Electrochemical intercalation of rubidium into graphite, hard carbon, and soft carbon.

ABSTRACT: The electrochemical insertion of Rb into carbonaceous materials, including graphite, was achieved herein. Rubidium ions were reversibly inserted into and extracted from graphite via electrochemical processes using different non-aqueous electrolytes containing rubidium bis(trifluoromethanesulfonyl)amide (RbTFSA) salts in carbonate esters, glymes, and ionic liquids, similar to the process used for other lighter alkali metal ions such as Li⁺ and K⁺. The chemical compositions of the rubidiated graphite were determined to be RbC₈, RbC₂₄, and RbC₃₆ at each step of the electrochemical reduction process. Graphite underwent a phase transition to RbC₈ exhibiting a stage-1 structure, with stage-3 RbC₃₆ and stage-2 RbC₂₄ as intermediates, as confirmed by ex situ and in situ X-ray diffraction and ex situ Raman spectroscopy, similar to the electrochemical phase evolution of staged potassium graphite intercalation compounds (K-GICs). Furthermore, Rb was reversibly inserted into and extracted from graphitizable and non-graphitizable carbons such as pitch-derived soft carbon and commercial hard carbon, along with other alkali metals such as Li, Na, and K.

SUBMITTER: Igarashi D 

PROVIDER: S-EPMC10583694 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature