It is widely recognized that CuO experiences volume expansion and conductivity issues, leading to unsatisfactory performance in sodium-ion batteries. A feasible approach to mitigate these challenges is the combination of Cu/CuO nanosheets with porous reduced graphene oxide aerogel (GA). In this study, an innovative composite of Cu/CuO nanosheets encapsulated within a 3D GA structure (GA/Cu/CuO) was synthesized via an alkaline exfoliation-mild self-assembly method. The results reveal that the Na+ storage properties of Cu/CuO/GA significantly surpassed those of pure CuO. Specifically, the GA/Cu/CuO exhibited a capacity retention of 320 mAh g–1 after 220 cycles at a current density of 0.1 A g–1, and demonstrated an optimized rate capability of 225 mAh g–1 at a current density of 1 A g–1. The enhanced rate and long-cycle performances are attributed to the synergistic effects of Cu/CuO nanosheets and porous GA, which shorten the Na+ transfer pathway, improve electronic/ionic conductivity, and buffer volume expansion during the discharge/charge process. Furthermore, the facile and innovative design strategy presented could be applicable to the synthesis of other composites for energy storage applications.