Total Ionic Conductivity Research Articles

Effect of Confinement on the Structure-Conductivity Relationship in PEO/LiTFSI Electrolytes in 3D Microporous Scaffolds.

Because 3D batteries comprise solid polymer electrolytes (SPEs) confined to porous scaffolds with high surface areas, the interplay between polymer confinement and interfacial interactions on SPE total ionic conductivity must be understood. This paper investigates contributions to the structure-conductivity relationship in poly(ethylene oxide) (PEO)-lithium bis(trifluorosulfonylimide) (LiTFSI) complexes confined to microporous nickel scaffolds. For bulk and confined conditions, PEO crystallinity decreases as the salt concentration (Li+:EO (r) = 0.0125, 0.0167, 0.025, 0.05) increases. For pure PEO and all r values except 0.05, PEO crystallinity under confinement is lower than in the bulk, whereas the glass transition temperature remains statistically invariant. At 298 K (semicrystalline), total ionic conductivity under confinement is higher than in the bulk at r = 0.0167 but remains invariant at r = 0.05; however, at 350 K (amorphous), total ionic conductivity in confinement is lower than in the bulk for both salt concentrations. Time-of-flight secondary ion mass spectrometry indicates selective migration of ions toward the polymer-scaffold interface. In summary, for the 3D structure studied, polymer crystallinity, interfacial segregation, and tortuosity play important roles in determining total ionic conductivity and, ultimately, the emergence of 3D SPEs as energy storage materials.

Effect of variable valence elements Se on Ti and P sites of LATP solid electrolyte

The NASICON solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 (LATP) has garnered significant attention owing to its low cost, excellent air stability, and high ionic conductivity. However, it exhibits low density and elevated grain boundary resistance due to suboptimal sintering performance. In order to improve the sintering performance and further increase the ionic conductivity, LATP solid electrolyte was synthesized by introducing Se4+ ion doping by solid phase method. The effects of different doping amounts of Se4+ ions on the structure and properties of solid electrolyte were systematically studied. It was observed that a low doping amount of Se4+ ion replaces Ti4+ ion which increases the crystal density and inhibits the formation of secondary phase LiTiPO5. While the doping amount is high, part of Se4+ ion transforms into Se6+ ion and replaces P5+ ion, causing lattice distortion and broadening the Li+ ion migration channel, but at the same time, it also promotes the precipitation of secondary phase LiTiPO5 and impedes the Li + transfer. The prepared sample with 2 wt% of SeO2 exbihits the total ionic conductivity of 0.41 mS/cm at room temperature and an improved bulk density of 2.93 g/cm3.

La1−xSrxF3−x: A Solid-State Electrolyte for Fluoride Ion Battery with High Ionic Conductivity and Wide Electrochemical Potential Window

Fluoride ion conductors are developed for use as solid-state electrolytes in fluoride ion batteries which are one of promising candidates for next-generation storage batteries. Ba-doped LaF3 (La0.9Ba0.1F2.9: LBF) is mainly used as a solid-state electrolyte in fluoride ion batteries. However, room temperature conductivity of LBF is considerably low, on the order of 10−6 S cm−1 and it is still unclear the optimal elements to be doped to LaF3. In this study, we have explored La0.9Sr x Ba0.1−x F2.9 system (x = 0, 0.01, 0.025, 0.05, 0.1), in which Ba in LBF is substituted for Sr and investigated the composition dependence of ionic conductivity. We elucidate that the higher concentration of Sr without Ba can significantly improve the ionic conductivity, and the maximum ionic conductivity of La0.9Sr0.1F2.9 is 1.5 × 10−5 S cm−1 at room temperature, which is one order of magnitude larger than that of LBF. The higher ionic conductivity of LSF is due to the larger grain size and higher sintering density of LSF compared to LBF, which results in lower grain boundary resistance. The LSF total ionic conductivity of 10−4 S cm−1 can be achieved at 350 K, which significantly lowers operating temperature of fluoride ion batteries down to 350 K.

