Direct separation, purification and regeneration of cathode materials for aged lithium ion battery using a novel low-temperature plasma assisted separation (LPAS) process

Lithium ion batteries (LIBs) have emerged as the battery of choice for rapidly growing markets in electric vehicles (EVs) and grid electricity storage. This spurs a great demand for lithium, graphite, cobalt, and nickel that could outstrip the supply of virgin materials. Thus, there is an enormous interest in the development of new technologies for recycling and recovery of valuable materials from secondary resources, especially from used lithium ion batteries. Recycling of spent batteries is also an important step in addressing stringent environmental regulations and resource conservation. Recycling can reduce the adverse effects of mining/brine extractions for virgin metals, raw material transportation, and energy consumption, while balance fluctuating cost dynamics and ensuring a steady supply of raw material. This Phase I project will develop a novel low-temperature plasma assisted separation (LPAS) process that will enable sorting, purification, and regeneration of cathode materials from aged lithium ion batteries, as well as adding new functionality to improve the cathode materials performance. The fast sorting and separation of damaged and intact cathode particles, which reduces steps for recycling cathode materials, is achieved in a novel gas phase centrifuging process by controlling the gas pressure and aerodynamics of gas flow. The swirling, low-temperature plasma process, which effectively removes impurities and prevents re- adsorption of highly reactive species, involves controlling the exposure time of cathode particles to plasma species as well as tuning the plasma discharge properties to be suitable for fast physical and chemical etching of impurities and coated layers. The LPAS process provides a novel method to precisely separate damaged particles, selectively remove chemically bonded impurities (fluorine, phosphorus), and repair or modify coating layers for cathode materials. This process further enables upgrading of low-performance outdated cathode materials to meet the current standards for high energy density and fire resistance as seen in newly developed and commercialized nickel-cobalt-manganese (NCM) and nickel-cobalt-aluminum (NCA) cathode materials. Compared to the current commercial high temperature pyrometallurgical or hydrometallurgical methods, the LPAS process has the potential to significantly shorten recycling time and costs, reduce waste generation, and produce high performance battery materials in a closed-loop system. Successful application of this technology will enable regenerating cathode and anode materials without completely breaking down the underlying chemical compounds, which will significantly reduce energy and chemical consumption compared to current industrial processes. Direct regeneration of the cathode materials by using the proposed technology will increase the commercial viability of LIBs and reduce battery cost, and thus accelerate the electrification of transportation and large scale energy storage for renewable energy in the near future. Moreover, the LPAS technology is transformative. If successful, it will create a new manufacturing process for LIB cathode materials from recycled batteries and establish the leadership of U.S. manufacturing of LIBs. The LPAS approach offers systematic advantages in costs, energy efficiency, and environmental protection by reusing, recycling, and reproducing lithium ion batteries within an optimized system. This invention brings new opportunities to recycle batteries with high energy efficiency and low environmental impact.