Amorphous Matrix-Integrated Si Anodes with Enhanced Elasticity and Conductivity for Li-Ion and All-Solid-State Li-Ion Batteries

Amorphous matrix-integrated Si nanocomposites were developed as high-performance anodes for Li-ion batteries (LIBs) and all-solid-state Li-ion batteries (ASSLIBs). Amorphous Ni 3 ZnSi 2 was employed as the elastic and conductive matrix because its unique crystal structure readily undergoes amorphization during high-energy milling, yielding a Si/a-Ni 3 ZnSi 2 nanocomposite in which Si nanocrystallites are uniformly encapsulated within the amorphous Ni 3 ZnSi 2 matrix. The amorphous Ni 3 ZnSi 2 matrix provides elastic recovery, high ionic/electronic conductivity, and effective buffering against large volume changes, thereby preserving electrode integrity during cycling. Incorporating a conductive graphite framework further produced dual-matrix Si/a-Ni 3 ZnSi 2 /G nanocomposites, where the amorphous Ni 3 ZnSi 2 and graphite frameworks synergistically enhance charge transport and mitigate mechanical stress. The Si/a-Ni 3 ZnSi 2 /G anode exhibited high initial Coulombic efficiency, high-rate capability, and long-term cycling stability in both LIBs and ASSLIBs. In LIB full cells comprising a Si/a-Ni 3 ZnSi 2 /G anode and a LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode, an energy density of 377.7 Wh kg –1 was achieved with stable cycling performance and high-rate capability. In ASSLIB configurations with Li 6 PS 5 Cl solid electrolytes, the full cell delivered energy densities exceeding 300 Wh kg –1 while maintaining electrochemical stability across wide ranges of temperature and current density. These findings highlight the scalability and potential applicability of Si/a-Ni 3 ZnSi 2 /G nanocomposites as next-generation anode materials for both LIBs and ASSLIBs.