Enhancing the thermal performance of phase-change materials (PCMs) for thermal energy storage and management has been a subject of great interest since the energy crisis of the 1970s. PCMs are materials that can absorb (solid to liquid) and release (liquid to solid) significant amounts of energy during the phase transition. However, the low thermal conductivity of PCMs hinders their effective heat transfer, despite their high latent heats of fusion. To address this issue, recent studies have focused on improving the thermal conductivity of PCMs through the addition of additives or other means. Nevertheless, the efficient distribution of these materials through additive manufacturing in a compact heat exchanger with a high surface-area-to-volume ratio and thin walls can mitigate the need to increase thermal conductivity. It is worth noting that the thickness of a material also plays a crucial role in determining its thermal resistance. Prior studies have demonstrated the successful stabilization of PCMs with appropriate polymers through methods such as injection molding, extrusion, and casting, which can then be expanded to 3D printing. Alternatively, microencapsulation of PCMs in compatible materials allows them to blend with otherwise non-compatible host polymers, thereby expanding the range of 3D-printable composite materials. This presentation aims to provide an overview of polymer heat exchangers, shape-stabilized PCMs, and advances in additive manufacturing for the creation of next-generation thermal energy storage devices.