Sn-seeded Si nanowire growth on N-doped rGO for high-power lithium-ion battery anodes

Despite significant advances in Si-based anodes for electrochemical energy storage, volume expansion/contraction-driven material degradation impacts their long-term stability. Composite anode materials containing Si nanowires (NWs) can be engineered to withstand these mechanical stresses and boost charge/discharge kinetics through enhanced electronic and ionic conductivity. Here we show that nitrogen-doped reduced graphene oxide (N-rGO) is an ideal host material for Si NWs due to its conductivity and mechanical properties. The Si-Sn-N-rGO composite exhibits more than double the capacity of the benchmark N-doped Sn-rGO material (628 mAh g⁻¹vs 294 mAh g⁻¹after 100 cycles at 0.5 A g⁻¹) and delivers 542 mAh g⁻¹after 150 cycles at high current density (2 A g⁻¹), with capacity retention of 99.8 % after the second cycle. The Si-Sn-rGO electrodes were also tested for Li-ion capacitors (LICs), achieving energy densities of 139 Wh kg⁻¹and 101 Wh kg⁻¹at power densities of 155 W kg⁻¹and 2306 W kg⁻¹, respectively. The Si-Sn-rGO composite is shown to be suitable for LICs and LIBs, representing a versatile active material for high-rate energy storage.