Researchers at Hasselt University in Belgium have proposed a new solid composite electrolyte for lithium-ion batteries: low eutectic solvents (DES) -- silicon dioxide composites. Gel electrolyte based on DES - the team called eutectogels (ETGs), its characteristic is high ionic conductivity (mS 1.46 cm - 1), (high), heat (up to 130 ° C) and electrochemical stability (up to 4.8 V), and be a chemical inertness to water and solvent.
Such ETGs may be easy to process and potentially less costly than ionic liquid-based composite electrolytes. In a paper published in the journal chemical materials of the American chemical society, the team noted that the Li/ETG/LiFePO4 cell showed stable cycling over 100 cycles of C/10, indicating that ETGs has a promising future for lithium-ion batteries.
Lithium-ion batteries have limitations, such as potential safety hazards, high prices, and storage limitations in weight/volume. This problem can be solved to the greatest extent by developing an ideal solid electrolyte. The organic liquid electrolyte in conventional lithium-ion batteries is flammable, prone to excessive oxidation when the potential is as low as 4.2v (versus Li), and cannot prevent the growth of lithium dendrites. As a result, an electrically conductive li-ion solid electrolyte with strong electrochemical and thermal stability is necessary to deploy the next-generation ion cathodes.
The team used the same ingredients to limit DES to a silicon oxide matrix using a non-aqueous sol-gel method. The resulting ETGs are transparent, homogeneous, and without cracks like glass boulders. The ETGs section shows a porous structure filled with DES.