mS Cm-1 Research Articles

Poly(Vinyl Alcohol)/Poly(Acrylic Acid) Gel Polymer Electrolyte Modified with Multi-Walled Carbon Nanotubes and SiO2 Nanospheres to Increase Rechargeability of Zn-Air Batteries.

Zn-air batteries (ZABs) are a promising technology; however, their commercialization is limited by challenges, including those occurring in the electrolyte, and thus, gel polymer electrolytes (GPEs) and hydrogels have emerged as substitutes for traditional aqueous electrolytes. In this work, PVA/PAA membranes were synthesized by the solvent casting method and soaked in 6 M KOH to act as GPEs. The thickness of the membrane was modified (50, 100, and 150 μm), and after determining the best thickness, the membrane was modified with synthesized SiO2 nanospheres and multi-walled carbon nanotubes (CNTs). SEM micrographs revealed that the CNTs displayed lengths of tens of micrometers, having a narrow diameter (95 ± 7 nm). In addition, SEM revealed that the SiO2 nanospheres had homogeneous shapes with sizes of 110 ± 10 nm. Physicochemical experiments revealed that SiO2 incorporation at 5 wt.% increased the water uptake of the PVA/PAA membrane from 465% to 525% and the ionic conductivity to 170 mS cm-1. The further addition of 0.5 wt.% CNTs did not impact the water uptake but it promoted a porous structure, increasing the power density and the stability, showing three-times-higher rechargeability than the ZAB operated with the PVA/PAA GPE.

Enhancing Lithium Conductivity Using High-Valence Cations in Cubic Spinel Halide Solid Electrolytes.

Halide solid electrolytes for all-solid-state batteries have recently emerged as competitors to oxide and sulfide solid electrolytes due to their excellent electrochemical properties. This ab initio study unveils the dynamic nature of Li2Sc2/3Cl4, a rare superionic conductor among cubic spinel halide materials. Li ions in Li2Sc2/3Cl4 prefer to occupy some of the tetrahedral 8a, octahedral 16c, and octahedral 16d sites, leading to disordered Li distribution. Li ions in Li2Sc2/3Cl4 diffuse through the single-ion diffusion mechanism rather than the concerted diffusion mechanism, providing a high conductivity of 1.36 mS cm-1. Li ions at the 16d site diffuse as actively as those at the 8a/16c site, an unexpected result that runs counter to the conventional view. In Li2MgCl4, the same cubic spinel as Li2Sc2/3Cl4, Li ions at the 8a/16c site diffuse actively, but those at the 16d site are almost immobile, resulting in a very low conductivity of 5.3 × 10-4 mS cm-1. The extremely higher conductivity in Li2Sc2/3Cl4 than in Li2MgCl4 is because the concentration of Sc3+/Mg2+ cations blocking the movement of Li ions at the 16d site is lower in Li2Sc2/3Cl4 than in Li2MgCl4. Designing cubic spinel materials containing high-valence cations is proposed as a way to increase conductivity by reducing the concentration of multivalent cations that impede Li diffusion. This study sheds new light on how to control conductivity using site-dependent Li mobility in solid electrolytes.

2PP-Hydrogel Covered Electrodes to Compensate for Media Effects in the Determination of Biomass in a Capillary Wave Micro Bioreactor.

Microbioreactors increase information output in biopharmaceutical screening applications because they can be operated in parallel without consuming large quantities of the pharmaceutical formulations being tested. A capillary wave microbioreactor (cwMBR) has recently been reported, allowing cost-efficient parallelization in an array that can be activated for mixing as a whole. Although impedance spectroscopy can directly distinguish between dead and viable cells, the monitoring of cells in suspension within bioreactors is challenging because the signal is influenced by the potentially varying properties of the culture medium. In order to address this challenge, an impedance sensor consisting of two sets of microelectrodes in a cwMBR is presented. Only one set of electrodes was covered by a two-photon cross-linked hydrogel to become insensitive to the influence of cells while remaining sensitive to the culture medium. With this impedance sensor, the biomass of Saccharomyces cerevisiae could be measured in a range from 1 to 20 g L-1. In addition, the sensor can compensate for a change in the conductivity of the suspension of 5 to 15 mS cm-1. Moreover, the two-photon cross-linking of hydroxyethyl starch methacrylate hydrogel, which has been studied in detail, recommends itself for even much broader sensing applications in miniaturized bioreactors and biosensors.

