Microstructural evolution in lithium plating process and its effect on the calendar storage life

Abstract

The growing demand for electric vehicles highlights the need for energy storage solutions with higher densities, spotlighting Li metal anodes as potential successors to traditional Li-ion batteries (LIBs). Achieving longer calendar aging life for Li metal anodes is crucial for their practical use, given their propensity for corrosion due to a low redox potential, which leads to compromised cycling stability and significant capacity loss during storage. Recent research investigated that this susceptibility is mainly dependent on the surface area of Li metal anode and the properties of the solid electrolyte interphase (SEI), particularly its stability and growth rate. Our research adds to this understanding by demonstrating that the amount of Li plating is a key factor in its corrosion during open-circuit storage, as assessed across various electrolytes. We discovered that increasing the Li plating amount effectively reduces Coulombic efficiency (C.E.) loss during aging, due to a lower surface area-to-Li ratio. This implies that the choice of electrolyte for optimal storage life should consider the amount of Li plating, with higher capacities promoting better storage characteristics.