Towards Recycling of LLZO Solid Electrolyte Exemplarily Performed on LFP/LLZO/LTO Cells

A study on recovery strategies of graphite from mixed lithium-ion battery chemistries using froth flotation

The growing electric vehicle industry has increased the demand for raw materials used in lithium-ion batteries (LIBs), raising concerns about material availability. Froth flotation has gained attention as a LIB recycling method, allowing the recovery of low value materials while preserving the chemical integrity of electrode materials. Furthermore, as new battery chemistries such as lithium titanate (LTO) are introduced into the market, strategies to treat mixed battery streams are needed. In this work, laboratory-scale flotation separation experiments were conducted on two model black mass samples: i) a mixture containing a single cathode (i.e., NMC811) and two anode species (i.e., LTO and graphite), simulating a mixed feedstock prior to hydrometallurgical treatment; and ii) a graphite-TiO2 mixture to reflect the expected products after leaching. The results indicate that graphite can be recovered with > 98 % grade from NMC811-LTO-graphite mixtures. Additionally, it was found that flotation kinetics are dependent on the electrode particle species present in the suspension. In contrast, the flotation of graphite from TiO2 resulted in a low grade product (<96 %) attributed to the significant entrainment of ultrafine TiO2 particles. These results suggest that flotation of graphite should be preferably carried out before hydrometallurgical treatment of black mass.

Toward Sustainable All Solid-State Li-Metal Batteries: Perspectives on Battery Technology and Recycling Processes

Lithium (Li)-based batteries are gradually evolving from the liquid to the solid state in terms of safety and energy density, where all solid-state Li-metal batteries (ASSLMBs) are considered the most promising candidates. This is demonstrated by the Bluecar electric vehicle produced by the Bolloré Group, which is utilized in car-sharing services in several cities worldwide. Despite impressive progress in the development of ASSLMBs, their avenues for recycling them remain underexplored, and combined with the current explosion of spent Li-ion batteries, they should attract widespread interest from academia and industry. Here, the potential challenges of recycling ASSLMBs as compared to Li-ion batteries are analyzed and the current progress and prospects for recycling ASSLMBs are summarized and analyzed. Drawing on the lessons learned from Li-ion battery recycling, it is important to design sustainable recycling technologies before ASSLMBs gain widespread market adoption. A battery-recycling-oriented design is also highlighted for ASSLMBs to promote the recycling rate and maximize profitability. Finally, future research directions, challenges, and prospects are outlined to provide strategies for achieving sustainable development of ASSLMBs.

Recycling of All-Solid-State Li-ion Batteries: A Case Study of the Separation of Individual Components Within a System Composed of LTO, LLZTO and NMC

With the current global projection of over 130 million electric vehicles (EVs), there soon will be a need for battery waste management. Especially for all-solid-state lithium-ion batteries (lithium ASSBs), aspects of waste management and circular economy have not been addressed so far. Within such ASSBs, the use of solid-electrolytes like garnet-type Li_6.5 La₃ Zr_1.5 Ta_0.5 O₁₂ (LLZTO) may shift focus on strategies to recover not only the transition metal elements but also elements like La/Zr/Ta. In this work, we present a two-step recycling approach using citric acid as the leaching agent to separate and recover the individual components of a model cell comprising of Li₄ Ti₅ O₁₂ (LTO) anode, Li_6.5 La₃ Zr_1.5 Ta_0.5 O₁₂ (LLZTO) garnet electrolyte and LiNi_1/3 Mn_1/3 Co_1/3 O₂ (NMC) cathode. We observe that by adjusting the concentration of citric acid, it was possible to separate the materials from each other without strong mixing of individual phases and also to maintain their principle performance characteristics. Thus, the process developed has a potential for upscaling and can guide towards considering separation capability of battery components in the development of lithium ASSBs.

Sustainable Reuse and Recycling of Spent Li-Ion batteries from Electric Vehicles: Chemical, Environmental, and Economical Perspectives

The rapidly increasing adoption of electric vehicles (EVs) worldwide is causing high demand for production of lithium-ion batteries (LIBs). Tremendous efforts have been made to develop different components of LIBs in addition to design of battery pack architectures as well as manufacturing processes to make better batteries with affordable prices. Nonetheless, sustainable use of LIBs relies on the availability and cost of rare metals, which are naturally concentrated in a few countries. In addition, toxic electrolytes used in LIBs pose concerns on environmental impacts if LIBs are not handled properly after decommissioned from EVs. Therefore, it is paramount to realize effective utilization of spent LIBs, where their remaining capacities can be reused in less demanding applications. Finally, electrode materials and other valuable components of LIBs can be recovered via recycling, completing their circular life cycle. In this review, available options of LIBs after their retirement from EV applications, including battery second use, repair of electrode materials by direct regeneration, and material recovery by hydrometallurgical or pyrometallurgical processes are discussed. Throughout the review, the discussion is based around current available technologies, their environmental impacts, and economic feasibility as well as provided examples of pilot and industrial scale adoption of the processes.