Tuning the Properties of Halide Nanocomposite Solid Electrolytes with Diverse Oxides for All-Solid-State Batteries.

Herein, we report halide nanocomposite solid electrolytes (HNSEs) that integrate diverse oxides with alterations that allow tuning of their ionic conductivity, (electro)chemical stability, and specific density. A two-step mechanochemical process enabled the synthesis of multimetal (or nonmetal) HNSEs, MO2-2Li2ZrCl6, as verified by pair distribution function and X-ray diffraction analyses. The multimetal (or nonmetal) HNSE strategy increases the ionic conductivity of Li2ZrCl6 from 0.40 to 0.82 mS cm-1. Additionally, cyclic voltammetry test findings corroborated the enhanced passivating properties of the HNSEs. Notably, incorporating SiO2 into HNSEs leads to a substantial reduction in the specific density of HNSEs, demonstrating their strong potential for achieving a high energy density and lowering costs. Fluorinated SiO2-2Li2ZrCl5F HNSEs exhibited enhanced interfacial compatibility with Li6PS5Cl and LiCoO2 electrodes. Cells employing SiO2-2Li2ZrCl5F with LiCoO2 exhibit superior electrochemical performance delivering the initial discharge capacity of 162 mA h g-1 with 93.7% capacity retention at the 100th cycle at 60 °C.

Pristine NASICON Electrolyte: A High Ionic Conductivity and Enhanced Dendrite Resistance Through Zirconia (ZrO2) Impurity-free Solid-Electrolyte Design.

Sodium batteries are considered a promising candidate for large-scale grid storage at tropical climate zone, and solid-state sodium metal batteries have a strong proposition as high energy density battery. The main challenge is to develop ultra-pure solid-state ceramic electrolyte and compatible metal interface. Here, a scalable and energy-efficient synthesis strategy of sodium (Na) Super Ionic CONductor, Na1+xZr2SixP3-xO12(x = 2, NZSP) solid electrolyte, has been introduced with the complete removal of unreacted zirconium oxide (ZrO2) impurities. Additionally, the reaction mechanism for the formation of pure phase NZSP is reported for the first time. The NZSP prepared by utilizing the Zr precursor, i.e., tetragonal zirconium oxide (t-ZrO2) derived from the Zr(OH)4 gets quickly and completely consumed in the synthesis process leaving no unreacted monoclinic ZrO2 impurities. The synthesis process only needs a minimum stay of 4 h, which is three times less than the conventional synthesis method. The elimination of ZrO2 impurities results in a 2.5-fold reduction in grain boundary resistivity, showcasing a total ionic conductivity of 1.75 mS cm-1 at room temperature and a relative density of 98%. The prepared electrolyte demonstrates remarkable resistance to dendrite formation, as evidenced by a high critical current density value of 1.4mA cm-2.

Missing-Linker Defect Functionalized Metal-Organic Frameworks Accelerating Zinc Ion Conduction for Ultrastable All-Solid-State Zinc Metal Batteries.

Solid-state polymer electrolytes (SPEs) are promising for high-performance zinc metal batteries (ZMBs), but they encounter critical challenges of low ionic conductivity, limited Zn2+ transference number (tZn2+), and an unstable electrolyte-electrode interface. Here, we present an effective approach involving a missing-linker metallic organic framework (MOF)-catalyzed poly(ethylene glycol) diacrylate (PEGDA)/polyacrylamide (PAM) copolymer SPE for single Zn2+ conduction and seamless electrolyte-electrode contact. The single-Zn2+ conduction is facilitated by the anchoring of the OTF- anions onto the unsaturated metal sites of missing-linker MOF, while the PEGDA and PAM chains in competitive coordination with Zn2+ ions promote rapid Zn ion transport. Our all-solid-state electrolyte simultaneously achieves a superior ionic conductivity of 1.52 mS cm-1 and a high tZn2+ of 0.83 at room temperature, alongside uniform Zn metal deposition (1000 cycles in symmetric cells) and high Zn plating/striping efficiencies (>99% after 600 cycles in asymmetric cells). Applications of our SPE in Zn//VO2 full cells are further demonstrated with a long lifespan of 2000 cycles and an extremely low-capacity degradation rate of 0.012% per cycle. This work provides an effective strategy for using a missing-linker MOF to catalyze competitively coordinating copolymers for accelerating Zn2+ ion conduction, assisting the future design of all-solid-state ZMBs.

