<p>The performance of lithium-ion batteries is often compromised by the volume expansion of iron oxide anode materials during charge/discharge cycles, leading to particle cracking, electrode pulverization, and consequently, poor reversibility and rapid capacity fading. In contrast, graphite carbon, while offering structural stability, has a limited theoretical capacity for lithium-ion battery anodes. Here, we introduce a novel anode material synthesized using a template method with soybean cake as the carbon source and potassium oxalate and calcium carbonate as structural templates. The resulting N-doped hierarchical porous carbon (NSAC) was decorated with iron oxide (Fe₃O₄) precursors via co-precipitation to form Fe₃O₄@NSAC composites. These composites demonstrated a remarkable capacity retention of 225.6&#xa0;mA h g⁻¹ after 1000 cycles at a current density of 600&#xa0;mA g⁻¹, significantly outperforming biochar without Fe₃O₄. The enhanced cycling performance of Fe₃O₄@NSAC is attributed to its innovative structure, where Fe₃O₄ nanoparticles are uniformly encapsulated within the porous carbon framework derived from soybean cake. This encapsulation strategy not only enhances the electrical conductivity of Fe₃O₄ but also effectively mitigates volume expansion during charge/discharge processes, thereby conferring superior electrochemical stability. Our approach not only achieves high-value utilization of an inexpensive agricultural byproduct but also paves the way for developing other transition metal oxide-based anode materials. This study offers a sustainable and high-performance solution for lithium-ion battery anode materials.</p>