Currently, a lot of research focuses on the development of high energy density lithium ion batteries. Silicon is a promising candidate as a high capacity anode active material and is already used in small quantities in state of the art products. One of the main hindrances for increasing the share of silicon within the anode is the high irreversible lithium loss that is characteristic for most silicon materials. Prelithiation offers a solution to this problem by introducing additional quantities of lithium into the cell. Accordingly, the interest in prelithiation technologies increased exponentially over the last years [1].

The concept of prelithiation covers a variety of different techniques. Some well-known approaches are the addition of lithium rich additives or the electrochemical prelithiation. In both cases, the stability and reactivity of the (pre)lithiated additives/electrodes under ambient humidity is a major concern. If only small amounts of lithium shall be introduced, the addition of air-stable positive electrode additives can be a good option. This approach is already actively investigated by industry players like e.g. Tesla [2]. However, if maximum energy density is targeted, the electrochemical prelithiation is likely the best choice [3] but the reactivity of the prelithiated electrodes towards even trace amounts of water remains a critical issue.

Even though there are many studies demonstrating the potential of electrochemical prelithiation to increase the energy density of a cell, the influence of the atmospheric composition during further processing is rarely investigated. Therefore, a systematic study of the behavior of prelithiated electrodes under different atmospheric conditions will be presented. C/SiOx composite anodes are prelithiated under Argon atmosphere and are subsequently subjected to varying levels of humidity. Afterwards the electrodes are analyzed for their electrochemical performance and variations in surface layer composition. The results highlight a strong dependence on moisture levels and give insight into the effect of industrially relevant atmospheres on the performance of prelithiated electrodes.

[1] Jin, L., Shen, C., Wu, Q., Shellikeri, A., Zheng, J., Zhang, C., & Zheng, J. P. (2021). Pre‐Lithiation Strategies for Next‐Generation Practical Lithium‐Ion Batteries. Advanced Science, 2005031.
[2] Gowda, S. R. et al., U.S. Patent 2020136142A1, 2020
[3] Holtstiege, F., Bärmann, P., Nölle, R., Winter, M., & Placke, T. (2018). Pre-lithiation strategies for rechargeable energy storage technologies: Concepts, promises and challenges. Batteries, 4(1), 4.