and should be sustainably sourced from earth-abundant materials. Here, we will highlight our research and development of low temperature molten salt batteries that employ active materials such as sodium, aluminum, iron, chloride, and iodide. We will demonstrate the promise of our approach through a low-temperature (100°C) molten sodium battery that comprises a molten sodium anode, a solid-state NaSICON ceramic separator, and a low-cost molten metal-halide salt catholyte. These batteries, with remarkable voltages greater than 3.1V, are capable of months of cycling as well as high current charge and discharge behavior, greater than 50mA/cm2. Here, we will not only highlight these performance metrics, but we will describe how we used specialized electrochemical and chemical characterization technique to understand the impacts of molten salt electrolyte composition, electrochemistry, and interfacial interactions on battery performance. By understanding the connections between specific electrochemical phenomena and battery chemistry, we have learned to improve battery performance through tuning of properties, such as molten salt Lewis acidity and current collector composition. This scientifically-motivated battery design approach continues to enable agile innovation and advances to realize the potential of molten salt batteries as a new, impactful stationary storage technology.Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Unveiling the electrochemical characteristics of acetonitrile-catholyte-based Na-CO2 battery

The development of metal-CO2 batteries has attracted intense attention because of their unique electrochemical reaction for utilization of CO2 gas. However, unlike the alkali metal-based O2 batteries, a limited number of combinations of aprotic electrolytes have been employed for Li(Na)–CO2 batteries due to the sluggish reaction for the formation of the Li(Na)2CO3 discharge product. Here, we demonstrate an acetonitrile (MeCN)-based catholyte for use in a hybrid cell type Na-CO2 battery. The presence of a solid ceramic separator in our hybrid cell allows the stable operation of the MeCN catholyte-based Na-CO2 battery, resulting in improved electrochemical characteristics such as low overpotential, high energy density, and long cycle stability compared to the conventional TEGDME-based electrolyte. In particular, results of molecular dynamics simulations suggest that the improved performance is mainly due to the enhanced Na+ diffusion in the electrolyte. The calculated barrier for Na+ diffusion in MeCN is approximately four times lower than that in TEGDME. Thus, this work provides a promising electrolyte combination and reveals the mechanism for the improved performance of the MeCN-based electrolyte used in the hybrid cell structure, promoting the development of Na-CO2 batteries as practical secondary energy storage devices.

Pharmaceutical wastewater treatment in ceramic separator MFC: Optimisation of operating parameters to improve organic removal and power generation

Microbial fuel cell (MFC) can be used to simultaneously treat wastewater and generate energy using microorganisms as biocatalysts. To improve its performance, optimization of the various process variables and determination of effects of their interactions needs to be explored. In the present study, a full factorial statistical experimental design study of 11 runs was conducted to analyse the effect of influent COD (1500–3500 mg/L), pH (5–9) and recirculation ratio (0–1:1) on power density and COD removal efficiency while treating pharmaceutical wastewater. Statistical models were developed using full factorial design (α = 0.05, p < 0.05). The main effects of the all the three factors were found to be significant on COD removal efficiency; however, the interaction effects were found to be insignificant. On the other hand, the main effects as well as the interaction effect of COD and pH were found to be significant on power density. It was predicted that the optimum COD removal efficiency of 68 % and power density of 219.4 mW/m3 can be achieved in an MFC with an influent COD of 1960 mg/L and pH of 8.9 at a recirculation ratio of 0.99.

Integrating Microbial Fuel Cell and Hydroponic Technologies Using a Ceramic Membrane Separator to Develop an Energy-Water-Food Supply System.

In this study, a microbial fuel cell was integrated into a hydroponic system (MFC-Hyp) using a ceramic membrane as a separator. The MFC-Hyp is a passive system that allows the transport of nutrients from wastewater in the microbial fuel cell (MFC) to water in the hydroponic vessel (Hyp) through a ceramic membrane separator, with no external energy input. The performance of this system was examined using potato-process wastewater as a source of energy and nutrients (K, P, N) and garlic chives (Allium tuberosum) as a hydroponic plant. The results showed that based on dry weight, the leaves of Allium tuberosum grew 142% more in the MFC-Hyp than those of the plant in the Hyp without the MFC, in a 49-day run. The mass fluxes of K, P, and NO3--N from the MFC to the Hyp through the ceramic membrane were 4.18 ± 0.70, 3.78 ± 1.90, and 2.04 ± 0.98 µg s-1m-2, respectively. It was apparent that the diffusion of nutrients from wastewater in the MFC enhanced the plant growth in the Hyp. The MFC-Hyp in the presence of A. tuberosum produced the maximum power density of 130.2 ± 45.4 mW m-2. The findings of this study suggest that the MFC-Hyp system has great potential to be a "carbon-neutral" technology that could be transformed into an important part of a diversified worldwide energy-water-food supply system.

Influence of Interfacial Voids and Grain Boundary Conductivity on Depletion Kinetics of Sodium Metal Anodes in All-Solid-State Batteries

An electrochemical micro-scale phase-field model is developed to simulate the stripping and plating kinetics of a Na-metal anode in all-solid-state Na-ion batteries. In this model, in addition to the metallic anode and ceramic separator regions, a highly conductive but Na-poor region representing the free space is assumed to simulate the shrinking of the Na-anode during electro-stripping and its growth during plating. For a perfect anode/separator interface, we find that the growth and depletion kinetics are linear. However, the presence of multiple interfacial voids at the anode/separator interface causes deviation from this linear behaviour. Finally, we show that depletion kinetics is also proportional to the ratio of the grain boundary conductivity to that of the grain conductivity (σgb/σg) in the separator phase, either with or without interfacial voids.

