Lithium (Li) metal is the most promising negative electrode to be implemented in batteries for stationary and electric vehicle applications. For years, its use and subsequent industrialization was hampered because of the inhomogeneous Li + ion reduction upon recharge onto Li metal leading to dendrite growth. The use of solid polymer electrolyte is a solution to mitigate dendrite growth. Li reduction leads typically to dense Li deposits but the Li stripping and plating process remain non-uniform with local current heterogeneities. A precise characterization of the behavior of these heterogeneities during cycling is then essential to move towards an optimized negative electrode. In this work, we have developed a characterization method based on X-ray tomography applied to model Li symmetric cells to quantify and spatially probe the Li stripping/plating 1 processes. Ante-and post-mortem cells are recut in smaller cells in order to allow a 1 µm voxel size resolution in a conventional laboratory scanner. The reconstructed cell volume is post-processed to numerically re-flatten the Li electrodes, allowing us a subsequent precise measurement of the electrode and electrolyte thicknesses and revealing local interface modifications. This in-depth analysis brings information on the location of heterogeneities and their impact on the electrode microstructure both at the electrode grains and grain boundaries. We show that the plating process (reduction) induces more pronounced heterogeneities compared to the stripping (oxidation) one. The existence of cross-talking between the electrodes is also highlighted. In addition, this simple methodology permits to finely retrieve and then surface-map the local current density at both electrodes based on the local thickness change during the redox process.