Selection and Optimisation of Silicon Anodes for All-Solid-State Batteries

In the field of energy storage, Lithium-ion (Li-ion) technology is currently most widespread on market. It widely integrated in portable electronic devices and gaining interest automobile sector due to development electrical vehicles. However, its performance are reaching limits. Solid-state Li-ion battery (SSB) a very promising for next generation storage promise higher densities enhanced safety [1] . SSB expected enable safe use lithium metal anodes. high reactivity with solid electrolyte lead fast degradation performances. Another issue dendrite growth during cycling [2] Consequently, silicon has been identified as anode material alternative. Its great abundance, reasonable working potential 0,4V vs Li/Li + theoretical specific capacity 3579mAh/g main advantages. formation an alloy ions up Li 15 Si 4 phase, will undergo strong volume expansion almost 300%. Various techniques described literature limit this phenomena mainly liquid electrolytes, such nano-sized particles [3]–[5] Moreover, little studied all solid-state batteries. work, cyclability two different materials sulphide-based was studied. The have morphology: one made commercial micrometric (SiMicro) (2-10µm) other nanowires (SiNWs) (10nm) synthesized laboratory by chemical process [6] silicon-based composite consists 30wt% silicon, 50wt% (Li 6 PS 5 Cl) 20wt% conductive additive (VGCF). powders mixed manual grinding minutes. To study effect ageing, either used directly electrochemical characterisation (Fresh Composite) or after few weeks glove box (Aged Composite). entire cell manufacturing carried out box. tests performed Biologic MPG2 VMP3 at room temperature, between -0.6V 1V vs. Li-In rate C/20. Normalized function number cycles composites SiNWs SiMicro without ageing shown Figure 1 (a – b). first striking result difference SiMicro. Indeed, aged causes stability compared new composite, 30% initial th cycle versus 60%. On contrary, no observed types composites. therefore possible assume that than SiNWs. understand what species formed why more reactive electrode used, XPS analyses were performed. First raw analysed, then ageing. largest differences could be S2p spectrum presented (c d). presence sulphur can explained synthesis conditions elements depending whether because alone. With regard powder, spectra obtained identical before whereas evolution characteristic doublet oxidised appears observe SiMicro, which agreement characterizations. Future work involve modifying surface compare synthesis. A. Kato et al. , 2018, doi: 10.1021/acsaem.7b00140. S. Cangaz 2020, doi : 10.1002/aenm.202001320 [3] R. Okuno 10.1149/1945-7111/abc3ff. [4] C. Keller 2021, 10.3390/nano11020307. [5] J. Sakabe 10.1038/s42004-018-0026-y. O. Burchak 2019, 10.1039/C9NR03749G.