TY  - CONF
AU  - Valencia, Helen
AU  - Rapp, Philip
AU  - Ahrens, Lara
AU  - Graf, Maximilian
AU  - Gasteiger, Huber
AU  - Basak, Shibabrata
AU  - Eichel, Rüdiger-A.
AU  - Mayer, Joachim
TI  - Tracking the crystalline-amorphous transition during lithiation of silicon microparticles
M1  - FZJ-2024-00494
PY  - 2023
AB  - With the aim of the European Commission to archive the first climate-neutral continent by 2025 the development of electrical energy systems is of great importance [1]. Therefore, the improvement of energy storage systems is crucial, making the development of the next generation of Lithium-ion batteries an up-to-date topic. Graphite-based anodes are nowadays widely used, but silicon-based anodes are of great interest due to their high theoretical capacity of 3579 mAh/g which is approximately ten-fold than that of the commonly used graphite-based anodes [2,3]. The biggest challenge that silicon-based anodes face is the degradation due to volume expansions of ~300 % upon (de)lithiation, resulting in a crystalline-amorphous transition. To overcome this hurdle, one approach is partial lithiation, by only using ~30 % of the silicon anode, meaning the silicon anode is cycled under its capacity limit. The benefit of this approach is a smaller volume expiation of only one-third of the maximal expansion which also helps to ensure that a crystalline silicon phase remains upon (de)lithiation [4]. Transmission electron microscopy (TEM) is the method of choice in order to correlate the microstructure, and chemical composition with the electrochemical performance of the crystalline and amorphous phases within partially lithiated polycrystalline silicon microparticles. Although silicon nanoparticles have been studied extensively and a core-shell model is proposed [2,5]. In the sample we investigated, we found out that additional amorphous veins form throughout the silicon crystal upon lithiation, which is supported by other literature sources [6]. This indicates that there are still unanswered questions regarding bulk silicon anodes. To further understand how the amorphous veins form in the silicon microparticles during lithiation and whether this stage can be investigated, an in-situ biasing TEM experiment was performed to lithiate a pristine sample by applying an electrical current.
T2  - The 20th of International Microscopy Congress
CY  - 10 Sep 2023 - 15 Sep 2023, Busan (South Korea)
Y2  - 10 Sep 2023 - 15 Sep 2023
M2  - Busan, South Korea
LB  - PUB:(DE-HGF)24
UR  - https://juser.fz-juelich.de/record/1021034
ER  -