Recycled Additive Manufacturing Feedstocks for Fabricating High Voltage, Low‐Cost Aqueous Supercapacitors

Abstract The first recycled conductive poly(lactic acid) (PLA) filament derived from post‐industrial waste sources for additive manufacturing (AM) is reported herein, presenting a paradigm shift in plastic waste recycling, AM filament production, and AM energy storage architectures. Filaments utilizing a base of recycled PLA, carbon black (CB) as a conductive filler, and polyethylene glycol (PEG) as a plasticizer are used to produce aqueous AM symmetric supercapacitor platforms that can reach capacitance values 75 times higher than commercially available conductive PLA filaments. Furthermore, through the rapid prototyping capabilities of AM and GCode modification, it is seen that changing the electrode architecture from solid to a mesh with additional inter‐layer spacing is able to further enhance electrode performance by 3.5 times due to improvements in the surface area, ion accommodating capabilities, and faster ion diffusion. The symmetric full cell device is capable of delivering 7.82 mF cm⁻², 4.82 µWh cm^−2, and 433.32 µW cm⁻² of capacitance, energy, and power density, respectively. Moreover, the material cost is £0.15 per electrode. This study represents a new direction for plastic waste recycling, in which low‐value recycled base products can be manufactured into high‐value end products in their second cycles.