Surface Chemistry in Cobalt Phosphide-Stabilized Lithium-Sulfur Batteries

Article abstract of DOI:10.1021/jacs.7b11434

Chemistry at the cathode/electrolyte interface plays an important role for lithium-sulfur batteries in which stable cycling of the sulfur cathode requires confinement of the lithium polysulfide intermediates and their fast electrochemical conversion on the electrode surface. While many materials have been found to be effective for confining polysulfides, the underlying chemical interactions remain poorly understood. We report a new and general lithium polysulfide-binding mechanism enabled by surface oxidation layers of transition-metal phosphide and chalcogenide materials. We for the first time find that CoP nanoparticles strongly adsorb polysulfides because their natural oxidation (forming Co-O-P-like species) activates the surface Co sites for binding polysulfides via strong Co-S bonding. With a surface oxidation layer capable of confining polysulfides and an inner core suitable for conducting electrons, the CoP nanoparticles are thus a desirable candidate for stabilizing and improving the performance of sulfur cathodes in lithium-sulfur batteries. We demonstrate that sulfur electrodes that hold a high mass loading of 7 mg cm^-2 and a high areal capacity of 5.6 mAh cm^-2 can be stably cycled for 200 cycles. We further reveal that this new surface oxidation-induced polysulfide-binding scheme applies to a series of transition-metal phosphide and chalcogenide materials and can explain their stabilizing effects for lithium-sulfur batteries.

Full text of DOI:10.1021/jacs.7b11434

Subscriber access provided by READING UNIV
Article
Surface Chemistry in Cobalt Phosphide-Stabilized Lithium-Sulfur Batteries
Yiren Zhong, Lichang Yin, Peng He, Wen Liu, Zishan Wu, and Hailiang Wang
J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.7b11434 • Publication Date (Web): 08 Jan 2018
Downloaded from http://pubs.acs.org on January 8, 2018
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Journal of the American Chemical Society is published by the American Chemical
Society. 1155 Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 6
Journal of the American Chemical Society
1
2
3
4
5
6
7
8
9
Surface Chemistry in Cobalt Phosphide-Stabilized Lithium-
Sulfur Batteries
Yiren Zhong,†,‡ Lichang Yin,§ Peng He,†,‡ Wen Liu,†,‡ Zishan Wu,†,‡ Hailiang Wang†,‡,*
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
†Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
‡Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, United States
§Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang
110016, China.
ABSTRACT: Chemistry at the cathode/electrolyte interface plays an important role for lithiumꢀsulfur batteries in which stable cyꢀ
cling of the sulfur cathode requires confinement of the lithium polysulfide intermediates and their fast electrochemical conversion
on the electrode surface. While many materials have been found to be effective for confining polysulfides, the underlying chemical
interactions remain poorly understood. We report a new and general lithium polysulfideꢀbinding mechanism enabled by surface
oxidation layers of transition metal phosphide and chalcogenide materials. We for the first time find that CoP nanoparticles strongly
adsorb polysulfides because their natural oxidation (forming CoꢀOꢀPꢀlike species) activates the surface Co sites for binding polysulꢀ
fides via strong CoꢀS bonding. With a surface oxidation layer capable of confining polysulfides and an inner core suitable for conꢀ
ducting electrons, the CoP nanoparticles are thus a desirable candidate for stabilizing and improving the performance of sulfur
cathodes in lithiumꢀsulfur batteries. We demonstrate that sulfur electrodes that hold a high mass loading of 7 mg cmꢀ2 and a high
areal capacity of 5.6 mAh cmꢀ2 can be stably cycled for 200 cycles. We further reveal that this new surface oxidationꢀinduced polyꢀ
sulfideꢀbinding scheme applies to a series of transition metal phosphide and chalcogenide materials and can explain their stabilizing
effects for lithiumꢀsulfur batteries.
of the LSB surface chemistry and rational design of highꢀ
performance cathode materials for better LSBs.