Borophosphate glass based electrolyte composite for high lithium ionic conductivity

The application requirements of solid-state lithium (Li) metal batteries are satisfied by the ionic conductivity of composite solid-state electrolytes, attributed to their minimal interfacial resistance. Herein, composite solid electrolytes were obtained by mixing a crystalline Li0.5La0.5TiO3 (LLTO) perovskite with different amount of 47Li2O-30B2O3-23P2O5 (LBP) glass phase. The results show that the crystal phase of the composite samples exhibit a tetragonal perovskite structure with a P4/mmm space group. Frequency dependent AC conductivity shows that composite containing 1 % LBP glass avoids the phenomenon of charge carrier blocking at low frequency and low temperature at the same time. The room temperature maximum total ionic conductivity was obtained for sample with 0.5 % LBP glass presenting a conductivity that is almost three times higher than that of pure LLTO. The factors influencing ionic conductivity are not only grain morphology and size, and activation energy, but also lithium content, and entropic effects contribute to the facility or difficulty with which Li+ can migrate into the LLTO solid electrolyte.

Composite Separators with Very High Garnet Content for Solid‐State Batteries

AbstractLithium‐metal solid‐state batteries are attractive as next generation of Li‐ion batteries due to higher safety and potentially higher energy density. To improve processability, solid‐composite separators combine advantages of inorganic and polymer separators in hybrid structure. We report a systematic approach to fabricate composite separators with high content (90–95 wt %) of ceramic Li‐ion conducting Li6.45Al0.05La3Zr1.6Ta0.4O12 (LLZO) powder embedded in a polyethylene oxide (PEO)‐LiTFSI (20 : 1) matrix and understand factors affecting their properties and performance. Separators with good mechanical flexibility and excellent thermal stability were obtained, by optimizing materials and processing parameters. It was found that PEO molecular weight strongly influences the microstructure and electrochemical properties of the separators. In optimized separator with 90 wt % of LLZO and PEO with Mw 300,000 g/mol, a total ionic conductivity of 1.4×10−5 S/cm at 60 °C was achieved. The ceramic‐rich separator showed excellent long‐term cycling stability for more than 460 cycles (1000 h) at 0.1 mA/cm2 in Li/Li symmetrical cells and achieved a critical current density of 0.25 mA/cm2. The separators also enabled initial discharge capacities of more than 160 mAh/g in full cells with Li metal anode and composite solid‐state LiNi0.6Co0.2Mn0.2O2 cathode, although rapid capacity fade was observed after 10 cycles in fully solid‐state configuration.

Electrochemical performance enhancement of perovskite-type Li0.3La0.57TiO3 ceramic electrolyte by controlling synthesis parameters

This study investigates the enhancement of the electrochemical performance of perovskite-type Li0.3La0.57TiO3 (LLTO) solid electrolytes through the optimization of synthesis parameters of a sol-gel process. The primary focus lies in examining the impact of calcination temperature on the structural, morphological, and electrochemical properties of LLTO. Our findings reveal that controlling the calcination temperature significantly influences the grain boundary resistance and overall ionic conductivity. The optimal calcination temperature was identified to be 800 °C, yielding a remarkable improvement in ionic conductivity at grain boundaries (0.88 mS/cm), and total ionic conductivity (0.54 mS/cm), at 30 °C. This enhancement is attributed to the refined microstructure, increased density, and reduced porosity, which collectively facilitate lithium-ion diffusion. These advancements in LLTO electrolytes present promising implications for their application in all-solid-state lithium-ion batteries, offering a safer and more efficient alternative to conventional liquid electrolyte systems.

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.

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.

Nonstoichiometry Induced Amorphous Grain Boundary of Na5SmSi4O12 Solid-State Electrolyte for Long-Life Dendrite-Free Sodium Metal Battery.

