Approaching the voltage and energy density limits of potassium-selenium battery chemistry in a concentrated ether-based electrolyte.

ABSTRACT: Potassium-selenium (K-Se) batteries offer fairly high theoretical voltage (∼1.88 V) and energy density (∼1275 W h kg_Se ^-1). However, in practice, their operation voltage is so far limited to ∼1.4 V, resulting in insufficient energy utilization and mechanistic understanding. Here, it is demonstrated for the first time that K-Se batteries operating in concentrated ether-based electrolytes follow distinctive reaction pathways involving reversible stepwise conversion reactions from Se to K₂Se _x (x = 5, 3, 2, 1). The presence of redox intermediates K₂Se₅ at ∼2.3 V and K₂Se₃ at ∼2.1 V, in contrast with previous reports, enables record-high average discharge plateau voltage (1.85 V) and energy de

SUBMITTER: Liu Q 

PROVIDER: S-EPMC8159323 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature