Battery Electrode and Materials Recycling by Rapid High-temperature Heating

Challenge

­Recycling end-of-life Lithium-ion batteries (LIB) for second use applications is an effective strategy to secure the supply chain of battery materials. Current commercial LIB recycling methods, including hydrometallurgical and pyrometallurgical processes, primarily aim to recover the valuable metals such as Li, Co, Ni, and Mn from the cathodes. The pyrometallurgical process does not ensure the pre-separation of spent LIB components before smelting, resulting in the involvement of both cathode and anode materials in the process. This method only recovers metals, causing the critical material graphite to be burned or exploited as a reducing agent. Currently, no methods available are suitable for commercial scale recycling of LIB graphite.

Solution

The inventors have developed a high efficiency, low-cost approach to recycling LIB graphite. Using an ultrafast electrified high-temperature processing method, spent graphite powders as well as full sheet anodes can be directly recycled to remove impurities. The recycled graphite anode shows the same or better battery performance as pristine graphite.

Advantages

• Ultrafast processing: Our process skips long, expensive hold times and complicated multistep protocols. Fast and continuous process keeps costs low.
• High performance: The microstructural characteristics of the spent graphite are completely restored in this recycling approach, allowing re-integration into LIBs without any loss in performance.

 (a) Schematic of direct whole electrode recycling and heating temperature profile. We load the full sheet anode electrode on a carbon heater with a rapid heating rate and cooling rate. (b) After thermal shock recycling, the impurities are removed, and the graphite powders are well maintained.