Oxide ceramics are considered promising candidates as solid electrolytes (SEs) for sodium metal batteries. However, the high sintering temperature induced boundaries and pores between angular grains lead to high grain boundary resistance and pathways for dendrite growth. Herein, we report a grain boundary modification strategy, which in situ generates an amorphous matrix among Na5SmSi4O12 oxide grains via tuning the chemical composition. The mechanical properties as well as electron mitigating capability of modified SE have been significantly enhanced. As a result, the SE achieves a room-temperature total ionic conductivity of 5.61 mS cm-1, the highest value for sodium-based oxide SEs. The Na|SE|Na symmetric cell achieves a high critical current density of 2.5 mA cm-2 and excellent cycle life over more than 2800 h at 0.15 mA cm-2 without dendrite formation. The full cell with Na3V2(PO4)3 as the cathode demonstrates impressive cycling performance, maintaining stability over 3000 cycles at 5C without observable loss of capacity.

Enhanced performance of graphene-incorporated electrodes for solid-state lithium-sulfur batteries through facilitated ionic diffusion pathways

Significant progress has been achieved in advancing all-solid-state lithium-sulfur batteries through the development of sulfide solid electrolytes. Nonetheless, a challenge lies in creating a percolated ion–electron conduction path with intimate contact between charge carriers throughout the cathode which is crucial for enhancing overall efficiency and addressing issues related to slow kinetics and impedance during battery operation. This study introduces a framework elucidating how the integration of graphene enhances electrode performance by refining ionic diffusion pathways. An idealized ionic diffusion pathway characterized by a continuous ionic network, facilitating minimum diffusion distances, is proposed. Through a parametric study substituting portions of ionic and electronic conductive agents with graphene, the impact on total ionic and electronic conductivity of positive electrodes was comprehended. The findings underscore the critical role of optimum graphene content, which fills the gaps between ionic conductive materials and creates the shortest diffusion paths for ions and electrons. While incorporating graphene into cathode electrodes is not novel, it is noteworthy that graphene, as a mixed ion–electron conductive material, significantly enhances ion mobility due to its 2D structure, addressing a crucial aspect of cathode performance. Upon achieving optimum composite formulation, empirical findings demonstrate substantial performance improvement, including a 17.7% increase in initial capacity and a remarkable 21% enhancement in capacity retention compared to electrodes without graphene.

Superior ionic conductivity of Zr–doped LiTa2PO8 ceramics

The recently discovered LiTa2PO8 ceramic material holds promise as a solid electrolyte for all–solid–state batteries. In this study, comprehensive characterization techniques, including XRD, MAS NMR, Raman spectroscopy, TMA, SEM/EDX, IS, DC potentiostatic polarization and Archimedes principle, were employed to investigate the influence of varying concentrations of Zr dopant on the electrical, microstructural, and structural properties of doped LTPO ceramics. Remarkably, the highest total ionic conductivity was observed for the LTPO–0.05Zr ceramic, reaching 0.92 mS/cm at 30 °C. Moreover, the grain conductivity values remained consistently around 1.6 mS/cm, irrespective of the Zr dopant concentration. Microstructural and phase purity analyses revealed that the content of secondary phases significantly impacted the total ionic conductivity. The presence of glassy LiZr2(PO4)3 material appeared to positively influence the electrical properties of the LTPO–Zr ceramics. A discussion about the accurate location of zirconium within the material was performed.

