3D Architected Carbon Electrodes for Energy Storage

摘要

The ability to design a particular geometry of porous electrodes at multiple length scales in a lithium-ion battery can significantly and positively influence battery performance because it enables control over distribution of current and potential and can enhance ion and electron transport. 3D architecturally designed carbon electrodes are developed, whose structural factors are independently controlled and whose dimensions span micrometers to centimeters, using digital light processing and pyrolysis. These free-standing lattice electrodes are comprised of monolithic glassy carbon beams, are lightweight, with a relative density of 0.1-0.35, and mechanically robust, with a maximum precollapse stress of 27 MPa, which facilitates electrode recycling. The specific strength is 101 kN m kg(-1), comparable to that of 6061 aluminum alloy. These carbon electrodes can reach a mass loading of 70 mg cm(-2) and an areal capacity of 3.2 mAh cm(-2) at a current density of 2.4 mA cm(-2). It is demonstrated that this approach allows for independent design of structural factors, i.e., beam diameter, electrode thickness, and surface morphology, enabling control over Li-ion transport length, overpotential and battery performance, not available for slurry-based electrodes. This multiscale approach to design of electrodes may open substantial performance-enhancing capabilities for solid- and liquid-state batteries, flow batteries, and fuel cells.