High-Entropy Electrolytes for Lithium-Ion Batteries.

ABSTRACT

One of the primary challenges to improving lithium-ion batteries lies in comprehending and controlling the intricate interphases. However, the complexity of interface reactions and the buried nature make it difficult to establish the relationship between the interphase characteristics and electrolyte chemistry. Herein, we employ diverse characterization techniques to investigate the progression of electrode-electrolyte interphases, bringing forward opportunities to improve the interphase properties by what we refer to as high-entropy solvation disordered electrolytes. Through formulating an electrolyte with a regular 1.0 M concentration that includes multiple commercial lithium salts, the solvation interaction with lithium ions alters fundamentally. The participation of several salts can result in a weaker solvation interaction, giving rise to an anion-rich and disordered solvation sheath despite the low salt concentration. This induces a conformal, inorganic-rich interphase that effectively passivates electrodes, preventing solvent co-intercalation. Remarkably, this electrolyte significantly enhances the performance of graphite-containing anodes paired with high-capacity cathodes, offering a promising avenue for tailoring interphase chemistries.