(Invited) Novel Materials for Future Li-Ion Batteries

Advancements in the capabilities of lithium-ion batteries have slowed down in the last decade. As conventional electrode materials approach their theoretical limits, substantial gains in battery energy density only come as a trade-off in safety or performance. This talk will discuss how replacing conventional active and inactive materials will significantly improve performance, drastically reduce the cost of Li-ion batteries, and pave the way for renewable energy technologies. For example, Sila's innovative drop-in-replacement nanocomposite silicon-based anode powder offers over five times higher gravimetric capacity than graphite, permits both fast charging and over 20% more energy density today over state-of-the-art lithium-ion, and enables radical product innovation - all without compromising performance. Most importantly, this material has been shipping for over a year and is scaling up for massive electric vehicle (EV) use by mid-decade.With Sila’s industrialized and scaled scientific innovation, wearables, portable electronics, and EV manufacturers can create breakthrough products today that will minimize our environmental impact tomorrow. This talk will also provide multiple examples of lightweight conversion-type cathodes, flexible ceramic separators, and other technologies that may become instrumental for the transition to a clean and energy-sustainable economy.

Raspberry-like micro-size polymer with high spherical shape-retention capability and adhesion as binder for ceramic separators

Surface coating with binders and ceramic particles is one of the most effective strategies to enhance thermal stability and electrolyte wettability of polyolefin separators, yet is still challenged by the issue of hole blocking and contradiction between adhesion and thermostability of binders. Herein, a raspberry-like micro-size polymer (RMP) binder with a soft core inside and hard spheres outside was prepared through seed swelling polymerization. The micron size helps RMP binder to effectively bond separator and electrode, solving the pore blocking problem encountered with traditional liner binders. The raspberry-like structure combines softness and rigidity, ensuring both high spherical shape-retention capability and good binding strength. The ceramic separator with RMP binder shows low thermal shrinkage and high ionic conductivity, achieving high cycling stability and low impedance of the batteries. This work provides new inspiration to construct novel binders for ceramic-coated separators with long-term stability for high-performance lithium-ion batteries.

Modified ceramic coated polyethylene separator – A strategy for using lithium metal as anode with superior electrochemical performance and thermal stability

Herein, we report the Li-ion conducting composite material, Li0.57La0.29TiO3 (LLTO), coated on a microporous polyethylene separator to use in rechargeable Lithium-metal batteries. Since the LLTO contains structural Li-ions and the three-dimensional conducting channels within, it not only improved the ionic conductivity of coated separator but also improved the surface electrolyte wettability and suppressed the dendrite formation. As a result, the Lithium-metal battery cycling stability and safety features are increased. Consequently, the ceramic composite separator enabled a specific capacity of 105.6 mAhg−1 for Li/LiMn2O4 coin cell, and 80 % capacity retention is observed even after 500 cycles at 1C, indicating its promising practical potential application. This work provides a feasible and efficient modification strategy of separators for improving the cycling performance and safety of Lithium-metal batteries. In addition, the ceramic composite-coated separator could instill confidence in using Lithium metal as the attractive anode for high-capacity Li-air and Li‑sulfur batteries with enhanced thermal and cyclic stability.

Non-flammable free-standing TiO2 nanotubular hybrid membrane prepared by a two-step anodization

In this study, we introduce a novel method for synthesizing a free-standing, high-aspect-ratio TiO2 nanotubular (TNT) hybrid membrane. The TNT membrane was fabricated using a two-step electrochemical anodization process, incorporating lactic acid as an additive to enhance mechanical properties and growth rate. The membrane was then hybridized with a rubber polymer binder. The high aspect ratio and structural integrity of the TiO2 nanotubular hybrid membrane make it an ideal candidate for improving non-flammable properties when employed as a ceramic separator. Flame retardation tests revealed that the TNT hybrid membrane kept its structural integrity even after prolonged exposure to flame. These findings suggest that this hybrid membrane could be a valuable addition to the field of secondary batteries, offering potential applications in enhancing battery safety and performance.

Polyethylene ceramic separators with semi-interpenetrating polymer network boosting fast-charging cycle capacity retention and safety for lithium-ion batteries

Fast-charging lithium-ion batteries (LIBs) have recently received significant attention. In current commercial LIBs, lithium precipitation frequently occurs under long-term cycling and fast-charging conditions, adversely affecting their cycle capacity retention and safety. The primary cause of lithium precipitation is electrolyte loss during long-term cycling. In this study, a thermoplastic polyurethane/polyurethane acrylate semi-interpenetrating polymer network ceramic separator with high electrolyte retention (200%) and interfacial adhesion (6.6 N) is prepared and without a decrease in the energy density. The LiNi0.8Mn0.1Co0.1O2/graphite batteries fabricated with this separator show excellent electrochemistry properties (300 cycles, 1.5 C, discharge capacity of 3677 mAh, capacity retention of 93%). Furthermore, this study presents a novel strategy to mitigate the issue of lithium precipitation in fast-charging LIBs. Therefore, this functional separator is a promising alternative for the conventional commercial polyvinylidene difluoride separators and provides a new avenue for developing the next generation of fast-charging devices.