We studied how the electron–electron (e–e) interaction enhances the strength of the Rashba spin–orbit coupling (RSOC) and opens the possibility of generating a spin-polarized output current from an unpolarized electric current without any magnetic elements. In this regard, we proposed a novel design of a graphene-like junction based on the e–e interaction and the RSOC. The results showed that the e–e interaction with RSOC opens a spin energy gap and extremely enhances the RSOC in this spin energy gap. Interestingly, the junction produces a large spin-polarized current and could act as a high-efficiency spin filter device (nearly 100% spin polarization) at room temperature even at low Rashba and e–e interaction strengths. However, with an appropriate design, we showed that RSOC could strongly weaken the spin-polarized current and the spin energy gap, which is solely produced by the e–e interaction, but a high spin polarization persists in some energy ranges.