Na3V2(PO4)3
(NVP),
a
NASICON-type
material,
has
gained
attention
as
promising
battery
cathode
owing
to
its
high
sodium
mobility
and
excellent
structural
stability.
Using
computational
simulation
techniques
based
on
classical
potentials
density
functional
theory
(DFT),
we
examine
the
defect
characteristics,
diffusion
mechanisms,
dopant
behavior
of
NVP.
The
study
found
that
Na
Frenkel
is
most
favorable
intrinsic
defect,
supporting
desodiation
process
necessary
for
capacity
enabling
vacancy-assisted
Na-ion
migration.
migration
anticipated
through
long-range
zig-zag
pathway
with
an
overall
activation
energy
0.70
eV.
K
Sc
preferentially
occupy
V
sites
without
creating
charge-compensating
defects.
Substituting
Mg
at
site
can
simultaneously
increase
content
by
forming
interstitials
reducing
band
gap.
Additionally,
doping
Ti
promotes
formation
vacancies
migration,
leading
notable
improvement
in
electronic
conductivity.
Abstract
Vanadium‐based
Na
superionic
conductor
(NASICON)
type
materials
(Na
x
VM(PO
4
)
3
,
M
=
transition
metals)
have
attracted
extensive
attention
when
used
as
sodium‐ion
batteries
(SIBs)
cathodes
due
to
their
stable
structures
and
large
+
diffusion
channels.
However,
the
poor
electrical
conductivity
mediocre
energy
density,
which
hinder
practical
applications.
Activating
V
4+
/V
5+
redox
couple
(V
≈4.1
vs
/Na)
is
an
effective
way
elevate
density
of
SIBs,
whereas
irreversible
phase
severe
structural
distortion
will
inevitably
result
in
fast
capacity
fading
unsatisfactory
rate
capability.
Herein,
a
high
entropy
regulation
strategy
proposed
optimize
detailed
crystal
structure
improve
reversibility
crystalline
transformation
material.
With
activated
reversible
couple,
structure,
electrochemical
kinetics,
material
3.2
1.5
Fe
0.1
Al
Cr
Mn
Cu
(PO
(NVMP‐HE)
exhibits
outstanding
performance
with
highly
specific
120.1
mAh
g
−1
at
C
excellent
cycling
stability
(92.4%
retention
after
1000
cycles
20
C).
Besides,
situ
X‐ray
diffraction
(XRD)
measurement
reveals
that
smooth
three‐phase
reaction
involved
this
high‐entropy
cathode
existence
mesophase
facilitates
transition.
Advanced Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 4, 2025
Abstract
The
flexible
ARSIBs
have
great
potential
in
portable
and
wearable
electronics
due
to
their
high
cost‐effectiveness,
safety,
amazing
flexibility.
Nevertheless,
achieving
both
outstanding
flexibility
energy
density
remains
a
challenge.
Herein,
battery‐supercapacitor
composite
material
Na
3
V
1.95
Ni
0.05
(PO
4
)
2
F
/10%NC‐KOH
(NVNPF/NCK)
with
coexistence
of
crystalline
amorphous
phases
is
fabricated
by
loading
nitrogenous
carbon
(NC)
onto
(NVNPF)
etching
KOH.
It
demonstrates
specific
capacity
(187.26
mAh
g
−1
),
ultrahigh
(262.16
Wh
kg
excellent
cycle
performance
(the
retention
81%
at
1
C
after
500
cycles).
achieved
doping
⁺
NC
KOH,
which
generates
vacancy
defects,
enhances
structural
stability,
accelerates
ion‐diffusion
kinetics.
Furthermore,
the
fully‐printed
(F‐NTP//NVNPF/NCK)
(60.37
(72.44
performance,
are
using
screen‐printing
technique
based
on
NVNPF/NCK
cathode
NaTi
1.7
Fe
0.3
(F‐NTP)
anode.
To
best
authors'
knowledge,
F‐NTP//NVNPF/NCK
highest‐performing
ARSIB
date.
In
particular,
these
batteries
can
achieve
tunability
shape
size,
integration,
high‐throughput
manufacturing.
Thus,
this
work
offer
greater
possibilities
for
development
high‐performance
ARSIBs.
Nanomaterials,
Год журнала:
2025,
Номер
15(6), С. 423 - 423
Опубликована: Март 10, 2025
Layered
sodium
trititanate
(Na2Ti3O7)
is
a
promising
anode
material
for
sodium-ion
batteries
due
to
its
suitable
charge/discharge
plateaus,
cost-effectiveness,
and
eco-friendliness.
However,
slow
Na+
diffusion
kinetics,
poor
electron
conductivity,
instability
during
cycling
pose
significant
challenges
practical
applications.
To
address
these
issues,
we
developed
template-free
method
synthesize
Na2Ti3O7-C
hollow
microspheres.
The
synthesis
began
with
polymerization-induced
colloid
aggregation
form
TiO2–urea–formaldehyde
(TiO2-UF)
precursor,
which
was
then
subjected
heat
treatment
induce
inward
crystallization,
creating
cavities
within
the
structure,
combined
conductive
carbon
matrix,
significantly
enhanced
performance
rate
capability
of
material.
When
used
as
an
anode,
microspheres
exhibited
high
reversible
capacity
188
mAh
g−1
at
0.2C
retained
169
after
500
cycles.
Additionally,
demonstrated
excellent
capacities
157,
133,
105,
77,
62,
45
current
densities
0.5,
1,
2,
5,
10,
20C,
respectively.
This
innovative
approach
provides
new
strategy
developing
high-performance
battery
anodes
has
potential
advance
field
energy
storage.
Chemical Communications,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
The
sacrificial
cathode
additive
(SCA)
method
holds
great
promise
for
industrial
application.
This
review
explores
recent
progress
in
SCA
presodiation
technology,
with
a
focus
on
optimizing
strategies
to
develop
near-ideal
SCAs.
