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 are suitable candidates for high energy density mobile and grid-storage energy applications. It is important to develop a strategy to obtain metals back used in their synthesis, either as pure or useful form for reutilization in batteries. In this work, we demonstrate a straight forward route based on hydrometallurgy using citric acid as the leaching agent to separate the battery components from each other. The recycled battery components could be directly obtained as active battery components.

Abstract

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_6.5La₃Zr_1.5Ta_0.5O₁₂ (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 Li₄Ti₅O₁₂ (LTO) anode, Li_6.5La₃Zr_1.5Ta_0.5O₁₂ (LLZTO) garnet electrolyte and LiNi_1/3Mn_1/3Co_1/3O₂ (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.

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