Synthesis of closo-CB₁₁H₁₂^- Salts Using Common Laboratory Reagents

Lithium and sodium salts of the closo-carbadodecaborate anion [CB₁₁H₁₂]^- have been shown to form stable solid-state electrolytes with excellent ionic conductivity for all-solid-state batteries (ASSB). However, potential commercial application is currently hindered by the difficult, low-yielding, and expensive synthetic pathways. We report a novel and cost-effective method to synthesize the [CB₁₁H₁₂]^- anion in a 40% yield from [B₁₁H₁₄]^-, which can be synthesized using common laboratory reagents. The method avoids the use of expensive and dangerous reagents such as NaH, decaborane, and CF₃SiMe₃ and shows excellent reproducibility in product yield and purity.