Non–closed–loop recycling strategies for spent lithium–ion batteries: Current status and future prospects

With the sudden increase in the number of retired power batteries, there is great pressure to develop environmentally–friendly and efficient recycling technologies. The pyrometallurgy, hydrometallurgy and direct regeneration methods are all designed to recycle the spent lithium ion batteries (LIBs) back into the same battery industry as the original, which is undoubtedly somewhat self–limiting. In fact, the abundant transition metals and carbon–based materials in spent LIBs can serve as an important source of catalysts, adsorbents, new energy storage electrodes, and among others. To date, a lot of researches on the non–closed–loop recycle of spent LIBs have been reported. However, due to the high divergence and lack of segregation, it is difficult for us to grasp the status and prospects of the research on battery recycling beyond traditional closed–loop recycle. Herein, to fill the gap of this area, we systematically introduce the research examples of non–closed–loop recycling of spent LIBs by comparing and evaluating the craftsmanship and the product performance from the industrial perspective of two different recycling modes. Additionally, we briefly summarize the challenges associated with non–closed–loop recycling at a macro level, along with the exceptional prospects for subsequent high–value applications.