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Enhancement of Flotation Separation Selectivity of
Cathode and Anode Materials from Spent Lithium-Ion Batteries
Using Plasma Treatment
X. Bu, Z. Tong, X. Ren, Z. Ma, J. Wang, M. Cao
China University of Mining and Technology, Xuzhou, China
L. Dong
Curtin University, Kalgoorlie, Australia
S. Qiu
Chinese Academy of Science, Suzhou, China
ABSTRACT: The recycling of spent lithium-ion batteries (LIBs) can not only reduce the potential harm caused
by solid waste piles to the local environment but also provide raw materials for manufacturing new batteries.
Flotation is an alternative approach to achieve the selective separation of cathode and anode materials from
spent LIBs. However, the presence of organic binder on the surface of hydrophilic lithium transition-metal
oxides results in losses of cathode materials in the froth phase. In this study, plasma treatment was utilized to
remove organic layers from cathode and anode materials. Differences in the flotation recoveries of cathode and
anode materials were enhanced with plasma modification prior to flotation, which is consistent with the contact
angle measurement. Flotation separation selectivity index (SI) was increased from 2.41 to 4.28 by plasma
modifications. The plasma-modification mechanisms of hydrophobicity of cathode and anode materials were
discussed according to Fourier Transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy
(XPS) analyses. The proposed method could be a promising tool to enhance the flotation separation efficiency
of cathode and anode materials for the recycling of spent LIBs.
INTRODUCTION
In 2022, Chinese manufacturers delivered a total of 6.89
million new energy vehicles (NEVs) (a rise of 93.4% year-
on-year), with a market share of 25.6% (Fu, 2023). By the
end of 2022, the number of NEVs reached 13.1 million,
accounting for about 13% of all vehicles (Wei, 2023). The
update of battery techniques and the growing environmen-
tal awareness of the awakening will strongly support the
further growth of the global market demand of NEVs (Zhu
et al., 2023). The ownership of commercial vehicles was
predicted to be about 36.61 million in 2025, 45.44 mil-
lion in 2030 and 55.85 million in 2035. In parallel, the
share of NEVs in total sales needs to reach around 60% by
2030 to stay the course and reach net zero CO2 in 2050.
Lithium-ion batteries (LIBs) are currently the most suitable
energy storage device for NEVs, which is attributed to their
attractive properties including high-energy efficiency, lack
of memory effect, long cycle life, high-energy density, and
high-power density (Ding et al., 2019). It is expected that
LIBs production is approximately $95 billion in 2025 (Roy
Enhancement of Flotation Separation Selectivity of
Cathode and Anode Materials from Spent Lithium-Ion Batteries
Using Plasma Treatment
X. Bu, Z. Tong, X. Ren, Z. Ma, J. Wang, M. Cao
China University of Mining and Technology, Xuzhou, China
L. Dong
Curtin University, Kalgoorlie, Australia
S. Qiu
Chinese Academy of Science, Suzhou, China
ABSTRACT: The recycling of spent lithium-ion batteries (LIBs) can not only reduce the potential harm caused
by solid waste piles to the local environment but also provide raw materials for manufacturing new batteries.
Flotation is an alternative approach to achieve the selective separation of cathode and anode materials from
spent LIBs. However, the presence of organic binder on the surface of hydrophilic lithium transition-metal
oxides results in losses of cathode materials in the froth phase. In this study, plasma treatment was utilized to
remove organic layers from cathode and anode materials. Differences in the flotation recoveries of cathode and
anode materials were enhanced with plasma modification prior to flotation, which is consistent with the contact
angle measurement. Flotation separation selectivity index (SI) was increased from 2.41 to 4.28 by plasma
modifications. The plasma-modification mechanisms of hydrophobicity of cathode and anode materials were
discussed according to Fourier Transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy
(XPS) analyses. The proposed method could be a promising tool to enhance the flotation separation efficiency
of cathode and anode materials for the recycling of spent LIBs.
INTRODUCTION
In 2022, Chinese manufacturers delivered a total of 6.89
million new energy vehicles (NEVs) (a rise of 93.4% year-
on-year), with a market share of 25.6% (Fu, 2023). By the
end of 2022, the number of NEVs reached 13.1 million,
accounting for about 13% of all vehicles (Wei, 2023). The
update of battery techniques and the growing environmen-
tal awareness of the awakening will strongly support the
further growth of the global market demand of NEVs (Zhu
et al., 2023). The ownership of commercial vehicles was
predicted to be about 36.61 million in 2025, 45.44 mil-
lion in 2030 and 55.85 million in 2035. In parallel, the
share of NEVs in total sales needs to reach around 60% by
2030 to stay the course and reach net zero CO2 in 2050.
Lithium-ion batteries (LIBs) are currently the most suitable
energy storage device for NEVs, which is attributed to their
attractive properties including high-energy efficiency, lack
of memory effect, long cycle life, high-energy density, and
high-power density (Ding et al., 2019). It is expected that
LIBs production is approximately $95 billion in 2025 (Roy