Lithium-stuffed garnets attract huge attention due to their outstanding potential as solid-state electrolytes for lithium batteries. However, there exists a persistent challenge in the reliable synthesis of these complex functional oxides together with a lack of complete understanding of the lithium-ion diffusion mechanisms in these important materials. Addressing these issues is critical to realizing the application of garnet materials as electrolytes in all solid-state lithium-ion batteries. In this work, a cubic phase garnet of nominal composition Li6.5Al0.25La2.92Zr2O12 is synthesized through a microwave-assisted solid-state route for the first time, reducing considerably the reaction times and heating temperatures. Lithium-ion diffusion behavior is investigated by electrochemical impedance spectroscopy (EIS) and state-of-art muon spin relaxation (mSR) spectroscopy, displaying activation energies of 0.55 0.03 eV and 0.19 0.01 eV respectively.  This difference arises from the high inter-grain resistance, which contributes to the total resistance in EIS measurements. In contrast, mSR acts as a local probe providing insights on the order of the lattice, giving an estimated value of 4.6210􀀀11 cm2s􀀀1 for the lithium diffusion coefficient. These results demonstrate the potential of this lithium-stuffed garnet as a solid-state electrolyte for all-solid state lithium-ion batteries, an area of growing interest in the energy storage community

Lithium diffusion investigation of nanostructured olivine LiFePO4 for the first time using muon spectroscopy (μSR).

Reversible Mg removal from MgCr2O4 (a high-voltage Mg-intercalation cathode material) was improved by nanosizing and introducing significant structural defects.

It has been shown that the introduction of several transition metal (TM) dopants into SnO2 lithium‐ion battery anodes can overcome the issues associated with the irreversible capacity loss from the conversion reaction of SnO2 and the aggregation of the metallic Sn particles formed upon lithiation. As the choice of the single dopant, however, plays a decisive role for the achievable energy density – precisely its redox potential – we investigate herein TM co‐doped SnO2, prepared by using a readily scalable continuous hydrothermal flow synthesis (CHFS) process, to tailor the dis‐/charge profile and by this the energy density. It is shown that the judicious choice of different elemental doping combinations in samples made via CHFS simultaneously improves the cycling performance and the full‐cell energy density. To support these findings, we realized a lithium‐ion full‐cell incorporating the best performing co‐doped SnO2 as negative electrode and high‐voltage LiNi0.5Mn1.5O4 (LNMO) as positive electrode–to the best of our knowledge, the first full‐cell based on such anode material in combination with LNMO as cathode active material.

Synchrotron high‐energy X‐ray diffraction computed tomography has been employed to investigate, for the first time, commercial cylindrical Li‐ion batteries electrochemically cycled over the two cycling rates of C/2 and C/20. This technique yields maps of the crystalline components and chemical species as a cross‐section of the cell with high spatiotemporal resolution (550 × 550 images with 20 × 20 × 3 µm3 voxel size in ca. 1 h). The recently developed Direct Least‐Squares Reconstruction algorithm is used to overcome the well‐known parallax problem and led to accurate lattice parameter maps for the device cathode. Chemical heterogeneities are revealed at both electrodes and are attributed to uneven Li and current distributions in the cells. It is shown that this technique has the potential to become an invaluable diagnostic tool for real‐world commercial batteries and for their characterization under operating conditions, leading to unique insights into “real” battery degradation mechanisms as they occur.

The Li+ ion diffusion characteristics of V- and Nb-doped LiFePO4 were examined with respect to undoped LiFePO4 using muon spectroscopy (µSR) as a local probe. As little difference in diffusion coefficient between the pure and doped samples was observed, offering DLi values in the range 1.8–2.3 × 10−10 cm2 s−1, this implied the improvement in electrochemical performance observed within doped LiFePO4 was not a result of increased local Li+ diffusion. This unexpected observation was made possible with the µSR technique, which can measure Li+ self-diffusion within LiFePO4, and therefore negated the effect of the LiFePO4 two-phase delithiation mechanism, which has previously prevented accurate Li+ diffusion comparison between the doped and undoped materials. Therefore, the authors suggest that µSR is an excellent technique for analysing materials on a local scale to elucidate the effects of dopants on solid-state diffusion behaviour.

Sodium titanate nanopowder (nominal formula Na1.5H0.5Ti3O7) is directly synthesized using a continuous hydrothermal flow synthesis process using a relatively low base concentration (4 M NaOH) in process. The as-made titanate nanomaterials are characterised using powder X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller analysis, and transmission electron microscopy, evaluated as potential electrode materials for Li-ion and Na-ion batteries. Cyclic voltammetry studies on half-cells reveal that the sodium titanate nanomaterial stores charge primarily through a combination of pseudocapacitive and diffusion-limited mechanisms in both systems. Electrochemical cycling tests at a high specific current of 1000 mA g-1 , reveal that the Li-ion and Na-ion cells retained relatively high specific capacities of 131 and 87 mAhg-1 , respectively, after 400 cycles. This study demonstrates the potential of CHFS-made sodium titanate nanopower as anode material for Li and Na ion cell chemistries.

Transition metal-doped cobalt–nickel sulfide spinel (Ni1.29Co1.49Mn0.22S4) nanocatalysts for secondary Zn–air batteries with an efficient and stable electrochemical performance.