<p>Silicon carbon void structures (Si-C) are
attractive anode materials for Lithium-ion batteries to cope with the volume
changes of silicon during cycling. In this study, Si-C with varying Si contents
(28 ‑ 37 %) are evaluated in all-solid-state batteries (ASSBs) for the first
time. The carbon matrix enables enhanced performance and lifetime of the Si-C
composites compared to bare silicon nanoparticles in half-cells even at high
loadings of up to 7.4 mAh cm<sup>-2</sup>. In full cells with nickel-rich NCM
(LiNi<sub>0.9</sub>Co<sub>0.05</sub>Mn<sub>0.05</sub>O<sub>2</sub>, 210 mAh g<sup>-1</sup>),
kinetic limitations in the anode lead to a lowered voltage plateau compared to
NCM half-cells. The solid electrolyte (Li<sub>6</sub>PS<sub>5</sub>Cl, 3 mS cm<sup>-1</sup>)
does not penetrate the Si-C void structure resulting in less side reactions and
higher initial coulombic efficiency compared to a liquid electrolyte (72.7 %
vs. 31.0 %). Investigating the influence of balancing of full cells using
3-electrode ASSB cells revealed a higher delithiation of the cathode as a
result of the higher cut-off voltage of the anode at high n/p ratios. During
galvanostatic cycling, full cells with either a low or rather high overbalancing
of the anode showed the highest capacity retention of up to 87.7 % after 50
cycles. </p>
Nanostructured Si-C Composites As High-Capacity Anode Material For All-Solid-State Lithium-Ion Batteries
