An advanced Na-NiCl2 battery using bi-layer (dense/micro-porous) β″-alumina solid-state electrolytes

• Published in: Journal of power sources 2018-08, Vol.396 (C), p.297-303
• Main Authors: Jung, Keeyoung, Chang, Hee-Jung, Bonnett, Jeffery F., Canfield, Nathan L., Sprenkle, Vincent L., Li, Guosheng
• Format: Article
• Language: English
• Subjects: Bi-layer composite; ENERGY STORAGE; MATERIALS SCIENCE; Na battery; Na-metal halide battery; Solid-state electrolyte; Stationary energy storage
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2018.06.039

Sodium metal halide (Na-MH) batteries present tremendous opportunities for grid scale energy storage applications. In this work, we describe an advanced Na-MH battery operating at 190 °C using a bi-layer (thin dense/thick porous layers) β″-alumina solid-state electrolyte (BASE). The novel design of the bi-layer BASE promotes high Na-ion transportation by reducing the Na+ ion path length. The excellent battery performances are achieved with a stable capacity retention of 350 W h/kg up to >350 cycles (∼6 months). Moreover, owing to the thin dense layer of BASE, the round trip energy efficiency (or discharging energy density) of the tested battery shows an ∼8% increase compared to that of state of the art Na-MH battery reported in the literature. Results from this work clearly demonstrate that advanced Na-MH batteries using bi-layer BASEs can have significant impacts on improving battery performances at lower operating temperatures, and further stretch its feasibility in stationary energy storage applications. [Display omitted] •Bi-layer (porous/dense) solid state electrolyte.•Infusion of molten Na through pore voids in the porous layer.•Lower battery over potentials.•High energy efficiency.