Solid state battery stability improves with ‘battery butter’


Solid state lithium batteries could represent an environmentally sound alternative to their lithium-ion counterparts, as the former rely on a solid ceramic electrolyte instead of a potentially flammable liquid. However, maintaining stability at high current densities remains a challenge as a result of reactivity at the interface between the solid electrolyte and the lithium metal anode. An interlayer paste-like material has been formulated by researchers from Chalmers University of Technology, Sweden, and Xi’an Jiaotong University, China, to address this performance barrier.

The soft, spreadable, “butter-like” substance is composed of nanoparticles of the ceramic electrolyte lithium-aluminum-germanium phosphate (LAGP) mixed with an ionic liquid. The liquid encapsulates the LAGP particles and renders the interlayer soft and protective, ensuring fast lithium‐ion transport and stability toward metallic lithium.

The ion-conducting interlayer was demonstrated to suppresses the severe thermal runaway typically observed for LAGP electrolyte at high temperatures and to deliver a tenfold increase in current density. As reported in Advanced Functional Materials, the material reduced interfacial resistance and allows the use of a high areal current density, 1.0 mA cm2, at ambient temperature, which is roughly an order of magnitude higher than previously reported., 12 June 2020