INTRODUCTION
The growing demand on energy storage technology for
large scale applications such as electrical vehicles and smart
Here we report a new surface chemistry phenomenon for
grids drives the exploration of nextꢀgeneration batteries to
LSB cathodes containing CoP nanoparticles and demonstrate
replace the current lithium ion batteries (LIBs).1ꢀ2 As a promisꢀ
the utilization of the distinct phenomenon to improve battery
ing candidate, lithiumꢀsulfur batteries (LSBs) carry an attracꢀ
cycle life. We have discovered that the strong binding of CoP
tive specific energy of 2600 Wh kgꢀ1, 5 times higher than that
nanoparticles to LPS originates from the oxidation layer genꢀ
of the stateꢀofꢀtheꢀart LIBs.3ꢀ5 However, the present LSBs are
erated on the nanoparticle surface under ambient conditions.
still subject to pronounced capacity fading over longꢀterm
Surface oxidation creates CoꢀOꢀP species and thus activates
cycling. One of the major causes to the short cycle life probꢀ
the Co sites for chemically binding the negatively charged S
lem is the dissolution and diffusion of the lithium polysulfide
sites of LPS. In contrast, nearlyꢀpristine CoP nanoparticles
(LPS) intermediates, which can result in active material loss
with a reduced surface hardly bind or adsorb any LPS. Existꢀ
and structural changes on the sulfur cathode as well as degraꢀ
ence of the surface oxidation layer unlocks the potential of
dation of the lithium anode.6ꢀ12
CoP nanoparticles for adsorbing and electrochemically conꢀ
verting LPS. Highꢀcapacity and stableꢀcycling sulfur cathodes
Using polarized material surfaces to confine LPS via chemꢀ
are thus achieved. Our sulfur electrode incorporating CoP
ical interactions has emerged as one of the most effective ways
nanoparticles delivers a high and stable areal capacity of ~5.6
mAh cmꢀ2 for 200 cycles. We further recognize that this surꢀ
face oxidationꢀinduced LPS binding phenomenon exists for a
number of transition metal phosphides and chalcogenides such
as MoP, Ni2P, FeP, CoS and CoSe2. Our results highlight the
importance of understanding the surface chemistry at the cathꢀ
ode/electrolyte interface in LSBs.
of improving the cycling stability of sulfur cathodes.13ꢀ22 For
example, utilizing NiFe2O4 nanosheets as a LPS confining
agent, we achieved a stable cycling performance for over 500
chargingꢀdischarging cycles with a capacity decay rate as low
as ∼0.009% per cycle.23 It has been identified that 3d transiꢀ
tion metal oxides interact with LPS via dominant oxygenꢀ
lithium binding and minor metalꢀsulfur binding.24 Recently,
we have reported that transition metal phosphides, with their
strong affinity for adsorbing LPS and good electronic conducꢀ
tivity for promoting electrochemical redox conversion of LPS,
are even better at stabilizing sulfur cathodes.25 Despite the
superior performance, it remains poorly understood how metal
phosphides chemically interact with LPS at the solid/liquid
interface, which is preventing molecularꢀlevel understanding
RESULTS AND DISCUSSION
CoP nanoparticles were grown on mildlyꢀoxidized multiwall
carbon nanotubes (CNTs)26ꢀ27 with a sequential synthesis
method in which Co3O4 nanoparticles were first anchored on
the CNTs via controlled hydrolysis of Co(OAc)2 (Figure S1)
and then the oxide was converted to the corresponding phosꢀ
ACS Paragon Plus Environment

Journal of the American Chemical Society
phide via a solid/gasꢀphase reaction with PH3.28 The CNTs are
Page 2 of 6
1
2
3
4
5
6
7
8
used as a support for the nanoparticles in order to facilitate
good size control and uniform dispersion of the nanoparticles
as well as to enhance electron conduction during electrochemꢀ
ical reactions. The scanning electron microscopy (SEM) imagꢀ
es reveal that the CoPꢀCNT composite material possesses a
wellꢀdefined morphology with 10ꢀ20 nm sized nanoparticles
uniformly covering the CNT surface (Figure 1a, S2a). The
natural CoP nanoparticles, having been stored under ambient
conditions for several days, gain a partially oxidized surface,
as evidenced by a Co 2p3/2 component at 781.1 eV and a P 2p
doublets at 133.6/134.5 eV in the corresponding Xꢀray photoeꢀ
lectron spectroscopy (XPS) spectra (Figure 1b, c). This surface
oxidation phenomenon is consistent with the literature on coꢀ
balt and other transition metal phosphide nanomaterials.29ꢀ31
The oxidized CoP surface can be reduced by a thermal treatꢀ
ment at 500 °C in an Ar/H2 atmosphere (Figure 1d). The reꢀ
sulting nanoparticles (CoPꢀR), which exhibit a comparable
size distribution (Figure 1e, S2b) and the identical crystal
structure (Figure 1f) as the original CoP nanoparticles, possess
a fully reduced surface (Figure 1b, c)
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 2. (a, b) HRTEM, (c, d) STEMꢀHAADF images, and (e, f)
EDS elemental distribution maps of (a, c, e) CoP and (b, d, f)
CoPꢀR nanoparticles supported on CNTs.
