Integrated assessment of deep eutectic solvents questions solvometallurgy as a sustainable recycling approach for lithium-ion batteries

TY - JOUR

T1 - Integrated assessment of deep eutectic solvents questions solvometallurgy as a sustainable recycling approach for lithium-ion batteries

AU - Wang, Mengmeng

AU - Xu, Zibo

AU - Dutta, Shanta

AU - Liu, Kang

AU - Labianca, Claudia

AU - Clark, James H.

AU - Zimmerman, Julie B.

AU - Tsang, Daniel C.W.

N1 - Funding Information: The authors appreciate the financial support from the Hong Kong Research Grants Council ( PolyU 15231522 ). Publisher Copyright: © 2023 Elsevier Inc.

PY - 2023/10/20

Y1 - 2023/10/20

N2 - Critical metals are key to lithium-ion batteries (LIB), but metal mining has inflicted many socio-environmental harms. Recovering metals from spent LIBs can partially overcome this challenge, but existing recovery and recycling techniques such as pyrometallurgy and hydrometallurgy are either energy intensive or require toxic chemicals. Solvometallurgy, using biodegradable deep eutectic solvents (DESs), has emerged as a greener option, but full life cycle sustainability of DESs remains unclear. Here, using an integrated assessment framework we show that, compared with pyrometallurgy and hydrometallurgy, the weak solubility of metal compounds in hydrogen bond donors (HBDs) and acceptors (HBAs) and their non-recoverability in chemical precipitation routes of the DES approach result in 3.1 times more CO2 eq, ∼5 times more ozone depletion, and 6.5–7.3 times higher costs. Although alternative electrodeposition routes can minimize HBA loss and alleviate chemical impacts, high energy consumption associated with HBDs exacerbates global warming potential. In situ repairing/regeneration of crystalline compounds in cathode materials could offer a more sustainable application for DESs.

AB - Critical metals are key to lithium-ion batteries (LIB), but metal mining has inflicted many socio-environmental harms. Recovering metals from spent LIBs can partially overcome this challenge, but existing recovery and recycling techniques such as pyrometallurgy and hydrometallurgy are either energy intensive or require toxic chemicals. Solvometallurgy, using biodegradable deep eutectic solvents (DESs), has emerged as a greener option, but full life cycle sustainability of DESs remains unclear. Here, using an integrated assessment framework we show that, compared with pyrometallurgy and hydrometallurgy, the weak solubility of metal compounds in hydrogen bond donors (HBDs) and acceptors (HBAs) and their non-recoverability in chemical precipitation routes of the DES approach result in 3.1 times more CO2 eq, ∼5 times more ozone depletion, and 6.5–7.3 times higher costs. Although alternative electrodeposition routes can minimize HBA loss and alleviate chemical impacts, high energy consumption associated with HBDs exacerbates global warming potential. In situ repairing/regeneration of crystalline compounds in cathode materials could offer a more sustainable application for DESs.

KW - carbon neutrality

KW - electric vehicle battery

KW - environmental impact

KW - green solvent

KW - metal recovery

KW - pyrometallurgy

KW - solvometallurgy

KW - sustainable development goals

KW - technology-critical element

KW - waste recycling

UR - http://www.scopus.com/inward/record.url?scp=85174203777&partnerID=8YFLogxK

U2 - 10.1016/j.oneear.2023.09.002

DO - 10.1016/j.oneear.2023.09.002

M3 - Article

AN - SCOPUS:85174203777

SN - 2590-3330

VL - 6

SP - 1400

EP - 1413

JO - One Earth

JF - One Earth

IS - 10

ER -