Simultaneous Inhibition of Vanadium Dissolution and Zinc Dendrites by Mineral-Derived Solid-State Electrolyte for High-Performance Zinc Metal Batteries.

Designing solid electrolyte is deemed as an effective approach to suppress the side reaction of zinc anode and active material dissolution of cathodes in liquid electrolytes for zinc metal batteries (ZMBs). Herein, kaolin is comprehensively investigated as raw material to prepare solid electrolyte (KL-Zn) for ZMBs. As demonstrated, KL-Zn electrolyte is an excellent electronic insulator and zinc ionic conductor, which presents wide voltage window of 2.73 V, high ionic conductivity of 5.08 mS cm-1, and high Zn2+ transference number of 0.79. For the Zn//Zn cells, superior cyclic stability lasting for 2200 h can be achieved at 0.2 mA cm-2. For the Zn//NH4V4O10 batteries, stable capacity of 245.8 mAh g-1 can be maintained at 0.2 A g-1 after 200 cycles along with high retention ratio of 81%, manifesting KL-Zn electrolyte contributes to stabilize the crystal structure of NH4V4O10 cathode. These satisfying performances can be attributed to the enlarged interlayer spacing, zinc (de)solvation-free mechanism and fast diffusion kinetics of KL-Zn electrolyte, availably guaranteeing uniform zinc deposition for zinc anode and reversible zinc (de)intercalation for NH4V4O10 cathode. Additionally, this work also verifies the application possibility of KL-Zn electrolyte for Zn//MnO2 batteries and Zn//I2 batteries, suggesting the universality of mineral-based solid electrolyte.

Superionic halide solid electrolyte Li1.7Zr0.7Ta0.3Cl6 for durable all-solid-state lithium batteries

Zirconium-based halide solid electrolyte, Li2ZrCl6, with low raw-material cost and high oxidative stability is a promising candidate for next-generation energy storage devices. However, the low ionic conductivity hinders its practical applicability. Herein, we report a new zirconium-based superionic conductor based on high-valence Ta5+ doping strategy. The optimized Li1.7Zr0.7Ta0.3Cl6 (LZTC) exhibits excellent ionic conductivity of 1.42 mS cm-1 at 25 °C. Moreover, it can be further increased up to 1.68 mS cm-1 with a low activation energy of 0.28 eV by slightly tuning Li+ concentration. In addition, LZTC possesses a big compact density of 2.67 g cm-3 under 250 MPa and is compatible with 4V-class cathodes. Density function theory (DFT) and bond valence site energy (BVSE) calculations reveal Ta5+ substitution significantly reduces the migration energy barrier of lithium ions due to the distortions and defects of local structural environment. The assembled all-solid-state batteries with Li1.7Zr0.7Ta0.3Cl6 as electrolyte and scNCM811 as cathode show excellent cycling performance for 600 cycles at 1C with a high-capacity retention of 85.7%.

Regulation of Molecular Microheterogeneity in Electrolytes Enables Ampere-Hour-Level Aqueous LiMn2O4||Li4Ti5O12 Pouch Cells.

Aqueous batteries are attractive due to their high safety and fast reaction kinetics, but the narrow electrochemical stability window of H2O limits their applications. It is a big challenge to broaden the electrochemical operation window of aqueous electrolytes while retaining fast reaction kinetics. Here, a new organic aqueous mixture electrolyte of manipulatable (3D)molecular microheterogeneity with H2O-rich and H2O-poor domains is demonstrated. H2O-poor domains molecularly surround the reformed microclusters of H2O molecules through interfacial H-bonds, which thus not only inhibit the long-range transfer of H2O but also allow fast and consecutive Li+ transport. This new design enables low-voltage anodes reversibly cycling with aqueous-based electrolytes and high ionic conductivity of 4.5 mS cm-1. LiMn2O4||Li4Ti5O12 full cells demonstrate excellent cycling stability over 1000 cycles under various C rates and a low temperature of -20°C. 1 Ah pouch cell delivers a high energy density of 79.3Wh kg-1 and high Coulombic efficiency of 99.4% at 1 C over 200 cycles. This work provides new insights into the design of electrolytes based on the molecular microheterogeneity for rechargeable batteries.

