Non-Uniform Distribution of Current in Plane of Large-Area Lithium Electrodes

Abstract

This work asserts that increasing the planar area of a lithium (Li) electrode is a challenge in view of ensuring a uniform plating and stripping and spatial uniformity for the state-of-health over the surface of lithium. A significant in-plane heterogeneity is observed for the symmetric Li cells with the stack area in the range of 24 to 96 cm 2. The cycling of the large-area lithium electrodes is performed inside a dedicated home-made electro-chemical setup capable of incorporating electrodes of different sizes. The cycling data and post-mortem analysis reveal a clear non-uniformity in the distribution of current and aging for the lithium electrodes having a size larger than the coin-cell and relevant to the commercial applications. It is shown that the inhomogeneous aging manifests mainly in the formation of dead Li film with a spatial variation in thickness and impedance over the surface of the Li electrode.