We first assessed the LPSꢀconfining capabilities of the natuꢀ
ral and reduced CoP nanoparticles. The natural CoP nanoparꢀ
ticles with an oxidized surface exhibit a strong affinity for LPS
(Figure 3a). The contribution from the CNT support can be
eliminated since the CNTs themselves do not adsorb LPS. In
striking contrast, the CoPꢀR with a reduced surface do not
adsorb LPS (Figure 3a). Additional control experiments show
that freshly synthesized CoP nanoparticles do not adsorb LPS
(Figure S4a), whereas reꢀoxidized CoPꢀR nanoparticles can
strongly adsorb LPS (Figure S4b), unambiguously correlating
the LPS adsorbing capability with the oxidized surface. We
then assembled symmetric cells comprising two identical CoPꢀ
CNT or CoPꢀRꢀCNT electrodes and a 0.4 M Li2S6ꢀ1,3ꢀ
dioxolane/dimethoxyethane (DOL/DME, 1:1 v/v) solution as
the electrolyte to probe the electrochemical conversion of LPS
at the electrode/electrolyte interface. Under identical measurꢀ
ing conditions, it is clearly observed that the cyclic voltammoꢀ
grams (CVs) of the CoPꢀCNT cell shows the highest current
which reflects the fastest redox conversion of LPS on the elecꢀ
trode surface. The fast electrochemical reaction on the oxiꢀ
dized CoP surface is a result of both the high surface coverage
of LPS and the low charge transfer resistance at the interface
(Figure 3d). The former is verified by the LPS adsorption exꢀ
periments, and the latter is confirmed by electrochemical imꢀ
pedance spectroscopy (EIS) measurements (Figure 3c).
Figure 1. (a) SEM image of CoP nanoparticles supported on
CNTs. (b) Co 2p3/2 and (c) P 2p XPS spectra of CoP and CoPꢀR
nanoparticles supported on CNTs. (d) Schematic illustration of the
removal of the surface oxidation layer on CoP nanoparticles
through thermochemical reduction to render CoPꢀR nanoparticles.
(e) SEM image of CoPꢀR nanoparticles supported on CNTs. (f)
XRD patterns of CoP and CoPꢀR nanoparticles supported on
CNTs.
Highꢀresolution transmission electron microscopy
(HRTEM) further reveals the attachment of both CoP and
CoPꢀR nanoparticles to CNTs as well as the lattice fringes
corresponding to the (002) crystallographic planes of the CoP
crystal structure (Figure 2a, b). Despite the identical bulk
structures, the CoP and CoPꢀR nanoparticles show different
surface structures under the scanning transmission electron
microscopy (STEM) mode recorded with a highꢀangle annular
darkꢀfield (HAADF) detector. A coreꢀshellꢀlike structure with
a lowerꢀcontrast outer layer corresponding to the surface oxiꢀ
dation region is observed for the CoP nanoparticles (Figure
2c), whereas the CoPꢀR nanoparticles show no obvious surꢀ
face layer (Figure 2d). Consistently, a much higher O content
is found in the CoPꢀCNT than that in the CoPꢀRꢀCNT material
by energy dispersive Xꢀray spectroscopy (EDS) (Figure S3).
EDS mapping reveals that the O atoms accumulate on the surꢀ
face of the CoP nanoparticles (Figure 2e). In contrast, the
CoPꢀR nanoparticles are almost free of O atoms on their surꢀ
face, with the majority of the O signals contributed by the
CNTs (Figure 2f).
