This study presents a method to design sustainable structural parts of a Rechargeable Energy Storage Systems using Design for CE and Computational Optimization. Principle solutions are developed and combined with sustainability criteria being a key factor in the concept evaluation. The battery tray, a subsystem of REESS, serves a case study in which intrusion, mass, and LCA are optimized by varying the recyclate, UD tapes and design. The resulting Pareto front reveals trade-offs between intrusion, mass and LCA results and highlights the potential to reduce environmental impact in early design.