  The lithium (Li) metal anode is essential for next generation high energy
density rechargeable Li metal batteries. Although extensive studies have been
performed to prolong the cycle life of Li metal batteries, the calendar life,
which associates with chemical corrosion of Li metal in liquid electrolytes,
has not been quantitatively understood. Here, by combing the Titration Gas
Chromatography (TGC) method and Cryogenic Focused Ion Beam (Cryo-FIB), we
established a quantitative relationship between the chemical corrosion rate and
electrochemically deposited Li morphology in various liquid electrolyte
systems. We identified that the corrosion rate is dominated by the porosity of
the deposited Li. The larger the porosity of deposited Li has, the faster the
corrosion rate will be. We further proposed strategies to mitigate the chemical
corrosion on Li thus to extend the calendar life of Li metal batteries. By
strictly controlling the stacking pressure during Li plating, Li deposits with
ultra-low porosity can be achieved, suppressing the corrosion rate to 0.08% per
day compared with 1.71% per day of the high-porosity Li.