Figure 3. (a) Results of LPS (5 mM Li2S6ꢀDOL/DME solution)
adsorption experiments with CNTs and CoP and CoPꢀR nanoparꢀ
ticles supported on CNTs. (b) CVs at the scan rate of 10 mV/s and
ACS Paragon Plus Environment

Page 3 of 6
Journal of the American Chemical Society
(c) EIS spectra in the frequency range of 50 mHz to 200 kHz of
particles with reduced Co and P species shows no discernable
spectral changes in either the Co2p3/2 or P 2p XPS spectra after
the nanoparticles are allowed to fully interact with LPS (Figꢀ
ure 4b, d), indicating that the CoPꢀR surface is unable to bind
LPS. Consistently, the corresponding S 2p and Li 1s spectra
possess negligible intensity (Figure 4e, S7).
1
2
3
symmetric cells containing a 0.4 M Li2S6ꢀDOL/DME solution as
the electrolyte and CNTs, CoPꢀCNT or CoPꢀRꢀCNT as the elecꢀ
trodes. (d) Schematic illustration of LPS adsorption and converꢀ
sion behavior on the natural vs. reduced CoP surfaces.
4
5
6
7
8
9
To elucidate the chemical interactions between surfaceꢀ
oxidized CoP and LPS, we performed XPS measurements for
both the CoP and CoPꢀR nanoparticles after they were soaked
in a LPS solution. The XPS studies were performed using
freeꢀstanding nanoparticles without CNT supports (Figure S5),
in order to avoid any interference from the CNTs. Both the Co
2p3/2 and P 2p spectra of the natural CoP nanoparticles maniꢀ
fest notable features of oxidized Co and P species (Figure 4a,
c). After the nanoparticles interacting with LPS, the intensity
of the CoꢀO component in the Co 2p3/2 spectrum greatly reducꢀ
es while that of the CoꢀP/S component increases concomitantꢀ
ly (Figure 4a).32ꢀ33 We attribute these spectral changes to the
formation of CoꢀS bonding between the Co atom in the surface
oxidation layer of the CoP nanoparticles and the S atom in the
LPS. This is consistent with the observed growth of the comꢀ
ponent at 161.5 eV in the S 2p spectrum, which can be asꢀ
signed to terminal SꢀCo bonding (Figure 4e).34ꢀ36 The P 2p
spectrum shows a minor decrease in the PꢀO component and a
minor increase in the PꢀCo component, suggesting a slight
reduction of the oxidized P species on the surface (Figure 4c),
likely induced by the LPS. No binding energy shift is observed
for the O 1s spectrum after the nanoparticles interacting with
LPS (Figure S6). In contrast, the surface of the CoPꢀR nanoꢀ
Taken together, the drastically different LPS binding and
adsorption behaviors of the CoP and CoPꢀR nanoparticles are
ascribed to their different surface structures. On the reduced
CoP surface, the CoꢀP bonds are weakly polarized. As a result,
neither the Co nor the P sites are capable of generating a
strong binding force for the Sδꢀ or the Li δ+ in the LPS, respecꢀ
tively. However, the oxidized CoP surface is dominated by
CoꢀOꢀPꢀlike species. The highly electronegative O creates
highꢀvalence Co sites which can react with shortꢀchain LPS
species to form CoꢀS bonding and leave LiꢀOꢀP moieties on
the surface (Figure 4f). Our control experiments reveal that the
oxidized species on the CoP nanoparticle surface highly reꢀ
semble those on a Co3(PO4)2 (CoPi) surface and bind LPS in a
similar way (Figure S8, S9). Taking CoPi as a proxy for the
oxidized CoP surface, our density functional theory (DFT)
calculations support that the interactions between LPS and the
reduced CoP surface are weak (Figure S10a, b) and that surꢀ
face oxidation can significantly enhance LPS binding via
strengthened CoꢀS interactions (Figure S10c, S11). The bindꢀ
ing modes of LPS on CoP nanoparticles are distinct from those
on metal oxides where LiꢀO interactions are dominant.24
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Figure 4. (a, b) Co 2p3/2, (c, d) P 2p and (e) S 2p XPS spectra of (a, c) CoP and (b, d) CoPꢀR nanoparticles before and after interacting with
Li2S6. (f) Proposed binding schemes of LPS on CoP and CoPꢀR surfaces.
