Improving the Cycle Life of Solid-State Batteries by Addition of Oxide Nanoparticles to a Complex Hydride Solid Electrolyte
Laura M. de Kort, Peter Ngene, Marcello Baricco, Petra E. de Jongh, Valerio Gulino
Abstract
High Resolution Image Download MS PowerPoint Slide We report that the addition of silica nanoparticles to the iodide-substituted LiBH 4 ( h -Li(BH 4 ) 0.8 (I) 0.2 ) improves the ion conductivity and, remarkably, the cycle life of the all-solid state batteries. The h -Li(BH 4 ) 0.8 (I) 0.2 -SiO 2 was synthesized by mechanochemical treatment and possesses a Li + conductivity of 9.3 × 10 –5 S cm –1 at RT. It has an electrochemical stability window of about 2.5 V vs Li + /Li and an improved stability against Li-metal, compared to h -Li(BH 4 ) 0.8 (I) 0.2, owing to the addition of oxide nanoparticles, which we ascribed to a greater mechanical stability of the solid-state electrolyte. The all-solid state battery Li| h -Li(BH 4 ) 0.8 (I) 0.2 -SiO 2 |TiS 2 demonstrated a good long-term cyclability, i.e., over 200 cycles at C/20 and even including a C-rate of C/5, demonstrating that the addition of oxide nanoparticles improves the cycling stability of the electrolyte.