3184 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
metals are recyclable infinitely. Cathode active materials,
for instance, contain many critical minerals and metals
including graphite, lithium, cobalt, nickel, and manga-
nese (Olivetti et al., 2017 Xu et al., 2020). The ability to
recycle metal components from spent battery materials
into virgin materials/metals is essential to close the loop of
materials used in Li-ion batteries (Bai et al., 2020 Ciez &
Whitacre, 2019). Recycling methods include pyrometal-
lurgy, hydrometallurgy, and physical separation processes.
Pyrometallurgy is a high-temperature smelting process
that converts both contained nickel and cobalt into metal
alloys (M. Chen et al., 2019 Yun et al., 2018), while all
other components are present in the form of slag and vola-
tile gasses. The mixed alloys are then sent to a downstream
hydrometallurgical process for further refining. In using
this technology, lithium is lost in the slag (Y. Chen et al.,
2019 Gaines, 2014), which makes this pyrometallurgical
method less favorable from an economic perspective. The
hydrometallurgical processes use acids or base to leach met-
als from cathode active materials. Various leaching reagents
have been developed including organic acids (Li et al.,
2013), inorganic acids (Jha et al., 2013 Lee &Rhee, 2003
Wang et al., 2009), ammonia (Joulié et al., 2014 Meng &
Han, 1996 Zheng et al., 2016), and deep eutectic solutions
(Schiavi et al., 2021). The pregnant leach solutions (PLS)
is purified using different solution purification methods.
Metals from PLS are recovered by precipitated, crystallized,
and/or electrowon to metal products (Dutta et al., 2018).
Physical separation processes sort and separate individ-
ual battery components from shredded spent Li-ion batter-
ies for downstream processes (Harper et al., 2019 Larouche
et al., 2020). The coarse fraction of the shredded Li-ion
batteries is composed of separators, stainless steel casing,
aluminum, and copper foils. The fine fraction consists of
anode and cathode active materials, which is also known
as the black mass. When Li-ion batteries are shredded and
active powder materials are delaminated from current foils
(Zhang et al., 2014), size separation method is commonly
used to separate coarse materials from fine electrode active
materials (Kang et al., 2010 Shin et al., 2005). In the coarse
size fraction, aluminum and copper can be easily separated
using pneumatic separation due to their density difference
(Zhu et al., 2021).
Various separation methods have been developed
to separate individual components from the black mass.
Electrostatic separation was developed to remove non-
conductive/polymer fraction from metal constituents
(Silveira et al., 2017). Magnetic separation separates mixed
materials by the difference in magnetic susceptibility. This
method has been demonstrated to remove remained Cu
and Al pieces from cathode powders (da Costa et al., 2015
Marinos &Mishra, 2015). It is also used to separate mag-
netic-conductive active materials such as lithium ferrous
phosphate (LFP) from other active powder materials (Bi et
al., 2019). The froth flotation method has been developed
to separate the two electrode active materials due to the dif-
ference in their surface hydrophobicity (Zhan et al., 2018).
Graphite particles are hydrophobic, and therefore they are
carried by air bubbles into froth layers. In contrast, cathode
active particles are hydrophilic, and they are collected as
a sink product (Yu et al., 2018 Yu et al., 2020). Coarse
flake particles can also be separated using froth flotation
by taking advantage of a significant difference in densities
between the anode flake materials and cathode flake mate-
rials, but the effective size range is 212–850 µm (Folayan
et al., 2023). The alternative method is the gravity separa-
tion method. The gravity separation method separates the
materials based on the differences in specific gravities. This
method has also been used to separate plastic separators
from black mass (Zhong et al., 2020) as well as for a separa-
tion between copper (Cu) and aluminum (Al) from Li-ion
batteries (Barik et al., 2016 Zhong et al., 2020). The effi-
ciency with the gravity separation in separating mixed elec-
trode materials from black mass was limited. The ability to
achieve a good separation between the recycled anode and
cathode materials from spent Li-ion batteries is essential to
achieve the circular economy of Li-ion batteries.
In this work, a new process was developed that enabled
a better separation between the two electrode active materi-
als from Li-ion batteries. The separation efficiency between
these two electrode active materials was determined.
MATERIALS AND EXPERIMENTS
Materials
De-ionized (DI) water was supplied from a Barnard Lab
water purification system (Thermo Fisher), and it had a
resistance of 18.2 MΩ∙cm. Electric vehicle (EV) Li-ion bat-
tery pouch cells were used. They were discharged to 2.8 V
at a C/5 rate and held at 2.8 V for at least 48 hours. The
electrode sheets were manually recovered, soaked in isopro-
panol alcohol (IPA) to remove remaining electrolyte and its
solvents, and dried under the fume hood. The active mate-
rials from electrode sheets were delaminated from current
collectors by a mechanical delamination process in water as
describe in the prior publication (Zhan et al., 2020). The
delaminated anode active materials contained graphite and
3–6% of binders, while cathode active materials contained
5–10% of PVDF binders and carbon additives. The delam-
inated electrode active materials were dried in the drying
oven at 100 °C overnight. Some of the black mass were
metals are recyclable infinitely. Cathode active materials,
for instance, contain many critical minerals and metals
including graphite, lithium, cobalt, nickel, and manga-
nese (Olivetti et al., 2017 Xu et al., 2020). The ability to
recycle metal components from spent battery materials
into virgin materials/metals is essential to close the loop of
materials used in Li-ion batteries (Bai et al., 2020 Ciez &
Whitacre, 2019). Recycling methods include pyrometal-
lurgy, hydrometallurgy, and physical separation processes.
