The
development
of
pseudocapacitive
materials
for
energy-oriented
applications
has
stimulated
considerable
interest
in
recent
years
due
to
their
high
energy-storing
capacity
with
power
outputs.
Nevertheless,
the
utilization
nanosized
active
batteries
leads
fast
redox
kinetics
improved
surface
area
and
short
diffusion
pathways,
which
shifts
electrochemical
signatures
from
battery-like
pseudocapacitive-like
behavior.
As
a
result,
it
becomes
challenging
distinguish
"pseudocapacitive"
"battery"
materials.
Such
misconceptions
have
further
impacted
on
final
device
configurations.
This
Review
is
an
earnest
effort
clarify
confusion
between
battery
by
providing
true
meanings
correct
performance
metrics.
A
method
battery-type
using
quantitative
analysis
outlined.
Taking
solid-state
supercapacitors
(SSCs,
only
polymer
gel
electrolytes)
as
example,
distinction
asymmetric
hybrid
discussed.
state-of-the-art
progress
engineering
summarized,
will
guide
real-pseudocapacitive
energy
storage
systems.
Abstract
Flexible
quasi‐/all‐solid‐state
supercapacitors
have
elicited
scientific
attention
to
fulfill
the
explosive
demand
for
portable
and
wearable
electronic
devices.
However,
use
of
electrode
materials
faces
several
challenges,
such
as
intrinsically
slow
kinetics
volume
change
upon
cycling,
which
impede
energy
output
electrochemical
stability.
This
study
presents
well‐aligned
molybdenum
dioxide@nitrogen‐doped
carbon
(MoO
2
@NC)
copper
cobalt
sulfide
(CuCo
S
4
)
tubular
nanostructures
grown
on
flexible
fiber
in
supercapacitors.
Benefiting
from
chemically
stable
interfaces,
affluent
active
sites,
efficient
1D
electron
transport,
MoO
@NC
CuCo
integrated
conductive
substrates
deliver
excellent
performance.
A
quasi‐solid‐state
asymmetric
supercapacitor
composed
negative
positive
achieves
an
ultrahigh
density
65.1
W
h
kg
−1
at
a
power
800
retains
favorable
27.6
12.8
kW
.
Moreover,
it
demonstrates
good
cycling
performance
with
90.6%
capacitance
retention
after
5000
cycles
mechanical
flexibility
by
enabling
92.2%
2000
bending
cycles.
provides
effective
strategy
develop
superior
