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The cubic garnet-type solid electrolyte Li7La3Zr2O12 with aliovalent doping exhibits a high ionic conductivity, reaching up to ∼10−3 S/cm at room temperature. Fully understanding the Li+ transport mechanism including Li+ mobility at different sites is a key topic in this field, and Li7−2x−3yAlyLa3Zr2−xWxO12 (0 ≤ x ≤ 1) are selected as target electrolytes. X-ray and neutron diffraction as well as ac impedance results show that a low amount of aliovalent substitution of Zr with W does not obviously affect the crystal structure and the activation energy of Li+ ion jumping, but it does noticeably vary the distribution of Li+ ions, electrostatic attraction/repulsion, and crystal defects, which increase the lithium jump rate and the creation energy of mobile Li+ ions. For the first time, high-resolution NMR results show evidence that the 24d, 96h, and 48g sites can be well-resolved. In addition, ionic exchange between the 24d and 96h sites is clearly observed, demonstrating a lithium transport route of 24d−96h− 48g−96h−24d. The lithium mobility at the 24d sites is found to dominate the total ionic conductivity of the samples, with diffusion coefficients of 10−9 m2 s−1 and 10−12 m2 s−1 at the octahedral and tetrahedral sites, respectively.

The cubic garnet-type solid electrolyte Li7La3Zr2O12 with aliovalent doping exhibits a high ionic conductivity, reaching up to ∼10−3 S/cm at room temperature. Fully understanding the Li+ transport mechanism including Li+ mobility at different sites is a key topic in this field, and Li7−2x−3yAlyLa3Zr2−xWxO12 (0 ≤ x ≤ 1) are selected as target electrolytes. X-ray and neutron diffraction as well as ac impedance results show that a low amount of aliovalent substitution of Zr with W does not obviously affect the crystal structure and the activation energy of Li+ ion jumping, but it does noticeably vary the distribution of Li+ ions, electrostatic attraction/repulsion, and crystal defects, which increase the lithium jump rate and the creation energy of mobile Li+ ions. For the first time, high-resolution NMR results show evidence that the 24d, 96h, and 48g sites can be well-resolved. In addition, ionic exchange between the 24d and 96h sites is clearly observed, demonstrating a lithium transport route of 24d−96h− 48g−96h−24d. The lithium mobility at the 24d sites is found to dominate the total ionic conductivity of the samples, with diffusion coefficients of 10−9 m2 s−1 and 10−12 m2 s−1 at the octahedral and tetrahedral sites, respectively.

Spinel lithium manganate octahedral nanoparticles have been prepared by high temperature solid-state combustion reaction using cellulose as fuel. The crystal structure, morphology, and electrochemical performance of the as-prepared materials are analyzed by X-ray diffraction (XRD), electron microscopy, and electrochemical testing. The XRD results show that the materials are single-phase and perfectly crystalline with a spinel structure. Microscopic observations reveal that the nanoparticles possess octahedral morphology, with an average particle size of about 165.4 nm and a uniform particle size distribution. The lithium manganate octahedral nanoparticles exhibit excellent initial discharge capacity of 118.5 and 78.3 mAh g-1, and about 72.49% and 94.6% of its initial discharge capacity can be retained even after 1600 cycles at 10 C and 3000 cycles at 20 C, respectively. The excellent electrochemical performance of the lithium manganate can be mainly attributed to the strong MnO6 framework mitigates the occurrence of Mn dissolution, maintains structural stability, and allows higher Li+ diffusion during electrochemical cycling. Furthermore, the nano-sized octahedral structure not only facilitates fast ion diffusion, but also mitigates the manganese dissolution due to the exposed (111) crystal planes, where the solid electrolyte interphase (SEI) forms.

The cubic garnet-type solid electrolyte Li7La3Zr2O12 with aliovalent doping exhibits a high ionic conductivity, reaching up to ∼10−3 S/cm at room temperature. Fully understanding the Li+ transport mechanism including Li+ mobility at different sites is a key topic in this field, and Li7−2x−3yAlyLa3Zr2−xWxO12 (0 ≤ x ≤ 1) are selected as target electrolytes. X-ray and neutron diffraction as well as ac impedance results show that a low amount of aliovalent substitution of Zr with W does not obviously affect the crystal structure and the activation energy of Li+ ion jumping, but it does noticeably vary the distribution of Li+ ions, electrostatic attraction/repulsion, and crystal defects, which increase the lithium jump rate and the creation energy of mobile Li+ ions. For the first time, high-resolution NMR results show evidence that the 24d, 96h, and 48g sites can be well-resolved. In addition, ionic exchange between the 24d and 96h sites is clearly observed, demonstrating a lithium transport route of 24d−96h− 48g−96h−24d. The lithium mobility at the 24d sites is found to dominate the total ionic conductivity of the samples, with diffusion coefficients of 10−9 m2 s−1 and 10−12 m2 s−1 at the octahedral and tetrahedral sites, respectively.

The cubic garnet-type solid electrolyte Li7La3Zr2O12 with aliovalent doping exhibits a high ionic conductivity, reaching up to ∼10−3 S/cm at room temperature. Fully understanding the Li+ transport mechanism including Li+ mobility at different sites is a key topic in this field, and Li7−2x−3yAlyLa3Zr2−xWxO12 (0 ≤ x ≤ 1) are selected as target electrolytes. X-ray and neutron diffraction as well as ac impedance results show that a low amount of aliovalent substitution of Zr with W does not obviously affect the crystal structure and the activation energy of Li+ ion jumping, but it does noticeably vary the distribution of Li+ ions, electrostatic attraction/repulsion, and crystal defects, which increase the lithium jump rate and the creation energy of mobile Li+ ions. For the first time, high-resolution NMR results show evidence that the 24d, 96h, and 48g sites can be well-resolved. In addition, ionic exchange between the 24d and 96h sites is clearly observed, demonstrating a lithium transport route of 24d−96h− 48g−96h−24d. The lithium mobility at the 24d sites is found to dominate the total ionic conductivity of the samples, with diffusion coefficients of 10−9 m2 s−1 and 10−12 m2 s−1 at the octahedral and tetrahedral sites, respectively.