Preparation and electrochemical properties of Li6La3Zr0.7Ti0.3Ta0.5Sb0.5O12 high-entropy Li-garnet solid electrolyte

Garnet-type solid electrolytes stand out as promising Li-ion conductors for the next-generation batteries. It has been demonstrated that the inherent properties of garnets can be tailored by introducing various dopants into their crystal structures. Recently, there has been a growing interest in the concept of high entropy stabilization for materials design. In this study, we synthesized high-entropy garnets denoted as Li6La3Zr0.7Ti0.3Ta0.5Sb0.5O12 (LLZTTSO), wherein Ti, Sb, and Ta occupy the Zr site. The formation of the cubic garnet phase in LLZTTSO was confirmed through X-ray diffraction (XRD), and the resulting lattice parameter agreed with predictions made using computational methods. Despite the substantial porosity (relative density 80.6%) attributed to the low sintering temperature, LLZTTSO exhibits a bulk ionic conductivity of 0.099 mS cm−1 at 25°C, and a total ionic conductivity of 0.088 mS cm−1, accompanied by an activation energy of 0.497 eV. Furthermore, LLZTTSO demonstrates a critical current density of 0.275 mA cm−2 at 25°C, showcasing its potential even without any interfacial modification.

Superior ionic conductivity of W-doped NASICON-type Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte

NASICON-structured Li1.3Al0.3Ti1.7(PO4)3 (LATP) solid electrolyte has low grain boundary conductivity, which impedes its practical application. Herein, W was adopted to partially replace the Al element in LATP to improve its grain boundary conductivity. The W doping reduces the crystal lattice of the electrolyte, which is detrimental to the grain conductivity. But the doping of W can make the grains closely connect and reduce the voids between the grains, which can greatly enhance the grain boundary conductivity. The LATP sample with the W doping content of 0.03 (LATWP003) exhibits the highest total ionic conductivity of 1.186 mS/cm at 30 ℃, which results from the optimum grain boundary conductivity of 2.315 mS/cm. Moreover, the LATWP003 electrolyte displays a negligible electronic conductivity of 2.01×10−9 S/cm. The LiFePO4/LATWP003/Li battery with PVDF-HFP polymer protective layer can be charged and discharged. Therefore, the W doped LATP sample is a promising electrolyte for lithium-ion batteries.

Transient Ruddlesden-Popper-Type Defects and Their Influence on Grain Growth and Properties of Lithium Lanthanum Titanate Solid Electrolyte.

Lithium lanthanum titanate (LLTO) perovskite is one of the most promising electrolytes for all-solid-state batteries, but its performance is limited by the presence of grain boundaries (GBs). The fraction of GBs can be significantly reduced by the preparation of coarse-grained LLTO ceramics. In this work, we describe an alternative approach to the fabrication of ceramics with large LLTO grains based on self-seeded grain growth. In compositions with the starting stoichiometry for the Li0.20La0.60TiO3 phase and with a high excess addition of Li (Li:La:Ti = 11:15:25), microstructure development starts with the formation of the layered RP-type Li2La2Ti3O10 phase. Grains with many RP-type defects initially develop into large platelets with thicknesses of up to 10 μm and lengths over 100 μm. Microstructure development continues with the crystallization of LLTO perovskite, epitaxially on the platelets and as smaller grains with thinner in-grain RP-lamellae. Theoretical calculations confirmed that the formation of RP-type sequences is energetically favored and precedes the formation of the LLTO perovskite phase. At around 1250 °C, the RP-type sequences become thermally unstable and gradually recrystallize to LLTO via the ionic exchange between the Li-rich RP-layers and the neighboring Ti and La layers as shown by quantitative HAADF-STEM. At higher sintering temperatures, LLTO grains become free of RP-type defects and the small grains recrystallize onto the large platelike seed grains via Ostwald ripening. The final microstructure is coarse-grained LLTO with total ionic conductivity in the range of 1 × 10-4 S/cm.

Scalable Dry Process for Fabricating a Na Superionic Conductor-Type Solid Electrolyte Sheet.