Enhancing Cycle Life of Rechargeable Zinc Hybrid Batteries in a Low-Cost, Nonfluorinated Dual-Cation Electrolyte.

Rechargeable zinc batteries (RZBs) are highly attractive as energy storage solutions due to their low cost and sustainability. Nevertheless, the use of fluorine-free zinc electrolyte systems to create affordable, ecofriendly, and safe RZBs has been largely overlooked in the battery community. Previously, we showcased the utilization of a fluorine-free, nonaqueous electrolyte comprising zinc dicyanamide (Zn(dca)2) in dimethyl sulfoxide (DMSO) to enable the electrochemical cycling of zinc. Herein we present a dual-cation-based electrolyte, [1.0 M Na(dca) +1.0 M Zn(dca)2]/DMSO, in pursuit of a rechargeable zinc hybrid battery. Fourier-transform infrared spectroscopy and molecular dynamics simulation studies indicate that the presence of Na(dca) diminishes ion-pairing in Zn(dca)2 through [dca]- anion bridging between Zn2+ and Na+ ions, thereby enhancing Zn2+ ion transport in the electrolyte. Thus, the electrolyte exhibits high ionic conductivity and transference numbers (tZn2+) of 7.9 mS cm-1 and 0.83, respectively, at 50 °C, making it particularly suitable for high-temperature battery applications. Furthermore, we demonstrate, for the first time, the cycling of a full cell with a zinc anode and triphylite sodium iron phosphate cathode (NFP) in an organic electrolyte, showcasing stable performance over 100 cycles at 0.1C rate. These encouraging findings pave the way for affordable battery technologies using, fluorine-free electrolyte.

Non-composted and blended agro-industrial by-products an as alternative soilless substrate affect potted zonal geranium (Pelargonium x hortorum) and murva (Murraya paniculata) production

Due to their hiking prices and import restrictions, peat moss and coco coir are not readily available in many developing countries including Pakistan. Therefore, it is necessary to explore alternative soilless substrates having low cost and comparable physico-chemical properties with peat moss and coco coir for local and global market. For this purpose, indigenous agro-industrial by-products, viz., sesame straw, date palm coir, sugarcane pressmud, sugar beet waste and pine bark were collected, cleaned, crushed (where needed) and blended for physico-chemical analyses. Zonal geranium ‘Pinto White’ and murva (Murraya paniculata Kaneh.) were used to evaluate the efficacy of various combinations of substrates on plant growth and production. Three experiments were conducted with six treatments of each experiment replicated three times. Blending of sesame straw with sugarcane pressmud and pine bark (4:4:2 by volume) yielded best results and marketable plants were produced with tallest height (35.8 cm), canopy diameter (20.8 cm), leaf area (29.2 cm2), leaf total chlorophyll contents (62.1 SPAD) and flowers per plant (5.0 No.) along with shortest production time (103 days). Same results were recorded when murva plants were grown in 4:4:2 blending of sesame straw, sugarcane pressmud and pine bark. Zonal geranium and murva plants did not perform well when sesame straw was blended with date palm coir and sugar beet waste. Blending of sesame straw with sugarcane pressmud and pine bark had low pH (7.0), electrical conductivity (1.37 mS cm-1), bulk density (0.29 g cm-3) while high water retention (34.7 %) as compared to other blended substrates. However, shrinkage of substrates in containers was highest (7.7 %) when sesame straw was blended with sugarcane pressmud and pine bark in 5:3:2 followed by 4:4:2. pH value of all blended substrates decreased at termination except when sesame straw, sugarcane pressmud and pine bark were blended in 4:4:2 and 5:2:3, which was increased from 7.0 to 7.1. Electrical conductivity of all blended substrates was decreased at termination of the experiments. It can be concluded that blending of sesame straw, sugarcane pressmud and pine bark in 4:4:2 (v/v/v) significantly improved physico-chemical characteristics of substrates as well as plant growth and production attributes of zonal geranium and murva. Therefore, this indigenous soilless substrate, which is cheaper and readily available to nurserymen can be used as alternative of peat moss and coco coir for containerized plant production.

