3198 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
treatment, which is the C-O stretching peak of primary
alcohol. This indicates that the oxidation of free radicals
generated by plasma introduces hydroxyl groups on the
surface of the cathode material, increasing the hydrophi-
licity of the cathode materials. However, no changes in
the characteristic absorption peaks of PVDF on cathode
material surfaces before and after plasma treatment are
detected. Thus, further characterization using XPS analy-
sis is employed to determine the changes of organic biners
before and after plasma treatment.
Figure 3 presents XPS results of anode materials before
and after plasma treatment. As seen from Figure 3 (a1),
peaks of C-C/C-H and COOR are detected at 284.8 and
at 285.64 eV, respectively. After plasma treatment, C=C
peaks with 36.38% relative content were observed at
285 eV (Figure 3 (a2)). In addition, the plasma treatment
leads to the fact that the relative content of C-C/C-H peaks
increases from 72.16% to 63.62%. The presence of C=C
hydrophobic group is helpful for enhancing the hydropho-
bicity of the anode materials, which is consistent with the
significant improvement in flotation rate constant of anode
material after plasma treatment (Table 1). O 1s XPS spec-
trums of anode materials before and after plasma treatment
are given Figure 3 (b). As seen from Figure 3 (b), the peaks
of C=O (or metal oxide M-O2+) are observed at 531.74 eV,
the peaks of C-O are observed at 532.41 eV, and the peaks
of C-O-C are observed at 533 eV, and the atomic O bonded
to the carbonyl group was observed at 534.05 eV. After
plasma treatment, the relative content of C=O/M-O2+
decreased from 57.46% to 25.06%, and the relative con-
tent of C-O is increased from 7.12% to 65.81%, and the
relative content of O-C=O is decreased from 18.28% to
9.14%. In general, the content of C=O hydrophilic groups
decreased while the content of C-O hydrophobic groups
increased. It is considered that plasma treatment can dis-
rupt the carbon oxygen double bond, thereby increasing
the hydrophobicity of the anode material by reducing the
number of hydrophilic groups.
XPS results of cathode materials before and after plasma
treatment are given in Figure 4. As seen from Figure 4 (a1),
the peaks of C-O are observed at 288.5 eV. The peaks of
PVDF (-(CF2CH2)-n) are at 286.05 and 290.68 eV. After
plasma treatment Figure 4 (a2), the relative content of
C-C/C-H hydrophobic groups is decreased from 77.64 to
29.25%, indicating that the hydrophilicity of the cathode
material is enhanced by plasma treatment. Meanwhile, the
peaks of C bonded to COOR, C=O, and O-C=O are gen-
erated after plasma treatment. Furthermore, the peak corre-
sponding to PVDF is observed only at 290.68 eV, indicating
that the structure of PVDF in the cathode is damaged by
plasma treatment, which can verify the FTIR results of cath-
ode materials (Figure 2 (d)). As seen from Figure 4 (b1), the
peaks of metal fluoride MF2, electrolyte (PF6)–, and PVDF
are observed at 685.1, 687.16, and 687.85 eV, respectively.
After plasma treatment (Figure 4 (b2)), the relative con-
tent of MF2is increased from 22.5% to 25.31%, and new
peaks of MF3 are observed. More metal fluoride products
are produced with plasma treatment, which indicates that
Figure 3. XPS results of anode materials without and with plasma treatment (C 1s (a) and O 1s (b))
treatment, which is the C-O stretching peak of primary
alcohol. This indicates that the oxidation of free radicals
generated by plasma introduces hydroxyl groups on the
surface of the cathode material, increasing the hydrophi-
licity of the cathode materials. However, no changes in
the characteristic absorption peaks of PVDF on cathode
material surfaces before and after plasma treatment are
detected. Thus, further characterization using XPS analy-
sis is employed to determine the changes of organic biners
before and after plasma treatment.
Figure 3 presents XPS results of anode materials before
and after plasma treatment. As seen from Figure 3 (a1),
peaks of C-C/C-H and COOR are detected at 284.8 and
at 285.64 eV, respectively. After plasma treatment, C=C
peaks with 36.38% relative content were observed at
285 eV (Figure 3 (a2)). In addition, the plasma treatment
leads to the fact that the relative content of C-C/C-H peaks
increases from 72.16% to 63.62%. The presence of C=C
hydrophobic group is helpful for enhancing the hydropho-
bicity of the anode materials, which is consistent with the
significant improvement in flotation rate constant of anode
material after plasma treatment (Table 1). O 1s XPS spec-
trums of anode materials before and after plasma treatment
are given Figure 3 (b). As seen from Figure 3 (b), the peaks
of C=O (or metal oxide M-O2+) are observed at 531.74 eV,
the peaks of C-O are observed at 532.41 eV, and the peaks
of C-O-C are observed at 533 eV, and the atomic O bonded
to the carbonyl group was observed at 534.05 eV. After
plasma treatment, the relative content of C=O/M-O2+
decreased from 57.46% to 25.06%, and the relative con-
tent of C-O is increased from 7.12% to 65.81%, and the
relative content of O-C=O is decreased from 18.28% to
9.14%. In general, the content of C=O hydrophilic groups
decreased while the content of C-O hydrophobic groups
increased. It is considered that plasma treatment can dis-
rupt the carbon oxygen double bond, thereby increasing
the hydrophobicity of the anode material by reducing the
number of hydrophilic groups.
XPS results of cathode materials before and after plasma
treatment are given in Figure 4. As seen from Figure 4 (a1),
the peaks of C-O are observed at 288.5 eV. The peaks of
PVDF (-(CF2CH2)-n) are at 286.05 and 290.68 eV. After
plasma treatment Figure 4 (a2), the relative content of
C-C/C-H hydrophobic groups is decreased from 77.64 to
29.25%, indicating that the hydrophilicity of the cathode
material is enhanced by plasma treatment. Meanwhile, the
peaks of C bonded to COOR, C=O, and O-C=O are gen-
erated after plasma treatment. Furthermore, the peak corre-
sponding to PVDF is observed only at 290.68 eV, indicating
that the structure of PVDF in the cathode is damaged by
plasma treatment, which can verify the FTIR results of cath-
ode materials (Figure 2 (d)). As seen from Figure 4 (b1), the
peaks of metal fluoride MF2, electrolyte (PF6)–, and PVDF
are observed at 685.1, 687.16, and 687.85 eV, respectively.
After plasma treatment (Figure 4 (b2)), the relative con-
tent of MF2is increased from 22.5% to 25.31%, and new
peaks of MF3 are observed. More metal fluoride products
are produced with plasma treatment, which indicates that
Figure 3. XPS results of anode materials without and with plasma treatment (C 1s (a) and O 1s (b))