Novel Mn2+-doped NASICON glass-ceramic electrolyte with engineered columnar microstructure for high lithium-ion conductivity

Glass-ceramic electrolytes are poised to revolutionize energy storage as breakthrough candidates for next-generation all-solid-state lithium batteries. This study introduces a high-performance and new Mn-doped NASICON-type (Li1.2Mn0.1Ti1.9(PO4)3) phase within a glass-ceramic electrolyte, synthesized via a melt-quenching and crystallization protocol. Crystallization analysis reveals a surface-to-bulk phase transformation via a one-dimensional nucleation process, with a low activation energy of 161.68 kJ.mol-1, enabling a Li-enriched NASICON matrix at reduced temperatures. Structural characterization through Rietveld-refined XRD, and 7Li and 31P MAS NMR spectroscopy, verified Mn2+ substitution within the crystal lattice, causing bottleneck size expansion and weakened Li+-O bonding, enhancing ion mobility. FT-IR and Raman spectra further confirm the successful formation of the Li-rich NASICON phase. SEM/TEM imaging revealed a unique columnar grain morphology that reduces grain boundary areas and porosity, while the residual glass phase (11.2%) enhances interfacial Li⁺ transfer. The optimized LMnTP-0GC composition (30Li2O-20TiO2-20MnO-30P2O5) delivered high-ionic conductivity (2.73×10-4 S.cm-1at RT), low electronic leakage (3.425×10-8 S.cm-1), and near-unity Li⁺ transference number (0.9998) outperforming undoped LiTi2(PO4)3 and Mn-enriched counterparts. The Li|LMnTP-0GC|Li cell achieves 2 mA.cm-2 CCD and stable cycling for 200 h, while the Li|LMnTP-0GC|LFP cell delivers 130.00 mAh.g-1 with 96.40% retention after 50 cycles at 0.1C

Next-generation Li1.3+xAl0.3AsxTi1.7-x(PO4)3 NASICON electrolytes with outstanding ionic conductivity performance

NASICON-type solid electrolytes feature prominently in the improved safety and energy density of solid-state lithium batteries (ASSLBs). Achieving high ionic conductivity in these electrolytes is key to optimizing their performance. In this study, we introduced a new class of NASICON-type materials by doping arsenic into the Li1.3Al0.3Ti1.7(PO4)3 framework, creating a series of Li1.3+xAl0.3AsxTi1.7-x(PO4)3 phases with varying arsenic content (x = 0, 0.1, 0.2, 0.3), synthesized using the standard solid-state reaction method. X-ray diffraction confirmed the successful formation of the Li1.3+xAl0.3AsxTi1.7-x(PO4)3 phases, which was further validated by Rietveld refinement. Structural analyses through FT-IR, Raman spectroscopy, NMR, and ICP-AES studies validate the effective incorporation of arsenic into the lattice. Among the different compositions, Li1.5As0.2Al0.3Ti1.5(PO4)3 phase stood out due to its high relative density of 89% and its pore-free microstructure, as observed through scanning electron microscopy results, revealing the largest grain and crystallite size. Notably, doping with arsenic resulted in a significant enhancement in ionic conductivity, increasing from 5.34×10-5 Ω-1.cm-1 for Li1.3Al0.3Ti1.7(PO4)3 to 8.57×10-4 Ω-1.cm-1 for the Li1.5As0.2Al0.3Ti1.5(PO4)3 at 25°C. With a lithium transference number of 0.99, and a conduction mechanism largely unaffected by changes in temperature or composition, demonstrating its suitability as a promising candidate for solid electrolyte applications

Novel Zn-doped Nasicon-based glass-ceramic with superior Li-conductivity and enhanced properties as a solid electrolyte

