Fast Li-Ion-Conducting Garnet-Related Li Fe LaZrO with Uncommon 4̅3 Structure.

Fast Li-ion-conducting Li oxide garnets receive a great deal of attention as they are suitable candidates for solid-state Li electrolytes. It was recently shown that Ga-stabilized LiLaZrO crystallizes in the acentric cubic space group 4̅3. This structure can be derived by a symmetry reduction of the garnet-type 3̅ structure, which is the most commonly found space group of Li oxide garnets and garnets in general.

Structural and Electrochemical Consequences of Al and Ga Cosubstitution in LiLaZrO Solid Electrolytes.

Several "Beyond Li-Ion Battery" concepts such as all solid-state batteries and hybrid liquid/solid systems envision the use of a solid electrolyte to protect Li-metal anodes. These configurations are very attractive due to the possibility of exceptionally high energy densities and high (dis)charge rates, but they are far from being realized practically due to a number of issues including high interfacial resistance and difficulties associated with fabrication. One of the most promising solid electrolyte systems for these applications is Al or Ga stabilized LiLaZrO (LLZO) based on high ionic conductivities and apparent stability against reduction by Li metal.

Synthesis, Crystal Chemistry, and Electrochemical Properties of Li(7-2x)La3Zr(2-x)Mo(x)O12 (x = 0.1-0.4): Stabilization of the Cubic Garnet Polymorph via Substitution of Zr(4+) by Mo(6+).

Cubic Li7La3Zr2O12 (LLZO) garnets are exceptionally well suited to be used as solid electrolytes or protecting layers in "Beyond Li-ion Battery" concepts. Unfortunately, cubic LLZO is not stable at room temperature (RT) and has to be stabilized by supervalent dopants. In this study we demonstrate a new possibility to stabilize the cubic phase at RT via substitution of Zr(4+) by Mo(6+).

Electrochemical properties of LaSrCoO thin films investigated by complementary impedance spectroscopy and isotope exchange depth profiling.

The oxygen exchange and diffusion properties of LaSrCoO thin films on yttria stabilized zirconia were analyzed by impedance spectroscopy and O tracer experiments. The investigations were performed on the same thin film samples and at the same temperature (400 °C) in order to get complementary information by the two methods. Electrochemical impedance spectroscopy can reveal resistive and capacitive contributions of such systems, but an exact interpretation of the spectra of complex oxide electrodes is often difficult from impedance data alone.