Electrochemical and Mechanical Performance According to Regulating Sintering Time of Cubic Li6.1Ga0.3La3Zr2O12 Solid Electrolyte

초록

The solid-state electrolyte is a promising candidate to replace the liquid electrolytes in lithium ion batteries, although it has a fatal drawback of inferior ionic conductivity. Garnet-type LiLaZrO can be regarded as a favorable material for all-solid-state lithium batteries since it has better lithium ion kinetics, non flammability, and outstanding electrochemical/thermal stability. The grain size is closely related to the microstructure, affecting the electrochemical and mechanical properties. Here, we control the grain size by adjusting the sintering time and demonstrate that Li6.1Ga0.3La3Zr2O12 (LGLZO) sintered at 1250 degrees C for 10 h delivers relative density of 97.5 +/- 0.5%, hardness of 9.1 +/- 0.46 GPa, ionic conductivities of 8.9 x 10-4 S/cm (Au/LGLZO/Au symmetric cell) and 4.2 x 10-5 S/cm (Li/ LGLZO/Li symmetric cell), and critical current density of 0.58 mA/cm2, which are superior to those of LGLZO sintered for 20 h. Therefore, we can conclude that regulating sintering time is a simple and easy approach for high performance all solid-state lithium ion batteries.

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