Finally, we incorporate CoP and CoPꢀR nanoparticles in
sulfur cathodes by depositing nanoparticleꢀcoated CNTs onto
preꢀmade sulfur electrodes, and compare their electrochemical
performance in LSBs. We first verify that CoP remains elecꢀ
trochemically inert within the operating potential range of
sulfur electrodes (Figure S12). The CVs of the two cells conꢀ
taining either the CoP or CoPꢀR nanoparticles show the typical
twoꢀstage discharging and oneꢀstage charging behavior of a
sulfur cathode (Figure 5a).6, 9, 37 It is noted that the CVs of the
CoPꢀR cell possess much broader current peaks and a larger
voltage hysteresis than those of the CoP cell. The difference in
overpotential is also reflected in the galvanostatic chargingꢀ
discharging curves (Figure S13a). This is consistent with our
finding in the symmetric cells that the electrochemical converꢀ
sion of LPS is faster on the oxidized than the reduced CoP
surface. The CoPꢀcontaining electrode with 3 mg cmꢀ2 of sulꢀ
fur retains a specific capacity of 835 mAh gꢀ1 after 200 cycles
at the 1C rate (Figure 5b). The cycling gives an average capacꢀ
ity decay of ~0.018% per cycle, together with the Coulombic
efficiency >99.8% (Figure S13b). The CoPꢀRꢀcontaining elecꢀ
trode has a comparable initial capacity which, however, fades
quickly to 683 mAh gꢀ1 after 200 cycles. The Coulombic effiꢀ
ciency also decreases upon cycling and falls obviously below
that of the CoPꢀcontaining cell (Figure S13b). In fact, the perꢀ
formance of the CoPꢀRꢀcontaining electrode is very close to
the electrode without any nanoparticles added, meaning that
the CoPꢀR nanoparticles do not confine LPS. This is also well
reflected in the postꢀcycling imaging results where the CoPꢀ
ACS Paragon Plus Environment

Journal of the American Chemical Society
Page 4 of 6
containing electrode maintains the original particulate morꢀ
AUTHOR INFORMATION
Corresponding Author
1
2
3
4
5
6
7
8
phology whereas the sulfur particles on the CoPꢀRꢀcontaining
electrode have fused into a gelꢀlike structure likely due to LPS
diffusion during the cycling process (Figure S14). To demonꢀ
strate usefulness toward practical applications, we further inꢀ
crease the sulfur mass loading in the CoPꢀcontaining electrode
to 7 mg cmꢀ2. The resulting electrode can still be stably cycled
for 200 times with a specific capacity of 790 mAh gꢀ1 and an
areal capacity of 5.6 mAh cmꢀ2 (Figure 5c).
hailiang.wang@yale.edu (H. Wang)
Author Contributions
The manuscript was written through contributions of all authors.
All authors have given approval to the final version of the manuꢀ
script.
Notes
9
The authors declare no competing financial interest.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACKNOWLEDGMENT
This work is partially supported by Yale University.
REFERENCES
(1)
(2)
(3)
Armand, M.; Tarascon, J. M. Nature 2008, 451, 652.
Goodenough, J. B.; Kim, Y. Chem. Mater. 2010, 22, 587.
Manthiram, A.; Fu, Y.; Su, Y. S. Acc. Chem. Res. 2013, 46,
1125.
(4)
Yin, Y. X.; Xin, S.; Guo, Y. G.; Wan, L. J. Angew. Chem. Int.
Ed. 2013, 52, 13186.
(5)
Bruce, P. G.; Freunberger, S. A.; Hardwick, L. J.; Tarascon, J.
M. Nat. Mater. 2012, 11, 19.
(6)
Xu, R.; Lu, J.; Amine, K. Adv. Energy Mater. 2015, 5,
1500408.
(7)
Lin, Z.; Liang, C. J. Mater. Chem. A 2015, 3, 936.
