Size-regulated Li-argyrodite particles via wet-chemical route for enhanced solid-state battery performance

초록

The cell performance of sulfide-based solid-state batteries is significantly affected by the microstructure of the solid electrolytes (SEs). In this study, size-regulated Li-argyrodite precursors were synthesized by inducing uniform isotropic growth and varying substrate Li2S sizes. Following low-temperature annealing, we successfully obtained uniform popcorn-shaped Li-argyrodite microstructures depending on the substrate size without any post-treatment. These results contribute to the electrochemical charge (ion/electron) transport and electrochemomechanical properties of cold-pressed cathode composites and the separator of SSBs cells. As the particle size decreased, the effective charge transfer kinetics in the cathode composites and the mechanical endurance against the Li metal anode were enhanced. The resulting cell comprising finest Li-argyrodite exhibited excellent reversible rate capability with a LiNbO3-coated LiNi0.8Co0.1Mn0.1O2 cathode (166.7 mA h g(-1) at 0.5C for 100 cycles with a capacity retention of similar to 90 %). Furthermore, as a separator SE, the finest Li-argyrodite also exhibited superior Li striping/plaiting overpotential for 1000 h (at 0.2 mA cm(-2)/0.2 mA h cm(-2)). This study demonstrates that our facile route enables the tailoring of SE microstructures for improved cell performance.

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