The cost reduction and mass production of oxide-based solid electrolytes are critical for the commercialization of all-solid-state batteries. In this study, an environmentally friendly, low-cost, and high-density oxide-based Na superionic conductor-type solid electrolyte sheet was fabricated via a dry process without the use of any solvent. The polytetrafluoroethylene (PTFE), used as a binder, was transformed into thin thread-like structures via shear force, resulting in a flexible solid electrolyte sheet. The solid electrolyte powder quantity was limited to 50 wt % for fabricating a uniform green sheet via the wet process. However, when the dry process was employed for green sheet fabrication, the solid electrolyte powder quantity could be increased to values exceeding 95 wt %. Therefore, the green sheets produced by using the dry process demonstrated a higher density than those fabricated by using the wet process. The binder content and particle size affected the ionic conductivity of a solid electrolyte sheet fabricated via a dry process. The sheet obtained via the blending of 3 wt % PTFE binder with a solid electrolyte powder, finely ground using a planetary ball mill, which exhibited the highest total ionic conductivity of 1.03 mS cm-1.

Synthesis and Sintering of Li1.3Al0.3Ti1.7(PO4)3@Li2O–2B2O3 Core–Shell Solid Electrolyte Powders Prepared via One‐Pot Spray Pyrolysis

Developing a rational design for oxide‐based solid electrolytes to promote ionic conductivity, decrease the sintering temperature, and improve stability with metallic Li is challenging. Herein, core–shell‐structured Li1.3Al0.3Ti1.7(PO4)3@Li2O–2B2O3 (LATP–LBO) microspheres are prepared using one‐pot spray pyrolysis. Phase separation between crystalline LATP and amorphous LBO leads to the formation of a core–shell‐structured LATP–LBO composite. On the surface of LATP–LBO composite, the LBO shell forms a liquid phase during low‐temperature sintering, thereby enhancing the densification. The LBO shell also decreases the grain boundary resistance by forming a thin layer between the LATP grains, thus increasing the total ionic conductivity. Because Li‐ion conductive LBO occupies the grain boundary, a total ionic conductivity of 1.519 × 10−4 S cm−1 is achieved at a low sintering temperature of 700 °C. Additionally, the LBO shell provides good electrochemical stability for LATP with metallic Li. The improved ionic conductivity and chemical stability can be attributed to the synergistic advantages of the spherical morphology, core–shell structure, and uniformity of LBO.

Enhanced ionic conductivity of Li1.3Al0.3Ti1.7(PO4)3 under the influence of graphene oxide

As a new type of clean and efficient energy storage device, lithium-ion batteries have been widely used in electronic products, electric vehicles, and other fields, and the accompanying safety issues are of increasing concern. Therefore, solid-state lithium-ion conductors have become a current research hotspot. This paper used graphene oxide material to design and prepare Li1.3Al0.3Ti1.7(PO4)3 solid electrolytes by the co-precipitation method and performed some relevant characterizations. The results showed that the addition of graphene oxide optimized the electrolyte structure improved the density of the powder, promoted grain growth, improved the transport path of lithium ions, and thus increased the total ionic conductivity. The optimal doping ratio was 0.5 wt%, and the total ionic conductivity reached the maximum of 2.42 × 10−4 S/cm. Compared to pure Li1.3Al0.3Ti1.7(PO4)3, the ionic conductivity increased by 154% after using the graphene oxide. It is believed that larger grains, fewer grain boundaries, and denser microstructure resulted in a less distorted migration pathway for lithium ions. Under the influence of graphene oxide, Li1.3Al0.3Ti1.7(PO4)3 exhibited better air stability than pure Li1.3Al0.3Ti1.7(PO4)3 electrolyte. The electrolyte prepared in this study showed great application potential in all-solid-state batteries.

