Dual-graphite cells based on the reversible intercalation of bis(trifluoromethanesulfonyl)imide anions from an ionic liquid electrolyte

摘要: Recently, dual-ion cells based on the anion intercalation into a graphite positive electrode have been proposed as electrochemical energy storage devices. For this technology, in particular electrolytes which display high stability vs. oxidation are required due to very operation potentials of cathode, may exceed 5 V Li/Li+. In work, we present highly promising results for use both anode and cathode material so-called “dual-graphite” or “dual-carbon” cell. A major goal system is find suitable electrolyte mixtures exhibit not only oxidative at but also form stable solid interphase (SEI) anode. As an system, ionic liquid-based mixture Pyr14TFSI-LiTFSI used combination with SEI-forming additive ethylene sulfite (ES) allows reversible Li+ ion TFSI− intercalation/de-intercalation into/from respectively. By addition ES, discharge capacity can be remarkably increased from 50 mA h g−1 97 g−1. X-ray diffraction studies conducted order understand influence structure cell performance.