Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Oct. 17, 2023
Ambient-temperature
sodium-sulfur
(Na-S)
batteries
are
potential
attractive
alternatives
to
lithium-ion
owing
their
high
theoretical
specific
energy
of
1,274
Wh
kg-1
based
on
the
mass
Na2S
and
abundant
sulfur
resources.
However,
practical
viability
is
impeded
by
sodium
polysulfide
shuttling.
Here,
we
report
an
intercalation-conversion
hybrid
positive
electrode
material
coupling
intercalation-type
catalyst,
MoTe2,
with
conversion-type
active
material,
sulfur.
In
addition,
MoTe2
nanosheets
vertically
grown
graphene
flakes
offer
catalytic
sites,
further
boosting
activity
for
redox.
When
used
as
a
composite
assembled
in
coin
cell
excess
Na,
discharge
capacity
1,081
mA
h
gs-1
S
fade
rate
0.05%
per
cycle
over
350
cycles
at
0.1
C
voltage
range
0.8
2.8
V
realized
under
loading
3.5
mg
cm-2
lean
electrolyte
condition
electrolyte-to-sulfur
ratio
7
μL
mg-1.
A
fundamental
understanding
electrocatalysis
revealed
in-situ
synchrotron-based
operando
X-ray
diffraction
ex-situ
time-of-flight
secondary
ion
spectrometry.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(12)
Published: Jan. 16, 2024
Abstract
The
kinetics
and
durability
of
conversion‐based
anodes
greatly
depend
on
the
intrinsic
stress
regulating
ability
electrode
materials,
which
has
been
significantly
neglected.
Herein,
a
dissipation
strategy
driven
by
multi‐interface
built‐in
electric
fields
(BEFs)
architected
structure,
is
innovatively
proposed
to
design
ultrafast
long‐term
sodium
ion
storage
anodes.
Binary
Mo/Fe
sulfide
heterostructured
nanorods
with
BEFs
staggered
cantilever
configuration
are
fabricated
prove
our
concept.
Multi‐physics
simulations
experimental
results
confirm
that
inner
in
multiple
directions
can
be
dissipated
at
micro‐scale,
structure
macro‐scale,
respectively.
As
result,
designed
anode
exhibits
superb
rate
capability
(332.8
mAh
g
−1
10.0
A
)
durable
cyclic
stability
over
900
cycles
5.0
,
outperforming
other
metal
chalcogenides.
This
offers
new
insight
for
developing
stable
structures
ACS Applied Materials & Interfaces,
Journal Year:
2024,
Volume and Issue:
16(11), P. 13858 - 13868
Published: March 5, 2024
Large
volume
strain
and
slow
kinetics
are
the
main
obstacles
to
application
of
high-specific-capacity
alloy-type
metal
tellurides
in
potassium-ion
storage
systems.
Herein,
Bi2Te3-x
nanocrystals
with
abundant
Te-vacancies
embedded
nitrogen-doped
porous
carbon
nanofibers
(Bi2Te3-x@NPCNFs)
proposed
address
these
challenges.
In
particular,
a
hierarchical
fiber
structure
can
be
achieved
by
polyvinylpyrrolidone-etching
method
is
conducive
increasing
Te-vacancy
concentration.
The
unique
together
defect
engineering
modulates
potassium
mechanism
Bi2Te3,
suppresses
structural
distortion,
accelerates
K+
diffusion
capacity.
meticulously
designed
Bi2Te3-x@NPCNFs
electrode
exhibits
ultrastable
cycling
stability
(over
3500
stable
cycles
at
1.0
A
g-1
capacity
degradation
only
0.01%
per
cycle)
outstanding
rate
capability
(109.5
mAh
2.0
g-1).
Furthermore,
systematic
ex
situ
characterization
confirms
that
undergoes
an
"intercalation-conversion-step
alloying"
for
storage.
Kinetic
analysis
density
functional
theory
calculations
reveal
excellent
pseudocapacitive
performance,
attractive
adsorption,
fast
ability
electrode,
which
essential
Impressively,
assembled
Bi2Te3-x@NPCNFs//activated-carbon
hybrid
capacitors
achieve
considerable
energy/power
(energy
up
112
Wh
kg-1
power
1000
W
kg-1)
(1600
10.0
g-1),
indicating
their
potential
practical
applications.
