Cycling stability and rate performance, widely adopted parameters for quantifying the performance of LIBs, have been investigated for COF@bio, COF@bio-20, COF@bio-40, and COF@bio/40. In the long-term cycle tests, a stable SEI was formed after three cycles of activation, and a high current density was utilized to evaluate the cycling stability of the prepared electrodes. As depicted in Fig. , the COF@bio-40 electrode exhibited initial discharge and charge capacities of 2017 mAh g⁻¹ and 1049 mAh g⁻¹, respectively, resulting in an initial Coulombic efficiency (CE) of 51.9%. The discrepancy between the initial discharge and charge capacities was due to electrolyte decomposition and SEI formation, which led to significant capacity fade and low CE. In the first three cycles, a low current density was applied, and both discharge and charge capacities exhibited a downward trend, a common phenomenon in organic anodes without pre-lithiation that formed a stable SEI. From the fourth cycle to the five-hundred-fourth cycle, the capacity of COF@bio-40 initially increased before decreasing under a current density of 2,000 mA g⁻¹. The initial increase was attributed to the activation process of the electrode materials. During this phase, the layer spacing of COF gradually increased, exposing more active sites for lithium storage and facilitating rapid Li-ion transport due to the abundant large π-conjugated structures and one-dimensional open channels. In the eighty-sixth cycle, the discharge capacity of COF@bio-40 reached a maximum of 804 mAh g⁻¹. Following this, the discharge capacity gradually declined, reaching 364 mAh g⁻¹ by the five-hundred-fourth cycle. In contrast, the CE exhibited a distinct trend, first increasing and then stabilizing around 100%, indicating the excellent stability of the COF@bio-40 anode.