Figure 5. (a) CVs of S cathodes (measured against a Li metal
anode) modified with CoPꢀCNT and CoPꢀRꢀCNT. (b) Cycling
stability of S cathodes (S mass loading: 3 mg cmꢀ2; rate: 1C) modꢀ
ified with CNT, CoPꢀCNT, and CoPꢀRꢀCNT. (c) Cycling perforꢀ
mance of a highꢀcapacity S cathode (S mass loading: 7 mg cmꢀ2;
rate: 0.2C) modified with CoPꢀCNT.
(8)
Pang, Q.; Liang, X.; Kwok, C. Y.; Nazar, L. F. Nat. Energy
2016, 1, 16132.
(9)
(10)
Yang, Y.; Zheng, G.; Cui, Y. Chem. Soc. Rev. 2013, 42, 3018.
Schaefer, J. L.; Lu, Y.; Moganty, S. S.; Agarwal, P.;
Jayaprakash, N.; Archer, L. A. Appl. Nanosci. 2011, 2, 91.
(11) Chen, Y.; Lu, S.; Zhou, J.; Qin, W.; Wu, X. Adv. Funct. Mater.
2017, 27, 1700987.
(12)
Lu, S.; Chen, Y.; Wu, X.; Wang, Z.; Li, Y. Sci. Rep. 2014, 4,
In addition to CoP, we find that other metal phosphide
and chalcogenide materials including Ni2P, FeP, MoP, CoS
and CoSe2 nanoparticles, most of which have been reported
for effectively confining LPS and improving sulfur cathode
performance,9, 18, 25, 38 all rely on a surface oxidation layer to
chemically bind LPS (Figure S15ꢀ17). This discovery reveals
that the surface oxidationꢀactivated LPS binding mechanism is
a general phenomenon and can explain the functions of many
transition metal phosphides and chalcogenides in stabilizing
sulfur cathodes, highlighting the critical importance of underꢀ
standing the surface chemistry in LSBs.
4629.
(13)
Liu, J.; Yuan, L.; Yuan, K.; Li, Z.; Hao, Z.; Xiang, J.; Huang,
Y. Nanoscale 2016, 8, 13638.
(14)
Mi, Y.; Liu, W.; Yang, K. R.; Jiang, J.; Fan, Q.; Weng, Z.;
Zhong, Y.; Wu, Z.; Brudvig, G. W.; Batista, V. S.; Zhou, H.; Wang, H.
Angew. Chem. Int. Ed. 2016, 55, 14818.
(15)
Pang, Q.; Kundu, D.; Cuisinier, M.; Nazar, L. F. Nat. Commun.
2014, 5, 4759.
(16)
Sun, J.; Sun, Y.; Pasta, M.; Zhou, G.; Li, Y.; Liu, W.; Xiong,
F.; Cui, Y. Adv. Mater. 2016, 28, 9797.
(17)
Sun, Z.; Zhang, J.; Yin, L.; Hu, G.; Fang, R.; Cheng, H. M.; Li,
F. Nat. Commun. 2017, 8, 14627.
(18)
Yuan, Z.; Peng, H. J.; Hou, T. Z.; Huang, J. Q.; Chen, C. M.;
Wang, D. W.; Cheng, X. B.; Wei, F.; Zhang, Q. Nano. Lett. 2016, 16, 519.
In summary, we have discovered a new and general LPSꢀ
binding mechanism enabled by surface oxidation layers of
transition metal phosphide and chalcogenide materials. As an
example, surface oxidation of CoP nanoparticles activates the
Co sites for strongly binding LPS via CoꢀS bonding. Based on
CoP nanoparticles with the surface oxidation layer binding
LPS and the inner core facilitating electron conduction, we
realize stableꢀcycling and highꢀcapacity sulfur cathodes.
(19)
Chen, H.; Wang, C.; Dong, W.; Lu, W.; Du, Z.; Chen, L.
Nano. Lett. 2015, 15, 798.
(20)
Liu, J.; Li, W.; Duan, L.; Li, X.; Ji, L.; Geng, Z.; Huang, K.;
Lu, L.; Zhou, L.; Liu, Z.; Chen, W.; Liu, L.; Feng, S.; Zhang, Y. Nano.
Lett. 2015, 15, 5137.
(21)
Zhang, J.; Yang, C. P.; Yin, Y. X.; Wan, L. J.; Guo, Y. G. Adv.
Mater. 2016, 28, 9539.
