An Integrated Chemicals‐Free Circular Model for Lithium Recovery From Spent Batteries to Direct Lithium Extraction From Brines

ABSTRACT The growing demand for lithium calls for integrated strategies that combine resource recovery with sustainable material synthesis. Here, we demonstrate a patented chemicals‐free circular approach that converts real spent lithium‐ion battery black mass into functional lithium–aluminum layered double hydroxide (Li/Al‐LDH). The process integrates a 5‐min microwave‐assisted carbothermic treatment, water‐only leaching, and spontaneous precipitation, enabling the formation of crystalline Li/Al‐LDHs alongside high‐purity Li₂CO₃ without the use of added chemical reagents. Structural characterization by synchrotron pair distribution function analysis, XRD, and SEM confirms the formation of phase‐pure LDHs with a hierarchical nanosheet‐based morphology and an exceptionally high surface area (more than 400 m 2 g −1 ). Preliminary adsorption–desorption experiments demonstrate the ability of the synthesized Li/Al‐LDHs to reversibly exchange lithium ions, supporting their potential application as sorbents for lithium recovery from aqueous systems. The sustainability analysis reveals a reduction of 60%–90% in environmental impacts, including embodied energy and carbon footprint, compared to conventional LDH synthesis routes. This work establishes for the first time a direct link between battery recycling and lithium extraction technologies, providing a scalable pathway toward a circular and low‐carbon lithium economy.