Engineering Robust Triazine Crosslinked and Pyridine Capped Anion Exchange Membrane for Advanced Water Electrolysis.

Exploring high-performance anion exchange membranes (AEM) for water electrolyzers (AEMWEs) is significant for green hydrogen production. However, the current AEMWEs are restricted by the poor mechanical strength and low OH- conductivity of AEMs, leading to the low working stability and low current density. Here, we develop a robust AEM with polybiphenylpiperidium network by combining the crosslinking with triazine and the capping with pyridine for advanced AEMWEs. The AEM exhibits an excellent mechanical strength (79.4 MPa), low swelling ratio (19.2 %), persistent alkali stability (» 5,000 hours) and high OH- conductivity (247.2 mS cm-1) which achieves the state-of-the-art AEMs. Importantly, when applied in AEMWEs, the corresponding electrolyzer equipped with commercial nickel iron and nickel molybdenum catalysts obtained a current density of up to 3.0 A cm-2 at 2 Vand could be stably operated ~430 h at a high current density of 1.6 A cm-2, which exceeds the most of AEMWEs. Our results suggest that triazine crosslinking and pyridine capping can effectively improve the overall performance of the AEMWEs.

Core-shell nanofiber separator incorporated with PDA-PEI co-modified Li0.33La0.57TiO3 nanowires prepared by co-axial electrospinning for dendrite-free lithium metal batteries

The core-shell nanofibers containing PDA-PEI co-modified Li0.33La0.57TiO3 (LLTO) perovskite nanowires in the shell layer were fabricated by co-axial electrospinning technique to apply as separator in dendrite-free lithium metal batteries. The PVDF-HFP with good mechanical properties and polar C–F bonds was used as the core material, and polyacrylonitrile (PAN) with high thermal stability was employed as the shell layer in nanofibers. The PDA-PEI co-modified Li0.33La0.57TiO3 nanowires, reacting with PF6− anions in LiPF6 salt can not only capture free anions but also provide a lithium-ion migration pathway. Moreover, the core-shell structured nanofibers exhibited high mechanical strength (9.2 N/mm2), robust thermal stability (>0% at 200 °C for 1 h), and favorable electrolyte affinity (electrolyte uptake of 732%). Gelation of PVDF-HFP in liquid electrolyte leads to high-ionic conductivity (3.52 mS/cm), Li+ transference number (tLi+ = 0.68), uniform Li+ flux, and smooth Li deposition. The Li plating/stripping test consisting of Li–Li cells (with CS/LLTO-PDA-PEI) carried out at 0.4 mA/cm2 was conducted for 1000 h without a short circuit. NCM-Li and NCM-Gr coin cells using the CS (core-shell)/LLTO-PDA-PEI separator retained long-term cycle stability and good Coulombic efficiency (CE).

Entropy-Driven Hydrated Eutectic Electrolytes with Diverse Solvation Configurations for All-Temperature Zn-ion Batteries.

Batteries always encounter uncontrollable failure or performance decay under extreme temperature environments, which is largely limited by the properties of electrolytes. Herein, an entropy-driven hydrated eutectic electrolyte (HEE) with diverse solvation configurations is proposed to expand the operating temperature range of Zn-ion batteries. The HEE possesses over 40 types of Zn2+ solvation structure with uniform distribution, contributing to its much higher solvation configurational entropy compared to the conventional aqueous counterpart (only 6 types). These effectively promote its anti-freezing ability under ultralow temperatures, with a high ionic conductivity of 0.42 mS cm-1 even at a low temperature of -40 °C. Moreover, the entropy-driven property can simultaneously enhance the thermal stability under a high temperature over +140 °C. Therefore, the HEE can enable full cells stably working over a wide temperature range of -40~+80 °C, performing over 1500 cycles with 100 % capacity retention at -40 °C and 1000 cycles with ~72 % capacity retention at +80 °C. This inspiring concept of entropy-driven electrolyte with quantized solvation configurational entropy value has charming potential for designing future special batteries with excellent adaptability towards extreme temperature environments.