Synthesis, structural investigations and properties of Si-modified Li1.5Al0.5Ge1.5(PO4)3 glass-ceramics

The properties of the Li1.5Al0.5Ge1.5(PO4)3 glass-ceramics were modified by the partial substitution of P5+ by Si4+, and the synthesis process is optimized. The thermal behavior of the original Li1.5+хAl0.5Ge1.5SixP3-xO12 (0 ≤ x ≤ 0.5) glasses was investigated using differential scanning calorimetry (DSC), optical dilatometry and heating microscopy. The glass transition temperature (Tg) decreases from 525 to 457 °C with increasing additive content from x = 0 to x = 0.5. Single-phase glass-ceramics with the NASICON-type structure were synthesized up to x = 1, which was confirmed by X-ray diffraction (XRD), Raman and energy-dispersive X-ray (EDX) mapping data. It has been shown that the SiO2 addition has a beneficial effect on the electrical properties of glass-ceramics, crystallized at 700 and 750 °C. However, heat treatment at 820 °C leads to a smaller increase in conductivity. Therefore, Si-containing glass-ceramics should be produced at lower temperatures than pure LAGP, which is 750 °C and correlated with the thermal analysis results. The influence of the SiO2 addition on the bulk and grain boundary conductivity of the Li1.5Al0.5Ge1.5(PO4)3 has been studied in detail. The Li1.52Al0.5Ge1.5Si0.02P2.98O12 glass-ceramics has the highest total ionic conductivity of 4.55·10−4 S/cm at RT and negligible electronic conductivity of 7.5·10−10 S/cm, therefore can be considered as promising solid electrolytes for all-solid-state batteries.

Facile Route to Synthesize a Highly Sinterable Li1.3Al0.3Ti1.7(PO4)3 Solid Electrolyte.

NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) is a widely used solid electrolyte in solid-state lithium batteries, owing to its excellent chemical stability against moisture and high total ionic conductivity. However, traditionally, densification of LATP has been achieved through a high-temperature sintering process (approximately 1000 °C) owing to its poor sinterability. Herein, we report a facile synthesis route to obtain highly sinterable LATP solid electrolyte using tetrabutyl titanate (C16H36O4Ti) as the titanium source and incorporating the traditional solid-state reaction method. The synthetic LATP powder mixed with a low ratio of LiTiPO5 exhibited a hybrid crystalline-amorphous phase structure, which facilitated grain fusion, promoted structural homogeneity, and facilitated structural densification under low-temperature sintering. The sintered LATP pellet, which exhibited an interconnected structure and indistinct grain boundaries, achieved a relative density of >90% and an ionic conductivity of 0.667 mS/cm at a sintering temperature of only 750 °C. Additionally, we systematically studied and demonstrated the synthesis reaction mechanism, sintering behavior, and ionic diffusion kinetics of LATP electrolytes. Our study paves the way for synthesizing highly sinterable LATP solid electrolytes using a simple, additive-free, and cost-effective method.

Effect of addition of LiAlSiO4 on microstructure, phase composition, and electrical properties of Li1.3Al0.3Ti1.7(PO4)3–based solid electrolyte

Li1.3Al0.3Ti1.7(PO4)3 (LATP) NASICON-type ceramic, due to its high bulk conductivity, is believed to be one of the most appropriate material for application as solid electrolyte in all-solid-state lithium-ion batteries. However, its highly resistant grain boundaries strongly limit the total ionic conductivity. Therefore, in this work, an attempt has been made to overcome this problem by introducing a Li-ion conducting additive LiAlSiO4 (LASO) to LATP base matrix in order to provide more conduction paths for lithium ions between grains. The properties of Li1.3Al0.3Ti1.7(PO4)3–xLiAlSiO4 (0.02 ≤ x ≤ 0.1) composite system were studied by means of: high-temperature X-ray powder diffractometry (HTXRD), 6Li, 27Al, and 31P magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), scanning electron microscopy (SEM), and impedance spectroscopy (IS) methods. The obtained ceramic LATP–LASO materials exhibited high values of bulk conductivity, above 10−3 S/cm, and good total conductivity, exceeding 10−4 S/cm. The factors responsible for the enhancement, but also for the deterioration of total conductivity, i.e. microstructure and grain boundaries, are identified and discussed in this work.