Si3N4 as an Alternative of Silicon for the Anode Application in All-Solid-State Li-Ion Batteries

The intermittent nature of renewable energy generation can be tackled by integrating them with electrochemical energy storage, which can also close the gap between supply and demand effectively. It has recently been demonstrated that Si₃N₄-based negative electrodes are a promising option for lithium-ion batteries due to their large theoretical capacity and appropriate working potential with extremely low polarization. In the present work, Si₃N₄ was utilized as anode material in all-solid-state lithium-ion battery with lithium borohydride as a solid electrolyte and Li foil placed as a counter electrode. The electrochemical properties were investigated using galvanostatic charge/discharge profiling whereas the mechanism of lithiation delithiation was investigated in detail using x-ray diffraction (XRD). The highest capacity of the composite materials was obtained as 1700 mAhg⁻¹ at 0.05 C current rate in the first cycle, which is reduced to 370 in 5 cycles. However, a stability in the capacity was observed in subsequent cycles and a retention of almost 88% could be achieved in 150 cycles. The interfacial resistance before and after the electrochemical cycling was observed as 326 Ω and 13 kΩ, respectively which is also supported by the microstructural investigations where the cracks are observed because of thermochemical reactions.