Batteries: Scientists see how and where disruptive structures form and cause voltage fading
(Phys.org)—Starting as a few atoms long, thorns forming on the electrode's surface in a specialized lithium battery cause the battery to gradually fade, according to scientists at Pacific Northwest National Laboratory (PNNL) and Argonne National Laboratory. Working with powerful imaging technologies in DOE's Environmental Molecular Sciences Laboratory (EMSL), the team determined that a kind of thorn with the crystallographic spinel structure grows out of the electrode material and eventually leads to the complete conversion of the whole electrode material into the spinel structure. Furthermore, growth of this spinel structure liberates lithium oxide molecules, causing cracking and pitting. The damaged electrode thereby fades, releasing less energy with each charge/discharge cycle.