Among the diverse array of solid electrolyte options, glass-ceramics hold great promise for application in all-solid-state lithium batteries. In this respect, we have effectively developed novel glasses and glass-ceramics through an innovative approach that integrates a glass-ceramic strategy with the newly introduced zinc-doped Nasicon phase. This was achieved by applying melt-quenching techniques coupled with meticulous control over the crystallization process, guided by a thorough study of crystallization kinetics. The crystallization kinetics have unveiled a two-dimensional nucleation mechanism with an activation energy of 165 kJ.mol-1. X-ray diffraction (XRD) analysis revealed the emergence of a novel Zn-doped Nasicon phase, identified as Li1.6Zn0.3Ti1.7(PO4)3, within the 30Li2O-20ZnO-20TiO2-30P2O5 glass-ceramic, a validation corroborated through Rietveld refinement. Indeed, FT-IR, Raman, and NMR analyses confirmed the formation of Li1+2xZnxTi2-x(PO4)3 Nasicon phase within the glass-ceramics structures. Moreover, SEM images, complemented by TEM observations and density assessments, provide evidence for the creation of a dense, pore-free glass-ceramic with a striped microstructure. The 30Li2O-20ZnO-20TiO2-30P2O5 glass-ceramic demonstrates outstanding chemical durability and robust mechanical properties. Notably, it exhibits high total ionic conductivity, reaching 7.14.10-4 Ω-1.cm-1 at room temperature, while displaying low electronic conductivity of 8.10-9 Ω-1.cm-1, aligning with findings from UV-visible spectroscopy. Additionally, the lithium transference number is confirmed to be 0.99, positioning the developed glass-ceramic as a highly competitive solid electrolyte in the field of energy storage. DFT calculations were conducted on the crystallized Li1.6Zn0.3Ti1.7(PO4)3 NASICON phase to gain detailed insights into its thermodynamic stability and electronic properties

Insights into structural, thermal, physical, optical, and electrical properties of novel ZnO-doped lithium–titanium-phosphate glasses

This study investigates novel ZnO-doped lithium-titanium-phosphate glasses, synthesized via the melt-quenching method, and characterizes their physical, structural, thermal, optical, chemical, mechanical, and electrical properties, with a focus on the impact of varying ZnO content on these properties. An increase in ZnO content from 20 mol% to 27.27 mol% induces significant local structural changes, promoting enhanced network polymerization, density, and chemical durability, while concurrently reducing thermal stability and mechanical strength. EPR analysis confirmed that titanium remained in the Ti4+ state, while optical measurements revealed an increased band gap, attributed to the role of ZnO in preventing Ti4+ reduction and minimizing localized states. The electrical conductivity decreases with increasing ZnO content, with the highest value measured at 1.73 × 10-10 Ω-1 cm-1. High-ZnO glasses exhibit mainly electronic conductivity of 4.02 × 10-9 Ω-1 cm-1 at room temperature. The frequency-dependent conductivity follows Jonscher's power law, with the charge transport governed by a correlated barrier-hopping mechanism, remaining stable across temperatures and compositions

NASICON As-doped and glass additive dual strategy for novel NASICON-glass composite with superior ionic conductivity

Due to their desirable properties, NASICON-type LATP materials are considered strong candidates for use as solid-state electrolytes in lithium batteries. However, their ionic conductivity, essential for optimal battery performance, remains lower than liquid electrolytes. This study highlights the effectiveness of a dual-strategy approach to improve LATP NASICON materials' ionic conductivity. By substituting titanium with arsenic, we developed a high-ion-conducting phase, Li1.5Al0.3As0.2Ti1.5(PO4)3, which showed significant advancements, achieving a high relative density of 89% and an average grain size of 51 nm, which contributes to its improved performance. These modifications led to a significant boost in the ionic conductivity of the arsenic-doped LATP phase, which rose from 5.34 × 10-5 S.cm-1 for LATP to 8.57 × 10-4 S.cm-1 for the Li1.5Al0.3As0.2Ti1.5(PO4)3 phase at room temperature with an activation energy of 0.30 eV and a transference number close to 1. To address remaining porosity and grain boundary resistance, we developed a novel glass-ceramic composition by incorporating a high-ion-conducting glass additive (45Li2O-10Li2WO4-45P2O5) into the new elaborated Li1.5Al0.3As0.2Ti1.5(PO4)3 matrix. The addition of 3 wt.% glass content notably enhanced the density and compactness of the material, increasing its ionic conductivity to 4.6 × 10-3 S. cm-1 at 25 °C with an activation energy of 0.25 eV, representing the highest ionic conductivity reported for NASICON and NASICON-composite materials. This work provides a cost-effective and efficient method for producing novel NASICON ceramics and glass-ceramic composites with superior ionic conductivity, setting a new benchmark for NASICON-composite materials and advancing the development of high-performance solid-state electrolytes for lithium batteries

