posted on 2023-11-17, 01:41authored byEtsuro Iwama, Toyomi TAKAZAWA, Koji MATSUYAMA, Daisuke Yamaguchi
<p></p><p>This paper presents an innovative approach wherein mechanical alloying and mechanical cation-disordering techniques are combined to synthesize peculiar zinc silicide phosphide (ZnSiP<sub>2</sub>) anode materials under controlled atmosphere. In this method, Zn atoms and P atoms are simultaneously incorporated into the parent Si crystal structure, resulting in A(II)<i><sub>x</sub></i>B(IV)<i><sub>y</sub></i>P<i><sub>x</sub></i><sub>+</sub><i><sub>y</sub></i> solid solutions with precise control over nanodomain structures of mixed crystalline-amorphous phases. This distinctive nanoarchitecture of the ZnSiP<sub>2</sub> anode, featuring an amorphous ionic-conduction phase network, facilitates the smooth transport of Li<sup>+</sup> ions, thereby enabling an exceptionally prolonged electrochemical cycling performance, surpassing 200 cycles. In this study, we attempted to unravel the microstructure of ZnSiP<sub>2</sub> using transmission electron microscopy (TEM). It was observed that when synthesized under an inert Argon atmosphere, the material formed a polycrystalline structure consisting of numerous nanocrystals (5–10 nm) assembled. Additionally, when attempts were made to reduce synthesis costs by conducting the synthesis under ambient atmospheric (Air) conditions, amorphous regions were generated. This amorphous region within the polycrystalline ZnSiP<sub>2</sub> microstructure represents a novel finding. The electrochemical impedance measurements and galvanostatic intermittent titration technique (GITT) analysis conducted in this study not only revealed but also characterized the enhanced cycling performance of this unique ZnSiP<sub>2</sub> anode structure.</p><p></p>
Funding
Achieving High-Speed and High-Efficiency Electrochemical Reactions through Ion Arrangement Control in Nanoparticle Crystals