(22)
Zheng, J.; Tian, J.; Wu, D.; Gu, M.; Xu, W.; Wang, C.; Gao,
F.; Engelhard, M. H.; Zhang, J. G.; Liu, J.; Xiao, J. Nano. Lett. 2014, 14,
2345.
(23)
Fan, Q.; Liu, W.; Weng, Z.; Sun, Y.; Wang, H. J. Am. Chem.
Soc. 2015, 137, 12946.
ASSOCIATED CONTENT
Supporting Information.
The Supporting Information including complete experimental
details, additional Xꢀray diffraction, electron microscopic, elecꢀ
trochemical and spectroscopic analyses, and additional LPS adꢀ
sorption results, is available free of charge via the internet at
http://pubs.acs.org.
(24)
Zhong, Y.; Yang, K. R.; Liu, W.; He, P.; Batista, V.; Wang, H.
J. Phys. Chem. C 2017, 121, 14222.
(25)
Mi, Y.; Liu, W.; Li, X.; Zhuang, J.; Zhou, H.; Wang, H. Nano
Res. 2017, 10, 3698.
(26)
Li, X.; Liu, W.; Zhang, M.; Zhong, Y.; Weng, Z.; Mi, Y.;
Zhou, Y.; Li, M.; Cha, J. J.; Tang, Z.; Jiang, H.; Li, X.; Wang, H. Nano.
Lett. 2017, 17, 2057.
(27)
Weng, Z.; Liu, W.; Yin, L. C.; Fang, R.; Li, M.; Altman, E. I.;
Fan, Q.; Li, F.; Cheng, H. M.; Wang, H. Nano. Lett. 2015, 15, 7704.
ACS Paragon Plus Environment

Page 5 of 6
Journal of the American Chemical Society
(28)
Wu, Z.; Li, X.; Liu, W.; Zhong, Y.; Gan, Q.; Li, X.; Wang, H.
(35)
Liu, W.; Hu, E.; Jiang, H.; Xiang, Y.; Weng, Z.; Li, M.; Fan,
ACS Catal. 2017, 7, 4026.
Q.; Yu, X.; Altman, E. I.; Wang, H. Nat. Commun. 2016, 7, 10771.
1
2
3
4
5
6
7
8
(29)
Huang, Z.; Chen, Z.; Chen, Z.; Lv, C.; Humphrey, M. G.;
(36)
Han, L.; Qin, W.; Zhou, J.; Jian, J.; Lu, S.; Wu, X.; Fan, G.;
Zhang, C. Nano Energy 2014, 9, 373.
Gao, P.; Liu, B. Nanoscale 2017, 9, 5141.
(30)
Xiao, P.; Sk, M. A.; Thia, L.; Ge, X.; Lim, R. J.; Wang, J.ꢀY.;
(37)
(38)
Zhang, S. S. Electrochim. Acta 2012, 70, 344.
Zhou, G.; Sun, J.; Jin, Y.; Chen, W.; Zu, C.; Zhang, R.; Qiu,
Lim, K. H.; Wang, X. Energy Environ. Sci. 2014, 7, 2624.
(31)
Yan, Y.; Xia, B. Y.; Ge, X.; Liu, Z.; Fisher, A.; Wang, X.
Y.; Zhao, J.; Zhuo, D.; Liu, Y.; Tao, X.; Liu, W.; Yan, K.; Lee, H. R.; Cui,
Y. Adv. Mater. 2017, 29, 1603366.
Chem. Eur. J. 2015, 21, 18062.
(32)
(33)
Pang, Q.; Kundu, D.; Nazar, L. F. Mater. Horiz. 2016, 3, 130.
Zhang, H.; Li, Y.; Zhang, G.; Xu, T.; Wan, P.; Sun, X. J.
Mater. Chem. A 2015, 3, 6306.
(34)
Higgins, D. C.; Hassan, F. M.; Seo, M. H.; Choi, J. Y.; Hoque,
9
M. A.; Lee, D. U.; Chen, Z. J. Mater. Chem. A 2015, 3, 6340.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACS Paragon Plus Environment

Journal of the American Chemical Society
Page 6 of 6
Artwork for TOC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
6
ACS Paragon Plus Environment