RbFSI {[Rubidium bis(fluorosulfonyl)imide], >99.95%} Powder as Electrolyte Additive for Lithium-Ion Battery, 10-50 g/bottle, CLIBEARbFSI

RbFSI (Rubidium bis(fluorosulfonyl)imide, {RbN(SO2CF3)2} is an alkali metal imide salt investigated as a functional additive in non-aqueous electrolytes for lithium-metal, lithium-sulfur, and liquid-polysulfide flow batteries. It combines the heavy alkali cation Rb+ with the flexible, weakly coordinating, highly fluorinated TFSI- anion.

Self-Healing Electrostatic Shield (SHES) Mechanism: In lithium-metal battery systems, local high electric fields at the tips of metallic lithium protuberances trigger non-uniform Li+ electrodeposition, leading to dendrite formation. The reduction potential of Rb+ (~ -2.93 V vs. SHE) is slightly lower than that of Li+ (~ -3.04 V. During high-rate charging, Rb+ ions accumulate at the sharp tips of growing Li dendrites without being reduced into rubidium metal. This forms a localized positively charged electrostatic shield that repels incoming Li+ ions toward flatter regions of the anode, driving smooth, dendrite-free lithium plating.

Solid Electrolyte Interphase (SEI) Modification & Polysulfide Interaction: (1) F-Rich & Inorganic Interphases: The TFSI- anion decomposes at low potentials to build an inorganic-rich interphase (containing LiF, Li2S, and Li3N species), suppressing continuous solvent breakdown. (2) Polysulfide Compatibility: In lithium-sulfur (Li-S) and lithium-polysulfide (LiPS) flow battery chemistries, the incorporation of RbTFSI enhances bulk electrolyte ionic conductivity and boosts Coulombic efficiency during long-term cycling.

Part Number	CLIBEARbFSI (C-LIB-EA-RbFSI)
Chemical Formula	RbN(SO2F)2
Appearance	White Powder
Purity	>99.95% (Battery Grade)
Molecular Weight	266.6 g/mol
Package Size	10 g, 25 g, and 50 g/bottle

Notes: Please store the RbFSI powder in the glovebox due to its sensitivity to humidity and oxygen 

References: 

1. T. J. Leckie, et al. Secondary alkali-metal salts in supporting electrolytes for lithium polysulfide flow batteries, EES Batteries, 2026, DOI: 10.1039/d6eb00050a.
   
2. Keigo Kubota, et al., Novel inorganic ionic liquids possessing low melting temperatures and wide electrochemical windows: Binary mixtures of alkali bis(fluorosulfonyl)amides, Electrochemistry Communications, 2008, 10, 1886-1888.