Charge-Delocalized Triptycene-Based Ionic Porous Organic Polymers as Quasi-Solid-State Electrolytes for Lithium Metal Batteries.

Ideal solid electrolytes for lithium (Li) metal batteries should conduct Li+ rapidly with low activation energy, exhibit a high Li+ transference number, form a stable interface with the Li anode, and be electrochemically stable. However, the lack of solid electrolytes that meet all of these criteria has remained a considerable bottleneck in the advancement of lithium metal batteries. In this study, we present a design strategy combining all of those requirements in a balanced manner to realize quasi-solid-state electrolyte-enabled Li metal batteries (LMBs). We prepared Li+-coordinated triptycene-based ionic porous organic polymers (Li+@iPOPs). The Li+@iPOPs with imidazolates and phenoxides exhibited a high conductivity of 4.38 mS cm-1 at room temperature, a low activation energy of 0.627 eV, a high Li+ transference number of 0.95, a stable electrochemical window of up to 4.4 V, excellent compatibility with Li metal electrodes, and high stability during Li deposition/stripping cycles. The high performance is attributed to charge delocalization in the backbone, mimicking the concept of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), which facilitates the diffusion of coordinated Li+ through the porous space of the triptycene-based iPOPs. In addition, Li metal batteries assembled using Li+@Trp-Im-O-POPs as quasi-solid-state electrolytes and a LiFePO4 cathode showed an initial capacity of 114 mAh g-1 and 86.7% retention up to 200 cycles.

Investigating the Influence of Sintering Temperature and Ascertaining Hopping Path in Sodium Superionic Conducting Electrolytes for Sodium-Ion Batteries

Recently, sodium super-ionic conducting (NASICON) type solid electrolytes have gained significant interest as potential candidates for next-generation batteries due to their exceptional properties such as high ionic conductivity, affordability, and remarkable chemical and electrochemical stability. Therefore, NASICON type solid electrolyte (Na3Zr2Si2PO12) is synthesized by solution assisted-solid state reaction (SA-SSR) method and sintered at three different temperatures, 1200 ℃, 1250 ℃ and 1300 ℃. Various experimental techniques are used to characterize and optimize the sintered electrolytes. The Rietveld refinement of X-ray diffraction pattern of prepared electrolytes revealed the monoclinic crystal structure having 3-dimension hopping channel for sodium ion migration through triangular bottleneck area. Complex impedance spectroscopy revealed, the highest bulk and grain boundary conductivity are found, 4.05 mS cm-1 and 0.31 mS cm-1, respectively, for the sample sintered at 1250 ℃. Using optimized electrolyte, sodium half-cell is demonstrated with Na3V2P3O12 (NVP) as cathode. The assembled cell delivers maximum discharge capacity 101.6 and 84.45 mAh g-1 at the current density 10 and 40 mA g-1, respectively with good capacity retention (~95.02%) upto 50 cycles. Figure 1

Role of Halogen Elements in Conductivity and Electrochemical Stability of Sulfide Based Solid Electrolytes

