Battery & Electrification Technology - May/June 2024 - 22

Next-Generation Binder for Lithium-ion Batteries
An advanced functional binder for silicon oxide electrodes used in Li-ion batteries enhances electrochemical
performance and durability.
Japan Advanced Institute of Science and Technology, Ishikawa, Japan
L
ithium-ion (Li-ion) batteries employ
binders that encounter challenges
such as poor conductivity and expansion
during charging. In a recent study,
scientists have developed a high-performing
binder using poly(vinylphosphonic
acid) for silicon oxide-based anodes
in Li-ion batteries. This binder offers
enhanced performance as demonstrated
by the superior durability, and discharging
capacity of the anodes compared to
conventional options. With patents filed
internationally, this technology holds
promise for broader applications in electric
vehicles and beyond.
Li-ion batteries are widely used in various
applications but need improved
binders to enhance their performance to
meet evolving demands. This is because
silicon oxide (SiO), a promising anode
material due to its high capacity and low
cost, faces several challenges. These include
poor conductivity, which leads to
slower charging rates, and significant
expansion during charging. Effective
binders are thus essential to address
these issues and ensure enhanced performance
and prolonged durability for lithium-ion
battery systems.
In a recent study published in the journal
ACS Applied Energy Materials, Professor
Noriyoshi Matsumi from the Japan
Advanced Institute of Science and
Technology (JAIST), along with doctoral
student Noriyuki Takamori, former Senior
Lecturer Rajashekar Badam, Dr. Tejkiran
Pindi Jayakumar (former student), and researchers
from Maruzen Petrochemical
Company Ltd., have utilized poly(vinylphosphonic
acid) (PVPA) as a binder for a micro-SiO
electrodes, achieving superior performance
compared to conventional cells.
According to Matsumi, " The PVPA binder
should prove to be very useful in extending
the life of high-performing lithium-ion secondary
batteries. Particularly in the application
of electric vehicles, there has been intense
interest in enabling long life for lithium-ion
secondary batteries. The use of
PVPA will offer improved alternatives to
22
Researchers have engineered a high-performance binder for micro-silicon oxide (SiO)-based
electrodes within lithium-ion batteries with poly(vinylphosphonic acid) (PVPA), which enhances
electrochemical performance and durability compared to conventional options.
(Image: Noriyoshi Matsumi, JAIST)
commercially available binders, such as
poly(acrylic acid) (PAA) and poly(vinylidene
fluoride) (PVDF), etc. "
The study involved fabricating electrodes
containing PVPA, PAA, and PVDF as
binders, and their performance was assessed
through electrochemical experiments
and density functional theory.
PVPA demonstrated notably stronger adhesion
(3.44 N/m) to a copper support
compared to conventional PAA (2.03
N/m), leading to significantly enhanced
durability in lithium-ion batteries.
The PVPA-based cell also delivered almost
twice the discharging capacity compared
to the PAA-based cell after 200 cycles,
with the PVPA-based half-cell achieving
1300 mAhg-1SiO after the same cycle
count. Even after 200 cycles of charge-discharge,
exfoliation from the current collector
was not observed in scanning electron
microscopy, unlike with PVDF or PAA binders.
Furthermore, the stronger adhesion of
PVPA helps stabilize the SiO-based anode,
preventing its exfoliation even with significant
volume expansion.
Additionally, Maruzen Petrochemical
Company Ltd., whose researchers were part
of the study, has established an industrial
production process for PVPA. Continuous
Battery & Electrification Technology, May/June 2024

Battery & Electrification Technology - May/June 2024

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