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Novel Zn-doped Nasicon-based glass-ceramic with superior Li-conductivity and enhanced properties as a solid electrolyte
No full textAmong 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
Novel Mn2+-doped NASICON glass-ceramic electrolyte with engineered columnar microstructure for high lithium-ion conductivity
No full textGlass-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
Insights into structural, thermal, physical, optical, and electrical properties of novel ZnO-doped lithium–titanium-phosphate glasses
No full textThis 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
Next-generation Li1.3+xAl0.3AsxTi1.7-x(PO4)3 NASICON electrolytes with outstanding ionic conductivity performance
No full textNASICON-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
NASICON As-doped and glass additive dual strategy for novel NASICON-glass composite with superior ionic conductivity
No full textDue 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