Dual-scale selection of martensite variants in shape memory intermetallic compounds during thermomechanical loading

Generating a pre-strain by mechanical loading during martensitic transformation stands as a crucial strategy to obtain memory effect in shape memory alloys (SMAs). As martensitic transformation is realized by an anisotropic lattice deformation, the formation of martensite variants is always governed by strain accommodation. In a stress-free state, the orientation variants are organized hierarchically into colonies with a fixed number of variants. Under an external load, the transformation becomes selective. Although variant selection has long been a subject of interest, knowledge on selection via the activation of the transformation shear system under a load and by local strain mitigation is limited. Here, by a combined in-situ neutron diffraction and exhaustive EBSD crystallographic examination, the variant selection under a compressive load during martensitic transformation was thoroughly investigated using Ni51Mn34In15 as an example alloy. Remarkably, a dual-scale selection mechanism, i.e., colony and intra-colony variants, was revealed, which is in stark contrast to the stress-free scenario. For colonies, those containing variants receiving the highest resolved shear stress on their dominant transformation shear system were selected. Within the colonies, the selection is on variant volume fraction. Those making the maximum contribution to the external compression strain were majorly selected. Nevertheless, due to local incompatible strains created by the favorable variants, the variants with deformation opposite to the external compression were also selected to mitigate local incompatible strain and promote further formation of the favorable variants. This study provides useful experimental evidence and analysis data for related crystal plasticity modeling and simulation

Controlling the Cold-Set Gelation of Bovine Serum Albumin Protein using Alcohol and Ionic Surfactant

Heating of globular protein solutions usually leads to protein denaturation and subsequent gelation at high temperatures. Under “cold gelation”, protein forms a gel at a much lower temperature than its original gelation temperature (TG), which can be achieved by modifying various physicochemical conditions such as the pH of the solution, the presence of salts, etc. In this study, we investigated the cold gelation of Bovine Serum Albumin (BSA) protein induced by ethanol and controlled by ionic surfactant, using small-angle neutron scattering (SANS), dynamic light scattering (DLS), and rheology The results show that the TG of the protein with ethanol is systematically decreased as compared to the that of pure BSA solutions (~80 ◦C), reaching ~60 ◦C at 10 wt% ethanol, ~55 ◦C at 20 wt% and finally as low as ~38 ◦C in presence of 30 wt% ethanol in the solution. Rheo-logical measurements demonstrate a significant strengthening of the gel network, with the enhancement in storage modulus (G′) from ~20 Pa at 0 wt% to ~250 Pa at 30 wt% ethanol. Structural characterization reveals an increase in fractal dimension with rising ethanol content, indicating denser and more branched gel networks. Interestingly, the addition of the anionic surfactant sodium dodecyl sulfate (SDS) inhibits the alcohol-assisted cold gelation of BSA protein, depending upon the relative amount of ethanol and SDS in solution. The results are explained based on the interplay of interactions in the protein, manipulated by the presence of alcohol, elevated temperatures, and ionic surfactant. Our study highlights the tunability of gelation pathways and offers useful inputs for controlled protein gelation in biomaterial and food industry