Pyrometallurgy is a high-temperature smelting process
that converts both contained nickel and cobalt into metal
alloys (M. Chen et al., 2019 Yun et al., 2018), while all
other components are present in the form of slag and vola-
tile gasses. The mixed alloys are then sent to a downstream
hydrometallurgical process for further refining. In using
this technology, lithium is lost in the slag (Y. Chen et al.,
2019 Gaines, 2014), which makes this pyrometallurgical
method less favorable from an economic perspective. The
hydrometallurgical processes use acids or base to leach met-
als from cathode active materials. Various leaching reagents
have been developed including organic acids (Li et al.,
2013), inorganic acids (Jha et al., 2013 Lee &Rhee, 2003
Wang et al., 2009), ammonia (Joulié et al., 2014 Meng &
Han, 1996 Zheng et al., 2016), and deep eutectic solutions
(Schiavi et al., 2021). The pregnant leach solutions (PLS)
is purified using different solution purification methods.
Metals from PLS are recovered by precipitated, crystallized,
and/or electrowon to metal products (Dutta et al., 2018).
Physical separation processes sort and separate individ-
ual battery components from shredded spent Li-ion batter-
ies for downstream processes (Harper et al., 2019 Larouche
et al., 2020). The coarse fraction of the shredded Li-ion
batteries is composed of separators, stainless steel casing,
aluminum, and copper foils. The fine fraction consists of
anode and cathode active materials, which is also known
as the black mass. When Li-ion batteries are shredded and
active powder materials are delaminated from current foils
(Zhang et al., 2014), size separation method is commonly
used to separate coarse materials from fine electrode active
materials (Kang et al., 2010 Shin et al., 2005). In the coarse
size fraction, aluminum and copper can be easily separated
using pneumatic separation due to their density difference
(Zhu et al., 2021).
Various separation methods have been developed
to separate individual components from the black mass.
Electrostatic separation was developed to remove non-
conductive/polymer fraction from metal constituents
(Silveira et al., 2017). Magnetic separation separates mixed
materials by the difference in magnetic susceptibility. This
method has been demonstrated to remove remained Cu
and Al pieces from cathode powders (da Costa et al., 2015
Marinos &Mishra, 2015). It is also used to separate mag-
netic-conductive active materials such as lithium ferrous
phosphate (LFP) from other active powder materials (Bi et
al., 2019). The froth flotation method has been developed
to separate the two electrode active materials due to the dif-
ference in their surface hydrophobicity (Zhan et al., 2018).
Graphite particles are hydrophobic, and therefore they are
carried by air bubbles into froth layers. In contrast, cathode
active particles are hydrophilic, and they are collected as
a sink product (Yu et al., 2018 Yu et al., 2020). Coarse
flake particles can also be separated using froth flotation
by taking advantage of a significant difference in densities
between the anode flake materials and cathode flake mate-
rials, but the effective size range is 212–850 µm (Folayan
et al., 2023). The alternative method is the gravity separa-
tion method. The gravity separation method separates the
materials based on the differences in specific gravities. This
method has also been used to separate plastic separators
from black mass (Zhong et al., 2020) as well as for a separa-
tion between copper (Cu) and aluminum (Al) from Li-ion
batteries (Barik et al., 2016 Zhong et al., 2020). The effi-
ciency with the gravity separation in separating mixed elec-
trode materials from black mass was limited. The ability to
achieve a good separation between the recycled anode and
cathode materials from spent Li-ion batteries is essential to
achieve the circular economy of Li-ion batteries.
In this work, a new process was developed that enabled
a better separation between the two electrode active materi-
als from Li-ion batteries. The separation efficiency between
these two electrode active materials was determined.
MATERIALS AND EXPERIMENTS
Materials
De-ionized (DI) water was supplied from a Barnard Lab
water purification system (Thermo Fisher), and it had a
resistance of 18.2 MΩ∙cm. Electric vehicle (EV) Li-ion bat-
tery pouch cells were used. They were discharged to 2.8 V
at a C/5 rate and held at 2.8 V for at least 48 hours. The
electrode sheets were manually recovered, soaked in isopro-
panol alcohol (IPA) to remove remaining electrolyte and its
solvents, and dried under the fume hood. The active mate-
rials from electrode sheets were delaminated from current
collectors by a mechanical delamination process in water as
describe in the prior publication (Zhan et al., 2020). The
delaminated anode active materials contained graphite and
3–6% of binders, while cathode active materials contained
5–10% of PVDF binders and carbon additives. The delam-
inated electrode active materials were dried in the drying
oven at 100 °C overnight. Some of the black mass were