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

All solid-state lithium-ion batteries (lithium ASSBs) are promising candidates for their use in high energy density applications like electric vehicles (EVs). With the current global projections of over 130 million EVs on road by 2030, there soon will be a need for lithium ASSBs waste management. For lithium ASSBs, various combinations of solid electrolytes and electrode materials could be imagined, e.g., with garnet electrolyte Li6.5La3Zr1.5Ta0.5O12 (LLZTO) and the use of a solid electrolyte might shift focus on recycling strategies. Not only the transition metals of the electrode materials will then be an important target, but also the recovery of La/Zr/Ta. In this work, we present a recycling approach based on a two-step leaching process with citric acid to separate and recover the individual components of a full model cell comprising of Li4Ti5O12 (LTO) anode, Li6.5La3Zr1.5Ta0.5O12 (LLZTO) garnet electrolyte and LiNi1/3Mn1/3Co1/3O2 (NMC) cathode. By treating the complex mixture of LTO/LLZTO/NMC in this process, we manage to separate the materials from each other without strong mixing of elements between the individual phases. We show that the battery components can maintain their principle performance characteristics, demonstrating that the developed process can serve as a basis to recover functional battery materials. Thus, the process developed has a potential for upscaling and can guide towards considering separation capability for battery components in the development of lithium ASSBs.