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allied
academies
Journal of Materials Science and Nanotechnology | Volume 2
July 23-25, 2018 | Moscow, Russia
Materials Science and Engineering
International Conference on
High-performance anode materials for next generation Na-ion batteries
EunAe Cho, TaeHee Kim
and
JaeWook Shin
Korea Advanced Institute of Science and Technology, South Korea
B
ecause of their high energy density, Li-ion batteries have
attracted attention as a large energy storage system
over their traditional use for portable and electric vehicle
applications. However, there are concerns about the scarcity,
uneven global distribution and high cost of lithium resources.
Compared with Li, Na has the advantages of natural abundance
and low cost. Furthermore, Na and Li are in the same main
group, exhibiting similar chemical properties, which translates
to a resemblance between operational characteristics in Li-ion
batteries and Na-ion batteries. Therefore, Na-ion batteries have
been suggested for the alternatives to Li-ion batteries for large-
scale systems. For the practical use of Na-ion batteries, studies
for finding suitable electrodematerialswithhigh energy density,
good cyclability and rate performance for Na-ion batteries have
been actively conducted. Although several cathode materials
have been suggested, the anode choices are severely limited
because of the unique characteristic of Na. Na-ions cannot be
stored in the commercial layered graphite because of their large
radius. Si basedmaterials are expected tobe themost promising
anode for Li-ion batteries, but it is electrochemically inactive
with Na. To explore a high-performance anode materials for
Na-ion batteries, we synthesized i) pure Sn electrodes with
various structures such as Sn nanofibers, Sn multilayer, and
Sn foam ii) MoS
2/
MoO
x
(2<x<3) composites using one-step
electrodeposition process. The Sn electrodes exhibited a high
reversible capacities and excellent cycle performances. After
cycling, the Sn electrodes exhibits no loss of active materials
and it was attributed to the pore volumes in the electrodes
which accommodated the volume change during sodiation/
desodation, and structural stabilities of them. The MoS
2
/MoO
x
showed highly reversible capacity and superior cycling stability.
After cycling, the electrode material showed almost no crack or
fracture and well maintained the contact with substrate, which
are attributed to the buffering action of MoO
x
phase during
sodiation/desodiation of Na
+
in MoS
2
phase.
e:
eacho@kaist.ac.krNovel conductive adhesive films materials for electronics packaging applications
Kyung W Paik
Korea Advanced Institute of Science and Technology, Korea
D
ue to the increasing demand for higher performance,
greater flexibility, smaller size, and lighter weight in
portable, wearable, and display electronic products, there
have been growing needs of various electronic packaging
products and interconnection technologies now and in near
future. To realize various portable, wearable, and display
electronic products, ultra-fine pitch and flexible packaging
& interconnection technologies are needed. As one of the
promising ultra-fine pitch and flexible interconnection
technologies, electrically conductive adhesive films
materials such as ACFs (Anisotropic Conductive Films) and
NCFs (Non-Conductive Films) are widely used. However,
ACFs have two technical limitations such as ultra-fine
pitch and current handling capability. For ultra-fine pitch
applications, novel Nano-fiber ACFs and APL (Anchoring
Polymer Layer) ACFs have been successfully invented by
KAIST for less than 20-micron pitch COG (Chip on Glass), COP
(Chip on Polymer), and COF (Chip On Flex) applications. In
addition, for high current handling applications, new solder
ACFs have been also newly introduced by KAIST to replace
the conventional metal particles based ACFs materials.
By solder ACFs, 30% lower contact resistance, 4X higher
current handling capability, and excellent reliability were
successfully achieved compared with conventional ACFs.
Furthermore, ACF interconnection method can provide the
excellent flexible interconnect solution for OLED COP and
COF/CIF (Chip in Flex) packages to realize totally wearable
electronic products.
Recentlynewinterconnectionmaterials, NCFs, are introduced
for stacking semiconductor chips in 3-dimensional (3-D) way
using the TSV (Through Silicon Via) technology. In the 3D-TSV
vertical interconnection, Cu pillar/Sn-Ag eutectic solder
bump combined with NCFs materials are the most promising
bonding and interconnection method. Recent HBMs (High
Bandwidth Modules) used as high-speed memory modules
for AI (Artificial Intelligence) and Cloud computing have been
packaged by NCFs materials. In this presentation, the novel
ACFs materials for various ultra-fine pitch interconnection
and the NCFs for 3D-TSV chip stacking applications will be
introduced.
e:
kwpaik@kaist.ac.kr