High-Throughput Graphite Recovery from Battery Anode Scrap, Impacts of Using In-Line Near-Infrared Processing on Material Integrity

Abstract

Graphite, the predominant anode material in lithium-ion batteries (LIBs), accounts for a substantial share of both battery mass and cost. However, the recycling of graphite anodes remains energetically and technically challenging since residual binders and electrically conductive additives hinder effective material recovery and can degrade reusability and electrochemical performance. This work outlines a new thermal approach to regenerate graphite anodes based on near-infrared (NIR) irradiation, which enables rapid binder deactivation, and benchmarks its performance against conventional furnace heat treatment. Model graphite anode composites comprising graphite, carbon black, and representative aqueous binders (carboxymethyl cellulose and styrene–butadiene rubber) were prepared and subjected to a range of furnace and NIR exposure conditions. Our results demonstrate that furnace treatment at 450–470 °C for 60–120 min and NIR irradiation at 100% intensity for only 15.6 s at a line speed of 2 m/minute can effectively deactivate binders without compromising the graphite crystal structure. In terms of electrochemical performance, the NIR-regenerated graphite (G–N100) delivered an initial specific capacity of 354.1 mAh g–1 at 10 mA g–1 and retained 99.9% of its capacity after 20 cycles; this represents a specific capacity that is 99.4% of pristine graphite (356.0 mAh g–1) under the same conditions. In contrast, furnace-regenerated samples (G–470 and G–450) exhibited higher specific capacities of 374.7 and 373.7 mAh g–1 at 10 mA g–1, slightly exceeding that of pristine graphite. This work demonstrates that NIR irradiation can provide a selective, ultrafast thermal route to decompose binder additives while also preserving the graphite structure and electrochemical performance with greenhouse gas emissions of 0.4 kgCO2e/kg compared with between 1.4 and 9 kgCO2e/kg for virgin anode grade graphite.