Chemical Prelithiation of Silicon Powder and its Role as Anode Material for All‐Solid‐State Batteries

This article explores a carrier-type approach for the chemical prelithiation of silicon (Si) powder and investigates the integration of prelithiated silicon (LixSi) as electrolyte-free anode in sulfide-based all-solid-state batteries. In comparison to a Si anode, the LixSi anodes showed improved cycle stability at 2 C, but revealed kinetic limitations at higher C-rates.

Silicon (Si) is a high-capacity material, which faces substantial volume changes during de-/lithiation, leading to severe degradation of the battery. Chemical prelithiation is a promising strategy to enhance the performance of Si anodes in lithium (Li)-ion based all-solid-state batteries (ASSB) by mitigating these volume changes and improving cycling stability. In this article, the possibility of the prelithiation of Si powder using a lithium–arene complex solution with subsequent recovery of the arene and solvent is explored. Using a variety of physiochemical analysis methods, like attenuated total reflection infrared spectroscopy, Raman spectroscopy, inductively coupled plasma optical emission spectroscopy, and soft X-ray emission spectroscopy, the success of an inhomogeneous prelithiation is confirmed. To study the electrochemical performance (galvanostatic cycling, electrochemical impedance spectroscopy) of the material, the obtained material is integrated in form of a casted electrode into a sulfide-based ASSB cell setup using a thin separator layer (≈30 μm) and a casted LiNi_0.6Mn_0.2Co_0.2O₂ (NMC622) cathode, and the findings is compared with thus of a casted Si anode. The obtained data reveal the enhanced cycle stability prelithiated Si exhibits under certain condition, proving the benefits of this chemical prelithiation approach for next-gen anodes in Li-ion battery applications.

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