The Diels-Alder reaction is a well-known [4+2] cycloaddition in organic chemistry, which is employed in this article as an efficient approach towards high-performance organic electrode materials since it can achieve the incorporation of more redox groups and extension of π systems in one step. As a proof-of-concept example, we reported that a hexalithium benzo[ghi]perylene hexacarboxylate (Li6-BPHC) by the lateral extension of well-known organic anode material, tetralithium perylene tetracarboxylate (Li4-PTC), via a facile Diels-Alder reaction, which has been demonstrated to not only store nearly six electrons per molecule at a current density of 280mAg−1 but also possess a highly stable cycling performance over 100 cycles.