Intermediate-Stage Sintered LLZO Scaffolds for Li-Garnet Solid-State Batteries

摘要

While significant progress has been achieved in the field of Li-garnet solidstatebatteries, their further development, is hindered by the formation ofcavities at the Li7La_3Zr_2O_(12) (LLZO)/Li interface at practically relevant currentdensities and areal capacities exceeding 1 mA cm?2 and 1 mAh cm?2. As aresult, the cells exhibit limited cycling stability due to the inhomogeneousdistribution of the applied current density, and therefore, the formation of Lidendrites. Another aspect of high importance is associated with the developmentof the fabrication methodology of thin LLZO electrolytes for achievingthe high energy density of Li-garnet solid-state batteries. To contribute tothese two challenging problems, in this work, a facile intermediate-stagesintering method of 50-μm thin and porous LLZO membranes with a meanpore size of 2.5 μm is presented. The employment of such porous LLZOmembranes not only provides an effective means of mitigating the formationof voids at the LLZO/Li interface due to the increased LLZO/Li surface area,but also maximizes achievable energy densities. It is demonstrated that fabricatedporous LLZO membranes exhibit long cycling stability of over 1480 h ata current density of 0.5 mA cm~（?2）.