for anode materials to replace graphite [3] in lithium batteries. The application of thin lithium foils is considered to enable an increase in energy density by nearly a factor of 2 in case of solid-state lithium metal batteries (SSLMBs). [4] Besides LIB-derived cathode materials, lithium anodes are often considered for conversion-type cathodes enabling S 8 ||Li and O 2 ||Li batteries as well. [5] Nevertheless, lithium as anode material in rechargeable batteries has been extensively studied over four decades [6] and still no commercial application could be realized. [7] Major challenges concern the safety and uncontrolled lithium electrodeposition that often leads to the formation of high surface area lithium (HSAL), frequently called "dendrites." The high reactivity of pristine lithium and especially electrodeposited lithium leads to severe side reactions with electrolytes which result in the formation of a solid electrolyte interphase (SEI). [8] This SEI, however, is fractured during consecutive lithium electrodeposition and electrodissolution resulting in an inhomogeneous interphase on the lithium surface. These inhomogeneities can cause uncontrolled lithium electrodeposition and the formation of HSAL deposits. [9] Such deposits can occur in needle-like ( = dendritic) morphology and puncture the separator. After growing to the cathode, an internal short-circuit may be caused which dramatically increases the risk of a thermal runaway. To overcome the described issues, various approaches were developed based on electrolyte and lithium anode interphase engineering, [10] minimizing volume changes by using stable hosts, [11] and preventing dendrite formation and propagation by the use of solid-state electrolytes. [12] The stability of materials in contact with its environment is a well-known research area for corrosion science. Corrosion, in general, is defined as the chemical or electrochemical reaction between a material and its environment that results in a deterioration of the material and its properties. [13] As energy storage and conversion systems imply materials in a thermodynamically non-equilibrium state, corrosion-related processes are highly relevant for such systems. Figure 1a presents an overview of possible corrosion-related phenomena in a battery cell. Herein, we only discuss corrosion phenomena which occur in the presence of an electrolyte.At the positive electrode side, dissolution of Al, [14] which is typically used as a positive electrode current collector, and the cathode electrolyte interphase (CEI) [15] formation are phenomena related to corrosion in a battery cell (Figure 1b-d). One of the two processes which leads to dissolution of Al is Lithium metal is considered to be the most promising anode for the next generation of batteries if the issues related to safety and low coulombic efficiency can be overcome. It is known that the initial morphology of the lithium metal anode has a great influence on the cycling characteristics of a lithium metal battery (LMB). Lithium-powder-based el...

Because of its high specific capacity, silicon is regarded as the most promising candidate to be incrementally added to graphite‐based negative electrodes in lithium‐ion batteries. However, silicon suffers from significant volume changes upon (de‐)lithiation leading to continuous re‐formation of the solid electrolyte interphase (SEI) and ongoing active lithium losses. One prominent approach to compensate for active lithium losses is pre‐lithiation. Here, the “contact pre‐lithiation” of silicon/graphite (Si/Gr) negative electrodes in direct contact with passivated Li metal powder (PLMP) is studied, focusing on the pre‐lithiation mechanism in “dry state” and after electrolyte addition. PLMP is pressed onto the electrode surface to precisely adjust the degree of pre‐lithiation (25%, 50%, and 75%). By in situ XRD and ex situ 7Li NMR studies, it is proven that significant lithiation of Si/Gr electrodes occurs by direct contact to Li metal, that is, without electrolyte. After electrolyte addition, de‐lithiation of silicon and graphite is confirmed, resulting in SEI formation. The amount of Li metal highly impacts the presence and durability of the LixC and LixSi phases. Finally, the challenges for homogeneous pre‐lithiation and SEI formation are identified, and the impact of electrolyte addition is assessed by analysis of the lateral and in‐depth lithium distribution within the Si/Gr electrode.

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