All-solid-state batteries (ASSBs) are a promising candidate for future energy storage technology with better safety and higher energy density [1]. Safety of solid state batteries come from solid electrolytes used instead of organic liquid electrolytes in conventional Li-ion batteries. The various types of solid electrolytes have already been reported for SSBs which can be divided into oxides, sulfides, halides and polymers based on their properties, advantages and disadvantages [2]. Among them, sulfide based solid electrolytes have advantages over other due to high conductivity and ductile nature of sulfides [3]. The discovery of Li10GeP2S12 solid electrolyte called LGPS structured sulfide electrolyte have shown great potential to replace liquid electrolyte as ionic conductivity of LGPS was found 1.2×10-2 S cm-1 at room temperature comparable to the conductivity of organic liquid electrolyte [4]. However, Li10GeP2S12 electrolyte suffers with poor cyclability in solid state batteries due to reduction of Ge+4 ions to Ge0, and instable against lithium metal anode [5, 6].The solid electrolytes (SEs) with high conductivity and better stability against lithium metal are most important requirements for successful commercialization of solid state battery (SSB) technology. Therefore, in the search for new SEs with above mentioned qualities, halogen elements (Cl, Br, I) are explored in Li-P-S-O system to prepare Li10GeP2S12 (LGPS) structured SEs. In all prepared SEs, LPSOBr and LPSOI compositions show highest conductivities of 0.55 mS cm-1 and 0.67 mS cm-1 at 25 °C. The phase identification of newly synthesized solid electrolytes is done by X-ray diffractometer technique along with Rietveld refinement analysis. The conductivity of prepared solid electrolytes is determined by electrochemical impedance spectroscopy. These similar compounds also show superior stability against lithium metal in symmetric cells (Li/Ses/SE) as well as in full SSB cells (NCA/SEs/graphite) tested with LiNi0.8Co0.15Al0.05O2 cathode and graphite anode. These compounds also show 5 times higher stability in ambient environment conditions as compared to non-doped LPSO compound.

In Situ Sodium Plating and Stripping at the Aluminum/Nasicon Interface

Solid-state sodium metal batteries have emerged as compelling alternatives to lithium-ion batteries due to their abundance, geopolitical stability, and cost. However, the development of solid-state sodium metal batteries faces challenges such as achieving high ionic conductivity in solid electrolytes, ensuring stable interfaces between the solid electrolyte and sodium metal anode, as well as the complexity of manufacturing due to the air reactivity of sodium metal. To overcome these challenges, the anode-free manufacturing process to fabricate is a promising approach to enable the commercialization of sodium metal batteries.In this work Na3.4Zr2Si2.4P0.6O12 (NaSICON) was synthesized and densified to >99 % relative density with a total ionic conductivity of 5 mS cm-1 using a solution assisted solid-state reaction process followed by rapid induction hot-pressing, respectively. Using the hot-pressed NaSICON in an anode-free cell design, we demonstrate the feasibility and ease of using commercially available aluminum foil with a sputtered metal layer as the current collector (CC). We show stable sodium plating of several microns at the NaSICON | CC interface with a current density of 0.5 mA cm-2 at room temperature. In addition, this study demonstrates good reversibility after several cycles of plating and stripping.This study not only explores the electrochemical behavior of in situ sodium plating contributing to the advancement of cost-effective energy storage solutions, but also offers valuable insights into practical manufacturing processes for solid-state sodium metal batteries.

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.

Solid-State Lithium-Ion Superionic Electrolytes with Reduced Moisture Sensitivity

The remarkable safety and high energy density of solid-state batteries (SSBs) created significant advantages in the development of next-generation energy storage. The properties of these batteries are highly dependent on the characteristics of solid-state electrolytes (SSEs), making them a crucial material in the development of such batteries. Following diverse principles of material design, lithium halide SSEs, particularly Li3InCl6, open new opportunities in the development of SSBs due to their unique properties including broad electrochemical stability window, high lithium-ion conductivity, and excellent deformability. Through a mechano-thermal synthesis approach, Li3InCl6 demonstrates substantial ionic conductivity at room temperature. We studied the temperature-dependent behavior of Li3InCl6 by using in-situ/operando techniques such as XRD and XPS. However, its susceptibility to moisture poses a significant challenge for practical implementation in SSBs. To overcome this limitation, this research is focused on a novel solution: hafnium doping of Li3InCl6. Integrating hafnium into the Li3InCl6 structure results in a substantial improvement in electrochemical performance. The Li2.6In0.6Hf0.4Cl6 solid-state electrolyte not only showcases heightened ionic conductivity but also demonstrates improved resistance to moisture. The achieved ionic conductivity reaches approximately 1 mS cm-1, marking a significant 3.5-fold increase compared to Li3InCl6. Noteworthy is the fact that, after 5 hours of exposure to air with 15% humidity, the observed reduction in ionic conductivity for Li2.6In0.6Hf0.4Cl6 is 37%, a notably lower decrease compared to the 57% reduction seen in Li3InCl6.The efficacy of hafnium doping provides a crucial advancement in the field of solid-state electrolytes, promising a transformative impact on next-generation energy storage systems.