Ductile (Ag,Cu)2(S,Se,Te)-based auxetic metamaterials for sustainable thermoelectric power generation

Abstract

Sustainable energy solution has resulted in significant interest in thermoelectric power generation, converting waste heat into electricity. However, the practical application of thermoelectric generators has been hindered by issues with their adaptability to arbitrary heat sources and durability in an operational environment. Here, we propose deformable auxetic thermoelectric metamaterials composed of high-entropy (Ag,Cu)2(S,Se,Te) ductile alloys, realized using finite element modelling and three-dimensional (3D) printing. We design a re-entrant auxetic structure with a negative Poisson's ratio to maximize the mechanical deformability and develop an (Ag,Cu)2(S,Se,Te) particle-based colloidal 3D printable ink, tailored with Te microparticles. The 3D-printed (Ag, Cu)2(S,Se,Te) alloy exhibit a ZT value of 1.15 coupled with high compressive strength (208 MPa) and fracture strain (17.5 %). The fabricated auxetic metamaterials exhibit excellent vibrational stability and adaptability to diverse curved surfaces, realizing efficient power generation on a synclastic curved heat source. Our approach offers a method to design durable and efficient heat recovery devices.