Hybrid Electrolytes Composed of Lithium-Ion Conducting Solid Particles and Liquid Electrolytes for Lithium-Ion Cells

摘要

Lithium ion batteries for automotive applications such as electric vehicles (EVs) have required to enhance power density, low temperature performance, energy density and safety. Recently, all-solid-state batteries using lithium-ion conducting solid electrolytes have been extensively studied to respond to these demands. However, all-solid-state batteries using solid electrolytes have some issues. Sulfide based solid electrolytes have low chemical stability and oxide electrolytes have large resistance at interfaces between active materials and solid electrolytes. We have developed hybrid electrolytes consisting of lithium-ion conducting solid particles and a gel polymer or liquid electrolyte. The cell with hybrid electrolytes exhibited a low internal resistance, particularly at low temperatures. Moreover, we proposed the mechanism for reducing of the resistance because cyclic carbonates such as PC and PF_6~- anion on the surface of lithium-ion conducting solid particles enhance Li~+ transference number.